Unit 3 Circulatory

Question 1

CS function

Answer 1

distribution of hormones

transport of waste products to excretory organs

Question 2

CS components

Answer 2

heart - pump
arteries
veins
capillaries

Question 3

arteries

Answer 3

1. carry blood away from he heart
2. vessels get progressively smaller
3. thicker wall than veins
4. resist changes in BP in larger arteries
5. regulate blood flow in arterioles

Question 4

veins

Answer 4

1. return blood to heart
   converge into progressively larger vessels
2. lower pressure then arteries
3. thinner walls and larger lumens than corresponding artery
4. have endothelial covered valves to ensure one-way flow

Question 5

capillaries

Answer 5

large number of thin walled vessels

site of exchange between blood and tissue

Question 6

pulmonary (RS) circuit

Answer 6

receives oxygen poor blood from tissues

pumps blood to lungs to get rid of CO2, pick up O2

Question 7

systemic (LS) circuit

Answer 7

receives oxygenated blood from lungs

pumps blood to body tissues

Question 8

atria

Answer 8

thinner walled

receive good from systemic

Question 9

ventricles

Answer 9

thicker walled

distributes blood to pulmonary or systemic circulation

Question 10

valves

Answer 10

1. maintain unidirectional flow of blood through heart
2. atrioventricular valves separate atria from ventricles
3. pulmonic valve separates right ventricle from pulmonary trunk
4. aortic valve separates left ventricle from ascending aorta

Question 11

cardiac skeleton

Answer 11

1. central region of heart surrounding valves
2. dense CT; may become calcified
3. provides support for valves and great vessels
4. anchors cardiac muscle
5. annuli fibrosae
6. triton fibrosae

Question 12

annuli fibrosae

Answer 12

surround valves

Question 13

triton fibrosae

Answer 13

triangular masses between annuli

Question 14

heart wall

Answer 14

1. endocardium
2. myocardium
3. epicardium

Question 15

endocardium

Answer 15

1. lined with endothelium
2. subendothelium
3. wubendocardial layer

Question 16

subendothelium

Answer 16

loose CT

Question 17

subendocardial layer

Answer 17

CT, nerves, conducting system of heart (purkinje fibers)

Question 18

myocardium

Answer 18

thickest layer, cardiac muscle, fibrous skeleton

Question 19

epicardium

Answer 19

aka visceral layer of pericardium

1. mesothelium
2. loose CT w/veins, nerves, autonomic ganglia
3. adipose tissue

Question 20

heartbeat impulse

Answer 20

1. Modified cardiac muscle cells
2. Sinoatrial node: in wall of right atrium near entrance of superior vena cava; cells spontaneously depolarize and initiate impulse
3. internodal tracts connect sinoatrial node with atrioventricular node
4. atrioventricular node – inferior wall of right atrium
5. interventricular bundle of His
6. left and right bundle branches – Purkinje cells
7. Purkinje cells conduct to apex of heart where contraction initiated

Question 21

vessel structure

Answer 21

1. tunica intima
2. tunica media
3. tunica adventitia

Question 22

tunica intima

Answer 22

inner lining of endothelium
subendothelial CT
internal elastic lamina (arteries)

Question 23

tunica media

Answer 23

middle, concentric layers of sm
elastic/reticular fibers, proteoglycans
ext. elastic lamina (lg. arteries)

Question 24

tunica adventitia

Answer 24

longitudinally arranged type I collagen fibers, elastic fibers, continuous with CT of surrounding organs

Question 25

vasa vasorum

Answer 25

1. walls of lg. vessels 2. provide nutrition for outer layers of media and adventitia of lg. vessels 3. more frequent in veins

Question 26

capillaries

Answer 26

1. 7-9 microns diameter 2. single layers of endothelial cells resting on basal lamina 3. cells held together by tight junctions 4. pericytes

Question 27

pericytes

Answer 27

1. in capillaries and post capillary venules 2. outside endothelial layer 3. after tissue injury can proliferate and differentiate to rebuild vessels

Question 28

types of capillaries

Answer 28

continuous fenestrated sinusoidal

Question 29

continuous capillary

Answer 29

1. widespread in muscle, lung, connective tissue, exocrine glands, nervous tissue 2. no pores (fenestrae) pinocytic vesicles invovled in transcellular transport

Question 30

fenestrated capillary

Answer 30

1. endothelial cells with fenestra (pores) and continuous basal membrane 2. where rapid exchange occurs kidney, intestine, endocrine glands

Question 31

sinusoidal capillary

Answer 31

1. much larger diameter 2. discontinuous endothelia wall with fenestra 3. macrophages in gaps between endothelial cells 4. in liver, bone marrow, spleen

Question 32

anastomoses

Answer 32

interconnections of blood vessels; connects arterioles and venules

Question 33

sphincters open

Answer 33

blood flows through true capillaries

Question 34

sphincters closed

Answer 34

blood flows through metarteriole bypassing true capillaries

Question 35

metarteriole

Answer 35

thoroughfare channel

Question 36

portal system

Answer 36

two capillary beds separated by vein or artery

Question 37

hepatic portal system

Answer 37

capillaries of gut to drain to hepatic portal vein then empty into capillaries of liver

Question 38

kidney portal system

Answer 38

glomerulus drains to efferent arteriole then to peritubular capillaries

Question 39

large arteries

Answer 39

elastic or conducting arteries 1. thick tunica intima 2. thick tunica media: fenestrated elastic lamina, smooth muscle 3. tunica adventitia relatively thin

Question 40

medium arteries

Answer 40

distributing, muscular arteries 1. media has more smooth muscle, less elastin 2. prominent internal and external elastic lamina

Question 41

small arteries/arterioles

Answer 41

1. tunica media 5-10 layers smooth muscle in small arteries; 1-4 layers in arterioles 2. adventitia: thin, blends in with surrounding connective tissue

Question 42

post capillary venules

Answer 42

1. similar to capillaries; larger lumen | 2. similar función to capillaries

Question 43

small and medium veins

Answer 43

1. thin media 2. well-developed adventitia 3. valves

Question 44

large veins

Answer 44

1. well developed intima 2. thin media 3. thick adventitia: in veins inferior to heart contains longitudinally arranges bundles of smooth muscle