BIO 202 - EXAM 1 REVIEW ( PART 3 )

Chapter 21

1) ___________________________ is the opening in blood vessels through which blood

flows.

2) ___________________________ is formed largely of endothelium and basement mem-

brane, and is the only layer in capillaries.

3) ___________________________ are tiny blood vessels that carry nutrients to walls of

blood vessels.

4) ___________________________ is composed of smooth muscle and elastic fibers; con-

traction permits vasoconstriction, relaxation permits vasodilation.

5) ___________________________ is a strong outer layer of blood vessels composed

mainly of elastic and collagenous fibers.

6) ___________________________ are known as exchange vessels; they are sites of gas,

nutrient, and waste exchange with tissues.

7) ___________________________ are known as resistance vessels; they play the primary

role in regulating moment-to-moment distribution of blood and in regulating blood pressure.

8) Sinusoids are wider, more leaky versions of this type of vessel:

________________________.

9) Reservoirs for about 60% of the volume of blood in the body; vasoconstriction (due to

sympathetic impulses) permits redistribution of blood stored here: ______________________,

_______________________, _______________________.

10) What is the difference between conducting arteries and distributing arteries?

11) What is the difference between an artery and a vein?

12) What is the difference between a thoroughfare channel and a true capillary?

13) What is the difference between a continuous capillary and a fenestrated capillary?

14) Veins have ( THICKER or THINNER ) walls than arteries. This structural feature relates

to the fact that the pressure in veins is ( MORE or LESS ) than in arteries. The pressure dif-

ference is demonstrated when a vein is cut; blood leaves a cut vein in ( RAPID SPURTS or

AN EVEN FLOW ).

15) A vascular (venous) sinus has ___________________________________________

which replaces the tunica media and tunica externa. In this way, sinuses have the ( STRUC-

TURE BUT NOT FUNCTION or FUNCTION BUT NOT STRUCTURE ) of veins. List two

places where such sinuses are found.

16) How are anastomoses protective to the body?

17) At rest, ( ARTERIES AND ARTERIOLES / CAPILLARIES / VENULES AND

VEINS ) contain most of the blood in the body.

18) ( SYMPATHETIC or PARASYMPATHETIC ) nerve impulses to venules and veins

cause vasoconstriction and release of blood from these vessels. Name two locations of ve-

nous “reservoirs” that can be activated to release blood when needed.

19) State two examples of circumstances that might activate distribution of reservoir blood.

20) DEFINE:

a) Simple Diffusion

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b) Bulk flow

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c) Transcytosis

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21) In the aorta and brachial artery, blood pressure is normally about 110 mm Hg immedi-

ately following ventricular contraction. This is called ( SYSTOLIC or DIASTOLIC ) blood

pressure. As ventricles relax (or go into ____________________), blood is no longer ejected

into these arteries. However, the normally ( ELASTIC or RIGID ) walls of these vessels re-

coil against blood, pressing it onward with a diastolic blood pressure of _______ mm Hg.

22) In a blood pressure of 120/80, the average of the two pressures (systolic and diastolic) is

100. However, the MABP (mean arterial blood pressure) for a BP of 120/80 is slightly less

than 100; it is about 93. REASON: During the typical cardiac cycle (0.8 sec), the ventricles

are in ( SYSTOLE or DIASTOLE) for about two-thirds of the cycle and in systole for only

about one-third of the cycle. As a result, the MABP is always slightly closer to the value of

the diastolic blood pressure.

23) Velocity of blood flow is greatest in ( ARTERIES / CAPILLARIES / VEINS ). Flow is

slowest in _____________________. As a result, ample time is available for exchange be-

tween capillary blood and tissues.

24) As blood moves from capillaries into venules and veins, its velocity ( INCREASES or

DECREASES ), enhancing venous return.

25) Inadequate blood flow to the brain is one cause of fainting, clinically known as

___________________________.

26) Hypertension means ( HIGH or LOW ) blood pressure.

27) CIRCLE ALL THE FACTORS LISTED BELOW THAT TEND TO DECREASE

BLOOD PRESSURE.

• Increase in cardiac output, as by increased heart rate or stroke volume

• Increase in vagal impulses from cardioinhibitory center

• Decrease in blood volume, as following a hemorrhage

• Increase in blood volume, by excess salt intake and water retention

• Increased systemic vascular resistance due to vasoconstriction of arterioles

• Decreased viscosity of blood via loss of blood protein or red blood cells

• Use of medications called dilators because they dilate arterioles, especially in areas

such as abdomen or skin

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28) Write ↑ or ↓ next to each hormone or other chemical listed below to indicate whether the

chemical/hormone increases or decreases blood pressure.

__________ ADH

__________ Angiotensin II

__________ Aldosterone

__________ Epinephrine of NE

__________ ANP

29) Autoregulation is a mechanism for regulating blood flow through specific tissue areas.

Unlike cardiac and vasomotor mechanisms, autoregulation occurs by ( LOCAL or ANS )

control.

30) When a tissue (such as an active muscle) is hypoxic, the cells of that tissue release

( VASOCONSTRICTING or VASODILATING ) substances. These may include

__________________ acid, built up by active muscle. Other products of metabolism that

serve as dilator substances include:

31) Compared to systemic vessels, pulmonary blood vessels respond ( SIMILARLY or OP-

POSITE ) to hypoxic conditions. Arterioles in hypoxic parts of the lungs will ( VASOCON-

STRICT or VASODILATE ). How can this mechanism be helpful to the body?

32) Define pulse.

33) Know the list of arteries/veins I gave you. Know where each artery branches from, and

what specific organ/tissue it supplies. As far as veins go, know what organ/tissue it serves,

and which vein it drains into.