Ch 38 - animal resp & cardiovascular system

for bio 81 exam 2

Single cell & simple multicell exchange how

simple diffusion

Where terrestrial vs aquatic organisms get their O2

• terrestrial = air

• aquatic = water

Diffusion relationship with SA & distance

• directly proportional to SA & conc difference: greater SA = better diffusion

• longer distance = lower diffusion

Pressure and Resistance (circulatory system)

• more narrow vessels = higher resistance

• need enough pressure to overcome resistance to flow

Arteries

carry o2 rich blood away from heart under HIGH pressure

Veins

return low O2 blood back to heart under low pressure

• thin walled

Which one’s thicker: arteries vs veins

Arteries

Arterioles

arteries branch into smaller diameter = arterioles

Capillaries

Arterioles connect to very small capillaries

Venules

veins branch into smaller venules - capillary drain into venules

Advantage of circulatory orgnaization

1. maintains same level of blood flow at all levels (increased resistance at capillaries offset by large number of them)

2. enable blood to flow more slowly in smaller vessels = give time to exchange gases

What happens when blood vessels constrict?

• resistance to flow increases = blood flow decreases

What happens when blood vessels dilate

• resistance decreases = blood flow increases

Describe the process of what happens when one exercises - how vessels react

• exercise = rate of cellular respiration increases = more CO2 produced

• this signals smooth muscles in arteries to relax = more blood flow to match O2 delivery

What are artery walls composed of

• multiple elastic layers - made of collagen & elastin

Rena cova

drains blood from brain&body back to heart

low pressure so blood accumulates within veins ????

Explain the bohr effect (increase in CO2)

• oxyhemoglobin dissociation curve shifts RIGHT

• increased CO2 = less affinity for O2 so unloading of O2 increases at tissue level

Explain the cooperative nature of O2 binding to hemoglobin

• once O2 binds = increases affinity for MORE O2

• S curve:

  • at low O2 conc, increase in O2 doesnt affect binding to hemoglobin that much

  • higher O2 = increases affinity

How does low pH affect dissociation curve

shift RIGHT

Myoglobin

• higher affinity for O2 than hemoglobin

• rich in muscle cells

• dissociation curve shift LEFT

example of dissociation curve shift left

• fetal hemoglobin - gets O2 from mom so need to hold on to it

• myoglobin

example of dissociation curve shift right

• increase in CO2

• low pH