The Transport System Transport oxygen, nutrients, and other substances throughout the body Removes...
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Transcript of The Transport System Transport oxygen, nutrients, and other substances throughout the body Removes...
The Transport System
Transport oxygen, nutrients, and other substances throughout the
body
Removes waste from tissues
The HeartMyocardium – heart muscle• Pumps blood through the circulatory system• Designed as a pair of side-by-side pumps
The Heart• The heart is divide into 4 chambers
Atrium – Receives blood
Ventricle – Pumps blood out of the heart
Blood Flow
From the heart:• Blood enters a large artery• To smaller artery branches• To arteriole (smallest artery)• To a capillary bed• To a venule (smallest type of vein)• To larger veins• To a large vein which takes blood back to the
heart to be pumped out once again
Blood Flow Through the Heart• Blood from the body enters the heart through the right
atrium, then to the right ventricle • Pulmonary Circulation – blood picks up oxygen and
releases carbon dioxide • Blood from the lungs enter through the left atrium• Systemic Circulation – flow of blood from the heart to the
rest of the body
Aorta – the artery that emerges from the heart
Blood Flow Through the Heart
Blood Flow Through the Heart
Valves – flaps of connective tissue located
between the atria and the ventricles• When blood moves from the atria to the ventricles those
valves open• When the ventricles contract valves close
Pulmonary Circulation• Blood cell enters the Right Atrium
• Blood cell is deoxygenated • After blood pools in the Right Atria it flows through the Right
Atrio-ventricular Valve to the Right Ventricle• Right Atria contracts to push remaining blood out to the Right
Ventricle• Once the volume of blood accumulates in the Right Ventricle
it contracts• During contraction the AV valve closes to prevent backflow• Blood pressure in the Right Ventricle opens the Right
Semilunar Valve allows blood to enter the pulmonary artery
Pulmonary Circulation• Blood enters a lung continues to move along smaller and
smaller arteries• Arteriole – the smallest of arteries
• Arteriole leads to a capillary bed• Capillaries walls are one cell think which allows for gas
transfer • Blood cell gives up carbon dioxide and takes a oxygen
molecule • Blood cell returns to the heart• Pulmonary veins take the now oxygenated blood back to the
heart
Systemic Circulation
• The same red blood cell example used in the pulmonary circulation is used here.
• Blood enters the Left Atria and in unison with the right atria blood seeps to the left ventricle
• Both atria contract, blood enters ventricles (in this example Left Ventricle through the Atrio-ventricular valve)
• Left Ventricles contract (Notice the Left Ventricle is thicker than the Right Ventricle)• When this occurs Atrio-ventricular valve closes to prevent
backflow• Increase in blood pressure in the Left Ventricle opens the
semilunar valve and allows blood through the aorta• Blood leaves the heart through the aorta
Systemic Circulation• Blood then goes into one of 2 pathways
1. Through the body system eventually to capillary beds to pass on oxygen and nutrients
2. The Hearts Blood Supply• The heart needs a constant supply of oxygen and
nutrients• It gets very little from the blood it pumps
Coronary Arteries – a pair of blood vessels which branch
from the aorta and run through the
heart tissue
Circulation
For the record:
• Blood is never Blue!• Blue represent deoxygenated blood: NO IT IS NOT
BLUE!!!• More like a dark verses a bright red
Control of Heart Rate
Cardiac Muscle – muscle tissue specifically
located in the heart
Myogenic Activity – the ability of cardiac muscle to
contract and relax without
nervous system control• This myogenic activity needs to be controlled in
order to keep the timing of the contractions to be unified and useful
Control of Heart Rate
Sinoatrial Node (SA Node)• Mass of tissue within the Right Atria• This is known as the pacemaker for the heart• SA Node sends an electrical signal to initiate
contraction to both atria• At 72 beats per min that is a signal every .8
seconds
Control of Heart RateAtrioventricular Node (AV Node)
• Receives signal from SA Node• Waits .1 seconds then sends another electrical
signal• This signal goes to the ventricles• So first the Atria contracts then the Ventricles
Heart Rate
• Heart Rate varies depending on your bodies needs.• During exercise your heart rate could increase to 200
beats per min.
Heart Rate• Heart rate is controlled as a result of carbon dioxide
levels in the blood• As carbon dioxide increases an area in the brain stem
the medulla chemically senses the levels• Medulla sends signal through a cranial nerve (AKA
Cardiac Nerve)• This increases the heart rate to an appropriate level
• This signal is sent to the SA Node• It does not change the mechanism of how the heart
beats just the timing
Heart Rate• AS CO2 returns to normal a signal is sent for the medulla
through the Vagus Nerve to return the heart rate to normal.
Adrenaline – a chemical released by your adrenal
glands during periods of high stress
or excitement. (AKA – Epinephrine)• Adrenaline causes the SA Node to fire more frequently,
increasing the heart rate
Blood Vessels
Blood Vessels
Arteries• Large Vessels that carry blood from the heart to
the tissues of the body.• Pulmonary arteries are the only ones that
carry blood poor in oxygen.• The rest carry oxygen rich blood
• They have thick smooth muscle layers used by the autonomic nervous
system to change the
diameter of the vessel• This regulates blood
pressure
Blood Vessels• From the arteries to the arterioles to the capillary bed.
Capillary Bed – a network of capillaries that typically all
drain into a single venule• When blood enters the capillary bed much of the
pressure is lost • Blood cells make it through the capillaries one cell at a
time
Blood Vessels
Capillaries• Smallest Blood Vessels• Thin walls allow for oxygen and nutrients to
diffuse from the blood to the tissue• Also CO2 and waste diffuse from tissue to blood
Blood Vessels
Veins• Returns blood to the heart from the
capillaries• Blood returns to the heart usually against
gravity• Skeletal muscle help “push” blood towards
the heart.• Valves prevent back flow• Blood pressure is low causing
blood flow to be slow
Components of Blood
Plasma – liquid portion of blood
Erythrocytes – red blood cells
Leucocytes – white blood cells (phagocytes and lymphocytes)
Platelets – cell fragments (assists in blood clotting)
Transport by Blood
Nutrients – glucose, amino acids, etc
Oxygen – reactant for aerobic cell respiration
Carbon Dioxide – waste produce of aerobic cell repiration
Hormones – transported from gland to target cells
Antibodies – protein molecules involved in immunity
Urea – nitrogenous waste (filtered out of the blood by the
kidneys’s)
Heat – Skin arterioles (can change diameter in order to
gain or lose heat)
Blood Pressure
• When the heart contracts it produces a wave of fluid pressure in the arteries
• Pressure decreases when the heart relaxes• System still remains under pressure due
to elasticity of the arteries• Pressure allows blood to continue to flow
through the arteries.
Blood Pressure
Sphygmomanometer • Device that measures blood pressure • Typical blood pressure in a healthy adult is
120/80• Top Number: Systolic• Bottom Number: Diastolic
Blood Pressure Lab• Record in your composition book
Step 1 - Choose the right equipment: 1. A quality stethoscope 2. An appropriately sized blood pressure cuff 3. A blood pressure measurement instrument such as an aneroid or mercury column sphygmomanometer or an automated device with a manual inflate mode.
Step 2 - Prepare the patient: Make sure the patient is relaxed by allowing 5 minutes to relax before the first reading. The patient should sit upright with their upper arm positioned so it is level with their heart and feet flat on the floor. Remove excess clothing that might interfere with the BP cuff or constrict blood flow in the arm. Be sure you and the patient refrain from talking during the reading.
Blood Pressure Lab
Step 3 - Choose the proper BP cuff size: Most measurement errors occur by not taking the time to choose the proper cuff size. Wrap the cuff around the patient's arm and use the INDEX line to determine if the patient's arm circumference falls within the RANGE area. Otherwise, choose the appropriate smaller or larger cuff.
Step 4 - Place the BP cuff on the patient's arm: Palpate/locate the brachial artery and position the BP cuff so that the ARTERY marker points to the brachial artery. Wrap the BP cuff snugly around the arm.
Step 5 - Position the stethoscope: On the same arm that you placed the BP cuff, palpate the arm at the antecubical fossa (crease of the arm) to locate the strongest pulse sounds and place the bell of the stethoscope over the brachial artery at this location.
Blood Pressure Lab
Step 6 - Inflate the BP cuff: Begin pumping the cuff bulb as you listen to the pulse sounds. When the BP cuff has inflated enough to stop blood flow you should hear no sounds through the stethoscope. The gauge should read 30 to 40 mmHg above the person's normal BP reading. If this value is unknown you can inflate the cuff to 160 - 180 mmHg. (If pulse sounds are heard right away, inflate to a higher pressure.)
Step 7 - Slowly Deflate the BP cuff: Begin deflation. The AHA recommends that the pressure should fall at 2 - 3 mmHg per second, anything faster may likely result in an inaccurate measurement.
Blood Pressure Lab
Step 8 - Listen for the Systolic Reading: The first occurence of rhythmic sounds heard as blood begins to flow through the artery is the patient's systolic pressure. This may resemble a tapping noise at first.
Step 9 - Listen for the Diastolic Reading: Continue to listen as the BP cuff pressure drops and the sounds fade. Note the gauge reading when the rhythmic sounds stop. This will be the diastolic reading.
Blood Pressure Lab
Step 10 - Double Check for Accuracy: The AHA recommends taking a reading with both arms and averaging the readings. To check the pressure again for accuracy wait about five minutes between readings.
• Typically, blood pressure is higher in the mornings and lower in the evenings.