Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Human Physiology > Cardiovascular system > Flashcards

Cardiovascular system Flashcards

(94 cards)

Start Studying
1
Q

3 principle components of CVS

A

heart
blood
blood vessels

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

what other systems impact the function of the CVS

A

endocrine
nervous
kidneys

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

2 loops of CVS

A

systemic
pulmonary

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

systemic loop

A

blood from heart to body to heart
blood leaves left ventricle via aorta which branches to form systemic arteries that branch to form the microcirculation (arterioles, capillaries, venules)
venules form veins which form into 2 large vessels: inferior vena cava and superior vena cava

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

inferior vena cava

A

collects blood from below heart

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

superior vena cava

A

collects blood from above heart

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

what is the function of the pulmonary system/loop

A

carries oxygen-poor blood to the lungs and back to the heart
blood leaves ventricle via pulmonary trunk which divides into pulmonary arteries
at the lungs there are arterioles, capillaries, venules, veins and blood returns to the left atrium via 4 pulmonary veins

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

2 categories of arteries

A

muscular
conduit/elastic

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

how is pressure in blood vessels measured

A

mm of mercury (Hg)

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

flow

A

volume moved, mm/min

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

definition for resistance

A

how difficult it is for blood to flow between 2 points at any given pressure difference

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

3 factors affecting resistance

A

blood viscosity (volume, number of erythrocytes)
total blood vessel length
blood vessel diameter (relaxed vessels decrease resistance, vasoconstricted vessels increase resistance)

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

vein vs artery

A

few layers of smooth muscle and connective tissue, few elastic layers, wider lumen

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

arteriole vs vein vs capillary

A

lumen endothelium smooth muscle cells
endothelium connective tissue
endothelial cells

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

elastic arteries

A

closer to heart
eg aorta
Large lumen vessels (low resistance) that contain more elastin
than the muscular arteries
pressure reservoirs
expand and contract (recoil) as blood is ejected by the
heart. This allows blood flow to be continuous.

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

muscular arteries

A

deliver blood to specific organs (mesenteric artery, renal artery etc.).
They have proportionally the most smooth muscle and are very active in vasoconstriction.
These arteries can play a large role in the regulation of blood pressure.

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

factors effecting pressure

A

volume
compliance (degree of stretch)

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

volume effecting pressure

A

Only about 1/3 of stroke volume
leaves arteries during systole
Rest of stroke volume remains in the arteries during systole, distending them, and raising the arterial pressure
After ventricular contraction, artery recoils passively, and blood
continues to be driven into arteriole

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

systolic blood pressure

A

Maximal arterial pressure reached during peak ventricular ejection

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

diastolic blood pressure

A

Minimal arterial pressure reached just before ventricular ejection

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

pulse pressure

A

difference between systolic and diastolic blood pressure

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

what are arterioles controlled by

A

neural, hormonal and local chemicals

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

arteriole function

A

control minute-to-minute blood flow in capillary beds
contraction diverts blood flow away from the tissues
dilation increases blood flow to the tissues
impact blood pressure

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

intrinsic tone

A

basal level of contraction of arterioles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
how is smooth muscle in arterioles regulated
autonomically by local or extrinsic control
26
how to decrease flow to tissues
increase resistance by vasoconstriction keep pressure constant
27
how to increase flow to tissues
increase pressure or vasodilate to reduce pressure
28
local control of arteriolar resistance
metabolism increases: oxygen dec, carbon dioxide, potassium ions, nitric oxide, hydrogen ions, adenosin increase causes vasodilation, reduces resistance, increases blood flow
29
extrinsic control of resistance
hormones sympathetic nerves
30
examples of hormones controlling resistance of arterioles
Epinephrine – vasodilates or constricts depending on the tissue Angiotensin II – constricts most arterioles Vasopressin – constricts most arterioles
31
3 types of capillary
continuous fenestrated sinusoidal
32
continuous capillary
found in skin, muscle, most common kind, have tight junctions.
33
fenestrated capillary
more permeable — intestines, hormone-producing tissues, kidneys
34
sinusoidal capillary
only one with an incomplete basement membrane; these are found in the liver, bone marrow and lymphoid tissues
35
how do capillaries grow and develop
angiogenesis
36
VEGF
angiogenic factor released by vascular endothelial cells
37
what does blood flow through the capillaries depend on
other vessels in the microcirculation eg, vasodilation of arterioles causes increased capillary flow
38
metarteriole
supplies some capillaries can be damaged by high blood pressure
39
precapillary sphincter
site at which a capillary exits from a metarteriole surrounded by a ring of smooth muscle that relaxes and contracts in responses to local stimuli
40
why is blood flow through capillaries slow
to maximise time for substance exchange across capillary wall
41
what is blood velocity dependent on
cross-sectional area of the blood vessel type smaller diameter reduces speed
42
pressure difference between veins and right atrium
veins (10-15 mmHG) and the right atrium (0 mmHG)
43
major functions of veins
act as low pressure conduits returning blood to heart maintain peripheral venous pressure
44
factors determining venous pressure
volume of blood in veins compliance of walls- their walls are very thin and compliant (low pressure)
45
how is unidirectional flow maintained in veins
valves
46
factors that can increase venous pressure
increase activity of sympathetic nerves to veins increase blood volume increase inspiration movements increase skeletal muscle pump
47
effect of increase in venous pressure
increase in venous return atrial pressure increases end-diastolic ventricular volume increases stroke volume increases
48
cardiac output
amount of blood pumped out of each ventricle in one minute. It is the product of heart rate (HR) and stroke volume (SV)
49
stroke volume
difference between end diastolic volume and the end systolic volume Volume of blood pumped from the left ventricle per beat. SV = EDV − ESV
50
myocardium
muscular wall of the heart formed from cardiac muscle cells
51
epicardium
fixes inner layer of pericardium to heart
52
pericardium
muscular sack enclosing heart
53
atrioventricular septum
muscular wall separating the ventricles
54
pulmonary semi lunar valve
blood from right ventricle to pulmonary trunk
55
aortic semi lunar valve
blood from left ventricle into aorta
56
Chordae tendinae
fasten AV valves to the papillary muscles
57
papillary muscles
limit movement to prevent backward flow of blood
58
bicuspid valve
2 fibrous cusps at left AV valve
59
tricuspid valve
right Av valve 3 fibrous cusps
60
how is permeability of capillaries determined
water filled interellular clefts | intercellular clefts are gaps between adjacent cells in endothelium
61
cardiac muscle cells
1-2 centrally located nuclei striated adjacent cells connected by intercalated disks gap junctions essential for electrical stimulation large mitochondria node cells-automaticity desmosomes
62
conducting system of the heart
cells with specialised features for heart excitation in electrical contact with cardiac muscle cells via gap junctions initiates the heartbeat and helps spread the impulse rapidly throughout the heart
63
control of increase in heart rate
sympathetic nervous system-innervates entire heart muscle and node cells releases norepinephrine which binds to beta-adrenergic receptors on cardiac muscle cells
64
control of decrease in heart rate
parasympathetic nervous system innervates node cells release acetylcholine which binds to muscarinic receptors
65
epinephrine
hormone released from adrenal medulla binds to same receptors as norepinephrine with same effects
66
how are action potentials transmitted through heart
gap junctions between myocardial cells
67
transmission/path of depolarisation
sinoatrial node atrial muscle cells through internodal pathway via gap junctions to AV node bundle of His left and right bundle branches left and right perkinje fibres ventricular muscle cells
68
signal delay at AV node
allows atria to contract and completely fill the ventricles before they contract
69
purkinje fibres and papillary muscles
purkinje fibres supply papillary muscles, signalling them to contract before the rest of the atria to help prevent backflow through valves
70
P wave on ECG
depolarisation wave from the SA node to the AV node. Atria contract 0.1 second after P wave starts
71
QRS complex on ECG
ventricular depolarisation and precedes ventricular contraction
72
T wave
ventricular repolarisation
73
effect of atrial fibrillation on ECG
electrical impulses in atria fire chaotically
74
what is stroke volume influenced by
volume of blood in ventricles, sympathetic nervous system, pressure heart is pumping against
75
effect of decreased heart rate on SV and CO
SV decreases CO maintained by increasing HR again
76
positive chronotropic factors
increase HR
77
negative chronotropic factors
decrease HR
78
frank starling mechanism
The ventricle contracts forcefully more during systole when it has been filled to a greater degree during diastole (more venous return) length-tension relationship. The greater the end diastolic volume, the more the muscles are stretched, and thus the greater the contraction
79
contractility
The strength of a contraction at any given end-diastolic volume Norepinephrine acts on beta-adrenergic receptors to increase ventricular contractility Plasma epinephrine also increases contractility
80
effect of increased contractility
increased stroke volume due to a more complete ejection of the end-diastolic volume
81
mean arterial pressure calculation (in terms of pressure)
Diastolic pressure + 1/3 (Systolic pressure − diastolic pressure)
82
mean arterial pressure calculation (in terms of CO)
Cardiac Output × Total Peripheral Resistance TPR is dependent on vasculature
83
mean cardiac output equation
stroke volume x heart rate where heart rate dependent on +/- chronotropic factors and sympathetic or parasympathetic activity
84
mean stroke volume equation
end diastolic volume - end systolic volume which are dependent on frank starling mechanism and contractility
85
arterial baroreceptors
respond to short term changes in arterial pressure; nerve endings are highly sensitive to stretch or distortion (degree of stretching is directly proportional to blood pressure) can adapt to long term changes
86
response of baroreceptors to increase in mean arterial pressure
increase frequency of action potentials
87
response of baroreceptors to decrease in mean arterial pressure
decrease frequency of action potentials
88
what receives impulses from baroreceptors
medullary cardiovascular centre in medulla oblongata input from baroreceptors determines frequency of action potentials from the CV centre
89
events after baroreceptors increase frequency of action potentials
decrease sympathetic outflow to heart, arterioles and veins and increase parasympathetic outflow to heart
90
decrease in arterial pressure-hormonal response
increase concentrations of angiotensin II and vasopressin which causes arterioles to constrict and increase arterial pressure again
91
renin-angiotensin system
intra-renal baroreceptors detect changes in stretching with lower blood volume-->increase production of renin
92
what happens within hours of blood loss
Compensatory movement of interstitial fluid into the capillaries to increase plasma volume (redistribution of fluid) also: increase in thirst, decrease in salt and water excretion
93
what happens within days of blood loss
Replacement of cells: erythropoiesis haematopoiesis
94
key concept of diuretics
increase excretion of sodium and water, decreasing cardiac output with no change in peripheral resistance

Human Physiology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions