Blood Vessels

Question 1

What are the three tunics common to most blood vessels?

Answer 1

Tunica intima, tunica media, tunica externa

Question 2

What are the distinguishing features of arteries?

Answer 2

Thicker tunica media, narrower lumen, more resilient, perfect circle, branch into smaller vessels, low blood pressure

Question 3

What are the distinguishing features of veins?

Answer 3

Thicker tunica externa, larger lumen, less elastic and collagen fibers, wall collapses if no blood, high blood pressure

Question 4

What is the structure of capillaries?

Answer 4

Only contain tunica intima

Question 5

What are elastic arteries also known as?

Answer 5

Conduction arteries

Question 6

Identify an example of an elastic artery.

Answer 6

Aorta, pulmonary trunk, common carotid, common iliac arteries

Question 7

What is the primary function of muscular arteries?

Answer 7

Distribute blood to specific body regions

Question 8

What are arterioles?

Answer 8

Smallest arteries that regulate systemic blood pressure and blood flow

Question 9

What is the composition of capillaries?

Answer 9

Endothelium and basement membrane

Question 10

What are the three types of capillaries?

Answer 10

• Continuous
• Fenestrated
• Sinusoids

Question 11

What defines continuous capillaries?

Answer 11

Endothelial cells form a continuous lining with intercellular clefts; large particles cannot pass

Question 12

What are fenestrated capillaries characterized by?

Answer 12

Pores (fenestrations) that allow movement of smaller plasma proteins

Question 13

Where are sinusoids found?

Answer 13

Bone marrow, spleen, and some endocrine glands

Question 14

What is the function of venules?

Answer 14

Smallest veins that drain capillaries

Question 15

What is the significance of veins as a blood reservoir?

Answer 15

Easily shifts into circulation with vasoconstriction and back with vasodilation

Question 16

What is a simple pathway in the circulatory system?

Answer 16

One major artery transports blood to the capillary bed and then into a venous blood vessel

Question 17

What is an arterial anastomosis?

Answer 17

Two or more arteries converge to supply the same region

Question 18

What is the relationship between total cross-sectional area and blood flow velocity?

Answer 18

Inverse relationship; high total cross-sectional area results in low blood flow velocity

Question 19

What increases the time for efficient capillary exchange?

Answer 19

Slow blood flow in the capillaries

Question 20

Define diffusion in the context of capillaries.

Answer 20

Movement of substances from high to low concentration

Question 21

What is vesicular transport?

Answer 21

Endothelial cells use pinocytosis to transport materials via vesicles

Question 22

What is bulk flow?

Answer 22

Movement of large amounts of fluid down a pressure gradient

Question 23

What promotes filtration in capillaries?

Answer 23

Hydrostatic pressure

Question 24

What promotes reabsorption in capillaries?

Answer 24

Colloid osmotic pressure

Question 25

What is net filtration pressure (NFP)?

Answer 25

Difference between net hydrostatic pressure and net colloid pressure

Question 26

What role does the lymphatic system play at the capillary bed?

Answer 26

Picks up excess fluid and returns it to the venous system

Question 27

What is meant by degree of vascularization?

Answer 27

Extent of blood vessel distribution within a tissue

Question 28

What is angiogenesis?

Answer 28

Creation of new blood vessels

Question 29

What is the myogenic response?

Answer 29

Response of arterioles to systemic blood pressure changes to maintain blood flow

Question 30

What is the difference between a vasodilator and a vasoconstrictor?

Answer 30

Vasodilator dilates arterioles; vasoconstrictor constricts arterioles

Question 31

How does tissue autoregulate local blood flow based on metabolic needs?

Answer 31

Increased tissue activity leads to vasodilation due to low oxygen and high carbon dioxide

Question 32

What happens during inflammation regarding blood flow?

Answer 32

Vasoactive chemicals cause arterioles to dilate

Question 33

Define blood pressure.

Answer 33

The force of blood against the vessel wall

Question 34

What is a blood pressure gradient?

Answer 34

Change in pressure from one end of the vessel to another

Question 35

Which blood vessels have the highest blood pressure?

Answer 35

Arteries

Question 36

What is pulse pressure?

Answer 36

Systolic pressure - diastolic pressure

Question 37

What is mean arterial pressure (MAP)?

Answer 37

Diastolic pressure + pulse pressure/3

Question 38

What assists blood movement in veins?

Answer 38

Skeletal muscle pump and respiratory pump

Question 39

What is resistance in the context of blood flow?

Answer 39

Amount of friction blood experiences as it's transported through blood vessels

Question 40

How does vessel radius influence resistance?

Answer 40

Direct relationship; increase in radius decreases resistance

Question 41

What happens to total blood flow as resistance increases?

Answer 41

Total blood flow decreases

Question 42

What short-term mechanisms regulate blood pressure?

Answer 42

Autonomic reflexes involving nuclei in the medulla oblongata

Question 43

What is the baroreceptor reflex?

Answer 43

Regulates blood pressure by altering cardiac output and resistance

Question 44

What hormones increase blood pressure?

Answer 44

* Angiotensin II * Aldosterone * ADH

Question 45

What is the renin-angiotensin system?

Answer 45

System that regulates blood pressure through renin and angiotensin

Question 46

What enzyme do the kidneys release in response to low blood pressure?

Answer 46

Renin ## Footnote Renin is released in response to low blood pressure or sympathetic nervous system action.

Question 47

What inactive substance does the liver produce that is involved in the renin-angiotensin system?

Answer 47

Angiotensinogen ## Footnote Angiotensinogen is converted into angiotensin I by renin.

Question 48

What does renin convert inactive angiotensinogen into?

Answer 48

Angiotensin I ## Footnote Renin catalyzes the conversion process.

Question 49

What enzyme converts angiotensin I into angiotensin II?

Answer 49

ACE (Angiotensin-Converting Enzyme) ## Footnote ACE is responsible for this conversion.

Question 50

What is the effect of angiotensin II on blood pressure?

Answer 50

Increases blood pressure ## Footnote Angiotensin II promotes vasoconstriction and stimulates thirst.

Question 51

List the three main effects of angiotensin II.

Answer 51

* Promotes vasoconstriction * Stimulates thirst * Stimulates secretion of aldosterone and ADH

Question 52

What is the role of aldosterone in blood pressure regulation?

Answer 52

Maintains blood volume and pressure ## Footnote Aldosterone increases sodium and water reabsorption in kidneys.

Question 53

Where is aldosterone released from?

Answer 53

Adrenal cortex ## Footnote It is part of a humoral response.

Question 54

What is the function of antidiuretic hormone (ADH)?

Answer 54

Increases water reabsorption in kidneys ## Footnote ADH is also known as vasopressin.

Question 55

What effect does atrial natriuretic peptide (ANP) have on blood pressure?

Answer 55

Stimulates dilation and increases urine output ## Footnote ANP is released when the atria are stretched by high blood volume.

Question 56

How does blood flow change during exercise compared to at rest?

Answer 56

Increases in heart, skeletal muscle, and skin; decreases in abdominal organs and kidneys ## Footnote This redistribution supports increased metabolic demands.

Question 57

What distinguishes pulmonary circulation from systemic circulation?

Answer 57

Pulmonary circulation carries deoxygenated blood; systemic circulation carries oxygenated blood.

Question 58

What veins return blood from systemic circulation to the right atrium?

Answer 58

Superior and inferior vena cava

Question 59

What is the function of the hepatic portal system?

Answer 59

Drains blood from digestive organs and spleen into the liver ## Footnote It processes digested nutrients and harmful agents.

Question 60

List the three main veins of the hepatic portal system.

Answer 60

* Splenic vein * Inferior mesenteric vein * Superior mesenteric vein

Question 61

How does blood leave the liver in the hepatic portal system?

Answer 61

Through hepatic veins that drain into the inferior vena cava