Cardiovascular System

Question 1

main heart structures

Answer 1

• pericardial fluid
• fibrous pericardium
• myocardium
• endocardium

Question 2

• provides lubrication
• reduces friction during heartbeats

Answer 2

pericardial fluid

Question 3

• protects heart from pathogens
• anchors cardiac structures

Answer 3

fibrous pericardium

Question 4

• cardiac muscle
• form walls of heart chambers

Answer 4

myocardium

Question 5

• layer of simple squamous epithelium cells
• lines chambers
• covers valves
• continuous w/ lining of blood vessels

Answer 5

endocardium

Question 6

blood vessel function

Answer 6

• provide continuous route for blood leaving heart to return to heart

Question 7

arteries

Answer 7

• several layers of muscle
• elastic & fibrous muscle
• carries blood away from heart
• no valves
• high-pressure system

Question 8

arterioles

Answer 8

• less elastic
• several layers of muscle
• carry blood to capilaries

Question 9

capillaries

Answer 9

• smallest vessel
• layer of endothelium
• site of exchange between blood & interstitial fluid

Question 10

venules

Answer 10

• receive blood from the capillaries
• convergent flow of blood

Question 11

veins

Answer 11

• carry blood to atria
• thinner walls and larger diameter that arteries
• contain valves = prevent back-flow

Question 12

• present in micro vessels
• induce vasoconstriction/dilation in capillary beds
• regulate vascular diameter \7 capillary blood flow

Answer 12

pericytes

Question 13

elastic recoil

Answer 13

• elastic properties allow for blood in arteries to recoil
• propagating pressure produced by heart in form of pressure waves

Question 14

pulmonary circulation

Answer 14

• carries deoxygenated blood to lungs
• exchanges for oxygenated blood at the lungs
• returns oxygenated blood to the heart
• pressure comes from the right ventricle

Question 15

systemic circulation

Answer 15

• carries oxygenated blood from heart to all
• returns deoxygenated blood to the heart
• pressure comes from left ventricle

Question 16

coronary circulatory system

Answer 16

• coronary arteries, veins & capillaries
• heart receives blood
• venous blood form myocardium returned directly to right atrium

Question 17

portal system

Answer 17

e.g. hepatic
- vessels divide into capillaries, reforms into a vessel, then divides into capillaries again

Question 18

lymphatic system

Answer 18

significant role in fluid homeostasis, lipid metabolism, immune control
- lymph vessels
- lymph nodes
- lymph

Question 19

lymph vessels

Answer 19

• have blind beginnings in interstitial spaces
• contain numerous valves permitting flow only towards heart
• circulation takes place via contractions of vessels & muscles
• form large lymph vessels that eventually reach vena cava

Question 20

lymph nodes

Answer 20

• nodular structures of varying sizes, located along course of vessels
• filter the lymph
• act as first defences against infection
• infection or inflammation often results in enlarged lymph nodes

Question 21

lymph

Answer 21

• little diff. between composition of lymph & interstitial fluid
• contains water, lymphocytes, inorganic salts & proteins

Question 22

lymph formation

Answer 22

• interstitial fluid not re-entering capillaries, recovered by lymph vessels

Question 23

primary function of cardiovascular system

Answer 23

• transport substances around the body
• types of substances: nutrients, water, gases, waste products

Question 24

cardiac cycle & phases

Answer 24

period between start of one heartbeat and beginning of the next
- atrial systole
- atrial diastole
- ventricular systole
- ventricular diastole

Question 25

period of relaxation

Answer 25

diastole

Question 26

period of contraction

Answer 26

systole

Question 27

- located in right atrium - pacemaker - initiates action potentials

Answer 27

sinoatrial node

Question 28

- impulses from SA node are conducted to AV node through internodal pathways

Answer 28

internodal pathways

Question 29

atrioventricular node

Answer 29

- the AV node conducts impulses more slowly than other myocardial cells

Question 30

Atrioventricular bundle

Answer 30

after leaving the AV node, the impulse accelerates through AV bundle & along bundle branches

Question 31

purkinje fibres

Answer 31

terminal arborisation of the Bundle branches directly depolarise ventricular cardiomyocytes

Question 32

efficient cardiac contraction

Answer 32

- atrial excitation & contraction need to be completed before contraction take place - excitation of cardiac muscle fibres should be coordinated, so each chamber contracts as a unit

Question 33

* have unstable membrane potentials - rising membrane potential never at rest

Answer 33

pacemakers

Question 34

- pace making current in sinoatrial node

Answer 34

funny current

Question 35

heart rate

Answer 35

- frequency of cardiac cycles - usually measured by number of beats per second

Question 36

blood pressure

Answer 36

- usually refers to arterial pressure - high point of arterial pressure during ventricular systole

Question 37

autonomic nervous system

Answer 37

- sympathetic stimulation increases heart activity - parasympathetic stimulation decreases heart activity

Question 38

baroreceptor reflex

Answer 38

- mechanoreceptors located within aortic arch & carotid sinuses - detect increase in blood pressure - mechanoreceptors located within vena cava & pulmonary veins - detects decreases in blood pressure

Question 39

chemoreceptor reflex

Answer 39

- peripheral chemoreceptors located in carotid & aortic bodies - central chemoreceptors are located on ventrolateral medullary surface in CNS

Question 40

endocrine system

Answer 40

cardiovascular function also influenced by endocrine hormones - ADH - renin - angiotensin - all involved in water reabsorption for purpose of blood pressure regulation

Question 41

blood vessel types

Answer 41

- arteries - arterioles - capillaries - venues - veins