Module 2 - Chapter 18

Question 1

What is the primary function of blood vessels?

Answer 1

Transport blood to tissues for gas, nutrient, and waste exchange, then back to the heart

Blood vessels play a critical role in the circulatory system.

Question 2

How do blood vessels regulate blood flow?

Answer 2

By controlling the diameter of the vessels and the amount of blood that passes through

This regulation is essential for maintaining tissue perfusion.

Question 3

What is one of the roles of blood vessels in relation to blood pressure?

Answer 3

Control blood pressure

Blood vessels can constrict or dilate to regulate pressure within the circulatory system.

Question 4

What types of chemicals do blood vessels secrete?

Answer 4

A variety of chemicals

These may include hormones and substances that affect vascular health.

Question 5

What are the two circuits that carry blood through the body?

Answer 5

Pulmonary circuit and systemic circuit

These circuits ensure efficient blood circulation throughout the body.

Question 6

What is the function of the pulmonary circuit?

Answer 6

Transports blood between the heart and lungs

This circuit is responsible for oxygenating blood.

Question 7

What is the function of the systemic circuit?

Answer 7

Transports blood between the heart and the rest of the body

This circuit delivers oxygenated blood to tissues and organs.

Question 8

What are the three kinds of blood vessels in pulmonary and systemic circuits?

Answer 8

Arteries, capillaries, and veins.

Question 9

What is the function of arteries?

Answer 9

They serve as the distribution system of vasculature, supplying most tissues in the body with blood.

Question 10

How do arteries change as they travel away from the heart?

Answer 10

They branch into vessels of progressively smaller diameter.

Question 11

What is the role of capillaries?

Answer 11

They function as the exchange system of vasculature, allowing for the quick exchange of gases, nutrients, wastes, and other molecules between tissue cells and blood.

Question 12

What are capillaries characterized by?

Answer 12

They are very small-diameter vessels that form branching networks (capillary beds) and have walls that are often only a single cell thick.

Question 13

What is the function of veins?

Answer 13

They act as the collection system of vasculature, draining blood from capillary beds and returning it to the heart.

Question 14

How do veins differ from arteries in structure?

Answer 14

Veins follow the opposite pattern of arteries, where small veins merge to become progressively larger vessels as they approach the heart.

Question 15

What are the three tunics of a blood vessel wall?

Answer 15

Tunica intima, tunica media, and tunica externa.

Question 16

What is the tunica intima composed of?

Answer 16

It is composed of endothelium, which is continuous with the inner lining of the heart (endocardium).

Question 17

What is the function of endothelial cells in the tunica intima?

Answer 17

They provide a smooth surface over which blood can flow with minimum friction and turbulence.

Question 18

What structures are found deep to the endothelium in the tunica intima?

Answer 18

A thin layer of subendothelial connective tissue and a layer of elastic fibers called internal elastic lamina.

Question 19

What properties do elastic fibers provide to blood vessels?

Answer 19

They give vessels properties of distensibility (ability to stretch) and elasticity (ability to recoil back to original size).

Question 20

What is the tunica media composed of?

Answer 20

It consists of a layer of smooth muscle cells arranged in a circular manner around the lumen and another layer of elastic fibers called external elastic lamina.

Question 21

What is the role of smooth muscle cells in the tunica media?

Answer 21

They control the diameter of the blood vessel and therefore the amount of blood that flows to organs.

Question 22

How are smooth muscle cells in the tunica media innervated?

Answer 22

They are innervated by sympathetic nervous system vasomotor nerves.

Question 23

What happens during vasoconstriction?

Answer 23

Sympathetic stimulation causes smooth muscle cells to contract, narrowing the diameter of the vessel.

Question 24

What occurs during vasodilation?

Answer 24

When sympathetic stimulation decreases, smooth muscle cells relax, and the vessel’s diameter increases.

Question 25

What is the primary function of blood vessels?

Answer 25

Transport blood to tissues, regulate blood flow, control blood pressure, and secrete chemicals.

Question 26

What are the two circuits that carry blood through the body?

Answer 26

* Pulmonary circuit * Systemic circuit

Question 27

What is the role of arteries in the vascular system?

Answer 27

Distribution system of vasculature; supply blood to tissues.

Question 28

What is the function of capillaries?

Answer 28

Exchange system of vasculature; facilitate gas, nutrient, and waste exchange.

Question 29

What do veins do in the circulatory system?

Answer 29

Collection system of vasculature; drain blood from capillary beds and return it to the heart.

Question 30

What are the three tunics of the blood vessel wall?

Answer 30

* Tunica intima * Tunica media * Tunica externa

Question 31

What is the tunica intima composed of?

Answer 31

Endothelium continuous with the inner lining of the heart.

Question 32

What is the function of the tunica media?

Answer 32

Controls diameter of blood vessel and regulates blood flow.

Question 33

What is the tunica externa made of?

Answer 33

Dense irregular collagenous connective tissue.

Question 34

What type of arteries are the largest in diameter?

Answer 34

Elastic arteries (conducting arteries).

Question 35

What are muscular arteries primarily composed of?

Answer 35

Well-developed tunica media with smooth muscle cells.

Question 36

What is the smallest type of artery called?

Answer 36

Arterioles.

Question 37

What is the role of baroreceptors in arteries?

Answer 37

Monitor blood pressure.

Question 38

What percentage of total blood volume is typically found in veins?

Answer 38

70%.

Question 39

Fill in the blank: Venous valves are extensions of _______.

Answer 39

[tunica intima].

Question 40

What are vascular anastomoses?

Answer 40

Locations where vessels connect via collateral vessels.

Question 41

What is hemodynamics?

Answer 41

Physiology of blood flow in the cardiovascular system.

Question 42

What drives blood flow in the cardiovascular system?

Answer 42

Pressure gradients created by the heart.

Question 43

What is blood pressure?

Answer 43

Outward force that blood exerts on walls of blood vessels.

Question 44

What is the equation that expresses the relationship between pressure change, cardiac output, and peripheral resistance?

Answer 44

ΔP = CO × PR.

Question 45

What factors influence blood pressure?

Answer 45

* Resistance * Cardiac output * Blood volume

Question 46

What is the average systemic arterial pressure?

Answer 46

About 95 mm Hg.

Question 47

What is mean arterial pressure (MAP)?

Answer 47

Average pressure in systemic arteries during the entire cardiac cycle.

Question 48

What is the typical systolic pressure?

Answer 48

Averages about 120 mm Hg.

Question 49

What is pulse pressure?

Answer 49

Difference between systolic and diastolic pressures.

Question 50

What happens to blood pressure as blood travels through the systemic circuit?

Answer 50

Blood pressure changes significantly, averaging about 95 mm Hg.

Question 51

True or False: Blood pressure remains high throughout the pulmonary circuit.

Answer 51

False.

Question 52

How does blood viscosity affect blood flow?

Answer 52

Higher viscosity increases resistance and decreases flow.

Question 53

What is the relationship between cardiac output and blood pressure?

Answer 53

When cardiac output increases, blood pressure increases.

Question 54

What is the consequence of increased blood volume on blood pressure?

Answer 54

Increases blood pressure.

Question 55

How does the length of a blood vessel affect resistance?

Answer 55

Longer vessels increase resistance.

Question 56

What is the typical pressure at the venular end of a capillary bed?

Answer 56

About 15 mm Hg.

Question 57

What is the systemic capillary pressure at the arteriolar end of the capillary bed?

Answer 57

Approximately 35 mm Hg

Question 58

What is the systemic capillary pressure at the venular end of the capillary bed?

Answer 58

About 15 mm Hg

Question 59

What causes the decrease in pressure from the arteriolar end to the venular end of the capillary bed?

Answer 59

Reduction in blood volume that takes place in capillaries

Question 60

What is the pressure in the inferior vena cava?

Answer 60

About 4 mm Hg

Question 61

What is the pressure in the right atrium?

Answer 61

As low as 0 mm Hg

Question 62

What factors contribute to the low pressure in the venous circuit?

Answer 62

High compliance of veins and declining resistance as vessels merge and become larger

Question 63

What prevents backward flow in some veins?

Answer 63

Venous valves

Question 64

What role do skeletal muscles play in venous return?

Answer 64

They squeeze blood in veins and propel it upward as they contract and relax

Question 65

What is the function of the respiratory pump?

Answer 65

Helps propel blood through thoracic and abdominal cavity veins

Question 66

What triggers the baroreceptor reflex arc?

Answer 66

Increase in blood pressure above normal range

Question 67

What is the primary role of the autonomic nervous system (ANS) in blood pressure maintenance?

Answer 67

Control of homeostasis through immediate effects on blood pressure

Question 68

What neurotransmitters are released by sympathetic axons to increase blood pressure?

Answer 68

Norepinephrine and epinephrine

Question 69

How does the parasympathetic nervous system affect blood pressure?

Answer 69

Decreases blood pressure by slowing heart rate and decreasing cardiac output

Question 70

What is the function of baroreceptors in blood pressure regulation?

Answer 70

Detect changes in blood pressure through arterial stretch

Question 71

What is the effect of angiotensin-II on blood pressure?

Answer 71

Powerful vasoconstrictor that increases peripheral resistance

Question 72

What is the role of atrial natriuretic peptide (ANP) in blood pressure regulation?

Answer 72

Causes mild decrease in peripheral resistance

Question 73

What is the primary function of capillaries?

Answer 73

Facilitate exchange of nutrients, gases, ions, and wastes between blood and tissue cells

Question 74

What are the three mechanisms of capillary exchange?

Answer 74

* Diffusion and osmosis through gaps and pores * Diffusion through membranes of endothelial cells * Transcytosis

Question 75

What are the three types of capillaries?

Answer 75

* Continuous capillaries * Fenestrated capillaries * Sinusoidal capillaries

Question 76

What distinguishes fenestrated capillaries from continuous capillaries?

Answer 76

Fenestrated capillaries contain pores that allow for faster diffusion

Question 77

What are the characteristics of sinusoidal capillaries?

Answer 77

Leakiest capillaries with discontinuous endothelium and large pores

Question 78

What is microcirculation?

Answer 78

Flow of blood within the body's capillary beds

Question 79

What are the two main types of local autoregulatory controls in tissue perfusion?

Answer 79

* Myogenic mechanism * Metabolic controls

Question 80

What drives the movement of water across capillaries?

Answer 80

Filtration driven by hydrostatic and osmotic pressures

Question 81

What is hydrostatic pressure?

Answer 81

Force that fluid exerts on the wall of a container

Question 82

How does hydrostatic pressure change from the arteriolar end to the venular end of a capillary?

Answer 82

Decreases from about 35 mm Hg to about 15 mm Hg

Question 83

What is the primary driver of blood flow through capillaries?

Answer 83

Pressure gradient from higher hydrostatic pressure to lower hydrostatic pressure

Question 84

What is net filtration pressure (NFP) in capillaries?

Answer 84

The difference between hydrostatic pressure and colloid osmotic pressure ## Footnote NFP drives water movement in capillaries; positive NFP indicates filtration, while negative indicates absorption.

Question 85

At the capillary’s arteriolar end, what are the hydrostatic and colloid osmotic pressures?

Answer 85

Hydrostatic pressure is about 35 mm Hg; colloid osmotic pressure is about 22 mm Hg.

Question 86

What is the NFP at the capillary’s arteriolar end?

Answer 86

13 mm Hg ## Footnote Calculated as 35 mm Hg (hydrostatic) - 22 mm Hg (colloid osmotic).

Question 87

What happens at the capillary’s venular end regarding NFP?

Answer 87

NFP is -7 mm Hg, indicating water flows into the capillary.

Question 88

What are common causes of edema?

Answer 88

* Increase in capillary hydrostatic pressure gradient due to hypertension * Decrease in colloid osmotic pressure due to liver disease, cancer, or starvation.

Question 89

What is peripheral edema?

Answer 89

Pronounced edema found in hands and feet due to increased hydrostatic pressure.

Question 90

What is ascites?

Answer 90

Excess water accumulation in the interstitial fluid of the abdomen.

Question 91

What is the largest artery in the body?

Answer 91

Aorta.

Question 92

What are the four divisions of the aorta?

Answer 92

* Ascending aorta * Aortic arch * Descending thoracic aorta * Descending abdominal aorta.

Question 93

What are the three large branches of the aortic arch?

Answer 93

* Brachiocephalic artery * Left common carotid artery * Left subclavian artery.

Question 94

What does the common carotid artery split into?

Answer 94

* External carotid artery * Internal carotid artery.

Question 95

What does the external carotid artery supply?

Answer 95

Superficial structures of head and face.

Question 96

What major arteries supply the brain?

Answer 96

* Internal carotid arteries * Vertebral arteries.

Question 97

What is the circle of Willis?

Answer 97

A circular anastomosis of arteries supplying the brain.

Question 98

What are the main arteries supplying the thorax?

Answer 98

* Anterior and posterior internal thoracic arteries * Bronchial arteries * Esophageal arteries.

Question 99

What supplies the majority of the abdominal organs?

Answer 99

Branches of the descending abdominal aorta.

Question 100

What is the function of the renal arteries?

Answer 100

Deliver blood to the kidneys.

Question 101

What artery serves as the main artery for the lower limb?

Answer 101

Femoral artery.

Question 102

What is the significance of pulse points?

Answer 102

Used to assess heart rate and blood flow.

Question 103

What is the primary drainage system for deoxygenated blood in the thorax?

Answer 103

Brachiocephalic veins.

Question 104

What veins drain the head and neck?

Answer 104

* Internal jugular veins * Vertebral veins * External jugular veins.

Question 105

What is the role of the dural sinus system?

Answer 105

Drains blood from the brain into venous channels.

Question 106

What is the azygos system?

Answer 106

A collection of vessels that drain the posterior thoracic and abdominal walls.

Question 107

What primarily drains the anterior thorax?

Answer 107

Internal thoracic veins ## Footnote These veins empty into the brachiocephalic veins.

Question 108

What drains the anteroinferior abdomen?

Answer 108

Inferior epigastric veins ## Footnote These veins empty into external iliac veins.

Question 109

What is the name of the system that drains the posterior thoracic and abdominal walls?

Answer 109

Azygos system

Question 110

Which vessels are part of the azygos system?

Answer 110

* Azygos vein (right) * Hemiazygos vein (left) * Accessory hemiazygos vein (left)

Question 111

Where do left lumbar veins and most left posterior intercostal veins drain?

Answer 111

Hemiazygos or accessory hemiazygos veins

Question 112

What does the azygos vein merge with?

Answer 112

Superior vena cava

Question 113

What drains the pelvic organs?

Answer 113

Internal iliac vein ## Footnote This vein empties into the common iliac vein.

Question 114

Which veins drain directly into the inferior vena cava?

Answer 114

* Common iliac veins * Several veins of abdominopelvic cavity

Question 115

What does the right gonadal vein drain?

Answer 115

Testes in males and ovaries in females

Question 116

Which veins drain the kidneys?

Answer 116

Renal veins

Question 117

What do the hepatic veins drain?

Answer 117

Liver

Question 118

Which vein drains the spleen?

Answer 118

Splenic vein

Question 119

What do gastric veins drain?

Answer 119

Stomach

Question 120

What does the superior mesenteric vein drain?

Answer 120

Small intestine and much of large intestine

Question 121

What does the inferior mesenteric vein drain?

Answer 121

Remainder of large intestine

Question 122

What type of circuit allows the liver to monitor nutrients and chemicals in venous blood?

Answer 122

Portal system

Question 123

How does processed blood exit the liver?

Answer 123

Via hepatic veins

Question 124

What does the superficial venous system of the upper limb begin with?

Answer 124

Dorsal venous arch

Question 125

What is the most common venous pattern in the forearm?

Answer 125

* Lateral cephalic vein * Middle median antebrachial vein * Medial basilic vein

Question 126

What connects the cephalic and basilic veins in the antecubital fossa?

Answer 126

Median cubital vein

Question 127

What do the radial and ulnar veins merge to form?

Answer 127

Brachial vein

Question 128

What does the axillary vein become after passing deep to the clavicle?

Answer 128

Subclavian vein

Question 129

What begins the superficial venous system of the lower limb?

Answer 129

Dorsal venous arch in foot

Question 130

Where does the great saphenous vein empty?

Answer 130

Femoral vein

Question 131

Where does the small saphenous vein empty?

Answer 131

Popliteal vein

Question 132

What do the deep veins of the foot drain into?

Answer 132

* Medial plantar veins * Lateral plantar veins

Question 133

What does the popliteal vein become after crossing into the anterior thigh?

Answer 133

Femoral vein

Question 134

What does the femoral vein become after passing deep to the inguinal ligament?

Answer 134

External iliac vein