Ch 21 - structure and function of arteries, veins , lymphatics and related organs

Question 1

what is the function of elastic fibers in arteries? what about vascular smooth muscle? (VSM)

Answer 1

• elastic fibers allow arteries to stretch and recoil
• VSM is responsible for vasodilation and vasoconstriction

Question 2

what propels the blood forward through an artery?

Answer 2

• the recoil you get with diastole after the expansion of the artery in systole

Question 3

what are the palpable arteries of the upper limbs?

Answer 3

brachial, radial and ulnar

Question 4

what are the palpable arteries of the lower limbs?

Answer 4

femoral, popliteal, posterior tibial, dorsalis pedis

Question 5

what is ischemia? what does complete blockage result in? what dose partial blockage result in?

Answer 5

• insufficient oxygen supply to some tissue became of a blockage in a blood vessel
• death of distal tissue
• insufficient supply especially seen when demand increases (like during exercise)

Question 6

what is PAD? what commonly causes it? what uncommonly causes it?

Answer 6

• disease of noncoronary arteries (usually the ones supplying the limbs)
• usually caused by atherosclerosis
• sometimes caused by embolism, arterial dissection and hyper-coagulable states

Question 7

what is the course of veins like?

Answer 7

the course of veins is parallel to the arteries but blood flow is the opposite

Question 8

what does the body have more of–veins or arteries? which are closer to the skin surface?

Answer 8

the body has more veins and they are closer to the skin surface

Question 9

how many sets of veins does each arm have? where is the one most responsible for venous return?

Answer 9

• each arm has two sets of veins: superficial and deep
• the superficial veins lie in the subcutaneous tissue and are mostly responsible for venous return

Question 10

what veins responsible for most of the venous return from the lower limbs? what kind of veins are they?

Answer 10

• the femoral and popliteal veins
• these are superficial veins

Question 11

what are the superficial veins in the leg? where does blood flow from them into?

Answer 11

• small and great saphenous
• blood flows from them into the deep veins

Question 12

what are perforator veins?

Answer 12

veins that connect the superficial veins to the deep veins

Question 13

what kind of system is venous flow? what are the three mechanisms used by veins to get blood flowing back to the heart?

Answer 13

• low pressure system
• skeletal muscle contraction
• pressure gradient created by breathing
• intraluminal valves

Question 14

how does breathing create a pressure gradient?

Answer 14

inspiration makes thoracic pressure decrease and abdominal pressure increase

Question 15

how do intraluminal valves work?

Answer 15

the open towards the heart and close tightly when they are filled to prevent back flow of blood

Question 16

in the legs, what is the intraluminal valve mechanism called?

Answer 16

the calf pump or peripheral heart

Question 17

how does the calf pump work?

Answer 17

when we walk, the gastrocnemius and soleus muscle squeeze the veins and direct blood flow towards heart–> because of the valves the blood only flows one way

Question 18

why are veins called capacitance vessels? what is this mechanism compensatory of?

Answer 18

• because of their ability to stretch
• it is a compensatory system to reduce stress to the heart

Question 19

what people are at risk for venous stasis?

Answer 19

people that have to do prolonged standing, sitting or bed rest

Question 20

what are other factors that increase risk for venous disease?

Answer 20

hypercoagulable states and vein wall trauma

Question 21

what is a hypercoagulable state?

Answer 21

condition where you have greater chance of developing a blood clot

Question 22

what creates incompetent valves?

Answer 22

varicose and dilated veins

Question 23

what do varicose or dilated veins increase? what does this lead to?

Answer 23

they increase venous pressure which further dilates the valves

Question 24

who gets varicose veins?

Answer 24

• genetic predisposition
• obesity
• women after multiple pregnancies

Question 25

what is the function of the lymphatic?

Answer 25

drain excess fluid and plasma proteins from the interstitial spaces back to the bloodstream

Question 26

what does the lymphatic system conserve?

Answer 26

fluid and plasma proteins that leak out of capillaries

Question 27

what does the lymphatic system form?

Answer 27

a major part of immune system that defends body against disease

Question 28

what does lymphatic system absorb?

Answer 28

lipids from the intestinal tract

Question 29

where do the lymphatic vessels converge and drain off into?

Answer 29

the thoracic duct and the right lymphatic duct

Question 30

where does the right lymphatic duct empties into?

Answer 30

the right subclavian vein

Question 31

where does the thoracic duct empty into?

Answer 31

the left subclavian vein

Question 32

what would happen without lymphatic drainage?

Answer 32

fluid would build up in the interstitial spaces and cause edema

Question 33

what are lymph nodes?

Answer 33

small oval clumps of lymphatic tissues located at intervals along vessels

Question 34

what do lymph nodes do?

Answer 34

they filter fluid before it is returned to the bloodstream

Question 35

what are the four functions of the spleen?

Answer 35

1. destroy old red blood cells 2. make antibodies 3. store red blood cells 4. filter out microorganisms

Question 36

what do the tonsils do?

Answer 36

they respond to local inflammation

Question 37

what is the function of the thymus?

Answer 37

developing B and T cells