chapter 18

The action potential from the brain to the heart travels along which nerve(s)?

vagus nerve

Capillary beds have precappillary _______ at the junction of the capillaries and the meterteriole

Sphincters

Determine whether the following statements are associated with a transient ischemic attack (TIA) or a stroke/cerebrovascular accident (CVA).

Stroke/CVA: 1) The sudden death (infarction) of brain tissue caused by ischemia 2) Can be produced by atherosclerosis, thrombosis, or a ruptured aneurysm 3)effects range from unnoticeable to fatal 4) Recovery depends on the ability of neighboring neurons to take over the lost function TIA: 1) brief episode of cerebral ischemia 2) temporary dizziness, loss of vision, weakness, paralysis, headache, or aphasia 3) lasts from just a moment to a few hours 4) may result from spasms of diseased cerebral arteries

What is(are) the physiological purposes of vasoreflexes?

To cause a generalized raising or lowering of blood pressure throughout the body and to selectively modify the perfusion of a particular organ by rerouting blood from one region of the body to another

Which is the most abundant plasma protein? Changes in its concentration can significantly affect blood volume, pressure, and flow.

albumin

In addition to water, blood plasma consists of which of the following?

albumins, globulins, fibrinogen, electrolytes, and nutrients

where are baroreceptors found?

aorta and subclavian veins

During exercise, the adrenal medulla and sympathetic nerves cause which of the following to occur?

arterioles dilate in response to epinephrine and norepinephrine

Which term refers to the feedback response to blood-pressure changes?

baroreflex

Red blood cells are also called

erythrocytes

A blood clot is based on a mesh framework of the protein.

fibrin

Which plasma component is not present in serum?

fibrinogen

When the sphincters are open, blood will _____ the capillary bed

fill

What are the three primary types of plasma proteins?

haptoglobulin: transports hemoglobin released by dead erythorcytes Ceruloplasmin: transports copper Prothrombin: promotes blood clotting

The percentage of the blood's volume composed of erythrocytes is called the

hematocrit

Which of the following will not increase the heart rate?

increased blood pressure

After a meal, the ____ receive priority, and the skeletal muscles receive very little flow.

intestines

Transferrin is a type of (β) globulin. What does it transport?

iron

Why is the liver considered part of the circulatory system?

it produces most of the plasma proteins

The formed elements of the blood are platelets, erythrocytes, and five types of leukocytes, which include eosinophils, basophils, neutrophils, monocytes and

lymphocyte

Which of the following contains chemoreceptors?

medulla oblongata

during exercise, the skeletal muscles receive ______ blood flow.

more

The cerebral arteries dilate when the systemic BP drops and constrict when it rises.

true

The lymphatic capillaries reabsorb as much as 20% of the fluid lost by the blood capillaries.

true

The net osmotic pressure is equal at both the arterial and the venous ends of the capillary.

true

When a person is still, blood accumulates in the limbs because venous pressure is not high enough to override the weight of the blood and drive it upward.

true

action potentials are conducted from the baroreceptors to the brain via which nerve?

vagus and glossopharyngeal nerve

Diastolic pressure is the minimum arterial blood pressure occurring during which of the following?

ventricular relaxation

What is the main component of blood plasma by weight?

water

Why does exercise increase venous return?

Blood vessels of the skeletal muscles, lungs, and coronary vessels constrict, increasing pressure.

Which of the following is not a mechanism that assists venous return?

Central venous pressure being greater than pressure in the venules

Match each component of blood with its description

Contains erythrocytes: hematocrit Contains WBC and platelets: plasma Fluid portion of the blood: buffy coat

Read the statements below and determine the stage of shock to which they belong.

Decompensated shock: 1) life-threatening positive feedback loops occur 2)poor cardiac output results in mycardial ischemia and infarction 3) slow circulation of the blood can lead to DIC 4) ischemia/acidosis of braintstem depress the vasomotor and cardiac centers 5) half of those who go into this type of shock die Compensated: 1)hypotension triggers the baroreflex 2)hypotension triggers the production of angiotensin II 3) brings about spontaneous recovery 4) when a person falls to a horizontal position, gravity restores blood flow to the brain

When this occurs, blood is ____ to tissue or organs elsewhere

Diverted

The hematocrit is the percentage of the blood volume composed of which of the following?

Erthrocytes

The hematocrit is the percentage of the blood volume composed of which of the following?

Erythrocytes

Increased sympathetic stimulation causes increased heart rate and stroke volume.

False

Increased sympathetic stimulation causes vasodilation, bringing elevated blood pressure back to normal

False

Heart rate and stroke volume decrease with a decrease in parasympathetic stimulation

Fasle

What does decompensated shock result in?

Ischemia and acidosis of the brainstem, myocardial ischemia, several life-threatening positive feedback loops, and disseminated intravascular coagulation

Which are functions of the circulatory system?

It helps to stabilize fluid distribution in the body. It carries oxygen from the lungs to peripheral tissues and CO2 from peripheral tissues to the lungs. It neutralizes toxins and helps to destroy pathogens.

The buffy coat is comprised of which of the following?

Leukocytes Platelets

What is the main chemical stimulus for cerebral autoregulation?

PH

Choose the components of blood.

Plasma Platelets White blood cells Red blood cells

What is serum?

Plasma from which fibrinogen has been removed

Most of the redirection will occur in the _____

Arterioles

What is the best way to estimate the MAP?

take diastolic pressure and one third of the pulse pressure

Why do fluids leave the capillaries at the arterial end?

the net filtration pressure of the blood is higher at the arterial end than it is at the venous end

Place the following vessels in the order through which blood would pass, beginning with blood entering the systemic circuit after exiting the heart.

1. Conducting arteries 2. distributing arteries 3. resistance arteries 4. arterioles 5. capillaries 6. post-capillary venules 7. muscular venules 8. medium veins 9. venus sinuses 10. large veins

What is the average volume of blood in an adult?

4-6 liters

Which would be a normal hematocrit?

45%

approximately what percent of fluid that exits the capillaries at the arterial end reenters the capillaries at the venous end?

90%

Match each type of plasma protein to its role.

Albumin: Solute transport, ph buffering, regulation of blood viscosity and osmolarity Globulins: Immunity Fibrinogen: clotting

What are the three primary types of plasma proteins?

Albumins, globulins, fibrinogen

What is(are) the advantage(s) of there being a low blood pressure in the pulmonary circuit? Check all that apply.

blood flows more slowly through the pulmonary capillaries and therefore has more time for gas exchangeit prevents fluid accumulation in the alveolar walls and lumens, which would compromise gas exchangeoncotic pressure overrides hydrostatic pressure, so pulmonary capillaries are engaged almost entirely in absorption

Which of the following is not detected by chemoreceptors in the carotid and aortic bodies?

blood pressure

Identify the incorrect statement regarding the fundamental causes of edema.

capillary reabsorbtion does not depend on oncotic pressure

Match each component of blood with its description. Instructions

contains ethryocytes = hemacrit contains wbc and platelets = buffy coat fluid portion of the blood = plasma

Where are arterial anastomoses, in which two arteries merge, found?

coronary circulation

How do materials get from the blood to the surrounding tissues?

diffusion, filtration and absorption, and transyctosis

Match the components of blood with their relative percentage.

plasma 37-52% Hemacrit 46-63% Buffy Coat 1% or less

what is serum?

plasma from which fibrinogen has been removed

Blood usually passes through one network of capillaries from the time it leaves the heart until the time it returns, but there are exceptions, notably the __________.

portal systems and anastomes

Blood flow is ______ according to metabolic needs

redirected

Constriction of these sphincters ______ the blood flow through their respective capillaries.

reduces