Practice Questions

Select all of the functions of the sympathetic nervous system.

- decreased end systolic volume, decreased smooth muscle contraction, increased resistance in most arterioles that go to the digestive system, increased cardiac output

Which blood vessels have a thin layer of endothelium?

All of the above are correct

An Arctic Tern (a bird) typically flies 44,000 miles a year during its annual migrations. What kind of muscle fibers likely make up the majority of its wings?

Slow oxidative

Which fiber type would be most prominent in a marathon runner's leg muscles?

Slow oxidative- fatigue resistant

Oxygen will pass from alveolar air space into blood via:

Simple diffusion across epithelial cells

Which structures are located in the medulla of the kidney?

collecting duct and loop of Henle

Which of the following is responsible for the rapid depolarization phase of an action potential within the pacemaker cells?

an increase in PCa

During beginning stages of inhalation, pressure is greatest in the

atmosphere

The partial pressure of oxygen is highest in the

atmosphere

Hypoventilation would lead to a(n) [blank] within the systemic arteries.

decrease in PO2 and increase in PCO2

If there is blood in urine, what might be causing that?

impaired filtration into Bowman's capsule

Which of the following would most likely cause an increase in air flow into the lungs

increased surfactant

During hyperventilation, PO2 in blood [blank] and PCO2 [blank].

increases; decreases

The image below shows a reflex for micturition, otherwise known as urination. The reflex shown below is what happens in babies, who do not control urination. Now that you understand reflexes, you should be able to figure out this diagram. The sensory neuron responds when the bladder stretches (i.e. filled with urine). The external sphincter is made of skeletal muscle and when it is contracted, urine cannot leave the bladder. When the external sphincter is relaxed, urination occurs. Note that two neurons are labeled A and B: neuron A is the red neuron in the spinal cord that makes a synapse on neuron B, and neuron B is making a synapse onto the external sphincter. Think about the logic of this circuit to figure out what type of neurons A and B are. Ignore the middle blue neurons; they are not important to answer this question. Neuron A is a/an inhibitory interneuron and neuron B is a/an motor neuron .

inhibitory neuron; motor neuron

Which chamber of the heart has the thickest musculature?

left ventricle

Contraction of the diaphragm is controlled by:

motor neurons

Which of the following muscle fibers would be most likely

muscle fibers with a low concentration of mitochondria; muscle fibers that do anaerobic respiration most of the time.

Which of the following does NOT contribute to the rapid diffusion of gases into and out of the blood within the lungs?

rapid blood flow

Which correctly describes path of red blood cell through nephron?

renal artery = afferent arteriole = glomerulus = efferent arteriole = peritubular capillary = renal vein

When the atria contract, they are in ____________________, which results in _____________________.

systole; movement of blood into the ventricles

When the pressure in the ventricles is greater than in the atria

the AV valves close; the ventricles are contracting

The second heart sound occurs when the semilunar valves close; thus it marks

the end of the ejection period

Which of the following would be expected to cause a decrease in the percent saturation of hemoglobin?

A decrease in blood pH

Which of the following would cause a decrease in mean arterial pressure?

A drop in total peripheral resistance resulting from relaxation of smooth muscles surrounding arterioles.

Which neurotransmitters control diaphragm contraction?

Acetylcholine only

What initiates heart beat?

Action potentials in SA node

How does aldosterone increase Na+ reabsorption?

Aldosterone and its intracellular receptor activate expression of the gene for the Na/K pump

Which of the following medications would be used to treat someone with tachycardia?

Beta blocker

What happens to oxygen transport when the body is cold (compared to normal)?

Blood in the systemic veins contains more oxygen

Why does ventricular pressure decrease part way through 3rd phase?

Blood in ventricle goes into the aorta

Which of the following descriptions of the autonomic innervation of the cardiovascular system is FALSE?

Both sympathetic and parasympathetic neurons innervate smooth muscle in arterioles.

Which of the following statements about gas transport is correct?

Hemoglobin transports oxygen and carbon dioxide

Which of the following would be a medication to treat hypertension?

Ca+2 channel blockers that cause vasodilation

Which of these blood vessels normally carries fully oxygenated blood?

Cartoid artery (the artery that brings blood to the brain)

Cortisol moves across capillary endothelial cells via

Diffusion across the plasma membranes

All veins contain deoxygenated blood.

False

The systemic circulatory system does not go to the lungs or heart.

False

True/false: An electrocardiogram recording is the same thing as an action potential.

False

Which of the following is found in cardiac muscle, but not in skeletal muscle?

Gap junctions

Which molecule is reabsorbed completely back into the blood in the proximal tubule?

Glucose

Predict how PCO2 affects hemoglobin affinity for oxygen.

Hb has lower affinity for oxygen.

Which of these will reduce arterial blood pressure?

Implanting a small electrical device on the aortic baroreceptors that caused them to fire more frequent action potentials

What change in CO2 concentration would cause bronchodilation?

Increased CO2

During exercise, the ventilation rate increases. How does that happen?

Increased frequency of action potentials in the motor neurons that control the inspiratory muscles

Which of the following leads to increased stroke volume?

Increased levels of epinephrine in the blood

You are startled by a friend and you notice you are breathing faster than before. What directly caused you to have a faster ventilation rate?

Increased signals from the respiratory center in the brain stem to motor neurons in the spinal cord.

How can we increase venous return?

Increased skeletal muscle contraction

Which cardiac event occurs during the QRS wave in the ECG?

Isovolumetric contraction

Oxygenated blood from the lungs first enters the heart via which chamber?

Left atrium

If you have a stroke in the right motor cortex that destroys the neurons, what would be the functional consequence?

Left side of body is paralyzed

What causes skeletal muscle relaxation?

Motor neuron does not fire action potentials

Which structure in the respiratory system has the most similar function to the heart?

Muscles in the chest, and the diaphragm

How does the sympathetic nervous system increase the heart rate?

Norepinpehrine (NE) binds adrenergic receptors in the SA node, activating the cAMP second messenger system that increases current through If channels

During this reflex, which muscles in the right leg are contracting?

Only hamstrings contract

What is TRUE about the blood in the pulmonary artery?

PO2 in the pulmonary artery is lower than PO2 in the pulmonary vein

Which of the following statements is correct?

PO2 is greater in the pulmonary vein than in the vena cava.

If baroreceptors increase their firing rate, what is the likely consequence?

Parasympathetic nervous system activated

What causes contractile heart muscle cells to depolarize to the action potential threshold?

Positive ions go through gap junctions

If patient has right posterior hemisection of their spinal cord, they will be paralyzed in their

Right leg only

What causes the action potential in the pacemaker cells in the SA node?

The action potentials are intrinsically produced by pacemaker cells that express If channels

Carbon dioxide is not an acid, but it can lower the pH of blood when it is abundant. Why is that?

The majority of carbon dioxide in the blood reacts with water to make bicarbonate and H+ ions.

During diastole, the pressure in the ventricles is much less than in the arteries (see the slide from lecture). If the pressure is greater in the arteries, then why doesn't blood go back into the ventricles?

The semilunar valves close when the pressure in the arteries is greater than in the arteries

Which of the following statements is true?

The sympathetic nervous system causes vasoconstriction and bronchodilation

If you were to go upside down into a handstand, blood pressure would momentarily increase (until the baroreceptor reflex corrects it). Why does blood pressure increase when you go upside down?

There is increased venous return

What is the function of the heart?

To provide the force for the movement of blood

True/false: In gas exchange in both the lungs and respiratory tissues, oxygen and carbon dioxide always move down their partial pressure gradients.

True

Write equation for volume of urine produced.

Urine volume = F-R+S

During exercise, what happens to the arterioles that bring blood to the active skeletal muscles?

Vasodilation

What causes the AV valves to close?

Ventricular contraction (increasing pressure in ventricles)

Which of the following is TRUE of the ventricular filling phase of the cardiac cycle?

Ventricular pressure is less than aortic pressure

Which of the following descriptions of blood vessels is NOT correct?

Venules: highest pressure of all blood vessels

Which of the following statements is true?

Water is primarily reabsorbed in the proximal tubule

What happens when the hormone ADH is present?

Water moves from the duct to the capillary (reabsorption)

When the pressure in the ventricles is greater than in the arteries

blood flows from ventricles into arteries; the semilunar valves open

Which of the following is the largest?

fluid filtered into Bowman's capsule each day

When the sympathetic nervous system is active, will be released onto the smooth muscles surrounding some blood vessels, causing , which affects the blood pressure.

norepinephrine; vasoconstriction

What will happen to pH of blood during intense exercise?

pH decreases

Postural muscles of the legs and back tend to have an high proportion of what fiber type?

slow oxidative

The [blank] nervous system causes increased force of contraction in the ventricles, which [blank] the mean arterial blood pressure.

sympathetic; increases

The Q-T interval is the time from the onset of the QRS complex to the T wave, which measures

the time of ventricular systole

Where is partial pressure of CO2 greatest?

vena cava