Chapter 19: Circulation and Short-Term Blood Pressure Regulation PNB 2265

Sort the 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.

1. Arteries 2. Arterioles 3. Capillaries 4. Venules 5. Veins

Match each of the following to its described impact on blood pressure: 1. Decreased HR 2. Increased SV 3. Increased blood vessel diameter

1. Decreased BP due to decreased CO 2. Increased BP due to increased CO 3. Decreased BP due to decreased R

Peripheral resistance is:

1. Directly proportional to the blood vessel length 2. 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: 1. Tunica intima 2. Tunica media 3. Tunica externa

1. Simple squamous endothelium 2. Smooth muscle and elastic connective tissue 3. Collagenous connective tissue

Arrange the capillary types in order of most to least permeable

1. Sinusoid capillaries 2. Fenestrated capillaries 3. Continuous capillaries

Match each capillary type to a location in which it is found. 1. Continuous 2. Fenestrated 3. Sinusoid

1. Skin 2. Small intestine 3. Bone marrow

Match each artery type to its description. 1. Elastic arteries 2. Muscular arteries 3. Arterioles

1. These arteries are closet to the heart and have relatively larger lumens than other arteries 2. These arteries have the thickest tunica media of any vessel type 3. These arteries can be so small that their wall is only an endothelium and a thin layer of smooth muscle fibers

Arrange the layers of a blood vessel wall from superficial to deep.

1. Tunica externa 2. Tunica media 3. tunica intima

A 61-year-old man presented to the emergency department complaining of vomiting, profuse sweating, and very severe chest pain. He described the pain as excruciating and tearing in nature. He also noted that the pain was radiating around to the middle of his back. An ECG test returned normal results. What is the likely problem the patient is suffering from?

Aortic dissection (tearing) 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 arteries are most directly responsible for controlling the amount of blood entering individual capillary beds?

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

Which vessel types may be porous enough to allow diapedesis?

Capillaries Venules *Post-capillary venules have walls that are thin enough to allow diapedesis

Which of the following effects would cause decreased venous return?

Decreased breathing rate * 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 physical examination, her lips appeared a little blue (cyanosis). During the past medical history, she explained 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 revealed the presence of multiple small lesions. During a physical examination, there was a normal pulse in her left leg, but almost no pulse in her right leg. What is the likely problem the patient is suffering from?

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 ED for 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?

Hypertension * The women 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

Which feature of the capillary call results from incomplete tight junctions?

Intercellular clefts

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

Assume that the following are the hydrostatic and osmotic conditions at the venous end of a capillary bed: CHP = 17 mm Hg, IFHP = 0 mm Hg, BCOP = 26 mm Hg, IFCOP = 12 mm Hg. Based on these conditions, which statement below correctly describes NFP and the direction of fluid movement?

NFP is 3 mm Hg, 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.

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 blood vessels carry oxygenated blood?

Pulmonary veins Systemic arteries

Which would you expect to change more following exercise, systolic or diastolic blood pressure? What impact would this have on pulse pressure? 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 withe diameters less than 5 micrometers?

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.

Explain the function of venous valves.

in veins, valves ensure that blood flow in unidirectional despite being under low pressure

If the viscosity (thickness) of a fluid moving through a tube were to decrease, what would happen to the value of ΔP?

ΔP would decrease