Cardio - Blood Flashcards
1
Q
Define thrombosis
A
formation of a clot (thrombus) inside a blood vessel
2
Q
what happens to platelets when they are activated
A
they change shape from smooth discoid to spiculated (spikey) and pseudopodia (protusions)
3
Q
benefits of platelets being activated
A
increases surface area and increases possibility of cell-cell interactions
4
Q
what happens to glycoprotein IIb/IIIa receptor when the platelet is activated
A
increases number of receptors
increases affinity of receptor for fibrinogen
fibrinogen links receptors, binding platelets together (platelet aggregation)
5
Q
what cells are part of the cellular component of blood?
A
red blood cells (erythrocytes)
leukocytes
platelets
6
Q
what makes up plasma components of blood
A
proteins and water
7
Q
what are the features of erythrocytes (RBCs)
A
anucleate
discoid
biconcave
8
Q
Where are erythrocytes (RBCs) formed in adults, children and foetus
A
adults- bone marrow of axial skeleton
children- all bones
foetus- liver, spleen &yolk sac
9
Q
what is the life span of erythrocytes (RBCs)
A
120 days
10
Q
what is the regulatory protein of erythrocytes (RBCs)
A
erythropoietin (produced by kidney and liver)
11
Q
why does haemoglobin have to be enclosed in a membrane
A
otherwise will clog up kidneys
12
Q
reticulocyte
A
an immature RBC
13
Q
features of platelets
A
anucleate & discoid
14
Q
function of platelets
A
involved in the clotting process & formation of platelet plug
15
Q
life span of platelets
A
7 to 10 days
16
Q
regulatory hormone for platelets
A
thrombopoietin (TPO) (produced by kidney and liver)
17
Q
nucelus, function and life span of neutrophils
A
multi-lobed nucelus phagocytosis of bacteria and foreign material
10 hours
18
Q
nucelus, function, appearance and life span of eosinophils
A
bi-lobed
very eosinophillic (pink)
combat parasites & neutralises histamine
8-12 hours
19
Q
nucelus, function, appearance and life span of basophils
A
bi lobed nucleus
very prominent dark blue granules of histamine
allergic reaction & histamine
8-10 hours
20
Q
nucelus, function and life span of monocytes and macrophages
A
reniform (kidney bean shaped) nucelus
phagocytotic role/ antigen presenting cells
8-12 hours
21
Q
what do monocytes differentiate into
A
macrophages and dendritic cells
22
Q
function, appearance and life span of lyphocytes
A
B= plasma cells/ memory cells & produce antibodies
T= Thelper, T cytoxic Tsupressor
8-12 hours
“ fried egg”
23
Q
what is the structure of haemoglobin
A
2 alpha chains
2 beta chains
Haem group containg fe 2+ in the centre
24
Q
how does foetal haemoglobin differ from adult
A
foetal has 2 alpha and 2 gamma chains (instead of 2 beta)
means has a higher affinity for oxygen which compensates for the relatively lower O2 saturation it receives
25
what causes the different shaped red blood cells in sickle cell disease
beta chains replaced by S chains
26
define haemostasis
the process to prevent and stop bleeding
27
coagulation
process by which blood changed from a liquid to a gel/solid
28
what happens to a vessel when it is damaged
constricts to limit blood flow to affected area
29
what mediates vascular constriction
endothelin-1
| neural control
30
what happens to platelets after the exocytosis of alpha granules
platelets become activated so there is more platelet cross linking and aggregation (spiculated and more glycoprotein IIaIIIb receptors)
31
what does asprin do to platelet amplification
inhibits pathway
32
what cross links platelets
fibrinogen
33
how does the platelet plug stay where its wanted
1) prostaglandins produced by undamaged endothelium inhibit platelet aggregation
2) NO released by undamaged endothelium cause vasodilation and inhibits platelet aggregation and activation
34
what are the vitamin K dependent clotting factors
10, 9, 7 and 2
| 1972
35
how are blood clots broken down
fibrinolytic pathway
36
explain the fibrinolytic pathway
plasminogen -> plasmin which breaks down fibrin
37
what % is cellular and fluid compartment of blood
cellular 45%
| fluid 55%
38
what is haemopoiesis
formation of the blood cells
39
what is the process of differentiation of red blood cells, white B cells and platelets called
RBC- erythropoiesis
white blood cells- myelopoiesis
platelets- thrombopoiesis
40
what is the hormonal growth factors that control haemopoiesis of red blood cells and platelets
red cells- erythropoitein
| platelts- thrombropoitein
41
what organs remove red blood cells
spleen, liver, bone marrow
42
function of dendritic cells
present antigens to the immune system
43
where to B and T lymphocytes mature
B- bone marrow
| T- thymus
44
function of B and T lymphocytes
B- generate antibodies when stimulated by antigens
| T- cell- mediated immunity and help B cells (Ab production)
45
what are the 2 types of T lymphocytes
T helper cells- suppress and regulate immune response
| Cytotoxic T cells- target damaged/ infected cells for death
46
define haemostasis
blood inside the vessels remains fluid
| blood outside the vessels should clot
47
how is blood kept fluid inside of vessels
1) platelets and proteins of the coagulation cascade circulate in an inactive state
2) endothelial cells, anticogulant pathway & fibrinolytic pathway keep it fluid
48
define anucleate cells
lacking a nucleus
49
what do platelets bind to when their is damage to the blood vessel
bind to collagen via glycoprotein Ia
| and GPIIIa/IIb bind to VWF in the subendothelium
50
after the platelets bind (adhere) to the endothelium what happens
they change shape/ activate and release contents (degranulate)
51
what granules do platelets release
electron dense granules and alpha granules (fibrinogen and VWF)
52
what happens after platelets release granules
aggregate to form a platelet thrombus
53
what is the role of GPIb
platelet adhesion
54
what is the role of GPIIb/IIIa
platelet cross-linking and aggregation
55
what is role of the dense storage granules
platelet activation and aggregation (when released)
56
what are the proteins in plasma
albumin
carrier proteins
coagulation proteins
immunoglobulins
57
what is the role of albumin
determines oncotic pressure of the blood (keeps intravascular fluid in that space)
58
how does the coagulation cascade affect fibrinogen
converts soluble fibrinogen into insoluble fibrin polymer
59
what is haemophilia
severe bleeding into muscles and joints
60
where are coagulation factors synthesised
liver
61
what are red cell antigens
red cell membrane proteins
62
what can cause a transfusion reaction
red blood cells (which are used in the transfusion) have antigens on cell membrane which the body recognises as foreign and the body produces antibodies against them
63
what surface antigens and antibodies are there in plasma for A, B, AB and O blood groups
A- A antigen, B antibodies
B- B antigen, A antibodies
AB- A and B antigens, no antibodies
O- no antigen, A and B antibodies
64
what is the universal blood donator group
O-
65
what is the universal blood recipient group
AB +
66
what is Rh D antigen
antigen on RBC surface which can cause an immune response
67
what does Rh D + and - mean
+ have D antigen
| - don't have D antigen
68
can - Rh D receive + or - blood
+ no
| - yes
69
can + Rh D receive + and - blood
yes can receive both
70
where is the glycoprotein IIb/IIIa located
on surface of platelet
71
why do platelets change shape when they are activated
increase surface area to inc the possibility of cell-cell interactions
72
what are the features of arteries
low resistance conduits
| elastic
73
conduits
channels for liquid (blood) flow
74
where is the principle site of resistance to vascular flow
arterioles
75
what is total peripheral resistance equal to
total arteriolar resistance
76
what do arterioles have a major role in determining?
arterial pressure and distributing flow to tissue/organs
77
role of arteries
cushion systole
| maintain blood flow to organs during diastole
78
difference between blood flow/ cardiac output to blood volume in circulation
blood flow- to organs
| blood volume- in circulation, arteries, arterioles, capillaries, veins, lymphatics, endothelium
79
describe vasoconstriction
vascular smooth muscle contracts
smaller radius of vessel
greater resistance and reduced flow
80
describe vasodilation
vascular smooth muscle relaxes
bigger radius
smaller resistance and greater flow
81
what is it called when the vascular smooth muscle never relaxes completely
myogenic tone
82
describe features of capillaries
large area and slow flow
| which allows time for nutrient and waste exchange
83
what determines flow in the capillaries
arteriolar resistance
| number of open pre-capillary spincters
84
are veins high or low resistance conduits
low resistance and compliant
85
how is blood returned to heart through veins against gravity (what aids it)
valves (also prevent backflow)
skeletal muscle (during contraction- squeezes the veins and forces more blood back to heart)
respiratory pump- inspiration, inc intra-abdominal pressure, transmitted to abdominal veins.
86
what is transported in the lymphatics and where is it returned to the heart
fluid/ protein excess filtered from capillaries
thoracic duct in left subclavian vein
87
what aids the unidirectional flow in lymphatics
smooth muscle in lymphatic vessels
skeletal muscle pump
respiratory pump
88
cardiac output CO equation
heart rate x stroke volume
89
blood pressure equation
Cardiac output x total peripheral resistance
90
how much longer is diastole than systole
x2
91
equation for pulse pressure
systolic - diastolic pressure
92
mean arterial pressure
diastolic pressure + 1/3 pulse pressure
93
ohm's law flow
flow= pressure gradient / resistance
94
poiseuilles equation
flow= radius ^4
95
define cardiac output
the amount of blood ejected by each ventricle per minute
| heart rate x stroke volume
96
define stroke volume
the volume of blood ejected by each ventricle with each beat
97
heart rate
the number of times the heart beats per minute
98
end diastolic volume
volume of blood in each ventricle at the end of diastole
| (just before heart contraction) 130ml
99
ejection fraction
percentage of end-diastolic volume ejected with each beat
100
end- systolic volume
volume of blood remaining in each ventricle at the end of systole
(contraction)
50ml
101
what can affect cardiac output
any factor that affects stoke volume and heart rate
| exercise, emotions, pregnancy, posture, sweating, age, gender
102
what 3 factors affect stoke volume
preload
myocardial contractility
afterload
103
what is preload and what happens if it is increased
end diastolic volume
| increase in EDV means increase in stroke volume
104
what is frank- starling law
within physiological limits, the force of contraction is directly proportional to initial length of muscle fibre
105
if increased end diastolic volume, what does frank-starling predict
increased EDV= increased fiber length= increases force of muscle contraction= increases stroke volume= increases cardiac output
106
what does preload depend on
venous return
atrial pump activity
ventricular compliance
107
what does venous return depend on
skeletal pump activity, ECF volume, sympathetic activity- venoconstriction
108
how does atrial pump activity affect preload
atrial contraction increases due to sympathetic activity
109
what is ventricular compliance
compliant ventricles= more filling
| less compliance= pathology- can't expand as much
110
what is myocardial contractility (inotropy)
increased contractility= increased stroke volume
111
what increases contractility
more ventricular muscle mass
sympathetic stimulation
hormones- acetylcholine
drugs and chemicals- caffeine
112
what is afterload
force against which ventricles contract/ eject
113
what is cardiac output inversely proportional to
peripheral resistance
114
what does peripheral resistance depend on
vessel diameter and viscosity of blood
115
how does vasoconstriction and increased viscosity affect stroke volume
they increase peripheral resistance which decreases stroke volume
116
what affects heart rate
autonomic activity
117
what causes increase in HR (tachycardia >100) and decrease in heart rate (bradycardia <60)
tachycardia- sympathetic stimulation
| bradycardia- vagal stimulation
118
how is Cardiac output maintained when heart rate increases or decreases
heart rate increase- the duration of diastole shortens so EDV decreases
heart rate decrease- diastole prolongs, ECV does not decrease as much as expected
119
how is frank-starling possible? how is force of contraction directly proportional to initial length of muscle fiber?
1) increased EDV= increased stretch of muscle fibers= increased interaction between thick and thin filaments= inc force of contraction
2) inc stretch opens stretch sensitive Ca2+ channels= inc cytosol calcium= inc force of contraction
3) stretch enhances affinity of troponin C for calcium= increased binding of calcium to troponin C= increased force of contraction
120
define systolic and diastolic BP
```
systolic= highest, when ventricles contract
diastolic= lowest, when ventricles relax
```
121
calculate mean arterial pressure
D + 1/3(S-D)
122
what is used to measure BP
sphygmomanometer
123
how does nitric oxide (NO) affect blood vessles
vasodilator
124
how does endothelin affect blood vessles
vasoconstrictor
