cardiovascular system

Question 1

what are the organs of the cardiovascular system?

Answer 1

heart, blood vessels, blood

Question 2

what are the layers of the heart?

Answer 2

pericardium, epicardium,myocardium,endocardium

Question 3

what are the structures of the cardiovascular system?

Answer 3

valves, chambers,major vessels, major cell types of blood

Question 4

what are the cell types the heart consists of?

Answer 4

-pericardium
-epicardium
-myocardium (cardiac myocytes)
-valves
-conducting nerve bundles
-pericardium
–blood vessels-endothelium

Question 5

what are the different blood cells the blood consists of?

Answer 5

-leukocytes-white blood cells
-erythrocytes-red blood cells

Question 6

what is the pericardium?

Answer 6

-dense,irregular connective tissue

Question 7

what is the epicardium?

Answer 7

a visceral layer of the serous pericardium

Question 8

what is the myocardium?

Answer 8

-a cardiac muscle layer

Question 9

what does the endocardium consist of?

Answer 9

camber lining and valves and a smooth lubricating layer

Question 10

how is the thickness of the cardiac walls?

Answer 10

-the myocardium of the left ventricle is thicker than the right ventricle

Question 11

what is the histology of the cardiac muscle?

Answer 11

-there is branching,intercalated discs with gap junctions, involuntary striated, single central nucleus per cell
-there are desmosomes between myocytes which allow the depolarisation of adjacent fibres

Question 12

how is the structure and function of the valves?

Answer 12

-they open and close in response to pressure changes as the heart contracts and relaxes
-dense connective tissue rings surround the valves of the heart and fuse with the inter ventricular system

Question 13

what is the physiological function of the heart?

Answer 13

-it pumps over 1mill gallons per year
-it has over 60,000 miles of blood vessels

Question 14

what is the physiological function of the vessels?

Answer 14

-they help to retain and circulate blood
-they help regulate pulse pressure

Question 15

what is the physiological function of the blood?

Answer 15

-erthrocytes-distribute oxygen from & CO2 to lungs
-leukocytes-circulate immune cells to combat infection

Question 16

what is the process of electrical conductance?

Answer 16

-SA node (right atrium)
-AV node
-AV bundle (bundle of His)
-right and left bundle branches
-purkinje fibres

Question 17

what is systole and diastole?

Answer 17

-systole-contraction
-diastole-relaxation

Question 18

what does an ECG represent?

Answer 18

the overall electrical activity of the heart

Question 19

how is heart rate regulated by the nervous system?

Answer 19

by nervous control from the cardiovascular centre in the medulla which involves:
-sympathetic impulses
-parasympathetic impulses
-baroreceptors

Question 20

what can heart rate be affected by?

Answer 20

-adrenaline
-noradrenaline
-thyroid hormones
-ions (Na,K,Ca2+)
-age,gender,physical fitness and temp

Question 21

what do sympathetic impulses do?

Answer 21

increase heart rate and force of contraction

Question 22

what do parasympathetic impulses do?

Answer 22

decrease heart rate

Question 23

what do baroreceptors do?

Answer 23

they are pressure receptors that detect change in BP and send info to the cardiovascular centre

Question 24

where are baroreceptors located?

Answer 24

in the arch of the aorta and carotid sinuses

Question 25

what is the route of systemic circulation?

Answer 25

left side heart to body and back to the heart

Question 26

what is the route of hepatic portal circulation?

Answer 26

capillaries of the GI tract to capillaries in the liver

Question 27

what is the route of pulmonary circulation?

Answer 27

right side of the hear to the lungs and back to the heart

Question 28

what is the route of foetal circulation?

Answer 28

from the metal heart through the umbilical cord to the placenta and back

Question 29

what are the 4 major divisions of the aorta?

Answer 29

-ascending aorta -arch of aorta -thoracic aorta -abdominal aorta

Question 30

where are superficial veins found?

Answer 30

beneath the skin

Question 31

where does venous blood drain to?

Answer 31

either superior or inferior vena cava or coronary sinus

Question 32

what do veins of the systemic circulation do?

Answer 32

drain blood from the entire body and return it to the right side of the heart

Question 33

where are deep veins found?

Answer 33

they parallel the arteries in the region

Question 34

what are the three major layers in the arteries and veins?

Answer 34

-the tunica internal (ft the endothelium) -tunica media (ft circular smooth muscle and elastic fibres) -tunica externa (ft elastic and collagen fibers)

Question 35

what are elastic arteries?

Answer 35

-large arteries with more elastic fibres and less smooth muscle and they are able to receive blood under pressure and propel it onward

Question 36

why are elastic arteries also called conducting arteries?

Answer 36

they conduct blood from the heart to medium sized muscular arteries

Question 37

what does the elasticity of large arteries mean?

Answer 37

-blood flow can proceed in a smooth and continuous manner, despite the start-stop pumping activity of the heart

Question 38

what are muscular arteries?

Answer 38

-medium sized arteries with more muscle than elastic fibres in the tunica media -they have relatively thick walls

Question 39

what are muscular arteries capable of?

Answer 39

-greater vasoconstriction and vasodilation to adjust the rate of flow due to their smooth muscle content, which influences blood flow and the regional distribution of blood flow

Question 40

why are muscular arteries called distributing arteries?

Answer 40

-because they direct blood flow

Question 41

what are arterioles?

Answer 41

-small arteries that deliver blood to the capillaries -they contain the tunica media containing few layers of muscle

Question 42

what do metarterioles do?

Answer 42

-form branches in the capillary bed -to bypass the capillary bed,precapillary splinters close and blood flows out of the bed in thoroughfare channel

Question 43

what is vasomotion in relation to capillary beds?

Answer 43

-intermittent contraction and relaxation of sphincters that allow the filling of the capillary bed 5-10 times/minute

Question 44

wat are capillaries?

Answer 44

-the site of gas exchange at the cellular level -they are found near every cell but are more extensive in highly active tissue e.g muscles,liver,kidneys and the brain

Question 45

when do capillary beds fill with blood?

Answer 45

-entire capillary beds fill with blood when tissue is active,;asking in epithelia of cornea and lens of eye and cartilage

Question 46

what are the capillary walls composed of?

Answer 46

-a single layer of cells (endothelium) and a basement membrane

Question 47

what are capillaries drained by?

Answer 47

-venules so they eventually feed into veins

Question 48

what are venules?

Answer 48

-small veins that collect blood from the capillaries -as venules develop they can develop tunica media with some smooth muscles and scattered fibroblasts