principles of cardiorespiratory system

Question 1

What are the 3 layers of the heart wall (outside to inside)?

Answer 1

1. epicardium
2. myocardium
3. endocardium

Question 2

Describe the myocardium microstructure?

Answer 2

• striated appearance
• intercalated discs
• branching pattern
• 1/2 nuclei per cell

Question 3

Describe smooth muscle?

Answer 3

• not striated
• one central nucleus per cell

Question 4

Describe the left lung

Answer 4

• 2 lobes
• oblique fissure

Question 5

Describe the right lung

Answer 5

• 3 lobes
• horizontal and oblique fissures

Question 6

What are the functions of smooth muscle?

Answer 6

• regulates diameter
• propels liquids and solids
• expels contents

Question 7

What are the layers of blood vessels?

Answer 7

• tunica intima
• tunica media
• tunica externa (adventitia)

Question 8

Describe the tunica intima layer of blood vessels

Answer 8

• lined by endothelium
• connective tissue

Question 9

What is the function of the tunica intima layer of blood vessels?

Answer 9

reduces friction for blood flow

Question 10

Describe the tunica media layer of blood vessels

Answer 10

• primarily smooth muscle
• connective tissue (elastic and collagen fibres)

Question 11

What is the function of the tunica media layer of blood vessels?

Answer 11

controls size and shape of artery

Question 12

Describe the tunica externa layer of blood vessels

Answer 12

• outer connective tissue layer (primarily collagenous)
• can contain nerves and vessels

Question 13

What is the function of the tunica externa layer of blood vessels?

Answer 13

connects artery to surrounding structures

Question 14

What is the main feature of the large elastic arteries?

Answer 14

tunica media contains many layers of elastin

Question 15

What is the main function of the large elastic arteries?

Answer 15

accommodates surges in blood

Question 16

Describe the large elastic arteries and some examples

Answer 16

• large diameter (over 10mm)
• only includes arteries closest to the heart (aorta, subclavian, common carotid arteries)

Question 17

Describe the medium muscular arteries

Answer 17

• smaller diameter (0.5-10mm)
• most other named arteries (femoral and popliteal arteries)

Question 18

What is the main feature of the medium muscular arteries?

Answer 18

tunica media contains a thick layer of smooth muscle

Question 19

What is the main function of the medium muscular arteries?

Answer 19

vasoconstriction and vasodilation

Question 20

Describe the small arteries and arterioles?

Answer 20

• small arteries = 0.3mm-0.5mm
• small arterioles = microscopic
• decreased thickness of all layers
• not normally named

Question 21

What is the main feature of small arteries and arterioles?

Answer 21

• tunica media predominantly smooth muscle
• 1-2 cell layers in thickness

Question 22

What is the main function of the small arteries and arterioles?

Answer 22

tonus dictates degree of filling of capillary beds

Question 23

What is the main feature of capillaries?

Answer 23

endothelial layer only (no tunica media or externa)

Question 24

What is the main function of the capillaries?

Answer 24

allow exchange between blood and extracellular fluid

Question 25

What are the two types of capillaries?

Answer 25

• continuous
• fenestrated

Question 26

Describe the continuous capillaries?

Answer 26

• uninterrupted endothelium
• most common

Question 27

Describe the fenestrated capillaries?

Answer 27

• has pores (fenestrae)

Question 28

What are the main features of veins?

Answer 28

• tunica media thinner
• large veins have well developed tunica externa

Question 29

Describe the venous valves?

Answer 29

• inward projection of intima
• strengthened by collagen and elastic fibres

Question 30

Where are the venous valves absent?

Answer 30

thorax and abdoment

Question 31

What is the name of the circulation that goes to just the lungs and heart?

Answer 31

pulmonary circulation

Question 32

What is the name of the circulation that goes between the heart and the rest of the body

Answer 32

systemic circulation

Question 33

Describe the intercalated discs in myocardium microstructure

Answer 33

• have fascia adherens and desmosomes (act as anchors)
• have gap junctions (free flow of ions for APs)

Question 34

Give examples of medium muscular arteries

Answer 34

femoral and popliteal arteries

Question 35

Which veins do I need to know?

Answer 35

• femoral
• popliteal
• great saphenous

Question 36

What factors aid the return of blood against gravity?

Answer 36

• valves
• arteriovenous pump
• respiratory pump
• musculovenous pump

Question 37

What is anastomosis?

Answer 37

vein connected to vein or artery connected to artery

Question 38

What are arteries with no anastomosis called?

Answer 38

end arteries

Question 39

What are the 2 types of end arteries?

Answer 39

• anatomic (true)
• functional (potential)