TopHat Circulation & Short-Term Blood Pressure Regulation Questions

Explain the function of venous valves.

In veins, valves ensure that blood flow is unidirectional despite being under low pressure.

How does the presence of large fenestrations within sinusoids affect the movement of cancerous cells or bacteria?

It makes the movement of bacteria or cancer cells easier throughout the body. This is one of the drawbacks of this type of arrangement.

Are the effects of gravity the same in the body when a person is swimming compared with standing or with lying down?

No, when swimming, people are at neutral buoyancy, minimizing the effects of gravity.

Which would you expect to change more following exercise, systolic or diastolic blood pressure? What impact would this have on pulse pressure? And why?

Systolic blood pressure will increase more than diastolic blood pressure. This will result in increased pulse pressure. Increased venous return and increased contractility of cardiac muscle causes increased stroke volume. Increasing stroke volume will increase systolic blood pressure and pulse pressure.

What would be the effect of capillaries with diameters less than 5 um?

The capillaries would quickly plug with red blood cells, making them ineffective in delivering nutrients to tissues.

Briefly describe the relationship between blood flow, blood pressure, and resistance using the formula discussed. What is the relationship between flow and pressure? What is the relationship between flow and resistance?

The general formula describing this relationship is F=ΔP/R. As shown, flow (F) varies directly with the difference in pressure (ΔP) and inversely with resistance (R). That is, as ΔP increases, F increases; as R increases, F decreases.

Why must the aorta and its branches be able to stretch and recoil so readily?

These arteries must be able to stretch when pressure rises during ventricular systole and then recoil when pressure falls during ventricular diastole.

What would be the impact on venous physiology if the tunica media had many smooth muscle cell layers?

You would lose venous compliance and the ability of the veins to store extra blood. This would increase the amount of blood within the arterial side of the circulatory system, and hence blood pressure.

Match each artery type to its description. a. elastic arteries b. muscular arteries c. arterioles 1) these arteries can be so small that their wall is only an endothelium and a thin layer of smooth muscle fibers 2) these arteries are closest to the heart and have relatively larger lumens than other arteries 3) these arteries have the thickest tunica media of any vessel type

a. 2 b. 3 c. 1 Elastic arteries have large lumens so that they can readily receive the blood

Match each of the following to its described impact on blood pressure. a. decreased HR b. increased SV c. increased blood vessel diameter 1) increased BP due to increased R 2) increased BP due to increased CO 3) decreased BP due to decreased CO 4) decreased BP due to decreased R

a. 3 b. 2 c. 4 CO and R are both directly related to BP. Increased SV causes increased CO; decreased HR causes decreased CO; increased blood vessel diameter causes decreased R.

Peripheral resistance is __________. Select all that apply. a. directly proportional to blood vessel length b. directly proportional to blood vessel diameter c. directly proportional to blood viscosity

a. directly proportional to blood vessel length c. directly proportional to blood viscosity Resistance is inversely proportional to blood vessel diameter; as diameter decreases, resistance increases.

Match each layer of the blood vessel wall to a description of its tissue content. a. tunica intima b. tunica media c. tunica externa 1) collagenous connective tissue 2) simple cuboidal epithelium 3) smooth muscle and elastic connective tissue 4) cardiac muscle tissue 5) reticular connective tissue 6)simple squamous epithelium

a. simple squamous epithelium (6) b. smooth muscle and elastic connective tissue (3) c. collagenous connective tissue (1) The tunica intima is a continuous simple squamous epithelium; it prevents leakage, reduces friction, and in the smallest of blood vessels is thin enough to allow for exchange. The tunica media is composed of smooth muscle and elastic connective tissue; this allows for control of the blood vessel's diameter and to stretch and recoil in response to fluctuating blood pressure. The tunica externa is a collagenous connective tissue that anchors the blood vessel in place.

Match each capillary type to a location in which it is found. a. continuous b. fenestrated c. sinusoid 1) skin 2) hyaline cartilage 3) cornea 4) bone marrow 5) small intestine

a. skin (1) b. small intestine (5) c. bone marrow (4)

Arrange the layers of a blood vessel wall, from superficial to deep. a. tunica externa b. tunica media c. tunica intima

a. tunica externa b. tunica media c. tunica intima Pulmonary veins carry oxygenated blood from the lungs back to the heart. Systemic arteries then carry that oxygenated blood blood toward the tissues of the body.

Sort these vessel types in the order of blood flow, starting with those that first carry blood away from the heart and finishing with those that eventually return blood to the heart. arterioles veins arteries venules capillaries

arteries arterioles capillaries venules veins Arteries carry blood away from the heart and branch into smaller and smaller vessels, eventually giving rise to arterioles. Arterioles deliver blood to capillaries which are drained by venules. Venules merge to form veins, and veins carry blood back to the heart.

Assume that the following are the hydrostatic and osmotic conditions at the venous end of a capillary bed: CHP = 17 mmHg, IFHP = 0 m Hg, BCOP = 26 mmHg, IFCOP = 12 mmHg. Based on these conditions, which statement below correctly describes NFP and the direction of fluid movement? a. NFP is 3 mmHg, reabsorption is occurring b. NFP is 3 mmHg, filtration is occurring c. NFP is -21 mmHg, reabsorption is occurring d. NFP is -21 mmHg, filtration is occurring

b. NFP is 3 mmHg, filtration is occurring NFP = (CHP + IFCOP) - (IFHP + BCOP) = (17 mm Hg + 12 mm Hg) - (0 mm Hg + 26 mm Hg) = 3 mm Hg. As NFP has a positive value, filtration is occurring. If you calculated NFP to be -21 mm Hg, you likely confused IFHP and IFCOP in your formula.

A 61-year-old man presents to the emergency department complaining of vomiting, profuse sweating, and very severe chest pain. He describes the pain as excruciating and tearing in nature. He also notes that the pain radiates around to the middle of his back. An ECG test returns normal results. What is likely the problem the patient is suffering from? a. myocardial infarction (heart attack) b. aortic dissection (tearing) c. severe muscle strains in the chest d. congestive heart failure

b. aortic dissection (tearing) The patient is suffering from an aortic dissection, or tear in the wall of the aorta. Aortic dissection is distinguished from a myocardial infarction by sudden, excruciating chest pain, but there is no evidence of abnormal ECG. Other common symptoms include dysphagia from esophageal compression (blood leakage), abdominal pain, fever, and severe anxiety.

Which vessel types may be porous enough to allow diapedesis? Select all that apply. a. arterioles b. capillaries c. venules d. veins

b. capillaries c. venules Capillaries are the most permeable type of blood vessel. Postcapillary venules have walls that are thin enough to allow diapedesis.

Look closely at Poiseuille's equation. If the viscosity (thickness) of a fluid moving through a tube were to decrease, what would happen to the value of ΔP? a. delta P would increase b. delta P would decrease c. delta P would decrease at first, but then begin to increase as viscosity gets smaller and smaller d. there would be no change to delta P. viscosity has not effect on delta P

b. delta P would decrease There is a direct relationship between viscosity and ΔP, so ΔP will decrease if viscosity were to decrease.

Which blood vessels carry oxygenated blood? Select all that apply. a. pulmonary arteries b. pulmonary veins c. systemic arteries d. systemic veins

b. pulmonary veins c. systemic arteries Pulmonary veins carry oxygenated blood from the lungs back to the heart. Systemic arteries then carry that oxygenated blood blood toward the tissues of the body.

Which arteries are most directly responsible for controlling the amount of blood entering individual capillary beds? a. elastic arteries b. muscular arteries c. arterioles

c. arterioles Arterioles feed directly into capillary beds and can either vasoconstrict or vasodilate to change local resistance to blood flow.

Which feature of the capillary wall results from incomplete tight junctions? a. pinocytotic vesicles b. fenestrations c. intercellular clefts d. vascular shunts

c. intercellular clefts Intercellular clefts are gaps between adjacent endothelial cells, resulting from incomplete tight junctions, that increase the permeability of capillaries.

Which of the following effects would cause decreased venous return? a. increased cardiac output b. increased muscle activity c. increased breathing rate d. decreased breathing rate

d. decreased breathing rate The respiratory pump help veins move blood back toward the heart, so decreased respiratory rate would cause decreased venous return. Increased cardiac output, increased muscle activity, and increased breathing rate all cause increased venous return.

A 28-year-old female presents to the emergency department for difficulty breathing for the past hour. During a physical examination, her lips appear a little blue (cyanosis). Additionally, there is a normal pulse in her left leg, but almost no pulse in her right leg. When giving her past medical history, she explains that she is a hairdresser and has been working while standing for about eight hours per day for the past thirteen years. An x-ray of her lungs reveal the presence of multiple small lesions. What is the likely problem the patient is suffering from? a. lung cancer b. exposure to toxic chemicals in the workplace c. congestive heart failure d. phlebitis e. deep vein thrombosis

e. deep vein thrombosis A shortness of breath and abnormal x-ray showing masses in the lungs would suggest cancer. But the cyanosis and problems with circulation in her legs suggests something else is at play. By requiring her to stand for long periods of the day, the valves within her leg veins began to weaken, leading to accumulation of clots within the legs - or deep vein thrombosis. These clots break off and can travel to her lungs - causing pulmonary embolism, resulting in peripheral cyanosis.

A 43-year-old woman presents to the emergency department with sudden memory loss, personality changes, trouble concentrating, and blackouts. Her spouse reports that she is in otherwise good health. When asked by the physician, the patient reports she routinely takes gingko and ginseng as dietary supplements, and that morning at work had an energy drink. What is the likely problem the patient is suffering from? a. stroke b. too much caffeine c. overdose on herbal supplements d. inner ear infection e. hypertension

e. hypertension The woman is suffering from acute hypertension brought on by the combination of gingko, ginseng and caffeine-laden drinks. Ginseng and gingko are well known to increase blood pressure in patients, as do caffeine-laden drinks.

Arrange the capillary types in order from most to least permeable. continuous capillaries fenestrated capillaries sinusoid capillaries

sinusoid capillaries fenestrated capillaries continuous capillaries