Circulatory system Flashcards

1
Q

What are the functions of the circulatory system

A

distribution of nutrients, support for metabolism (O2 delivery), distribution of water and electrolytes, transportation and distribution of hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the principle components of a circulatory system

A

Fluid that circulates through the system, mechanism that applies force to drive the fluid, system of tubes for the fluid to pass through, valves or septa to ensure unidirectional flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Open circulatory system

A

incomplete system of vessels. Contains a circulating fluid called haemolymph which flows through vessels and freely percolates through intracellular spaces. Bathes internal organs and therefore directly reaches every cell of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Open circulation in insects

A

Use tracheal system to transport nutrients and CO2. Circulation can be less efficient when respiratory gases are handled through a separate system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Features of a closed system

A

complete and continuous system of blood vessels, blood, heart propels blood through vessels, intercellular spaces filled with interstitial fluid. Lymph in lymphatic vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where does diffusion occur in the circulatory system

A

between blood vessels and interstitial fluid at the capillary bed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Requirements of an efficient circulatory system

A

Efficient O2 carriers in blood or haemolymph, efficient gas exchange and delivery of nutrients, diversification of oxygenated fluid to systemic organs and deoxygenated fluids to respiratory organs, fast flow of fluids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Flow rate formula

A

change in pressure/ resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

pressure and resistance in a closed circulatory system

A

high change in pressure and high resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

pressure and resistance in an open circulatory system

A

change in pressure is low and resistance is low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Functions of the mammalian cardiovascular system

A

distribution of O2 and nutrients, transportation of CO2 and removal of metabolic waste, distribution of water, electrolytes and hormones, thermoregulation, immune system infrastructure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

arrangement of the mammalian cardiovascular system

A

4 chambered heart (unidirectional flow), blood supplies to systemic vascular bed run in parallel, pulmonary circulation runs in series, high pressure system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Components of a blood vessel

A

endothelium, smooth muscle, connective tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Function of the endothelium

A

lining of blood vessels, lines entire cardiovascular system, keeps blood in system, allows transfer between vessels and surroundings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

where does the blood stream exchange things

A

through tissue fluid and endothelial cells. Junctional complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Cycle of the circulatory system

A

heart, elastic arteries, muscular arteries, arterioles, capillaries, venuoles, veins, nheart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Elastic arteries function

A

smoothing. Catch blood that comes out of the heart and when the heart ventricle pumps it produces a burst of very high-pressure blood into the elastic arteries which expand, increasing their volume and reducing the pressure, when blood moves back out, elastic arteries shrink back in and increase the pressure again

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Muscular arteries function

A

can be big and decrease in size as they get longer, muscles contract to control the diameter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

arteriole function

A

controls blood flow to the capillaries at sufficient pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Capillary function

A

gas exchange. Thin and delicate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Venule function

A

Can exchange fluid with surroundings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

General structure of blood vessels (except capillaries and sinusoids)

A

tunica intima (endothelium+CT), tunica media (smooth muscle + CT), tunica adventitia (CT), internal elastic lamina (IEL), extrernal elastic lamina (boundaries of t.media)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the arrangement of smooth muscle

A

long and thin, circular (controls diameter), narrow, small muscular artery + vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Elastic arteries: aorta, pulmonary artery

A

very big lumen, thick walls, smooth muscle cells are contractile, elastic fibres organised into sheets, parallel to one another and run around the vessel, arranged concentrically and circular lumen, collagen to resist tension,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Blood supplies to large arteries

A

thick walls of busy, living vells that requiire gases, vessels above certain sizes have their own circulation in walls, walls too thick to receive adequate O2 nutrient supply and waste disposal from centre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are muscular arteries lined with

A

endothelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Arteriole structure

A

same structure as larger vessels. Thicker wall and smaller lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Capillary network

A

terminal arterioles that control blood flow to the capillary bed. Pressure must be enough to get blood flow but not too much to burst capillaries. Sinusoid - one cell thick

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Continuous endothelium

A

sit on top of basement membrane, all sit in complete layer, found in most layers and exchange solutes and gases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Fenestrated endothelium

A

cells have pores between them, sit on top of intact basement membrane, found in capillaries in endocrine glands, exchange larger molecules (hormones)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Discontinuous endothelium

A

gaps between cells, gaps in basal lamina, cells don’t fit properly together, found in sinusoids, exchange whole cells, leaking tissue fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Venules and veins

A

thinner wall and larger lumen, bigger than capillaries, liquid exchange between plasma and tissue fluid, difference between venules and veins is the tunica media (vein is smaller), substantial T. adventita. Arterial pulse massages blood along vein, increases pressure in the veins. Muscle contraction squeezes and moves blood through valves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Valves

A

Folds of tunica intima (one way flow), valves point to the heart, pocket shaped structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Blood (haemolymph) pressure

A

Difference between the pressure in the system and the ambient pressure (transmural pressure)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are the 2 components of blood pressure

A

dynamic pressure (produced by the pump) and hydrostatic pressure of the fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What does the resistance of the system equal

A

sum of individual resistances of all elements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What can decrease resistance of the system

A

decreasing the number of resistors and adding more conductors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Artery function

A

conduit for blood to capillary beds, act as pressure resevoir to drive blood into arteries, damp oscillations in pressure and flow, control differential distribution to different organs and tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Veins functions

A

conduit for blood to return to heart, act as blood resercoir, flow influenced by external factors

40
Q

Blood vessels providing resistance

A

as vessel diameter increases, blood flow decreases. Constriction of arterioles increases resistance.

41
Q

Where is the site of greatest resistance

A

arterioles - they can change size of lumen. Blood enters arterioles with high speed and as the blood exits the pressure and speed is greatly reduced

42
Q

What can cause a change in smooth muscle tone

A

neurotransmitters, hormones, endothelium derived substances, metabolites, pressure, heat

43
Q

How do arteries regulate and distribute blood flow

A

change in smooth muscle tone - vasoconstriction and vasodilation

44
Q

Arteriole pulse pressure

A

top number (systolic) - the bottom number (diastolic)

45
Q

Total fluid energy

A

potential energy acquired from the beating of the heart, kinetic energy of the fluid itself, potential energy of the fluid that it possessed because of its position in the gravitational field, the fluid flows from where its total fluid energy is higher to where its total fluid energy is lower

46
Q

What does pressure increase in proportion to

A

the height of the colum

47
Q

Affect of height above the heart

A

arterial pressure decreases, acting against gravity

48
Q

Affect of height below the heart

A

increase arterial pressure

49
Q

Why does blood pool in lower limbs when stood upright

A

venous return is reduced, leads to a decrease in cardiac stroke volume, lower arterial blood pressure, immediate decrease in blood flow to brain

50
Q

Vasoconstriction and vasodilation in a giraffe

A

when stood upright gravity causes vasoconstrcition (prevents blood pressure from falling) of vessels in lower body. When it lowers its neck the aortic pressure decreases causing vasodilation of vessels in lower body

51
Q

Define cardiac output

A

the total volume of blood pumped by the heart in one minute

52
Q

cardiac output (L/min) formula

A

heart rate (beats/min) x stroke volume (L/beat)

53
Q

What does the P wave show

A

electrical activity in the right atria (depolarisation)

54
Q

What does the QRS complex show

A

depolarisation of the ventricles

55
Q

What does the T wave show

A

repolarisation of the ventricles

56
Q

What does the PR interval show

A

conduction through AV node

57
Q

What does the QT duration show

A

ventricular depolarisation and repolarisation

58
Q

What is the heart rate modified by

A

autonomic nervous system (parasympathetic and sympathetic) and circulating hormones

59
Q

What does the parasympathetic and sympathetic nervous system do to heart rate

A

Parasympathetic - slows
Sympathetic - increases

60
Q

Calcium’s role in muscle contraction

A

binds to myofilaments in order to contract

61
Q

How is electrical activity coordinated

A

contraction is highly organised, atria contracts followed by ventricles, relaxation is also coordinated to allow filling

62
Q

How do valves ensure one way flow of blood

A

atria contract and eject blood into relaxed ventricles, AV valves close as ventricle contracts. Aortic and pulmonary valves open to allow blood out of ventricle

63
Q

What is systole

A

contraction of chambers and ejection of blood

64
Q

What is diastole

A

relaxation and filling

65
Q

What is troke volume modified by

A

intrinsic control (degree of stretch of cardiac muscle - starlings law) and extrinsic control (sympathetic stimulation - modulation of Ca availability)

66
Q

Where is the heart located

A

In the chest cavity, behind sternum. Centre/left. Top of diaphragm between the lungs in mediastinum. Bulges into the left lung so left lung is smaller than right.

67
Q

What keeps the heart into position

A

by the pericardium and large blood vessels entering and leaving

68
Q

Serous pericardium function

A

lines inside of the fibrous pericardium. Secretes a watery fluid between its layers allowing free movement

69
Q

What does the visceral layer line

A

is attached and lines the heart

70
Q

What does the parietal layer line

A

fibrous pericardium

71
Q

Function of the fibrous pericardium

A

prevents over expansion of the heart

72
Q

Coronary arteries

A

fewer interconnections (anastomoses). Easily blocked = heart attack. Coronary artery bypass surgery - graft leg veins to bypass blocked cpranry arteries

73
Q

Internal anatomy of the heart

A

muscular septum divides into left and right halves. Atrium and ventricle on each side. All chambers lined by smooth lining (endocardium)

74
Q

Anatomy of the right atrium

A

thin walled. Receives blood from superior vena cava (blood from head, arms and thorax), inferior vena cava (lower body), coronary sinus (heart walls)

75
Q

Anatomy of right ventricle

A

thick walled. Recieves blood from the atrium. Pumps into pulmonary trunk and legs.

76
Q

Where is the tricuspid valve located

A

Right atrium and right ventricle

77
Q

Where are the semilunar valves located

A

between ventricle and pulmonary trunk

78
Q

Where are the bicuspid valves located

A

left atrium and left ventricle

79
Q

Anatomy of the left atrium

A

thin walled, receives 2 pulmonary veins from each lung. Foramen oval

80
Q

Anatomy of the left ventricle

A

very thick wall. Blood from atrium. Blood to aorta

81
Q

What is the foramen ovale

A

a flap between the right and left atria. The foetus gets nutrients by O2/CO2 exchange across the placenta, so most blood bypasses the lungs using the foramen ovale. Another route is ductus arteriosus between pulmonary trunk and aorta

82
Q

What happens to the foramen ovale and the ductus after the baby is born

A

the foramen seals permanently. (hole in the heart is when it doesnt seal). Ductus goes into spasm and closes (fuses shut and becomes fibrous tissue)

83
Q

Atrioventricular valve function

A

prevent ventricle to atrium flow when ventricles contract

84
Q

Function of the valve between the right atrium and coronary sinus

A

stops back flow of blood into coronary veins when atrium contracts

85
Q

chorda tedinae function

A

maintain the position and tension of the atrioventricular valves

86
Q

papillary muscle function

A

helping to prevent leakage through the AV valves during systole

87
Q

What is the myocardium

A

Muscle layer

88
Q

What is the epicardium

A

visceral pericardium

89
Q

Describe the endocardium

A

lining of the heart. Appears rigid (trabeculae carnae) - underlying bundles of muscle fibres. Made up of endothelium and underlying connective tissue

90
Q

What makes up the myocardium

A

cardiac muscle fibers and connective tissue

91
Q

What links cells together end to end

A

intercalated discs, allows cells to branch and join with other fibers

92
Q

What are intercalated discs

A

3 types of cell-cell junctions link the heart muscle cells

93
Q

What do adherent junctions link

A

actin cytoskeleton (sarcomere contractions)

94
Q

What do desmosomes link

A

intermediate filaments - strength

95
Q

What do gap junctions link

A

cytosol and allow cell-cell comms coordinate contraction cell to cell along the heart muscle fibres