Blood Vessels (1)

Question 1

closed system

Answer 1

blood vessels form a closed delivery system that begins and ends at the heart

Question 2

arteries

Answer 2

• large-sized arteries/elastic arteried/conducting arteries

- medium-sized arteries/muscular arteries/distributing arteries

Question 3

What carried blood away from the heart?

Answer 3

arteries

Question 4

three layers of the artery wall

Answer 4

tunica interna/tunica intima
tunica media
tunica externa/tunica adventitia

Question 5

tunica interna

Answer 5

artery wall. also called the tunica intima. innermost layer consisting of endothelium (simple squamous)

Question 6

Tunica Media

Answer 6

maintains elasticity and contractility due to smooth muscle fibers for vasoconstriction and vasodilation

Question 7

tunica externa

Answer 7

also called the tunica adeventitia. elastic and collagen fibers. In large arteries and veins it has it’s own blood supply called vasa vasorum.

Question 8

How do small blood vessels get their nutrients?

Answer 8

diffusion

Question 9

large-sized/elastic/conducting arteries

Answer 9

thick walled artery near heart (aorta, pulmonary), tunica media has more elastic fibers and less smooth muscle, conducts blood from the heart to medium sized arteries.

Question 10

Medium sized/muscular/distributing arteries

Answer 10

most arteries are this (brachial, femoral), deliver blood to specific body organs

Question 11

arterioles

Answer 11

small arteries that deliver blood to capillaries, key role in regulating blood flow (blood pressure)

Question 12

capillaries

Answer 12

absent from cornea and lens of eye, epidermis, and cartilage. diameter of RBC. thin walls consisting ONLY of tunica interna. exchange of waste and nutrition. solid endothelial lining.

Question 13

Continuous Capillaries

Answer 13

solid endothelial lining, most common. diffusion of water and small solutes

Question 14

fenestrated capillaries

Answer 14

oval shaped pores in endothelial lining, rapid exchange of water and high transfer rate of substances into or out of the capillary, found in kidney, vili of small intestine and ciliary processes of the eves

Question 15

sinusoidal capillaries

Answer 15

large holes. permit passage of blood cells. found in liver, spleen, and bone marrow. phagocytic cells monitor blood at sinusoids by removing bacteria and debris from the blood.

Question 16

Metarteriole

Answer 16

emerges from arteriole, passes through the capillary network and nourishes it, then empties into the venule.

Question 17

proximal portion of metarterioles

Answer 17

surrounded by scattered smooth muscle fibers whose contraction and relaxation help regulate blood flow and pressure. closer to artery

Question 18

precapillary sphincters

Answer 18

rings on arterioles that control blood flow rate through true capillaries.

Question 19

true capillaries

Answer 19

vessels branching from the proxiaml portion of the metarteriole and reconnecting to the distal portion of the metarteriole

Question 20

distal portion of a metarteriole

Answer 20

empties into a venule, has no smooth muscel fiber and is called a thoroughfare channel.

Question 21

venules

Answer 21

smallest vessels that continue from the capillaries and merge to form veins

Question 22

veins

Answer 22

return blood to the heart, consists of the same three tunics as arteries but have a thinner tunica interna and tunica media. valves in some veins

Question 23

venous valves

Answer 23

thin folds of tunica interna, needed because venous blood pressure is very low, barely enough pressure to overcome the force of gravity pulling it back down, numerous in veins of limbs

Question 24

varicose veins

Answer 24

dilated and tortuous veins caused by leaky valves, walls lose elasticity and become stretched and flabby

Question 25

which is thicker, arteries or veins?

Answer 25

arteries

Question 26

systemic veins and venules

Answer 26

60% of blood volume. called blood reservoirs

Question 27

What are the principle blood reservoirs?

Answer 27

veins of the abdominal organs and veins of the skin.

Question 28

vasomotor center

Answer 28

increased muscle activity causes this to send more sympathetic impulses to veins that serve as blood reservoirs. Medulla oblongata

Question 29

What are the 3 ways substances enter and leave capillaries?

Answer 29

simple diffusion vesicular transport, exocytosis bulk flow (filtration and reabsorption)

Question 30

bulk flow

Answer 30

movement of large numbers of molecules or solutes in the same direction as a result of pressure differences. Net filtration pressure

Question 31

starlings law of the capillaries

Answer 31

normally the volume of reabsorbed water and solutes is ALMOST as large as the volume filtered, the near equilibirum.

Question 32

edema

Answer 32

filtration greatly exceeds reabsorption. not noticeable until fluid volume has increased to about 30% above normal.

Question 33

How many liters of interstitial fluid go to tlymph

Answer 33

1.5

Question 34

causes of edema

Answer 34

increased amount of fluid exiting capillaries and entering interstitial fluid, fluid not entering capillaries so the fluid remains in the interstitial fluid, fluid is retained in the body because the person has trouble excreting fluids, blockage of lymph vessels