Anatomy of blood vessels

Question 1

Blood vessel facts

Answer 1

• named mor either the specific part of the body they supply or an area surrounding that specific part
• veins and arteries generally share the same name (exceptions include sap heinous vein, vena cava, aorta)

Question 2

Artery

Vein

Answer 2

A: A vessel that carries blood away from the heart

V: A vessel that carries blood toward the heart

Question 3

Arteries

Answer 3

• elastic arteries: large number of collagen and elastin filaments in the tunica media, which gives it the ability to stretch in response to each pulse
• muscular arteries: medium-sized artery that draws blood from an elastic artery and branch into resistance vessels
• arteriales: small branch of an artery leading into capillaries
• metarteriole: short vessels that directly connect the arterioles and venules at opposite ends of the beds

Question 4

Capillaries

Answer 4

• true: branch from arterioles and provide exchange between tissue and
• continuous: endothelial cells provide an uninterrupted lining, and they only allow smaller molecules, such as water and ions to pass though their intercellular clefts (BBB)
• fenestrated: found in tissues where there is extensive molecular exchange with the blood such as the kidney, endocrine glands, small intestine. Pores that allow larger molecules through
• sinusoid: wide diameter and found in spleen, lymph nodes, bone marrow. Can be any of the 3 cap types above

Question 5

Veins

Answer 5

• venules: a very small vein, esp one collecting blood from the capillaries
• vessels tha carry blood toward the heart
• veins have thinner walls with less smooth muscle than arteries
• venous vessels increase in size as blood returns to the heart
  Venules>small veins>medium veins>large veins>vena cava
• larger veins below the heart have valves to prevent backflow
• pooling and clotting in veins can be a problem during prolonged mm inactivity, such as on a long airline flight

Question 6

Tunica intima

Answer 6

1. Endothelium: in contact with blood and continuous with the endocardium lining of the heart
2. Basement membrane
3. Internal elastic lamina

Question 7

Tunica media

Answer 7

• muscular and connective tissue layer that helps regulate diameter of the lumen
• contains Nervi vasorum and vaso vasorum
• arteries and veins only

Question 8

Tunica externa

Answer 8

Helps anchor the vessels to surrounding tissue

Question 9

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Answer 9

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Question 10

Arteries

Answer 10

• the walls are thick, primarily from smooth muscle
• regulate blood pressure and shunt blood flow to where it is needed most
• the smooth muscle of arteries regulates blood pressure, distribution, and volume
• help propel blood onward while the ventricles are relaxing
• *main transporters of oxygenated blood

Question 11

Arterioles

Answer 11

• the smallest arteries
• carry blood from arteries to capillaries and regulate blood flow to specific capillary beds
• contain smooth muscle and can regulate blood flow
• *diameter is adjusted to regulate blood flow

Question 12

Capillaries

Answer 12

• blood flow through capillaries is call microcirculation
• thin walls allow for effective exchange of material between plasma and interstitial fluid
• most important vessels functionally because they allow the delivery and collection of substances
• exchange of oxygen, carbon dioxide, nutrients, and waste materials occur here (the other vessels are merely channels for the passage of blood)
• the body does not have a sufficient volume of blood for all capillary beds to be open at once
• capillaries do not contain smooth muscle, precapillary sphincters in arterioles serve to control blood flow into capillaries
• *diffusion occurs across thin walls

Question 13

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Answer 13

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Question 14

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Answer 14

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Question 15

Venules

Answer 15

Small blood vessels that collect blood from capillaries and join together to form veins

Question 16

Varicose veins

Answer 16

Pooling of blood in veins causes

• loss of elasticity in the walls of the veins
• chronic high venous blood pressure
• loss of strength in valves
• decreased muscular pump

Question 17

Clots

Answer 17

• a clot (thrombus) can block circulation
• if the clot breaks loose it will move though the circulatory system (embolus)
• once an am plus moves through the heart it will encounter smaller vessels and can become lodged in a capillary bed somewhere in the body
• if the embolus blocks pulmonary capillaries it is called pulmonary embolism
• an embolism in the brain is a stroke/cerebrovascular accident (CVA)

Question 18

Deep vein thrombosis

Answer 18

Clot that has formed in a deep vein, and is very dangerous

Question 19

Circulatory routes

Answer 19

• three vessel networks or major circulatory routes for the blood
  1. Systemic circulation: carries blood from the heart to the body and back again
  2. Pulmonary circulation: carries blood from the heart to the lungs and back again
  3. Hepatic portal circulation: carries blood through the hepatic portal vein of the liver

Question 20

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Answer 20

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Question 21

Systemic circulation

Answer 21

• closed-loop system (heart is pump)
• the right side of the heart receives deoxygenated blood from the body
• capillaries > venules > veins > vena cava
• the left side of the heart pumps oxygenated blood to the body
• aorta > arteries > arterioles > capillaries
• includes most of the vessels of the body

Question 22

Systemic arteries

Answer 22

• the aorta is the main systemic artery, serving as a trunk from which all other arteries branch
• ascending aorta conducts blood upward out of the L ventricle
• the coronary arteries are branches of the ascending aorta
• descending aorta conducts blood downward from the arch of the aorta
• thoracic and abdominal aorta

Question 23

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Answer 23

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Question 24

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Answer 24

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Question 25

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Answer 25

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Question 26

Systemic veins

Answer 26

• venous blood from the head, neck, UE, and thoracic cavity (except lungs) drains into the superior vena cava
• venous blood from the LE and abdomen drains into the inferior vena cava

Question 27

Pulmonary circulation

Answer 27

• a closed-loop system with the heart as the pump
• pulmonary arteries carry deoxygenated blood from from the heart to the lungs
• pulmonary veins carry oxygenated blood from the lungs to the heart

Question 28

Hepatic portal circulation

Answer 28

• portal: venous blood flows through a second capillary network before returning to the heart
• veins from the spleen, stomach, pancreas, gallbladder and intestines send blood to the liver by means of the hepatic portal vein
• liver stores glucose as glycogen after meal (aids in homeostasis of blood glucose levels)
• liver filters toxins prior to returning blood to systemic circulation
• blood mingles with capillary blood and is then drained from the liver by the hepatic veins (goes into the inferior vena cava)