PHYSIOLOGY LAB PRACTICALS REVIEW

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CRITERIA

I. SKILLS ( 50% )

A. Able to perform the procedure correctly 15% B. Able to perform the procedure completely 15% C. Able to choose or identify the material appropriate for the test 10% D. Communicates ideas clearly when performing the procedure 10%

II. ATTITUDE ( 25% )

A. Respect for subject & facilitator / teacher 15% B. Arrives on time 10%

III. KNOWLEDGE ( 25% )

A. Accuracy of info 15% B. Ability to explain (side questions, principles, mechanisms & results) 10%

EXPERIMENT NO. V Differentiating Isotonic from Isometric Contraction

A. ISOTONIC CONTRACTION

MATERIAL

Dumbbell PROCEDURE

a. Place the subject’s extended elbow in between the thigh at mid-thigh level. This is the starting point (Pe).

b. Start with 2.5 lbs. weight. From Pe, the subject fully flexes his elbow (Pf).

c. Rest for 30 seconds. Continue adding weights at 2.5 lb increments and fully flex elbow each time.

d. Determine the subject’s RM. Record the heaviest weight in which full flexion & extension was done. *RM = repetition maximum which the weight or resistance which a person can move throughout a joint movement only once, after which one can no longer repeat the movement

e. Add another weight and take note of the weight when the subject is unable to complete the range of motion and angle eat which motion ceased.

DISCUSSION

Explain why one can no longer flex elbow to the whole ROM beyond the 1 RM? - Because the maximum strength of contraction has already been

reached.

B. ISOMETRIC CONTRACTION

MATERIAL

Hand grip PROCEDURE

a. Using the dominant hand, grasp the hand grip. b. Squeeze the handle. c. Grip the handle for 10 minutes or as long as you can.

DISCUSSION

Why are you not able to sustain your grip on the handle for 10 minutes? - Because of muscle fatigue

ISOTONIC vs. ISOMETRIC CONTRACTION

ISOTONIC ISOMETRIC

1. Length of the muscle

Clear shortening of the muscle length during contraction

Remains the same during contraction

2. Tension No change in tension occurs

Tension increases during contraction

3. External work Work done No external work done

EXPERIMENT NO. VI Hematology Experiment

A. RBC & WBC COUNT DETERMINATION

MATERIALS

Hemocytometer For RBC:

- Pipette with RED BEAD - Bulb marked 0.5, 1 & 101 (has a volume of 200 x the capacity of

the capillary lumen from the tip to the 0.5mL mark) For WBC:

- Pipette with WHITE BEAD - Bulb marked 0.5, 1 & 11 (bulb has a volume 20x the capacity of

the capillary lumen from the tip to the 0.5 mark)

Diluting fluid: For RBC: Isotonic saline solution (to preserve RBC) For WBC: 1% acetic acid (to lyse RBC)

Microscope

Filter paper / cotton PROCEDURE

a. Swab fingertip with alcohol b. Prick finger with lancet c. Suck blood up to 0.5 mark & wipe off excess blood with filter

paper Dilution & Mixing: For RBC:

- Suck isotonic (0.9%) saline solution up to the 101 mark For WBC:

- Suck 1% acetic acid into the pipette up to the 11 mark d. Shake the pipette doing figure of 8 motions with your wrists for

3 minutes Charging the Counting Chamber

e. Place the cover slip over the counting chamber f. Shake pipette from side to side about 5 times g. Discard the first few drops. Allow a drop of the solution to form

at the tip of the pipette h. Place drop at the edge of cover slip. Fluid will flow under the

cover slip by capillarity i. There should be NO excess fluid in the gutter which may push

up the cover slip

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Counting the cells For RBC:

- Count the red cells in 5 MEDIUM SQUARES: those on the corners & one in the middle. Each medium square contains 16 small squares

For WBC: - Count the WBC in the 4 CORNER BIG SQUARES and get the

average *TO AVOID DOUBLE-COUNTING: Just count the cells touching the UPPER & LEFT BORDERS of a given square, ignoring the ones on the lower & right borders COMPUTATION: #RBC = E/80 X 400 X 200 X 10 Where: E = no. of RBC counted in the 5 medium (80 small) squares 400 = total number of small red squares 200 = dilution factor of the pipette with the red bead 10 = factor of depth #WBC/cu mm = L x 20 x 10 Where: L = average no. of WBC in 1 big square (#WBC / 4) 20 = diluting factor of the pipette with the white bead 10 = factor of depth DISCUSSION 1. Normal range of RBC count:

Male: 4.5 – 5.5 million/mm3

Female: 4 – 4.5 million/mm3

2. Possible sources of error from the procedure & its effect on RBC count

SOURCES OF ERROR EFFECT ON RBC COUNT

Improper sample mixing False ↑ or ↓ Too diluted False ↓ Error in charging False ↓ Error in counting False ↑ or ↓ Old sample (hemolyzed RBC) False ↓

3. Physiologic & pathologic conditions that will lead to HIGH RBC

count

PHYSIOLOGIC PATHOLOGIC

High altitude

Strenuous exercise

Cigarette smoking

Dehydration

Polycythemia

Severe burns

Hemochromatosis

Heart disease

4. Physiologic & pathologic conditions that will lead to LOW RBC

count

PHYSIOLOGIC PATHOLOGIC

Pregnant women (1st

trimester)

Menstrual period

Over hydration

Anemia

Shock / Hemorrhage

Kidney Failure

Thalassemia

5. Components of the results of CBC determination

RBC count & morphology

RBC indices (MCV, MCH, MCHC

WBC & differential count

Hemoglobin

Hematocrit

6. Normal range of WBC count and its differentials 5,000 – 10,000 / mm

3

Differential WBC Count:

Neutrophils = 40 – 75%

Lymphocytes = 20 – 45%

Monocytes = 2 – 4%

Eosinophils = 1 -4%

Basophils = 0 – 1%

Stabs = 3 – 5%

7. Indications of increased WBC:

Neutrophils – acute bacterial infections

Lymphocytes – usually viral infections

Monocytes – chronic bacterial infections

Eosinophils – parasitic infections

Basophils – allergic reactions

B. HEMOGLOBIN DETERMINATION

MATERIALS

Sahli Hellige hemometer

Diluting fluid: 10 N HCl

Lancet, cotton ball with alcohol

Distilled water *Principle: Conversion of hemoglobin into acid hematin with dilute HCl and then matching the brownish yellow color of this solution with a standard. PROCEDURE

a. Obtain blood sample. Suck into the hemometer pipette up to the 20mm

3 mark, wipe off excess blood

b. Place 5 drops 10 N HCl into the tube c. Immerse the tip of the pipette in acid and blow the blood into

the tube. Rinse the pipette 2-3x with HCl solution. Shake the tube until solution is well mixed

d. Add water drop by drop, mixing with the stirring rod until the color of the solution matches that of the standards. Read the scale of the tube

DISCUSSION 1. Normal range of Hemoglobin

Male: 14 – 16 g/dL

Female: 12 – 14 g/dL 2. Possible sources of error in the determination of hemoglobin

Procedural errors (addition of too much blood or solution, wrong diluent, insufficient mixing)

Faded Sahli Hellige comparator

Presence of other pigments in the blood

Color blindness of observer

C. BLEEDING TIME & CLOTTING TIME

MATERIALS

Lancet, cotton ball with alcohol

Slide for clotting time

Pin or matchstick

Absorbent paper for bleeding time

Timer PROCEDURE

Prick subject’s finger to obtain blood sample. BLEEDING TIME

- Note the time when prick was done & mark this as time zero - Blot a drop of blood from the puncture site with absorbent

paper without touching the skin - Repeat every 3o seconds until no more blood stain forms on the

paper - Note the time & subtract time zero. This is the bleeding time

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(the time it took for the bleeding to stop). CLOTTING TIME

- Drop globule of blood on slide (do not touch the slide directly). - Draw from the center of the globule of blood on the slide to its

periphery using the tip of a pin/matchstick. Repeat at 10 sec intervals until thread-like strands seen.

- Note the time & subtract time zero. This is the clotting time (the time it takes for the blood to form a clot).

DISCUSSION 1. Normal bleeding time: 1 – 3 minutes 2. Factors in the performance of the procedure that affect bleeding

time:

Depth of puncture

Vasoconstriction 3. What does bleeding time measure?

Platelet function

Endothelial injury 4. Normal clotting time: 3 – 6 minutes 5. What triggers the coagulation cascade?

In vitro (laboratory): exposure to (-) charged surface (silica) or any wettable or non-porous materials

In vivo: exposure to collagen & elastin 6. What does APTT (activated Partial Thromboplastin Time) measure?

Give its significance.

Screen intrinsic & common pathway. Measures all factors except VII & XIII

APTT monitors effect of heparin therapy on coagulation system 7. Why does the circulating blood remain in fluid form?

Because of the following:

Laminar blood flow

Fast / rapid circulation time

Smoothness of endothelium

Circulating coagulation factors are in active form

Endogenous anticoagulant (heparin)

D. BLOOD TYPING

MATERIALS

2 test tubes (containing saline solution)

Slide with 2 concavities

Matchsticks

Blood typing sera *Principle: Presence or absence of agglutinogen (Ag) on RBC membrane PROCEDURE

a. Obtain 0.3 ml of blood sample & place into a test tube with saline solution.

b. On the slide with 2 concavities place 1 drop of antiserum A in one concavity & a drop of antiserum B in the other concavity

c. Add 1-2 drops of RBC suspension to each antiserum d. Mix with a matchstick & observe for 5-20 minutes for any

agglutination reaction DISCUSSION

ABO BLOOD TYPE ANTI-A ANTI-B

A (+) agglutination (-) agglutination B (-) agglutination (+) agglutination O (-) agglutination (-) agglutination AB (+) agglutination (+) agglutination

(+) agglutination indicates the presence of the antigen reacting with the anti-sera of known specificity

1. What are the other classifications of blood groups besides the ABO system? What is their medical significance?

Rh blood group system – possession of D antigen; may cause hemolytic disease of the newborn

Duffy blood group system – associated with resistance to malaria, marker for African Black Race, hemolytic transfusion reactions

Lewis System – production of fucosyltransferase enzyme, may cause in vivo & in vitro hemolysis

Kidd blood group system – common cause of hemolytic transfusion reactions, associated with infrequent & mild cases of HDN

2. What are the clinical applications of blood typing?

Blood transfusion, paternity dispute, organ transplant 3. What are the major indications & contraindications of whole blood

transfusion?

Indication: replacement of lost blood due to hemorrhage

Contraindications: Pulmonary embolism, pulmonary edema, congestive heart failure, autoimmune hemolysis

E. CROSS MATCHING

MATERIALS

2 test tubes (containing saline solution)

Slide (plain)

Applicator stick PROCEDURE

a. Centrifuge the 2.5mL clotted blood sample for 10-15 minutes at the speed of 15 rpm until the serum is expressed from the clot

b. Place one drop of your serum on a slide & add a drop of RBC suspension from another subject

c. Mix with applicator stick & observe for 3-5minutes for any agglutination reaction

DISCUSSION 1. Major Cross Match (PSDR)

- Patient/Recipient Serum vs. Donor erythrocyte (RBC) - Checks for preformed antibodies in patient’s serum that could

hemolyse - donor RBC 2. Minor Crossmatch (PRDS)

- Patient/Recipient erythrocyte (RBC) vs. Donor Serum - Checks for preformed antibodies that could hemolyse - recipient

RBC - Unlikely to produce HTR due to hemodilution (dilution of –

donor serum) Cite some medical applications of cross matching

- Blood transfusion, organ donation, exchange transfusion

F. RBC FRAGILITY TEST

MATERIAL

Big rack with 12 test tubes containing different concentrations of saline solution

0.5% stock solution

Distilled water

dropper *Principle: Osmotic Fragility (OF) Test or Red Blood Cell Osmotic Fragility is an indication of the ability of RBCs to take on water without lysing. In this test, RBCs are placed in graded dilutions of sodium chloride. Swelling of the cells occurs at lower concentrations of NaCl as they take on water in the hypotonic solution. PROCEDURE

a. Arrange a series of 12 test tubes in a rack & number them 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, and 14

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b. Place 0.5% stock solution in each test tube using a clean dropper. The number of drops to place in each test tube corresponds to the number of the test tube

c. Using another dropper, add distilled water to bring the volume to a total of 25 drops in each test tube

d. Mix the solution well in each tube by inverting the tube covered with plastic/paraffin film or clean fingers. The percentage of salt solution in any tube may be computed by multiplying the tube number by 0.02

e. Add one drop of blood into each test tube. Mix the cells with the solution immediately by inverting the test tube once while covering the top with your finger. DO NOT shake the test tubes

f. Let the test tube stand for 2 hours at room temperature. After 2 hours, examine the test tubes to determine if hemolysis of RBC took place

DISCUSSION *Hemolysis can be recognized by the color of the supernatant fluid:

Partial Hemolysis = faintly pink

Complete hemolysis = homogenous red color with or without sediments

DEGREE OF HEMOLYSIS

TEST TUBE NUMBER CONCENTRATION

OF SOLUTION

NONE 22 – 25 0.44

PARTIAL 21 (22) 0.42 (0.44)

COMPLETE 17 (18) 0.34 (0.36)

Give the clinical significance of the osmotic fragility test.

Detects whether RBCs are more likely to breakdown

Evaluates hemolytic anemia

Detects hereditary spherocyctosis and thalassemia

Evaluates immune hemolytic states

CLINICAL CONDITION FRAGILITY

Hemolytic Disease (G6PD) ↑

Hereditary Spherocytosis ↑

Thalassemia ↓

Sickle cell ↓

G. HEMATOCRIT DETERMINATION

MATERIAL

Wintrobe tube containing anticoagulant or microhematocrit pipette, heparinized

*Principle: To determine the ratio of the total cellular elements to fluid in the blood PROCEDURE Microhematocrit pipette

a. From the syringe containing 3mL of blood sample, draw blood into the pipette by capillary motion

b. Centrifuge for 5 minutes at a speed of 15rpm c. Compare RBC volume from the Microhematocrit Reader Chart

DISCUSSION 1. Normal Value of Hematocrit:

Male = 47 +/- 5% Female = 42 +/- 5%

2. Correlation

DISEASE RBC COUNT HEMOGLOBIN HEMATOCRIT

Polycythemia ↑ ↑ ↑

Anemia ↓ ↓ ↓

EXPERIMENT NO. VII Respiratory Experiment

A. STATIC LUNG VOLUME

MATERIAL

Spirometer PROCEDURE TIDAL VOLUME

a. Take a normal inspiration & exhale normally into the spirometer b. Repeat & take the average

TIDAL PLUS EXPIRATORY RESERVE a. Take a normal inspiration & make a maximal expiration into the

spirometer b. Repeat & take the average

VITAL CAPACITY a. Take the deepest possible inspiration (start at the end of a

normal expiration) and then make a maximal expiration into the spirometer

b. Repeat & take the average DISCUSSION DEFINITIONS:

VITAL CAPACITY (4.6 L): the maximum amount of air that can be expired forcefully after a maximal inspiratory effort

TOTAL LUNG CAPACITY (5.8 L): the volume of air present in the lungs at the end of maximal inspiration

TIDAL VOLUME (500 mL) : the volume of air inspired or expired during quiet breathing

EXPIRATORY RESERVE VOLUME (1 L): the volume of air that can be expired with a maximum expiratory effort after passive expiration

INSPIRATORY RESERVE VOLUME (3 L): the volume of air inspired with a maximal inspiratory effort in excess of the tidal volume

RESIDUAL VOLUME (1.2 L): the volume of air left in the lung at the end of a maximal expiratory effort

MINIMAL AIR: amount of air left in the lungs after collapsing

RESPIRATORY MINUTE VENTILATION (6L/min): the amount of air that leaves & enters the lung per minute

ALVEOLAR VENTILATION (4.2L/min): the amount of air reaching the alveoli per minute without considering the physiologic dead space

FEV1: the fraction of vital capacity expired during the 1st

second of a forced expiration

FVC: the total volume expired forcefully with greatest force & speed after a maximal inspiration *decreased FEV1/FVC ratio – obstructive lung disease * normal or increased FEV1/FVC ratio – restrictive lung disease

B. RECORDING RESPIRATORY MOVEMENTS

MATERIALS

Pneumograph, kymograph, timer PROCEDURE

a. Adjust the pneumograph to the subject’s chest & connect it to the recording tambour. Time your records. Keep the sidearm of the connecting T tube open while making adjustments.

b. Record the respiratory movements in 1 minute under the following conditions b.1. normal respiratory movements , while silently reading a

non-stimulating book b.2.while attention is focused on breathing b.3. Hyperventilate by breathing deeply for 30ec, followed

immediately by concentrated reading or mathematical computation, so as to keep attention away from breathing movements

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b.4. while reading aloud b.5. place a paper bag filled with several breaths of expired air

over the nose & mouth and breath in & out of the bag. c. Note the depth or amplitude of the respiratory movements,

rhythm & rate based on your tracings. DISCUSSION 1. What do you observe with the rate, amplitude & regularity of the

respiratory movements in the different procedures?

PROCEDURE RATE AMPLITUDE RHYTHM

B1 NORMAL NORMAL REGULAR B2 NORMAL ↑ REGULAR B3 ↑ ↑ REGULAR B4 NORMAL ↑ IRREGULAR B5 NORMAL ↑ REGULAR

2. What is the mechanism involved in the control of respiration in

each of the above procedures? B1, B2, B4 – NEURAL B3, B5 – CHEMICAL

C. DURATION OF VOLUNTARY APNEA

MATERIALS

Pneumograph, kymograph, timer PROCEDURE

a. Take records using slow drum speed b. Determine how long you can hold your breath under the

following conditions b.1. Hyperventilate by breathing fast & deep for 30 sec, followed

immediately with breath holding at the end of expiration b.2. Make a maximal forced expiration and hold at its end b.3. Take the deepest breath possible and hold at its end b.4. Take a few breaths from a paper bag partially filled with

expired air and hold at the end of inspiration DISCUSSION 1. In what procedure can you voluntary hold your breath the longest?

Why? - Procedure B.1. (Hyperventilation). Because among the 4

procedures, it’s the only one with increased O2 - The cortex (voluntary breathing) overpower the dorsal

respiratory group (involuntary breathing) while a person holds his breath until the PaCO2 concentration is so great that the DRG eventually overpowers the cortex to make the person breath again

2. What is the lung volume in each procedure?

PROCEDURE LUNG VOLUME QUALITY OF AIR

B1 Functional Residual Capacity (FRC)

↓CO2, ↑O2

B2 Residual Volume (RC) ↓ CO2, ↓O2 B3 Total Lung Capacity (TLC) No change B4 FRC + Tidal Volume ↑CO2, ↓O2

3. What are the factors that determine the duration at which one can

hold his breath voluntarily? - Carbon dioxide & oxygen tension

D. MEASUREMENT OF PEAK EXPIRATORY FLOW RATE

MATERIALS

Peak flow meter PROCEDURE

a. Attach the plastic mouthpiece on the input. Make sure that the sliding indicator is at the bottom side of the scale or base of the meter

b. Hold the meter so that your fingers do not block the outlet

opening or prevent the sliding indicator from moving the full length of the scale

c. Place mouthpiece in mouth & seal lips around it. BLOW AS HARD AS POSSIBLE. One quick & sharp blast

d. The final position of the indicator is your PEFR (peak expiratory flow rate)

e. Repeat the procedure 3x, note the highest of the 3 readings – this is your personal best

DISCUSSION PEAK EXPIRATORY FLOW RATE

- Measures the maximal rate of exhalation & determines airway obstruction

- It is the greatest flow rate achieved during the maneuver of inhaling maximally & then exhaling rapidly & completely as possible

Advantages of PEFR monitoring

Monitoring respiratory distress

Detect lung abnormalities

Differentiate obstructive from restrictive lung disease Clinical conditions where PEFR is useful:

Asthma

Chronic bronchitis

Emphysema

E. EXAMINATION OF THE CHEST & LUNGS

MATERIALS

Stethoscope PROCEDURE Physical examination of the chest (subject removes his shirt) INSPECTION

a. Observe the chest movements during inspiration & expiration. Check for equal excursions/expansion of the chest on both sides (right & left) and retractions

PALPATION Feel for tactile fremitus (the palpable vibrations transmitted through the bronchopulmonary tree to the chest wall when the subject speaks)

a. Place the tips of your fingers at the back of the subject at the interscapular area

b. Instruct the subject to talk (e.g. ask the subject to repeat the words “ninety-nine”, “one-one-one”, or “blue moon”)

c. Note the vibration of the subject’s voice on the tip of your fingers

d. Repeat steps a to c in the different areas illustrated below e. Compare the vibrations on the right & left lung fields

Note: Normally, fremitus is most prominent in the interscapular area than in the lower lung fields, and is often more prominent on the right side than on the left. It disappears below the diaphragm because more & more tissue impedes sound transmission as you progress down.

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PERCUSSION a. Place your left middle finger on the interscapular area between

the ribs b. Hit your left middle finger with your right middle finger c. Listen and take note of the percussion note produced d. Repeat steps a to c in the different areas (*omit the areas over

the scapulae – the thickness of muscle & bone alters the percussion notes over the lungs)

e. Compare the percussion notes on the right & left lung fields

Note: Hollow areas like the lungs with air will sound resonant. Solid areas like bone or muscle will sound flat. Relatively dense organ like liver or spleen sound dull. AUSCULTATION

a. Place the diaphragm of your stethoscope over the back of your subject at the following areas of the lungs (see illustration above)

b. Instruct the subject to breath in through the nose & out through the mouth

c. Listen for at least one full minute in each location. Normal Breath Sounds: VESICULAR

- soft & low pitched - heard through inspiration, continue without pause through

expiration, and then fade away about one third of the way through expiration

BRONCHOVESICULAR - with inspiratory & expiratory sounds about equal in length, at

times separated by a silent interval BRONCHIAL

- louder & higher in pitch, with a short silence between inspiratory & expiratory sounds

- expiratory sounds last longer than inspiratory sounds

DISCUSSION

INSPECTION (note the

expansion of the chest)

PALPATION (note the vibration

produced)

PERCUSSION (note the

percussion sound

produced)

AUSCULTATION (note the

characteristic breath sounds

heard)

Symmetric chest expansion (-) retractions

Normal fremitus

Resonant Vesicular breath sounds

1. Vibration, Percussion note & Breath sounds on the following

conditions:

VIBRATION PERCUSSION

NOTE BREATH SOUNDS

Air in the pleural cavity

Decreased Hyperresonant Decreased

Fluid in the pleural cavity

Decreased Dull Decreased

Solidification of lung segment

Increased Dull Increased

2. When do you hear the following adventitious sounds?

Wheezes: in obstructive lung diseases such as asthma or emphysema

Crackles or Rales: in patients with pneumonia, pulmonary fibrosis, pulmonary edema, early bronchitis

3. Egophony – is an increased resonance of voice sounds heard when auscultating the lungs, often caused by lung consolidation & fibrosis.

EXPERIMENT NO. IX Examination of the Heart & Pulses

MATERIALS

Stethoscope, Watch with second hand PROCEDURE EXAMINATION OF HEART SOUNDS

a. Place the ear pieces of the stethoscope in the ear canal opening. Be sure that the curves from the ear pieces are facing backward

b. Listen to the heart sounds on the following physiologic clinical areas of auscultation on the chest:

Aortic Area 2nd

ICS RPSB

Pulmonic Area 2nd

ICS LPSB

Tricuspid Area 4th

ICS LPSB

Mitral Area 5th

ICS LMCL

c. Determine the heart rate on one area for a full minute EXAMINATION OF THE ARTERIAL PULSES

a. Place the tip of the first 2 fingers of your left hand over the subject’s right radial artery

b. While palpating for the radial pulse, locate the left carotid artery using your right hand and feel the pulse

c. Count and compare the pulses of the 2 areas simultaneously for 1 full minute

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TIMING OF PULSE & HEART RATE a. With a stethoscope held by right hand, listen to your partner’s

heart sounds at the aortic area b. With your left hand palpate the radial artery of the right wrist of

subject DISCUSSION 1. Physiologic or anatomic causes of S1 (1

st heart sound): Closure of

the mitral valve / systole / isovolumetric contraction 2. Physiologic or anatomic causes of S2 (2

nd heart sound): Closure of

the aortic valve / diastole / isovolumetric relaxation 3. Are S3 & S4 heart sounds normal?

- S3 is normal in children but not in adults. It arises from rapid deceleration of the column of blood against the ventricular wall early in diastole.

- S3 can be heard in patients with volume overload (e.g. mitral or tricuspid regurgitation, CHF)

- S4 is pathologic. It marks atrial contraction. It immediately precedes S1 of the next beat, and reflects a pathologic change in ventricular compliance (stiff valves).

- S4 can be heard in patients with conditions like hypertensive heart disease, coronary heart disease, aortic stenosis, cardiomyopathy, pulmonic stenosis

4. The radial pulse coincides with what heart sound? S2 5. Is there an observable difference between the heart rate & pulse

rate of a normal subject when taken simultaneously? NONE 6. What is the range of normal heart rate? 60 – 100 bpm 7. What anatomic structure of the heart determines the heart rate?

Why? - SA Node. Because it is the pacemaker of the heart. It has the

highest firing rate / highest rate of discharge of impulse (70-80/min) among the other pacemakers, thereby overpowering the rest.

EXPERIMENT NO. X Arterial Blood Pressure Determination

MATERIALS

Sphygmomanometer

Stethoscope 3 Essential Parts of Sphygmomanometer: 1. Cuff or armlet – a flat rubber bag covered by an undistensible

envelope made of cotton or synthetic with Velcro or hooks 2. Manometer – either mercurial or aneroid which measure the

pressure 3. Rubber bulb & needle exhaust valve – used to introduce or remove

pressure into the system Parts of stethoscope: 1. Ear piece (angled towards the nose when inserted in the ear) 2. Metal tubing/ear tubes/binaural tubes 3. Rubber tubing 4. Stem 5. Chest piece

- Diaphragm – detects high-pitched sounds - Bell – detects low-pitched sounds

PROCEDURE PALPATORY METHOD

a. With the subject seated, wrap the cuff snugly around the arm, about 2cm above the cubital fossa

b. Connect the manometer to the cuff & place the manometer in such a way that the readings can be seen only by the observer< NOT the subject

c. Palpate the subject’s radial pulse using your 2nd

& 3rd

fingertips over the artery. NEVER use the thumb for you may feel your own pulse

d. Inflate the cuff up to a point when the pulse can no longer be felt

e. Slowly release the pressure by deflating the bag and note the manometer reading at which the pulse first reappears. This is the systolic pressure reading

f. Continue releasing pressure until bag is completely deflated AUSCULTATORY METHOD

a. Let the subject rest for at least 5 minutes and then wrap the cuff snugly & smoothly around the arm 2cm above the cubital fossa

b. Connect the manometer to the cuff & portion it so that you can see it but the subject cannot

c. Put the stethoscope on the cubital fossa approximately over the brachial artery. Avoid undue pressure on the artery

d. Inflate the bag with the rubber bulb at a pressure higher than the palpatory reading (about 30mmHg higher). Sounds from the environment should not be audible through the stethoscope

e. Deflate the bag at about 2-4mmHg per pulse f. Note the manometric reading at the appearance of first sound,

which has a clear faint tapping quality. This is the SYSTOLIC PRESSURE

g. Continue releasing the pressure at that rate & note the changes in the quality of the sounds (Korotkov sounds) until such time it disappears. Note the manometer reading before the sound disappeared (last sound). This is the DIASTOLIC PRESSURE

h. The needle valve may now be opened completely to release all the pressure in the system

Note: Remember to completely deflate the cuff & allow the subject to rest before repeating the process of taking his blood pressure DISCUSSION 1. What are the physiologic determinants of blood pressure?

Cardiac Output - Heart rate, systolic volume

Total Peripheral Resistance 2. Why do you record systolic reading only in palpatory method?

- Palpatory method only records the systolic reading because the gush of blood from the systolic pressure which is much stronger than diastolic pressure can be palpated, unlike diastolic pressure which is too weak.

3. Why is it important to take the palpatory BP prior to taking the auscultatory BP? What is an auscultatory gap? - To prevent obtaining inaccurate readings by not measuring the

auscultatory gap. - AUSCULTATORY GAP – the interval of pressure where Korotkoff

sounds indicating the systolic pressure fade away & reappear at a lower pressure point during the manual measurement of blood pressure

- Auscultatory gap is usually seen in patients who are hypertensive or present with arterial stiffness and atherosclerotic disease

4. Enumerate the precautionary measures to be considered when taking the blood pressure

The subject should be mentally & physically relaxed

The size of the cuff should be proportionate to the circumference of the arm of the subject

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The zero reading of the manometer should be kept at the level of the heart

Blood pressure should be detected first by palpatory method before recording by auscultatory method

Pressure must be raised 30mmHg above the palpatory level

The cuff pressure should be decreased to zero level between successive trials

5. Is gender a factor to consider in determining BP & HR? -YES - Females have lower blood pressure due to lower blood volume

because of menstrual periods. Also, due to the effect of estrogen that relaxes the smooth muscles of the blood vessels.

- Females have faster heart rate - Males have higher BP because they have greater muscle mass,

hence, higher blood volume. EFFECT OF POSTURE ON BLOOD PRESSURE A. Standing to lying

Immediate response: Decreased resistance to gravity → increased venous return → increased cardiac output →increased arterial pressure → increase in BP

Compensatory response: Increased arterial pressure in the heart & upper body → increase in pressure sensed by baroreceptors in the carotid sinus → sends impulse to the vagus nerve →increase stimulation to the cardiac inhibitory center → decrease in HR & BP

B. Lying to standing

Immediate response Gravity increases pooling of blood in the lower extremities → decreased venous return → decreased cardiac output →decreased arterial pressure → decrease in BP

Compensatory response Decreased arterial pressure in the heart & upper body → Decreased stimulation of baroreceptors in the carotid sinus → increased stimulation of sympathetic nervous system → increase in HR & BP

EFFECTS OF EXERCISE ON BLOOD PRESSURE & HEART RATE Isotonic Exercise: Treadmill (15mins), Stationary Bike (15mins) Isometric Exercise: Hand grip (5mins) Before the start of exercise: ↑ HR (in anticipation) During exercise: ↑HR & ↑BP After exercise: ↓HR & ↓BP Isotonic Exercise vs. Isometric Exercise

ISOTONIC EXERCISE ISOMETRIC EXERCISE

↑ Heart rate (HR) proportionately with the severity of exercise

↑HR at the start of exercise (mainly due to decreased vagal tone)

↑ Cardiac output (CO) markedly due to ↑ in HR & stroke volume (SV)

SV changes relatively little

↑ Systolic pressure Diastolic pressure increases in MILD exercise, and does not change or decreases slightly in MODERATE exercise and always decreases in SEVERE EXERCISE

Sharp ↑ in systolic & diastolic pressure

↑ Blood flow to exercising muscle

↓ Blood flow to exercising muscle

Note: In isometric exercise, the exercising muscles are tonically contracted. Peripheral resistance increases, which increases the diastolic pressure.

EFFECT OF HYPERVENTILATION Determine the BP & HR of the subject after 5min rest Ask subject to hyperventilate for 30sec & record BP in the last 5 sec Determine BP & HR 5min after hyperventilation 1. Which determinant of BP is affected most by hyperventilation?

- Cardiac Output - During hyperventilation, the thoracic pressure is decreased,

decreasing also the right atrial pressure, thus increasing the pressure gradient & will allow the venous return to increase, as well as the stroke volume & blood pressure

2. Enumerate the factors that affect venous return

Valve competence

Blood volume

Right atrial pressure

Gravity, posture

Degree of filling of systemic circulation

COLD PRESSOR TEST

MATERIALS

Pain perception scale

Bucket of ice cold water (0-5oC)

Sphygmomanometer

Stethoscope Principle: BP is modified by emotional disturbance or pain. The cold pressor test is a method of determining the lability of blood pressure with a standard sensory stimulus PROCEDURE

a. Let the subject lie down on the table & rest for 5 minutes b. Record the pain perception of the subject based on the scale c. Take the BP readings at 1min intervals for 5min or longer if

satisfactory stable pressure is not obtained. This is the control BP

d. Immerse the subject’s hand in the bucket of ice cold water (0-3

oC)

e. Record the exact time of onset of subject’s discomfort f. While hand is immersed in the bucket, take the blood pressure

30sec later & determine the intensity of pain according to the pain perception scale. Repeat BP reading 30sec later (after 1min of immersion)

g. Remove hand from the bucket & continue taking BP readings at 1 min intervals until BP returns to the control

DISCUSSION 1. Both systolic and diastolic BP will change.

Increase SBP is related to pain sensation of the patient causing a fight/flight response or SNS stimulation

Increased DPB is due to the vasoconstriction brought by the cold temperature. This increases the TPR thereby increasing diastolic BP

2. Classifications of reactions (difference between control BP to response BP) a. Hyporeactor: 0-10 mmHg b. Normoreactor: 11-20 mmHg c. Hyperreactor:>20 mmHg (suggest a risk of developing future

high blood pressure) 3. After removing hand from the bucket, hyperemia will be expected.

This is a compensatory response after vasoconstriction or occlusion of the blood vessel wall. Decrease in oxygen will be sensed by chemoreceptors thus there would be parasympathetic stimulation causing vasodilation. (Reactive hyperemia)

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EXPERIMENT NO. XI Kidney Function Test

MATERIALS

Clean small bottles for urine collection

Graduated cylinder

Dip stick

Urinometer PROCEDURE 24 HOUR INPUT-OUTPUT DETERMINATION

a. Empty bladder & discard 1st

voided urine. – HOUR ZERO b. Measure 24hr fluid intake & record type & amount of the fluid

taken c. Measure the volume of each urine void in the 24hr period. Note

the time of each void, volume, color & transparency of each sample. Take 3oml aliquot sample from every voided urine & refrigerate. The last sample should coincide with 24

th hr of

collection d. Determine the specific gravity of each sample using the

urinometer e. Note the activities for the day of the experiment as well as the

ambient temperature DILUTION TEST

a. Eat, but do not drink any other liquid aside from 150cc of water (1.5hr before the actual experiment)

b. Empty bladder & discard urine c. Drink 1,500mL of plain water within 30min d. Collect urine every 30min & determine the volume, color,

transparency & specific gravity of 8 samples CONCENTRATION TEST

a. Eat supper (not later than 9PM), do not drink extra fluids, only 1 glass (270mL) of water

b. Empty bladder before sleep & discard the urine c. Collect 30mL sample upon waking up (6AM), one hour after

(7AM) d. Eat breakfast but do not drink any fluid. Collect sample one hour

after breakfast (8AM) e. Note volume, color, transparency of the samples. Label &

refrigerate f. Determine the specific gravity of the 3 samples using

urinometer EFFECTS OF THE INTAKE OF DIFFERENT FLUIDS ON URINE VOLUME & SPECIFIC GRAVITY

a. Eat, but do not drink any other liquid aside from 150cc of water (1.5hr before the actual experiment)

b. Empty bladder & discard urine c. Drink 500mL of assigned fluid in 3mins or less d. Collect urine every 30min for a total of 3 urine samples and

determine the volume, color, transparency & specific gravity of all urine samples from the different subjects assigned to drink different kinds of fluid

*Types of fluid used: Buko, black coffee plain tea, mt. dew, regular cola, unsweetened choco, very sweet juice DISCUSSION 24 HOUR INPUT-OUTPUT DETERMINATION 1. Total volume of INTAKE > OUTPUT 2. ↓ urine volume = ↑ specific gravity = darker color 3. ↑ urine volume = ↓ specific gravity = lighter color 4. ↑activity → ↑sympathetic stimulation → afferent arteriole

constriction → ↓GFR → ↓urine volume 5. ↑BMR (↑Body temp) → vasodilation of cutaneous vessels

(shunting) → ↓renal blood flow & ↓GFR → ↓urine volume

DILUTION TEST

Events that bring about dilute urine: ↑ water intake → ↓plasma osmolarity → inhibits osmoreceptors in the anterior hypothalamus → ↓secretion of ADH from posterior pituitary → ↓water permeability in distal convoluted tubule & collecting duct → ↓water reabsorption → ↓urine osmolarity → ↑urine volume

CONCENTRATION TEST 1. ↑specific gravity = less transparent = darker color = ↓urine vol. 2. ↓specific gravity = more transparent = lighter color = ↑urine vol. 3. How does kidney form concentrated urine?

↑plasma osmolarity → stimulates osmoreceptors in anterior hypothalamus → ↑secretion of ADH from posterior pituitary → ↑water permeability of late distal tubule & collecting duct → ↑water reabsorption → ↑urine osmolarity & ↓urine volume

EFFECTS OF THE INTAKE OF DIFFERENT FLUIDS ON URINE VOLUME & SPECIFIC GRAVITY

Black coffee, tea, cola, Mountain Dew, unsweetened choco - Contains caffeine, a xanthine derivative, which increases

glomerular filtration and inhibits reabsorption of Na+ within nephrons

- Diuretic/natriuretic effect: ↓ ADH → ↑excretion of Na+ and water OR ↓ Na+ and water reabsorption

- Caffeine dilates the afferent and the efferent arterioles, thus increasing blood flow to the glomerulus → ↑ GFR

- Caffeine also causes the HR to increase: ↑ HR → ↑BP → ↑ hydrostatic pressure → ↑ filtration → ↑ urine output

- Can be affected by tolerance of an individual to caffeine.

Buko juice - Causes pressure diuresis - Can be used as ORS replacement - ↑plasma volume → ↑hydrostatic pressure → ↑in filtration

rate → ↑ urine volume - Works as a plasma expander

Very sweet juice - Has an osmotic diuretic effect - High glucose level causes an ↑in the filtration, as glucose

takes/attracts water with it, therefore ↑urine volume

EXPERIMENT NO. XII General Senses

I. CUTANEOUS SENSES

A. PUNCTIFORM DISTRIBUTION OF SENSORY RECEPTORS

MATERIALS

Large handkerchief for blindfolding the subject

Graphing paper with 10x10 mm square hole

Fine bristle or horse hair

Pin head

Container with ice cold water

4 colored pens / pencils PROCEDURE

a. Cut out a 10x10mm square hole from a piece of graphing paper b. Blindfold the subject c. Lay this piece of paper on the volar surface of the forearm.

Divide this square hole into 4 smaller squares & label them A, B, C, D

d. Test squares A, B, C & D with the following: 1. Fine bristle or horse hair - touch 2. Heated pin head (dip in hot water container) – warmth spots 3. Cold pin head (dip in iced cold water container) – cold spots

BACKROW Notes Page 10 of 16

4. Pin or fine needle point – for pain spots Note: Stimulate 15 random spots per test square for each type of stimulus

e. Ask the subject each time if he/she feels the stimulus for each spot tested. There should be a total of 60 different stimuli tested per square. Draw the results.

f. Lay the paper on the back of the nape (avoid the hairy portions) of the subject. Repeat procedure d & e

DISCUSSION 1. Sensation – an impression produced by the stimulation of a

sensory receptor site & transmission of the nerve impulse along an afferent fiber to the brain Examples: touch, tickle, itch, cold, warmth, pain, taste

2. Perception – the conscious recognition & interpretation of sensory stimuli that serves as a basis for understanding a particular action or reaction Examples: depth perception, stereognostic perception

3. Stimuli arranged according to the number of receptors felt: Pain > Touch > Cold > Warmth

4. Volar surface of the forearm (anterior) has more sensory receptor sites as compared to the nape (posterior). [No. of receptors: Anterior > Posterior]

B.1. ATTRIBUTES OF SENSATION: CONTRAST

MATERIALS

Large handkerchief for blindfolding

Beaker 1 – filled with warm water

Beaker 2 – filled with tap water

Beaker 3 – filled with ice water PROCEDURE

a. Blindfold the subject b. Place the subject’s left index finger in beaker 1 (warm water) &

right index finger in beaker 3 (ice water). Maintain this position for about 30sec

c. Ask the subject what sensation he/she feels & record d. After recording the sensation, remove both fingers from their

previous locations & place simultaneously into beaker 2 (tap water). Ask the subject what sensation he now feels in each of his index fingers

DISCUSSION Sensation felt:

INDEX FINGER BEAKER 1 or 3 BEAKER 2

LEFT Warm (1) Cold

RIGHT Cold (3) Hot

CONTRAST EFFECT – exposure to a stimulus of different value enhances or diminishes the other, relative to what would normally be perceived without the other stimulus 2 TYPES: 1. Successive contrast – when 2 opposite sensations are introduced,

the first event lowers the threshold of the successive opposite sensation *This was the contrast experienced by the subject

2. Simultaneous contrast – 2 stimuli presented at the same time Note: Temperature sensations are not absolute but relative to the baseline previously established by sensory adaptation

B.2. ATTRIBUTES OF SENSATION: SUMMATION

MATERIALS

Basin filled with warm water

Large handkerchief for blindfolding the subject

PROCEDURE a. Blindfold the subject b. Gradually immerse the subject’s hand into the basin, staring first

with the fingertips then slowly moving the hand downwards until the wrist is submerged. The entire procedure should be done within 10 seconds

c. Ask the subject to rank the degree of sensation felt according to the extent of immersion

DISCUSSION

SENSATION EXTENT OF IMMERSION

WARM Fingertips

WARMER Palm

WARMEST Wrist

*The sensation that the subject felt is due to spatial summation (more receptors are being stimulated to cause more intense warm sensation) ↑surface area → ↑nerve fibers recruited/stimulated → ↑stimulus strength ↑signal strength

B.3. ATTRIBUTES OF SENSATION: ADAPTATION

MATERIALS

Basin filled with warm water

Large handkerchief for blindfolding the subject

Piece of cork

Thermometer PROCEDURE

a. Blindfold the subject Procedure A

b. Immerse the subject’s whole hand into the water basin for 5minutes

c. Make sure that the temperature of the water remains constant during the experiment

Procedure B b. Place a piece of cork on the forearm of the blindfolded subject,

and leave it there for 1-2 minutes DISCUSSION *The sensation felt for the both procedures weakened due to sensory receptor adaptation ADAPTATION

- is the change in frequency of the sending of impulses with constant stimulus, and therefore a decline in sensation

- when a continuous sensory stimulus is applied, the receptor responds at a high impulse rate at first and then at a progressively slower rate until finally the rate of action potentials decreases to very few or often to none at all.

Types of Adaptation

FAST ADAPTING RECEPTORS SLOW ADAPTING RECEPTORS

Sends information related to changing stimuli

Send information regarding ongoing stimuli

Shorter sensation due to fast conduction velocity

Longer sensation due to slow conduction velocity

Examples: stretch receptors, pacinian corpuscles, olfactory receptors

Examples: pain receptors, proprioception, baroreceptors

*Both the procedures demonstrated FAST ADAPTATION

C. PRESSURE SENSE

MATERIALS

Large handkerchief for blindfolding the subject

Small bucket with water & sand

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PROCEDURE a. Blindfold the subject b. Dip the index finger of the subject & ask him/her to determine

which art of the finger feels the greatest sensation of pressure in each of the following positions: 1. When only the fingertip is touching the surface of the sand 2. Entire finger is immersed in the sand stationary 3. Entire finger is immersed in the sand slowly moving sideways

DISCUSSION

POSITION AREA IN THE FINGER FEELING THE GREATEST PRESSURE

1 Fingertip

2 Lateral sides of the finger

3 Lateral sides of the finger

Touch – tactile reception on the superficial skin (Meissner’s corpuscle, Ruffini’s endings) Pressure – sensation felt deeper in the tissue (Pacinian corpuscle); force acting on any direction against resistance

Position 1 stimulated touch receptors, position 2 stimulated pressure receptors. Both were stimulated by position 3

The shift from position 1 to position 2 elicited the greatest difference in pressure.

D. ARISTOTLE’S EXPERIMENT

MATERIALS

Large handkerchief for blindfolding the subject

Marble or any rounded object PROCEDURE

a. Blindfold the subject b. Cross the subject’s right middle finger over the right index

finger. Place a small round object between the ends of these fingers. Roll the object. How many object/s does he perceives?

DISCUSSION

Number of objects perceived with: - Crossed fingers: 2 - Uncrossed fingers: 1

Relate the concept of cortical representation to the results of the experiment: Cortical map

- describes the distribution of minicolumns (vertical group of neurons through the cortical layers of the brain, each responsible for a particular receptive field) in the brain cortex.

Cortical representation - The marble was perceived as two objects with the crossed

fingers because ordinarily, one would not feel one object on the lateral side of the index finger and medial side of the middle finger at the same time. Non-adjacent neurons were stimulated, thus 2 different cortical areas, so the marble was perceived as two objects.

- When the fingers were uncrossed, adjacent neurons which have the same cortical area were stimulated, leading to the perception of one object.

E.1. SYNTHETIC SENSES: TWO-POINT DISCRIMINATION

MATERIALS

Large handkerchief for blindfolding the subject

Double pointed compass

Ruler PROCEDURE

a. Blindfold the subject b. Determine the threshold for two-point discrimination on the

following regions: 1. Fingertip 2. Nape

Set the 2 points of the compass together & test the above area. Separate the 2 points 2mm apart & test the same area. Increase the distance between the 2 points until they can be perceived as 2 separate stimuli. Measure the distance in mm. this is called two-point threshold. The 2 points must be applied gently, simultaneously & with equal pressure

c. Do 2 trials each region & record DISCUSSION

TWO-POINT DISCRIMINATION – ability to perceive two distinct stimuli as separate.

Fingertip is more sensitive than the nape.

Threshold is inversely proportional to sensitivity

Peripheral Innervation Density (PID) – the number of nerves innervating an area; the number of receptive fields in a unit area of skin

Peripheral Receptive Field (PRF) – the area by which a stimulus of sufficient magnitude will evoke a response in the sensory unit

PRF is inversely proportional to sensitivity

AREA SENSITIVITY PID PRF

Fingertip Higher High Small

Nape Lower Low Big

E.2. SYNTHETIC SENSES: STEREOGNOSIS

MATERIALS

Large handkerchief for blindfolding the subject

3 different common objects (e.g. coin, pen, key) PROCEDURE

a. Blindfold the subject b. Place one object at a time in the subject’s hand. Allow him/her

to feel the object for a minute c. Instruct subject to identify the object

DISCUSSION

Stereognosis – the ability to identify an object, in the absence of vision, by using concepts of size, form, texture

Graphesthesia – the ability to recognize writing on the skin in the absence of vision

What sensations are necessary in identifying objects when blindfolded? - Touch, pressure, prior knowledge of the object

Synthetic senses – perception of something you’ve known before (for integration) for cortical analysis

Graphesthesia & Stereognosis are synthetic senses

E.3. VIBRATION SENSE (PALLESTHESIA)

MATERIALS

Tuning fork

Timer (watch with a second hand) PROCEDURE

a. Make the tuning fork vibrate by hitting it against your palm b. Place the base of the vibrating tuning fork on the various bony

prominences (e.g. malleolus, olecranon, patella). Record the

BACKROW Notes Page 12 of 16

duration of vibration felt c. Place the base of the vibrating tuning fork on various muscular

regions. Record the duration of the vibration felt DISCUSSION

Duration of vibration: Bones > muscles

Tissue density & vibration conduction are directly proportional. Bony prominences have higher densities, hence, more capable of preserving vibrations

Pathway of vibration through the CNS (Dorsal Column Medial Lemniscus Pathway): Receptor → dorsal column of medulla → cross midline (internal arcuate fibers) → medial lemniscus → ventral posterolateral (VPL) area of the thalamus → Postcentral gyrus (Brodmann area 3,1,2)

II. MUSCLE & JOINT SENSES (PROPRIOCEPTION)

A. STATIC POSITION SENSE

PROCEDURE a. Ask the subject to balance himself on one leg while performing

the following: - Eyes open - Eyes closed - With your eyes closed & head tilted to one side

DISCUSSION

Eyes open – balanced; Eyes closed – unsteady; Eyes closed & head tilted to one side – no balance

Static position sense – the conscious perception or orientation of the parts of the body in relation to each other

Balance is dependent on several modalities: visual, vestibular (main), proprioception from muscles & joints

How do you explain what happens when you attempt to balance yourself with eyes closed & head tilted to one side? - In closing your eyes, you lose the ability to measure your

balance with respect to the room, the addition of tilting your head to one side will change the orientation of your vestibular system with regards to the position of your body. This will send signals to your brain that do not coordinate with each other, thus resulting to the loss of balance

B. KINESTHESIA

MATERIALS

Protractor PROCEDURE

a. Let the subject wear only his undershirt to eliminate the influence of cutaneous sensations. Blindfold the subject

b. Place the subject’s arm at various positions, measuring each angle formed by the arm against the trunk (use a protractor). These will be called test angles

c. After each position, drop his arm to his side & ask him to duplicate the previous position. Measure the angle formed by the arm against the trunk. This is called the response angle. Note the time it takes for the subject to duplicate the position

DISCUSSION

TEST ANGLE RECEPTORS

STIMULATED REACTION

SPEED PERCENT

ERROR

Narrow angles Less Slower More

Wide angles More Faster Less

Kinesthesia – the perception of limb movement and position, rate of movement sense, and dynamic proprioception.

The kinesthetic system is usually based on three variables: perception of limb position, limb movement and force.

Wider angles correspond to greater stretch of the ligaments and deep tissues, which result in a greater number of receptors stimulated, thus less percent error.

EXPERIMENT NO. XV Temperature Regulation

MATERIALS

Digital thermometer

Reading material

Watch or timer

Snacks

Cotton balls with alcohol PROCEDURE

a. Let the subject rest for 5-10 minutes then record the subject’s baseline temperature (axillary), pulse rate, and respiratory rate.

b. Have the subject read silently for 5 minutes then record the subject’s temperature, pulse rate & respiratory rate

c. Let the subject rest for 5-10 minutes then record the subject’s temperature (axillary), pulse rate, and respiratory rate.

d. Have the subject jog around the room for 5-10 minutes then record the subject’s temperature, pulse rate & respiratory rate

e. Let the subject rest for 5-10 minutes then record the subject’s temperature (axillary), pulse rate, and respiratory rate.

f. Have the subject eat a snack for 5-10 minutes. Record the temperature, pulse rate & respiratory rate 10-15 minutes after the subject finished eating

DISCUSSION

Two main factors that determine body temperature: 1. Heat input/production 2. Heat output/loss

↑ in physical activity results in ↑ body temperature & ↑ heat production. This is due to Muscle Contraction and ATP hydrolysis.

Eating also ↑ metabolic activity, which also results in production of body heat

EXPERIMENT NO. XVI Reflexes in Man

MATERIALS

Cotton – for corneal reflex

Penlight – for pupillary light reflex

Tongue depressor – for gag reflex

Neurologic/reflex hammer – for jaw, knee, ankle jerk reflex & plantar reflex

PROCEDURE Corneal Reflex

- Touch the cornea gently with a thread of wisp of cotton(ensure that you do NOT touch the subject’s eyelashes)

Pupillary Light Reflex - Let the subject look into the distance. Shine a flashlight

obliquely into the right eye. Repeat with the other eye. Note the change in pupillary size before & after flashing light

Gag / Vomiting Reflex - Touch the uvula or the posterior pharyngeal wall with an

applicator Jaw Jerk

- With the patient’s jaw sagging loosely open, the examiner rests a finger across the chin. Strike the finger a crisp blow from the neurological hammer

Abdominal Reflex - Stroke the external abdominal muscle medial ward (towards the

umbilicus) with a blunt probe on all 4 quadrants of the abdomen Knee Jerk

- Let the subject sit down on a table & cross his legs. Tap the patellar tendon just below the knee cap with a reflex hammer

BACKROW Notes Page 13 of 16

Ankle Jerk - Let the subject stand with one knee resting on a chair. Tap the

tendon of Achilles at the ankle Plantar Reflex

- With a blunt probe, stroke the lateral half of the sole of the foot starting from the heel going towards the toes

DISCUSSION TYPICAL SPINAL REFLEX ARC

ANAL REFLEX Afferent/Efferent Nerve: Pudendal Nerve Center: S3, S4 - Elicited by stroking the skin near the anus. Observe the contraction

of the external anal sphincter CREMASTERIC REFLEX Afferent/Efferent Nerve: Genitofemoral Nerve Center: L1, L2 - Elicited by lightly stroking the superior & medial part of the thigh.

The normal response is an immediate contraction of the cremaster muscle that pulls up the testis on the side stroked

BABINSKI SIGN - dorsiflexion of the big toe and fanning of the other toes on stimulation of the sole, occurring in lesions of the pyramidal tract and is a pathognomonic feature of upper motor neuron paralysis; a normal reflex in infants & disappears by 2 years.

CLASP KNIFE REFLEX - exists only in certain pathological conditions (e.g. upper motor neuron disease). Under these conditions, there is an extensor spasticity that resists any attempt to flex the limbs, especially the arms. If the arm is gradually, forcibly flexed by someone other than the patient, a point will be reached when the resistance to flexion suddenly melts away, and the limb collapses easily into full flexion.

WITHDRAWAL REFLEX – an involuntary process that causes a part of the body to automatically pull away from something that is causing pain (noxious stimulation)

CROSSED EXTENSOR REFLEX – a withdrawal reflex. When the reflex occurs, the flexors in the withdrawing limb contract & the extensors relax, while in the other limb, the opposite occurs

EXTENSOR THRUST REFLEX – extension of flexed leg when the sole of the foot is stimulated. Present in infants up to 2 months. Examples of visceral reflexes:

Micturition reflex

Defecation reflex

Swallowing reflex

EXPERIMENT NO. XVII Motor System Examination

MATERIALS

Neurologic/reflex hammer – for deep tendon reflexes PROCEDURE MUSCLE GROUP TESTED for STRENGTH

1. FACIAL MUSCLES - Subject wrinkles forehead, squeezes the eyes shut, and shows

the teeth 2. NECK MUSCLES

- Subject resists attempts by the examiner to flex & extend the neck by exerting pressure on the occiput & forehead, respectively

3. ARM ABDUCTORS - Subject holds his arm laterally at right angles to the body

while the examiner pushes down on the elbow 4. HIP FLEXORS

- In a sitting position, the subject holds the knee up off the chair against resistance

5. ANKLE EXTENSORS - The subject resists attempts to bend from 90 degrees angle

COORDINATION

1. FINGER TO NOSE TESTING - The subject is asked to touch alternately his nose & then

the examiner’s finger with the tip of his index finger. The examiner’s finger must be far enough away so that the subject must fully extend the arm with the eyes open & then with the eyes closed

BACKROW Notes Page 14 of 16

2. HEEL TO SHIN TESTING - The subject places the heel carefully on the opposite knee

and slides it slowly along the edge of the tibia to the ankle & back up the knee again

3. RAPID ALTERNATING TEST - Alternately patting the front & back of the hand on the knee

as rapidly & regularly as possible

GAIT & STATION 1. STATION

Romberg’s Test: subject stands straight with the heels together first with eyes open then with eyes closed. Note for any excessive postural swaying of loss of balance (+ Romberg)

2. GAIT

- Observe certain aspects of the gait while patient does the following: a. Walk normally back & forth at a moderate rate b. Walk on heels c. Walk on toes d. Tandem walk along straight line (i.e. touching heel to toe) e. Hop on each leg

Note the following during each of the different steps listed above: - Length of step (vertical distance between the heel of one foot &

the toe of the other foot) - Width of base (horizontal distance between both heels)

- Abnormal leg movements (e.g. excessively high step) - Instability (gait ataxia) - Associated postural movements (e.g. pelvic swaying)

MUSCLE TONE (to passive resistance on elbows, wrists, knees) Ensure that the patient is relaxed, and assess tone by: 1. Alternately flexing & extending the elbow and wrist 2. Alternately flexing & extending the knee joint. Note the resistance + Hypotonia ++ Normal +++ Hypertonia ++++ Hypertonia with clonus REFLEXES 1. JAW JERK – ask the patient to relax jaw. Place finger on the chin &

tap with hammer

2. TRICEPS JERK – strike the patient’s elbow a few inches above the

olecranon process. Look for elbow extension & triceps contraction

3. BICEPS JERK – ensure patient’s arm is relaxed & slightly flexed.

Palpate the biceps tendon with the thumb & strike with tendon hammer. Look for elbow flexion & biceps contraction

4. KNEE JERK – ensure that the patient’s leg is relaxed by hanging it

over the edge of the bed. Tap the patellar tendon with the hammer & observe quadriceps contraction and plantar flexion

BACKROW Notes Page 15 of 16

DISCUSSION STRENGTH

- Power of muscle group in performing specific action according to: age, occupation, physical activity & muscular development

LEVELS OF STRENGTH:

NORMAL – level of strength expected for that person

MILD WEAKNESS – level of strength less than expected but not sufficient to impair any daily function

SEVERE WEAKNESS – strength sufficient to activate the muscle & move it against gravity but not against any added resistance

COMPLETE PARALYSIS – no detectable movement

GRADE DESCRIPTION

0/5 No muscle movement

1/5 Visible muscle movement but no movement at joint

2/5 Movement at joint but not against gravity

3/5 Movement against gravity but not against added resistance

4/5 Movement against added resistance but less than normal

5/5 Normal strength

COORDINATION

- Coordination of muscle movements requires that four areas of the nervous system function in an integrated way: 1. The motor system – for muscle strength 2. The cerebellar system (also part of the motor system) – for

rhythmic movement & steady posture 3. The vestibular system – for balance & for coordinating eye,

head & body movements 4. The sensory system – for position sense

DYSMETRIA - refers to a lack of coordination of movement typified by the

undershoot or overshoot of intended position with the hand, arm, leg, or eye

- indicates lesion on the lateral zone of cerebellum; abnormal finger-to-nose test result

DYSDIADOCHOKINESIA - inability to perform rapidly alternating movements, such as

rhythmically tapping the fingers on the knee - indicates lesion on the lateral zone of cerebellum

ATAXIA - an impaired ability to coordinate movement, often

characterized by a staggering gait & postural imbalance Can be classified into:

Sensory Ataxia: results from the loss of sensory input from the lower extremities due to diseases of peripheral nerves, dorsal roots, dorsal columns of the spinal cord or medial lemnisci

Cerebellar Ataxia: results from a lesion or degeneration focused in the body’s gait and balance center: the vermis of the cerebellum.

GAIT & STATION

Walking on heels is the most sensitive way to test for foot dorsiflexion weakness, while walking on toes is the best way to test early foot plantar flexion weakness.

Abnormalities in heel to toe walking (tandem gait) may be due to ethanol intoxication, weakness, poor position sense, vertigo and leg tremors. These causes must be excluded before the unbalance can be attributed to a cerebellar lesion. Most elderly patients have difficulty with tandem gait purportedly due to general neuronal loss impairing a combination of position sense, strength and coordination.

Romberg’s Test - To achieve balance, a person requires 2 out of the following 3

inputs to the cortex: 1. Visual confirmation of position 2. Non-visual confirmation of position (including proprioceptive

and vestibular input) 3. A normally functioning cerebellum.

*Therefore, if a patient loses their balance after standing still with their eyes closed, and is able to maintain balance with their eyes open, then there is likely to be lesion in the cerebellum. This is a positive Romberg. REFLEXES

REFLEXES RESULTS CRANIAL NERVE / SPINAL

ROOT INNERVATION

Jaw Jerk + CN V

Triceps Jerk ++ C6, C7 (Radial Nerve)

Biceps Jerk ++ C5, C6 (Musculocutaneous Nerve)

Knee Jerk ++ L2, L3, L4 (Femoral Nerve)

Ankle Jerk ++ S1, S2 (Tibial Nerve)

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REFLEX CLASSIFICATION OF

REFLEX AFFERENT NERVE

CENTER (CRANIAL CENTER OR SPINAL CORD SEGMENT)

EFFERENT NERVE RESPONSE

CORNEAL Polysynaptic Superficial

Somatic

Ophthalmic Division of Trigeminal Nerve

(V1)

Spinal Trigeminal Nucleus

Facial Nerve (CN VII) Blinking of both eyes

PUPILLARY LIGHT Polysynaptic Superficial

Somatic Optic Nerve (CN II) Pretectal nucleus

Oculomotor Nerve (CN III)

Constriction of both pupils

GAG / VOMITING Polysynaptic Superficial

Somatic

Glossopharyngeal Nerve (CNIX)

Solitary nucleus Vagus Nerve (CN X)

Elevation of soft palate, bilateral contraction of

pharyngeal muscles

JAW JERK Monosynaptic

Deep Tendon Reflex Somatic

Trigeminal Nerve (CN V)

Trigeminal motor nucleus

Trigeminal Nerve (CN V)

Slight jerking of mandible upwards

ABDOMINAL Polysynaptic Superficial

Somatic Thoracic Nerve T8 – T12 Thoracic Nerve

Contraction of abdominal muscles

KNEE JERK Monosynaptic

Deep Tendon Reflex Somatic

Femoral Nerve L2 – L4 Femoral Nerve Contraction of

quadriceps, extension at knee joint

ANKLE JERK Monosynaptic

Deep Tendon Reflex Somatic

Tibial Nerve S1, S2 (Primarily S1) Tibial Nerve Contraction of calf muscles, plantar

flexion of the foot

PLANTAR Polysynaptic Superficial

Somatic Tibial Nerve L5, S1 Tibial Nerve

Inversion & dorsiflexion of the ankle with flexion (curling) of all toes

*Classification of reflex:

No. of synaptic connection: monosynaptic or polysynaptic

Location or receptor: superficial or deep tendon reflex

Location of effector organ: somatic or visceral