Cardiovascular System II

Question 1

Arteries Function

Answer 1

Carries blood away from the heart

Question 2

Arterioles Function

Answer 2

Carries blood to capillary beds/regulates blood pressure

Question 3

Capillaries Function

Answer 3

Exchange network for blood/interstitial fluid

Question 4

Venules Function

Answer 4

Collects blood from capillary beds

Question 5

Veins Function

Answer 5

Returns blood to the heart

Question 6

Features of the Capillary Bed

Answer 6

Entry to capillary bed has precapillary sphincter to constrict blood flow into capillary bed
Containts Arteriovenous anastomosis
Increased density of capillary beds in structures that need high O2 delivery (smooth muscle)

Question 7

Function of Arteriovenous Anastomosis

Answer 7

Blood vessel used to transport blood quickly, bypassing the capillary bed
Used if capillary bed is damaged

Question 8

Distribution of Blood Volume (%)

Answer 8

Systemic Venous System - 64%
Systemic Arterial System - 13%
Systemic Capillaries - 7%
Heart - 7%
Pulmonary Circuit - 9%

Question 9

3 Layers of Blood Vessel Structure

Answer 9

Tunica intima
Tunica media
Tunica externa
Has endothelium lining inside

Question 10

Differences between veins and arteries

Answer 10

No smooth muscle in veins
Veins have valves,, arteries don’t

Question 11

Tunica Intima Features

Answer 11

Inner layer
Encompasses endothelial lining
Connective Tissue Layer
Elastic membrane to provide passive elasticity to arteries, to withstand high blood pressure

Question 12

Endothelium Function

Answer 12

Releases vasoactive substances which affect vascular tone, blood pressure and blood flow
Maintains vascular homeostasis
Releases Nitric Oxide (vasodilator)
Releases Endothelin (vasoconstrictor)

Question 13

Tunica Media Features

Answer 13

Contains concentric sheets of smooth muscle in loose connective tissue
Encircles endothelium that lines the lumen
Binds to inner and outer layers

Question 14

Tunica Externa Features

Answer 14

Anchors vessel to adjacent tissue
Contains collagen, elastic fibers, smooth muscle cells
Contains Vasa Vasorum (smaller arteries and veins in larger arteries and veins)

Question 15

Types of Arteries

Answer 15

Elastic Arteries (e.g. Aorta)
Muscular Arteries (e.g. Femoral Artery)
Arterioles

Question 16

Characteristics of Arteries

Answer 16

Elastic contain great amount of elastic fibers = more elasticity
Muscular contains more smooth muscle = greater control of vasoconstriction/dilation
Arteries have no tunica intima/externa = focus on blood flow regulation

Question 17

3 Types of Capillaries

Answer 17

Continuous
Fenestrated
Sinusoid

Question 18

Capillary Features

Answer 18

No Tunica media/externa
Similar diameter to RBC

Question 19

Continuous Capillary Features

Answer 19

Found in all tissues
Have complete endothelial lining
Permit diffusion of water, small solutes and lipid-soluble materials

Question 20

Fenestrated Capillary Features

Answer 20

Have pores in endothelial lining
Permit rapid exchange of water and larger solutes (e.g. hormones)
Found in Endocrine Organs, Kidneys, Intestinal Tract

Question 21

Sinusoid Capilary Features

Answer 21

Have gaps between adjacent endothelial cells
Permit free exchange of water and large plasma proteins
Found in Liver, Spleen, Bone Marrow, Endocrine Organs

Question 22

Main differences of veins from arteries

Answer 22

Larger diameter
Thinner Walls
Lower blood pressure
Valves

Question 23

Venous Valves Features

Answer 23

Folds of tunica intima
Prevents blood from flowing backwards
Weakened walls of veins near valves = varicose veins

Question 24

Skeletal Muscle Pump Definition

Answer 24

Contraction of Skeletal Muscle that aids the opening/closing of valves
When a muscle contracts, the valve superior to the muscle opens whilst the valve inferior to the muscle closes

Question 25

Relationship between blood flow and cardiac output

Answer 25

Total capillary blood flow = cardiac output
Flow is proportional to pressure gradient/resistance (^P/R)

Question 26

Pressure Gradient Definition

Answer 26

Difference in Pressure from one end of a vessel to the other

Question 27

Total Peripheral Resistance Definition

Answer 27

Resistance of entire cardiovascular system
Overcame by Circuilatory Pressure

Question 28

Factors affecting total peripheral resistance

Answer 28

Vascular Resistance
Blood Viscosity
Turbulence

Question 29

Vascular Resistance Definition

Answer 29

Resistance due to friction between blood and vessel walls

Question 30

Factors affecting Vascular Resistance

Answer 30

Vessel Length
Vessel Diameter

Question 31

Normal Blood Pressure

Answer 31

120/80

Question 32

Hypertension Definition

Answer 32

Abnormally high blood pressure
Greater than 140/90

Question 33

Hypotension Definition

Answer 33

Abnormally low blood pressure
Less than 90/60

Question 34

Responses to Exercise

Answer 34

Increased Heart Rate
Increase in Systolic Blood Pressure
Redistribution of Blood Flow

Question 35

Parasympathetic ANS Regulation of Heart Rate

Answer 35

Slows Heart Rate by inhibiting SA and AV Node
Via Vagus Nerve

Question 36

Sympathetic ANS Regulation of Heart Rate

Answer 36

Increases Heart Rate by stimulating SA and AV Node
Via Cardiac Accelerator Nerves

Question 37

Ways to change stroke volume

Answer 37

Increased Sympathetic ANS activation
Increased end diastolic volume, leading to increased stretch of sarcomeres

Question 38

Relationship between contraction and stroke volume

Answer 38

Increased force of contraction = increased stroke volume