Cardiovascular System

Question 0

How many miles of blood vessels

Answer 0

60,000

Question 1

Cvs role in homeostasis

Answer 1

Transport and deliver blood. Carry nutrients to tissue. Carry waste away.

Question 2

5 types of blood vessels

Answer 2

Arteries arterioles capillaries venues veins

Question 3

Three layers of a blood vessel

Answer 3

Intima-epithelial lining media- smooth muscle externa- connective outer covering

Question 4

Tunica intima

Answer 4

Direct contact with blood, continuous with endocardial lining, secretes chemicals influencing contractile state of vessel, facilitates efficient blood flow by reducing friction

Question 6

Parts of tunica intima

Answer 6

Deep to endothelium is the basement membrane which is for strength and resilience made of collagen fibers and outermost layer is internal elastic lamina which is thin elasticity with windows for diffusion

Question 7

Tunica Media

Answer 7

Muscular and connective layer.greatest variation between vessels. Regulates diameter of lumen. This in turn regulates blood flow through constriction and dialation which affects blood pressure. Also produces elastic fibere which allow vessel to stretch and recoil.

Question 8

external elastic lamina

Answer 8

network of elastic part of tunica media. separates tunica media from tunic a externa

Question 9

tunica externa

Answer 9

outer covering of blood vessel which consist of collagen and elastic fibers. Contains nerves tiny blood vessels to supply tissues of the vessel (vasa vasorum- vessel to vessel) also anchors vessel to surrounding tissue

Question 10

elastic arteries

Answer 10

largest arteries which include garden hose size aorta and pulmonary trunk to finger size branches of aorta. well defined internal and external elastic lamina. function to propel blood onward while ventricles relax, by elastic recoil which moves blood along. Also known as conducting arteries

Question 11

muscular arteries

Answer 11

medium sized arteries. tunica media contains more smooth muscle and less elastic fibers. greater ability to vasoconstrict/dialate. well defined internal elastic lamina but thin external elastic lamina.

Question 12

muscular arteries size

Answer 12

range from pencil sized (femoral and axillary) to as little as .5 mm. vessel wall comprises 25% of total vessel diameter. also known as distributing arteries. tunica externa is often thicker than tunica media and contains fibroblasts collagen fibers and elastic fibers longitudinally which prevents shortening or retraction of vessel when cut

Question 13

muscular artery function

Answer 13

cannot recoil to help propel blood like elastic arteries. contract and maintain a state of partial contraction (vascular tone). important in maintaining vessel pressure and efficient blood flow.

Question 14

arterioles

Answer 14

small arteries which regulate flow into capillaries 15-300 micrometers and wall thickness is 1/2 of total vessel diameter. thin tunica interna, thin fenestrated elastic lamina which disappears at terminal end. tunica media is 1-2 layers of smooth muscle with circular orientation. tunica externa contains sympathetic nerves which alter diameter of arterioles also known as resistance vessels which affect BP

Question 15

METARTERIOLE

Answer 15

TAPERS toward capillary junction. distal most muscle cell which regulate resistance to blood flow

Question 16

capillaries

Answer 16

smallest blood vessels. diameter of 5-10 microns. lack tunica media and externa. composed of single layer of endothelial cells and a basement membrane rbc have diameter of 8 microns so they have to fold to squeeze through. lots of SA which makes contact wit all cells. called exchange vessels capillary network varies with metabolic activity

Question 17

precapillary sphincters

Answer 17

when relaxed blood flows, when contracted BF stops. flow is intermittent due to alternating contraction and relaxation of smooth muscle of metarteriole. vasomotion partly from chemicals released by endothelial cells

Question 18

thoroughfare channel

Answer 18

direct route from arteriole to venule by passing capillaries.
diatal end of vessel has no smooth muscle

Question 19

continuous capillaries

Answer 19

continuous tubes interrupted only by intercellular clefts

Question 20

fenestrated capillaries

Answer 20

contain fenestration (70-100 nm) found in kidneys, villi of small intestines, and choroid plexuses

Question 21

sinusoids

Answer 21

wider and winding than other caps. large fenestrations. incomplete or absent basement membrane. large intracellular clefts which allow proteins and new RBC to pass through

Question 22

venules

Answer 22

thin walls that do not maintain shape

Question 23

post cap venules

Answer 23

drain cap blood and begin to return to heart (10-50 micron) very porous significant site of nutrients and waste wbc emigration

Question 24

muscular venules

Answer 24

1-2 layer of smooth muscle prevent exchange of nutrients and waste. thin walls allow for expansion and serve as reservoir

Question 25

veins

Answer 25

not much structural change like artery. thin walls. (.5mm -3cm) same layers as arteries but thickness differs. interna and media is thinner but externa is thicker. no internal or elastic lamina

Question 26

vein characteristics cont.

Answer 26

adaptable to volume but not designed to withstand high pressure. lumen is flattened in cross section BP IS LOWER THAN ARTERIES. contain valves from tunica interna. project into lumen and point toward heart which prevents backflow

Question 27

vascular sinus

Answer 27

wein with thin endothelial wall no smooth muscle. dense connective tissue replaces tunica media and externa for support.

Question 28

anastomotic veins

Answer 28

connected like a latter

Question 29

blood distribution

Answer 29

veins and venules 64%. arteries and arterioles 13%. capillaries 7%. pulmonary blood vessels 9%. heart 7%.

Question 30

blood reservoirs

Answer 30

liver, spleen, veins, and venules can hold diverted blood if needed from venoconstriction