III Blood Vessels

Question 1

General Function of Arteries

Answer 1

1. Carry blood AWAY from the heart - continuously

Question 2

General Function of Veins

Answer 2

Carry blood TO the heart

Question 3

Structure of Large Arteries

Answer 3

1. Smooth muscle & elastic tissue

Question 4

Function of Large Arteries

Answer 4

Store pressure from the heart
(ventricles contract, and arteries stretch)
Ventricles relax and ELASTIC arteries RECOIL, pushing blood onward

Question 5

Structure of Medium-sized Arteries

Answer 5

Mostly muscle, less elastic

Question 6

Function of Medium-sized arteries

Answer 6

Distribute blood to various regions

Question 7

Aneurysm

Answer 7

Weak point in an artery or heart wall

Question 8

Structure of Arterioles

Answer 8

Small

Muscle + endothelium + connective tissue

Question 9

Function of Arterioles

Answer 9

Regulate flow to tissues and pressure

Question 10

Arterioles Vasoconstriction

Answer 10

Flow DECREASES

Pressure INCREASES

Question 11

Arterioles Vasodilate

Answer 11

Flow INCREASES

Pressure DECREASES

Question 12

Metarterioles

Answer 12

Like arteries to capillaries. Have sphincters

Question 13

Structure of Capillaries

Answer 13

thin-walled
Single layer of endothelial cells
in all tissues of body

Question 14

Function of capilaries

Answer 14

Permit exchange of: nutrients, waste, O2, CO2

Question 15

Precapillary Sphincters

Answer 15

Open and close to allow blood to get to areas of need. Only around 1/4 open at a time

Question 16

Veins General info

Answer 16

Hold more blood than areteries
Lower pressure 10 mm Hg
54% of blood

Question 17

Venules Structure

Answer 17

Small vessels, little muscle and no elastic tissue

Question 18

Structure of Veins (and difference with arteries)

Answer 18

Same layers as arteries but:
Thinner walls
Less elastic tissue
One-way Valves
Larger Lumens

Question 19

Blood pressure changes through body

Answer 19

Drops as it goes. (smaller vessels offer more resistance)

Aorta 100 mm Hg
Arteries 85 mm Hg
Arterioles 35 mm Hg
Capillaries 20 mm Hg
Venous System 0 mmHg

Question 20

Where is largest drop in pressure?

Answer 20

Arteries –> Arterioles

Question 21

3 main factors affecting blood pressure

Answer 21

1. Cardiac Output
2. Blood Volume
3. Peripheral Resistance

Any increase in these 3 increases blood pressure

Question 22

Factors influencing blood volume

Answer 22

concentration of solutes in body fluids, blood

Question 23

Regulation of blood volume

Answer 23

Fluid consumption and excretion through the kidneys

Question 24

Peripheral Resistance

Answer 24

Any force the opposes movement

Question 25

Factors that influence Peripheral Resistance

Answer 25

blood viscosity blood vessel length blood vessel diameter total cross section area of vessels

Question 26

Speed of flow in different parts

Answer 26

Fastest in Aorta Slow in Capillaries Moderate in Veins

Question 27

Factors that impact flow

Answer 27

Friction | Resistance to flow in small vessels

Question 28

Which two systems regulate blood pressure?

Answer 28

Nervous System | Endocrine System

Question 29

Endocrine System impact on blood pressure during stress

Answer 29

Epinephrine & Norepinephrine vasoconstriction on most vessels (pressure ++) vasodilation on cardiac and skeletal muscles - more blood to limbs and heart

Question 30

Antidiuretic hormone -> blood pressure impact

Answer 30

Causes fluid retention | Increases blood pressure

Question 31

Aldosterone -> blood pressure

Answer 31

response to low blood pressure | causes vasoconstriction

Question 32

Nitric Acid & Prostagalandis --> blood pressure

Answer 32

Response to trauma, inflammation, and local oxygen depletion vasodilation

Question 33

Capillary Exchange

Answer 33

Exchange of nutrients, wastes, and gasses between blood and interstitial fluids

Question 34

Main forces of capillary exchange

Answer 34

``` Osmotic Pressure (OP) Hydrostatic Pressure ```

Question 35

Factors that impact venous return

Answer 35

1. Muscle contraction 2. Decreased venous compliance 3. Respiratory inspiration/expiration 4. Vena cava compressoin 5. Gravity

Question 36

END Arteries

Answer 36

an artery that is the only supply of oxygenated blood to a portion of tissue

Question 37

3 examples of END arteries

Answer 37

Arteries of: | Spleen, kidney, lungs, metaphyses of longbones