BISC 4145 - Unit 3

Which is TRUE regarding the regulation of heart rate?

- Stimulation of parasympathetic nerves to the heart causes a slowing of heart rate. - Stimulation of sympathetic nerves to the heart causes an increase in heart rate. - A person whose heart lacks autonomic innervation has a faster heart rate at rest than a person with a normally innervated heart.

A female patient has a blood test, and her doctor tells her that she is anemic. Which of the following is most likely to be the woman's hematocrit?

32%

During a physical examination, Joe learns that his resting tidal volume is 550 mL; his average resting respiratory rate is 15 breaths per minute; his total lung capacity is 6,000 mL; and his anatomic dead space is 150 mL. Joe's resting alveolar ventilation is:

6.0 L/min.

What causes the opening and closing of the heart valves?

A pressure difference on the two sides of the valve

Tina is a hard-working sales clerk in a busy department store. She has stood completely still behind the check-out counter for an 8-hour shift. At the end of Tina's shift she finds that she feels somewhat dizzy and guesses that her blood pressure is quite low. All of the following factors normally contribute to homeostatic blood pressure regulation. Which one is most likely contributing to her symptoms?

Decreased activity of the skeletal muscle pump

Carbonic anhydrase catalyzes a reaction that combines which of the following?

H2O and CO2

Jane donates a pint of blood to a blood bank. A few minutes later, which of the following would be increased compared to pre-donation values?

Her heart rate and total peripheral resistance

Which of the following factors would NOT tend to increase systemic arterial blood pressure?

Increased parasympathetic stimulation

Which of the following would cause a decrease in the binding affinity of hemoglobin for oxygen?

Increased temperature of the blood

Which of the following statements regarding pulmonary surfactant is TRUE?

It increases the compliance of the lungs.

Which is TRUE about the pleural sac?

It is a closed sac surrounding each lung that contains only a tiny volume of lubricating fluid.

Which is normally TRUE about the intrapleural pressure?

It is lower than alveolar pressure.

Which of the following statements about erythropoietin is true?

It promotes the proliferation and differentiation of the erythrocyte lineage.

You have a patient who is showing signs of edema (tissue swelling) all over his body. In addition to visible swelling in his hands, feet, and face, you can also see evidence of swelling around his organs when viewing his CAT scan images. Thinking about what you know about the factors that regulate fluid flow from the blood vessels. Which of the following causes of edema seem most likely?

Low plasma protein concentration due to liver failure

Increased activity in the brain leads to an increase in blood flow. In the brain, this occurs because of:

a local response to increased CO2 and decreased O2

According to Boyle's Law, a decrease in volume leads to:

an increase in pressure.

The first heart sound represents which portion of the cardiac cycle?

closing of the atrioventricular valves

Sinoatrial node cells:

exhibit spontaneous depolarization that is accelerated by activation of their beta-adrenergic receptors.

Action potentials in the heart spread from cell to cell through

gap junctions

You've just been told by your doctor that you have a heart murmur between the first and second heart sounds. You go home to search for more information on this condition on the Internet and find that you have

insufficiency of an AV valve or stenosis of a semilunar valve.

Of the four Starling forces that determine capillary filtration, which two are normally very small?

interstitial fluid hydrostatic pressure and interstitial fluid osmotic pressure

A small amount of vasodilation in an arteriole prompts a ________.

large decrease in resistance

The majority of ventricular filling occurs during:

prior to contraction of the atria

Venoconstriction increases which of the following? (venoconstriction is constriction of veins)

return of blood to the heart

You (a healthy individual) are swimming underwater when you can no longer resist the urge to breathe. This overwhelming urge is probably due to

the increase in plasma H+.

The Frank-Starling mechanism of the heart describes:

the relationship between end-diastolic volume and stroke volume

Which of the following lists the heart valves in order, starting from the inferior vena cava?

tricuspid, pulmonary semilunar, mitral, aortic semilunar

The first step in hemostasis is ________.

vascular spasm

The pleura that surrounds the lungs consists of two layers, the ________.

visceral and parietal pleurae.

In a patient with a mutation that causes an inactive von Willebrand factor (vWF), which of the following would be TRUE?

Platelets will not adhere to collagen.

What is one function of the type II alveolar cells?

Production of surfactant

Which component of the heart's conduction system would have the slowest rate of spontaneous depolarization?

Purkinje fibers

Which structure is NOT part of the "anatomical dead space"?

Respiratory bronchiole

You're resting on the couch watching TV. Which of the following is the most likely reflection of the values in your body? Regarding the partial pressures of O2 and CO2, which of the following statements is true in a normal person at rest?

The PO2 in the systemic arteries is approximately 100 mmHg and the alveolar PO2 is approximately 105 mmHg.

You are learning to read electrocardiograms. You know that the patient you are examining has a pathology affecting the depolarization of his ventricles, therefore you're looking for a change in what portion of his EKG?

The QRS complex

Maria is a patient who was recently in a motor vehicle accident. Her injuries are causing her a lot of pain, and as a consequence to the morphine she's been given, her respiratory rate is quite low. Which of the following is likely to be TRUE?

The level of H+ ions in her blood has increased.

The volume of air flowing into the alveoli during inspiration is increased when there is an increase in which of these?

The pressure gradient from the atmosphere to the alveoli

Contraction of the external intercostal muscles causes which of the following to occur?

The ribs and sternum move upward.

In which form is most of the oxygen carried in arterial blood?

Bound to hemoglobin

Which of the following statements concerning the differences between action potentials in skeletal muscle cells and in ventricular cardiac muscle cells is TRUE? (note: influx = ion enters cell; efflux = ion leaves cell)

After sodium influx through voltage-gated channels occurs in ventricular cells, prolonged influx of calcium from the extracellular fluid occurs. No such calcium influx occurs in skeletal muscle cells.

You embark on a hiking trip on Mt. Kilimanjaro (altitude = 19,000 ft; Atmospheric air pressure = 379 mmHg). As you ascend, what happens to the PO2 in the alveoli?

Alveolar PO2 decreases.

After CO2 is produced by tissues, in what form is most of that carbon transported to the lungs for removal from the body?

As dissolved HCO3-

Which of these is demonstrated by the oxygen-hemoglobin dissociation curve?

At normal resting systemic arterial PO2, hemoglobin is almost 100% saturated with oxygen.