Midterm Review

Question 1

Which is not an example of Phenotypic flexibility?
a) the metabolic rates of mammals being higher in winter than in summer
b) Birds decreasing the size of their digestive tract during migration to save weight
c) A squirrel growing up when there is little food attaining a permanently smaller adult size than those growing up in a good food year.
d) An athlete developing large leg muscles due to weight training
e) All of the options demonstrate phenotypic flexibility

Answer 1

c)

Question 2

The physiology of an animal results from an interaction between the animal’s _______ and the environment during development and is considered to be part of its _______.

a) phenotype; diet
b) ancestry; fitness
c) genotype; phenotype
d) ancestry; phenotype
e) genotype; ancestry

Answer 2

c) genotype; phenotype

Question 3

which of the following statements about conformers and regulators is correct?
a) In a regulator, internal conditions mimic external changes
b) An organism can be a conformer some physiological systems and a regulator for others
c) in a regulator, internal conditions regulate external changes
d) both A and B
e) none is correct

Answer 3

b)

Question 4

The mammalian heart will continue to beat even after the nervous supply is cut off. This type of heart is referred to as:
a) neurogenic
b) independent
c) Myogenic
d) necrotic
e) Myocardium

Answer 4

c) Myogenic

Question 5

When a penguin dives it undergoes bradycardia. Bradycardia is a term that refers to:
a) uncoordinated contraction of the heart
b) lower than normal heart rate
c) the effect of pressure on stroke volume
d) accelerated heart rhythm
e) when valves between atria and ventricles open rapidly

Answer 5

b)

Question 6

The intiation of the mammalian heart contraction:
a) takes place at the SA node
b) requires neural input
c) takes place at the AV node
d) takes place at the SA node and requires neural input
e) takes place at the AV node and requires neural input

Answer 6

a)

Question 7

Some reptiles stop breathing for periods of time (apnea). During these periods, blood may become shunted within their hearts. How would you expect the pattern of blood flow change during apnea?

a) Blood is shunted from the pulmonary circuit to the systemic circuit
b) Blood is shunted specifically to the brain
c) Blood is shunted from the systemic circuit to the pulmonary circuit
d) The pattern does not change when they dive.
e) Blood is shunted away from the brain

Answer 7

a)

Question 8

Blood flows in a similar way through bird and mammalian hearts. The cardiac cycle of birds has two different phases (like mammals),

a) Diastole in which the atria relax, and systole in which the ventricles relax
b) Systole in which the atria relax, and diastole in which the atria contract
c) systole in which the ventricles contract, and diastole in which the ventricles relax
d) Systole in which the atria contract, and diastole in which the ventricles contract
e) Diastole in which the ventricles contract, and systole in which the ventricles relax.

Answer 8

c)

Question 9

Tuna are considered an “atheltic” fish species, capable of sustained activity. Tuna hearts receive oxygen primarily from
a) pulmonary arteries
b) blood in the heart chambers
c) coronary vessels running through compact myocardium
d) pericardial fluid
e) the spongy myocardium

Answer 9

c)

Question 10

The Frank-Starling mechanism describes the relationship between
a) forces in the left and right ventricles
b) cardiac output and maximum heart contraction frequency
c) blood pressure and peripheral vascular resistance
d) stroke volume and heart rate
e) end-diastolic volume and stroke volume

Answer 10

e)

Question 11

When a dog or cat’s heart beats, the contraction of the atria and ventricles is kept separate. This is because of the delay in the depolarization of the:
a) cardiac ganglion
b) aortic collagen
c) SA node
d) sinus venosus
e) AV node

Answer 11

e)

Question 12

On an electrocardiogram, the P wave indicates:
a) depolarization of the ventricle
b) repolarization of the atria
c) repolarization of the ventricle; and repolarization of the atria
d) depolarization of the atria
e) A and B are both correct

Answer 12

d)

Question 13

Heart cells (cardiomyocytes) must communicate with each other to ensure a coordinated contraction. This communication is through:
a) desmosomes
b) tight junctions
c) gap junctions
d) synapses
e) the extended plateau phase of the action potential

Answer 13

c)

Question 14

In a classic cardiomyocyte action potential, the plateau phase is primarily because:
a) voltage gated Na+ ion channels are open
b) voltage gated K+ ion channels are closed
c) “funny” channels are closed
d) voltage gated Ca++ ion channels are open
e) voltage gated CL- ion channels remain open

Answer 14

d)

Question 15

Which of the following results in the unstable membrane potential of a pacemaker cell?
a) membrane permeability to K+ gradually increases
b) Na+ ions enter the cell via non-specific cation channels (Funny channels)
c) the decrease in membrane permeability to CL-
d) the closing of voltage gates Ca++ ion channels
e) None of the above

Answer 15

b)

Question 16

What physiological features prevent giraffes from getting an edema in their legs when standing?
a) muscular arteries controlling blood flow to the legs
b) tight skin around their legs and ankles
c) veins with 1-way valves
d) capillaries with a thickened tunica media
e) both A and B are correct

Answer 16

e)

Question 17

Insects and many invertebrates possess ______ circulatory systems in which hemolymph completely bathes the organs/tissues and is not typically contained in distinct arteries or veins.
a) open circulatory systems
b) closed circulatory systems
c) solid circulatory systems
d) fluid CS
e) insects don’t have circulatory systems

Answer 17

a) open CS

Question 18

Which of the following is NOT required for a functioning circulatory system?
a) circulating fluid
b) Erythrocytes
c) A pump or propulsive structure
d) tubes, channels or sinuses
e) generation of a pressure gradient

Answer 18

b)

Question 19

Excluding the movement of blood between the lungs and the heart, which of the vessels carry CO2-rich (and oxygen-poor) blood back toward the heart?
a) venules
b) veins
c) arterioles
d) arteries
e) both venules and veins

Answer 19

e)

Question 20

Fluid moves across capillary walls. Which of the following is false?
a) fluid moves into the capillaries via osmosis
b) Hydrostatic pressure inside the capillaries exceeds the pressure outside the capillaries
c) There is a net loss of lfuid from capillaries to the interstitial space
d) Low arterial pressure in the pulmonary circuit helps prevents fluid build-up in lungs
e) There is no false answer. All of the above choices are true.

Answer 20

e)

Question 21

Which of the following has the largest effect on velocity of fluid in a blood vessel?
a) vessel length
b) pressure in the vessel
c) strength of the vessel walls
d) vessel diameter
e) viscosity of the fluid

Answer 21

d)

Question 22

In birds and mammals the left side of the heart is responsible for the systemic circuit and the right side is responsible for the pulmonary circuit
a) systemic; aortic
b) systemic; pulmonary
c) cutaneous; arterial
d) pulmonary; systemic
e) None of the above

Answer 22

b)

Question 23

Which of the following statements is false about the mammalian pulmonary circuit?
a) blood pressure in the pulmonary circuit is relatively low compared with the systemic circuit
b) blood pressure is lower than the osmotic pressure in vessels of the pulmonary circuit
c) pulmonary vessel walls are relatively thick compared with vessels in the systemic circuit
d) vessel resistance in the lungs are low because pulmonary vessels are short and wide
e) There is no false answer. All above are true.

Answer 23

c)

Question 24

When an animal requires increased blood flow to a particular organ or tissue,
a) blood pressure will increase
b) capillaries will decrease in size
c) capillaries will increase in number
d) arterioles will dilate in that area
e) venules in that area will constrict

Answer 24

d)

Question 25

Which of the following is false about myogenic autoregulation in arterioles?
a) it prevents excessive blood flow into tissues
b) it helps ensure constant blood flow through vessels
c) relies on negative feedback
d) is controlled by stretch of smooth muscle
e) there is no false answer. All of the above choices are true.

Answer 25

e)

Question 26

Which statement about vertebrate circulatory systems is NOT true?
a) In mammals, deoxygenated blood leaves the heart through the pulmonary artery
b) In amphibians, deoxygenated blood enters the heart through the right atrium
c) In reptiles, the blood in the pulmonary artery has a lower oxygen content than the blood in the aorta
d) In fish, oxygenated blood from the gills returns to the heart through the left atrium
e) In birds & mammals the pressure in the aorta is higher than the pressure in the pulmonary artery

Answer 26

c)

Question 27

In the oxygen cascade, oxygen enters the mitochondria
a) by convection at a rate that depends on the flow of the oxygenated blood in capillaries
b) by diffusion at a rate that is dependent on the difference in O2 partial pressure between the blood systemic capillaries and the mitochondria
c) by diffusion at a rate that is dependent on the flow of the oxygenated capillary blood
d) by diffusion at a rate that is dependent on the difference in O2 partial pressure between the blood systemic capillaries and the mitochondria
e) None of the above

Answer 27

b)

Question 28

The rate at which gasses diffuse across the membranes is described by the Fick equation [Q= DA(P1-P2)/L] where Q= rate of diffusion, D = diffusion coefficient, A = cross sectional area, P1 and P2 are partial pressures of gas, L = diffusion distance (path length). Which components of the equation can animals adjust to maximize gas exchange?
a) surface area of the membrane (cross sectional area)
b) partial pressure gradient
c) diffusion distance
d) all of the above
e) none of the above

Answer 28

d)