BellworkBellwork

What are capillaries? Why is it important What are capillaries? Why is it important for them to be small and thin walled? for them to be small and thin walled?

Circulatory and Circulatory and respirationrespiration

The lungs are the site for COThe lungs are the site for CO22 and O and O22

exchangeexchange

Negative pressure breathing - Negative pressure breathing - Mammals pull air into their lungs Mammals pull air into their lungs

Partial pressurePartial pressure

The pressure exerted by a particular gas The pressure exerted by a particular gas in a mixture. in a mixture.

In the airIn the air OO22 ~160 mm Hg ~160 mm Hg

COCO22 ~.29 mm Hg ~.29 mm Hg

Due to this – ODue to this – O22 diffuses into the blood and diffuses into the blood and

COCO22 diffuses out of the blood diffuses out of the blood

Partial pressurePartial pressure

HemoglobinHemoglobin

Hemoglobin carries 4 oxygen molecules (OHemoglobin carries 4 oxygen molecules (O22))

Hemoglobin loads OHemoglobin loads O22 in the lungs and unloads in the lungs and unloads it in other parts of the bodyit in other parts of the bodyHow does Hemoglobin know when to do this?How does Hemoglobin know when to do this? Bohr shift – more acidic environment (because of Bohr shift – more acidic environment (because of

COCO22) makes hemoglobin unload O) makes hemoglobin unload O22

Cooperativity – If one OCooperativity – If one O22 molecule binds, it changes molecule binds, it changes the shape so the other three bind. If one is the shape so the other three bind. If one is unloaded it changes shape to release the others.unloaded it changes shape to release the others.

Hemoglobin also helps carry out COHemoglobin also helps carry out CO22

molecules and buffers the bloodmolecules and buffers the blood

7% of the CO2 is transported by plasma7% of the CO2 is transported by plasma

23% binds to hemoglobin peptide chains23% binds to hemoglobin peptide chains

70% is transported by erythrocytes as 70% is transported by erythrocytes as bicarbonate ionsbicarbonate ions The Hydrogen ions are carried by hemoglobin The Hydrogen ions are carried by hemoglobin

(minimizing pH change in the blood)(minimizing pH change in the blood)

The evolution of circulatory systems allowed The evolution of circulatory systems allowed larger and more-complex animals to arise.larger and more-complex animals to arise.

a.a. Describe the respiratory and digestive Describe the respiratory and digestive systems’ specialized structures that facilitate systems’ specialized structures that facilitate the movement of oxygen and glucose into the the movement of oxygen and glucose into the circulatory system of mammals. circulatory system of mammals.

b.b. Explain how oxygen and glucose are Explain how oxygen and glucose are transported within the circulatory system of transported within the circulatory system of mammls.mammls.

c.c. Explain the transfer of oxygen and glucose Explain the transfer of oxygen and glucose from the blood and into the active cells of from the blood and into the active cells of mammals.mammals.

In water, fish use countercurrent In water, fish use countercurrent exchange exchange

Questions for fish labQuestions for fish lab

For # 3 be sure to use words such as For # 3 be sure to use words such as vasoconstriction, vasodilatation and talk vasoconstriction, vasodilatation and talk about the speed of erythrocytes in about the speed of erythrocytes in capillariescapillaries

Capillaries

Norepinephrine – sympathetic (fight Norepinephrine – sympathetic (fight or flight) increase heart and or flight) increase heart and

respiratory rate, dilated pupils, respiratory rate, dilated pupils, open up airwaysopen up airways

Caffeine and Nicotine release Caffeine and Nicotine release norepinephrine in the brain (increase norepinephrine in the brain (increase blood pressure, increase wakefulness, blood pressure, increase wakefulness, increase in respiration, increase energy). increase in respiration, increase energy). They are also vasoconstrictors, which They are also vasoconstrictors, which should reduce the flow of blood in the should reduce the flow of blood in the periphery. periphery.

Alcohol - decreases of norepinephine Alcohol - decreases of norepinephine (which is a vasoconstrictor in the skin or (which is a vasoconstrictor in the skin or tail of a fish). Blood flow should increase tail of a fish). Blood flow should increase in periphery as a result- vasodilatation.in periphery as a result- vasodilatation.