Respiratory SystemRespiratory System

RESPIRATIONRESPIRATION3 levels3 levels

• External:External:– Moving gases from Moving gases from

outside environment outside environment into lungs and back.into lungs and back.

– Breathing.Breathing.• Internal:Internal:

– Moving O2 from lungs Moving O2 from lungs through bloodstream to through bloodstream to mitochondrion of tissue mitochondrion of tissue cells and CO2 back.cells and CO2 back.

• Chemical:Chemical: – Aerobic respiration Aerobic respiration

within the within the mitochondrion.mitochondrion.

– C6H12O6 + 6O2 --- 6CO2 C6H12O6 + 6O2 --- 6CO2 + 6H2O + "e"+ 6H2O + "e"

– ADP + P + "e" ----- ATPADP + P + "e" ----- ATP

Control of BreathingControl of Breathing• You breath to get O2 to You breath to get O2 to

Mitochondrion of cells Mitochondrion of cells to carry out the to carry out the breakdown of glucose.breakdown of glucose.

• CC66HH1212OO66 + 6O + 6O22 --- 6CO --- 6CO22 + + 6H6H22O + "e"O + "e"

• 6 O6 O22's in equals 6 CO's in equals 6 CO22's 's outout

• The control of The control of breathing is breathing is maintaining a delicate maintaining a delicate balance (Homeostasis) balance (Homeostasis) between the between the concentrations concentrations (pressures) of these (pressures) of these two gasses in your two gasses in your blood.blood.

Respiration / Breathing Respiration / Breathing Control CenterControl Center

• Located in Medulla Located in Medulla /Pons of brain./Pons of brain.

• Coordinates with Coordinates with sensors in spinal sensors in spinal cord, rib muscles and cord, rib muscles and lungs.lungs.

• Monitors pH of blood Monitors pH of blood and signals rib and signals rib muscles and muscles and diaphragm to diaphragm to contract / relax.contract / relax.

Place in order OPlace in order O2 2 would would follow.follow.• TracheaTrachea

• Body CellsBody Cells

• PharynxPharynx

• SinusesSinuses

• BronchiBronchi

• BronchiolesBronchioles

• LarynxLarynx

• Nasal PharynxNasal Pharynx

• AlveoliAlveoli

• Bronchiole TubesBronchiole Tubes

• Blood CapillariesBlood Capillaries

• Red Blood CellsRed Blood Cells

• GlottisGlottis

• MitochondriaMitochondria

• Nasal OpeningsNasal Openings

• HemoglobinHemoglobin

BREATHINGBREATHING• Respiration Center in Respiration Center in

Medulla sends impulse Medulla sends impulse to intercostals and to intercostals and diaphragm to contract diaphragm to contract (14 / min)(14 / min)

• Air is drawn into lungs Air is drawn into lungs and due to pressure and due to pressure and concentration and concentration differences O2 & CO2 differences O2 & CO2 diffuse into and out of diffuse into and out of blood capillaries blood capillaries through alveoli.through alveoli.

Breathing (2)Breathing (2)

• Stretch sensors in lungs and Stretch sensors in lungs and pH sensors in brain and pH sensors in brain and spinal cord react and spinal cord react and control breathing center control breathing center impulses. (Feedback impulses. (Feedback systems)systems)– if stretch sensors detect if stretch sensors detect

overfilling - suppress impulses overfilling - suppress impulses until overridden by pH sensors.until overridden by pH sensors.

– pH sensors monitor build-up of pH sensors monitor build-up of carbonic acid---as pH goes carbonic acid---as pH goes down in blood Pons / Medulla down in blood Pons / Medulla increase impulse rate and visa increase impulse rate and visa versaversa

Breathing (3)Breathing (3)• O2 level has little to do O2 level has little to do

with the rate as monitors with the rate as monitors deal primarily with CO2 deal primarily with CO2 levels....remember 6O2's levels....remember 6O2's in = 6CO2's out in = 6CO2's out

• Can consciously override Can consciously override the system but only the system but only temporarily....I'm going temporarily....I'm going to hold my breath until I to hold my breath until I die!!!!!! die!!!!!!

STEPS IN RESPIRATIONSTEPS IN RESPIRATION

• Medulla sends signal out to Medulla sends signal out to rib muscles and diaphragm.rib muscles and diaphragm.

• Rib muscles and diaphragm Rib muscles and diaphragm contract (ribs move upwards contract (ribs move upwards and outwards and and outwards and diaphragm moves diaphragm moves downwards) expanding the downwards) expanding the chest cavity.chest cavity.

• A negative pressure or A negative pressure or vacuum is created causing vacuum is created causing outside air to be drawn outside air to be drawn inwards by BULK FLOW.inwards by BULK FLOW.

STEPS IN RESPIRATION STEPS IN RESPIRATION (2)(2)

• Air moves in through nose, Air moves in through nose, sinuses, nasal pharynx, past sinuses, nasal pharynx, past epiglottis and through glottis, epiglottis and through glottis, down trachea, bronchi, down trachea, bronchi, bronchioles and into alveoli of bronchioles and into alveoli of lungs.lungs.

• Oxygen DIFFUSES from alveoli Oxygen DIFFUSES from alveoli into blood capillaries and into into blood capillaries and into red blood cells where it is red blood cells where it is picked up and carried by picked up and carried by hemoglobin.hemoglobin.

• Oxygen moves by BULK FLOW Oxygen moves by BULK FLOW throughout blood circulation throughout blood circulation to cells where concentrations to cells where concentrations are lower are lower

STEPS IN RESPIRATION (3)STEPS IN RESPIRATION (3)

• Oxygen DIFFUSES out of Oxygen DIFFUSES out of hemoglobin in red blood hemoglobin in red blood cells and into cells and cells and into cells and finally to mitochondria.finally to mitochondria.

• Cellular respiration occurs Cellular respiration occurs and oxygen in consumed and oxygen in consumed and carbon dioxide is and carbon dioxide is generated as a waste gas.generated as a waste gas.

• Carbon dioxide DIFFUSES Carbon dioxide DIFFUSES out of cells and into blood out of cells and into blood capillaries where it moves capillaries where it moves through red blood cells and through red blood cells and is converted to bicarbonate is converted to bicarbonate ions and carried in the blood ions and carried in the blood serum as carbonic acid. serum as carbonic acid.

STEPS IN RESPIRATION (4)STEPS IN RESPIRATION (4)• Carbonic acid moves by BULK Carbonic acid moves by BULK

FLOW throughout blood FLOW throughout blood circulation and back to lung circulation and back to lung capillaries.capillaries.

• Carbonic acid moves through Carbonic acid moves through red blood cells, is converted red blood cells, is converted back to carbon dioxide and back to carbon dioxide and DIFFUSES into alveoli of lungs.DIFFUSES into alveoli of lungs.

• Medulla signals rib muscles Medulla signals rib muscles and diaphragm to relax, (ribs and diaphragm to relax, (ribs move down and inwards and move down and inwards and diaphragm moves upwards) diaphragm moves upwards) causing a positive pressure in causing a positive pressure in chest cavity.chest cavity.

STEPS IN RESPIRATION (5)STEPS IN RESPIRATION (5)

• Air is forced back out Air is forced back out of the system by of the system by BULK FLOW.BULK FLOW.

• Air moves out of Air moves out of alveoli of lungs, alveoli of lungs, through bronchioles, through bronchioles, bronchi, and trachea, bronchi, and trachea, through glottis and through glottis and past epiglottis, up past epiglottis, up through nasal through nasal pharynx, sinuses and pharynx, sinuses and out through the nose.out through the nose.

Blood Carriers of GasBlood Carriers of Gas• OO22 diffuses from lungs into blood capillaries to diffuses from lungs into blood capillaries to

RBC and is picked up by iron atom in Hemoglobin RBC and is picked up by iron atom in Hemoglobin molecule.molecule.

• COCO22 diffuses out of Mitochondrian of cells, into diffuses out of Mitochondrian of cells, into capillaries and through RBCcapillaries and through RBC– in RBC COin RBC CO2 2 + H+ H220 --- H0 --- H22COCO33 (carbonic acid) (carbonic acid)– Hemo causes change of H2CO3 to HCOHemo causes change of H2CO3 to HCO33 + H+ ions + H+ ions

(bicarbonate) (bicarbonate) – Bicarbonate diffuses out of RBC and into Bicarbonate diffuses out of RBC and into blood serumblood serum– H+ ions carried by HemoglobinH+ ions carried by Hemoglobin– * In lungs reaction is reversed* In lungs reaction is reversed– HCOHCO33 + H - + H - H H22COCO33 - - H H22O + COO + CO22

– COCO22 diffuses out of blood into alveoli diffuses out of blood into alveoli