Cardiovascular Flashcards
1
Q
the pulmonary valve is
A
between right ventricle and pulmonary artery
2
Q
the aortic valve is
A
between left ventricle and the aorta
3
Q
right atrium receives deoxygenated blood from
A
IVC/SVC/coronary sinus
4
Q
left atrium receives oxygenated blood from
A
right and left pulmonary veins
5
Q
anterior/sternocostal surface of heart
A
mostly R ventricle
6
Q
inferior/diaphragmatic surface of heart
A
mostly L ventricle
7
Q
posterior surface/base of heart
A
L atrium + pulmonary veins
8
Q
apex of heart
A
L ventricle
9
Q
right border of heart consists of
A
right atrium
10
Q
inferior border of heart consists of
A
L ventricle + R ventricle
11
Q
left border of heart consists of
A
L ventricle (some of L atrium)
12
Q
superior border of heart consists of
A
R/L atria and great vessels
13
Q
surface marking for apex of heart
A
mid-clavicular line
5th intercostal space
14
Q
auscultation of mitral valve
A
apex
15
Q
auscultation for tricuspid valve
A
left lower sternal border 5th intercostal space
16
Q
auscultation for pulmonary valve
A
left of sternum 2nd intercostal space
17
Q
auscultation for aortic valve
A
right of sternum 2nd intercostal space
18
Q
the first heart sound (S1) is
A
the closing of tricuspid/mitral valves at beginning of systole
19
Q
the second heart sound (S2) is
A
the closing of aortic/pulmonary valves at beginning of diastole
20
Q
superior mediastinum contains (5)
A
arch of aorta - 3 branches superior vena cava - 4 tributaries vagus nerve phrenic nerve thymus/trachea/oesophagus etc
21
Q
middle mediastinum contains (6)
A
heart pericardium bifurcation of trachea origins of great vessels cardiac plexus phrenic nerves
22
Q
what is the floor of the inferior mediastinum
A
the diaphragm
23
Q
posterior mediastinum contains (5)
A
oesophagus descending aorta - branches azygous veins sympathetic nerve trunks thoracic splanchnic nerves
24
Q
where does the right coronary artery arise from
A
anterior aortic sinus and runs in coronary sulcus
25
what does the right coronary artery supply
SAN
AVN
R atrium/R ventricle
26
where does the left coronary artery arise from
left posterior aortic sinus and divides in the atrioventricular groove
27
dominance refers to
70% people RCA supplies PDA
20% co-dominant from RCA and Cx
10% Cx supplies PDA
28
right marginal artery supplies
right ventricle and apex
29
left anterior descending supplies
R ventricle L ventricle and interventricular septum
30
left marginal artery supplies
left ventricle
31
left circumflex artery supplies
left atrium left ventricle
32
why are LV walls x3 thicker than RV
increased resistance of systemic circulation compared to pulmonary circulation
33
brachiocephalic trunk landmark
second right costal cartilage
34
the pericardium consists of
fibrous layer
| serous layer= parietal and visceral
35
what is the pericardial cavity
space between parietal and visceral layers
36
mneumonic for pericardium
fart police smell villains
37
where is the oblique sinus
pericardial space behind the left atrium
38
what is the blood supply of the pericardium
pericardiacophrenic arteries
| internal thoracic arteries
39
what innervates the pericardium
phrenic nerve
40
what supplies parasympathetic innervation of the heart
the vagus nerve
41
what supplies sympathetic innervation of the heart
sympathetic trunk via cardiac nerves
42
what provides motor innervation to the diaphragm
phrenic nerve
43
why do we get referred pain from heart damage
pain felt in cutaneous regions because dermatomes responsible for cutaneous pain are supplied by same spinal cord levels as visceral afferents from the heart
44
where is pain felt during myocardial infarction
right shoulder region
45
what are the nerve roots of the phrenic nerves
anterior rami of C3 C4 C5
46
what structures are supplied by the vagus nerve (6)
```
pharynx
larynx
heart
lungs
foregut
midgut
```
47
left common carotid artery supplies
most of cerebral hemisphere + L face and neck
48
left subclavian artery supplies
vertebral
thyrocervical
axillary arteries
49
what supplies the SAN
60 % people RCA
| 40% people LCA
50
what supplies the AVN
posterior descending artery
51
what is haemocrit
the percentage of RBCs in the cellular component of blood
52
components of blood proportions are
45% cellular
55% fluid
45% haemocrit
53
where are erythrocytes formed in adults
bone marrow in axial skeleton
54
where are erythrocytes formed in children and foetuses
bone marrow in bones in children
| liver/yolk sac/bone marrow in foetus
55
what is the erythrocyte regulatory hormone
erythropoietin
56
5 types of leukocytes
```
eosinophil
neutrophil
basophil
monocyte
lymphocyte
```
57
eosinophil characteristics
bilobed nucleus
upregulated in parasitic infection
decrease histamine
bright pink/orange granules
58
neutrophil characteristics
most abundant
multilobed nucleus - increase with age
granular cytoplasm
acute inflammation/phagocytic function
59
basophil characteristics
bilobed nucleus
dark blue granules fill cell
precursor to mast cells
contain histamine = allergic response
60
monocyte characteristics
kidney shaped nucleus
pale blue cytoplasm
differentiate into dendritic cells/macrophages
adaptive immunity
61
lymphocyte characterists
fried egg appearance
B or T cells
immature = bigger than RBC
62
B lymphocytes become
plasma and produce antibodies
63
what do T cells do
mediate inflammation
64
platelet features
anucleate and discoid
stain blue
4 types of granules
65
where are platelets formed
from megakaryocytes in the bone marrow
66
platelet life span
5-10 days
67
platelet regulatory hormone
thrombopoietin
68
name 4 soluble plasma proteins
albumin
carrier proteins
coagulation factors
immunoglobulins
69
what is haemostasis
maintenance of balance of blood flow so it is liquid in vessels but clot outside
70
what allows blood to stay liquid
coagulation factors and platelets are INACTIVE
71
what activates platelets
tissue factor found on all cells except endothelial cells
72
what happens when you cut yourself
vessel damage leads to vessel constriction
slow of blood flow to area and endothelial surfaces press together
bleeding is stopped by platelet plug and coagulation cascade
73
formation of platelet plug 5 steps
1. endothelium disrupted = expose collagen fibres
2. platelets adhere to VWF which is bound to collagen
3. binding causes release of dense granules and thrombin form platelet
4. platelet is activated = spiculated shape
5. fibrinogen binds to platelets to allow more platelets to aggregate
74
what does the release of platelet dense granules do
causes platelet amplification
75
what does the release of thrombin do
platelet activation and further thrombin release via positive feedback
76
how does the platelet plug stay where its wanted
prostaglandins produced by undamaged endothelium = inhibit aggregation
nitric oxide from undamaged endothelium = vasodilation and inhibit aggregation
77
why do we have a coagulation cascade
occurs around platelet plug to support and reinforce
78
what enzyme converts prothrombin to thrombin
clotting factor Xa
79
what is the role of thrombin enzyme
convert soluble fibrinogen to insoluble fibrin
80
fibrinolytic pathway
plasminogen converted to plasmin to break down fibrin
81
what level is the arch of the aorta
T4
82
type A have
A antigen on surface of RBC and anti-B antibodies in plasma = co-dominant
83
type B have
B antigens on surface of RBC and anti-A antibodies in plasma = co-dominant
84
type AB have
A and B antigens on surface of RBC but no anti-A or anti-B in plasma = universal recipient
85
type O have
no A or B on surface of RBC but BOTH anti-A and antiB antibodies in plasma = universal donor
86
what is rhesus
C, D, E antigens
87
what is rhesus postivie
D antigen present
88
what is rhesus negative
D antigen NOT present
89
what is rhesus sensitisation in pregnancy
mother has RhD negative baby has positive
mothers blood recognises as foreign = makes antibodies against
takes time so 1st baby unaffected but mother = sensitised to RhD positive blood
90
what is rhesus disease
mother has antibodies against RhD positive baby
attacks baby RBC
causes anaemia and jaundice
91
4 features of a cardiac myocyte
intercalated discs
centrally nucleated
striated
branching
92
what is systole
isovolumetric ventricular contraction and ventriucular emptying (not completely)
0.3 secs
93
what is diastole
isovolumetric ventricular relaxation and ventricular filling
| 0.5 secs
94
isovolumetric definition
change in pressure but not in volume
95
what is responsible for 80% ventricular filling
rapid ventricle filling - rest is slow filling due to equalising pressures
96
what is diastis
little to no net movement of blood
97
what is atrial booster
sudden pressure increase due to atrial contraction (SAN) allowing ventricles to be actively filled
98
what is the length of a cardiac cycle
0.8 secs
99
what is starling's law
the larger the volume of the heart the greater the energy of its contraction and amount of chemical change at each contraction
larger end diastolic volume = larger stroke volume
100
what is compliance
relationship between change in stress and the resultant strain e.g. how easily blood chamber expands when filled with blood
101
what is diastolic distensibility
pressure required to fill the ventricle to the same diastolic volume
102
what is elasticity
myocardial ability to recover its normal shape after removal of systolic stress
103
parasympathetic stimulation of the heart casues
decrease heart rate
decrease force of contraction
decrease CO
104
sympathetic stimulation of heart causes
increase heart rate
increase force of contraction
increase CO
105
myosin structure
2 heavy chains and 2 light chains
106
what is actin
polymerised globular protein with troponin and tropomyosin
107
what is titin
elastic filaments that maintain sarcomere alignment
108
molecular sarcomere contraction 4 steps
1. action potential inhibits calcium pumps = calcium escape from sarcoplasmic reticulum
2. calcium binds to troponin = changes shape so moves tropomyosin to expose myosin binding site on actin
3. myosin head bind to actin bridges formed = ADP released = myosin head move forward = contraction
4. energy from atp pulls z lines closer together = contraction
5. ATP attach to myosin head = breakdown of bridges
109
where are calcium ions stored
sarcoplasmic reticulum
110
what is excitation-contraction coupling
1. motor neuron connect with muscle at neuromuscular junction
2. Acetylcholine diffuse along synaptic cleft depolarise sarcolemma
3. depolarisation = Ca2+ released to stimulate contraction
111
pressure of pulmonary circulation
20/8
112
pressure of systemic circulation
120/80
113
what constitutes microcirculation
arterioles capillaries and venules
114
artery features
thick muscular wall to sustain force of LV contractions
elastic for systole
diastolic pressure supplies elastic recoil
115
arteriole features
smooth muscle walls
site of resistance to vascular flow
determines arterial pressure
distributes flow to tissues/organs
116
capillary features
endothelial cells and pericytes
| fenestrated
117
what is the role of precapillary sphincters
control blood flow to tissue
118
what happens to substances and fluid that move into tissue
it becomes lymph
119
how much of total blood do veins hold
70%
120
3 functions that allow venous return against gravity
valves prevent backflow
muscle action peristalsis
respiratory pump
121
lymph vessels features
```
low pressure
valves
drains excess fluid from tissues
no RBC/large proteins but all other blood components
fluid is eosinophilic
```
122
where does lymph drain
subclavian veins
123
stroke volume equation
end diastolic volume - end systolic volume
124
cardiac output equation
heart rate x stroke volume (typically 5L/min)
125
blood pressure equation (BP)
CO x total peripheral resistance
126
pulse pressure equation (PP)
systolic - diastolic pressure
127
mean arterial pressure (MAP)
diastolic pressure + 1/3rd pulse pressure
128
Ohm's Law, force =
pressure gradient / resistance
129
what is the end systolic volume
volume of blood left in ventricle after contraction
130
what is the end diastolic volume
volume of blood in ventricle before contraction (how much filled)
131
Poiseuille's equation, flow =
radius of blood vessel to power of 4
132
what does PACE stand for
preload
afterload
contractility
'eart rate
133
preload definition
volume of blood in LV which stretches cardiac myocytes before LV contraction
134
what happens if preload increases
increased end diastolic volume
myocardial fibres stretch more
increase force of contraction = starling
increase stroke volume
135
afterload definition
pressure LV must overcome to eject blood during contraction
136
what happens of afterload increases
decreases stroke volume
137
increase venous return would cause
increase EDV
increase stretch of muscle
increase force of contraction
increase stroke volume and cardiac output
138
what is contractility
the force in which the heart contracts
| independent of load and reliant on sympathetic innervation/hormonal factors
139
increase contractility would cause
heart contracts with more strength = higher pressure
140
what is vascular resistance
resistance that must be overcome to push blood through the circulatory system
141
which cells are auto-rhythmic
pacemaker cells
142
which cells are non-autorhythmic
cardiac contractile cells
143
which clotting factors is vitamin K necessary for
2, 7, 9, 10
| remember as 1972
144
cardiac myocyte action potential 6 steps
1. action potential from adjacent cells = Na+ into cells = rapid depolarisation
2. opens K+ channels = K+ out of cell = partial repolarisation
3. Ca2+ channels open and enter = plateau
4. Ca2+/Na+ channels close only K+ open and moving out = repolarisation
5. resting potential maintained
145
3 differences between cardiac action potential and regular action potential
```
cardiac = calcium leaving cell causes a plateau
cardiac = 200-300ms vs 1ms
cardiac = longer refractory period
```
146
why does cardiac action potential have a longer refractory period
to prevent muscle fatigue
147
pacemaker action potential
1. HCN channels allow Na+ in = depolarisation
2. threshold is -40mV
3. Ca2+ voltage gated channels = calcium in = even more positive
4. too positive = K+ open and exit = repolarisation
5. resting potential restored
148
why does the SAN determine the pace of the heart
because resting potential is closer to threshold = action potential initiated more rapidly than in AVN
149
speed of transmission through pacemaker cells is
slower than through cardiac myocites because in pacemaker Ca2+ used to depolarise = slower
150
sympathetic stimulation of pacemaker action potential
adrenaline/noradrenaline bind to Beta1 = increase Na permeability so threshold reached faster
151
parasympathetic stimulation of pacemaker action potential
acetylcholine bind to muscarinic receptor = decrease Na permeability so threshold reached slower
152
what regulates peripheral resistance
vasoconstriction/vasodilation
autonomic NS - sympathetic = constriction
blood viscosity
MAINLY ARTERIOLE RESISTANCE
153
3 types of vasoconstrictors and examples
```
local = endothelin 1
hormonal = adrenaline/angiotensin 2/ADH
medulla = pressor region
```
154
role of pressor region
increases blood pressure by increasing vasoconstriction = increase cardiac output
155
name 7 local causes of vasodilation
```
NO
H+
lactic acid
hypoxia
increased CO2
bradykinin
prostaglandin/prostacyclin
```
156
3 hormonal vasoconstrictors
angiotensin 2, vasopression, adrenaline
157
medulla source of vasodilation is
depressor region = inhibits pressor region
158
where are central baroreceptors located
atria
ventricles
pulmonary artery
159
role of central baroreceptors
inhibit pressor region
RAAS
ADH if increased pressure
= decrease BP
160
where are central chemoreceptors located
in the medulla
161
role of central chemoreceptors
respond to changes in pH as CO2 cant cross BBB
162
where are peripheral baroreceptors/chemoreceptors located
```
aortic arch (vagus nerve)
carotid sinus (glossopharyngeal nerve)
```
163
role of peripheral chemoreceptors
stimulated by decrease O2/pH/increase CO2 = decrease BP
164
role of peripheral baroreceptors
stimulated by high BP = lower BP
165
nervous system involvement in lowering BP
decrease sympathetic NS
| increase parasympathetic NS
166
what is the developmental significance of the ligamentum arteriosum
remnants of shunt between PA and aorta
| shunt closes at birth
167
how may fibrous pericardium contribute to reduction in ventricular filling
pericardium swells with fluid over time
will limit ventricular filling = lower stroke volume
this increases heart rate to try and increase cardiac output as pericardium is resistant to stretch
168
what phase of the cardiac cycle do coronary arteries fill
pressure is highest during systole so some CA fill but most in the myocardium so squeezed empty
during diastole pressure in myocardium decreases so CA fill
169
where is the SAN located
superior end of crista terminalis at the junction of SVC and RA
170
what is the thoracic duct
main lymphatic channel draining lymph from half of body back to bloodstream
171
what does the greater splanchnic nerves supply and where is pain felt
foregut but felt in epigastrum
172
what does the lesser splanchnic nerves supply and where is pain felt
midgut but felt round umbilicus
173
what does the least splanchnic nerves supply and where is pain felt
hindgut but felt suprapubic region
174
what structures drain blood into the azygous system
body walls
mediastina viscera
lateral/posterior chest wall
lateral/posterior abdo wall
175
difference between L and R laryngeal nerve
left passes through thorax
176
where do the sympathetic nerves attach to the nervous system
T1-T12
| L1-L2
177
sympathetic nerves to head/neck disrupted leads to
Horner's syndrome
178
what factors affect BP (5)
```
CO
compliance
volume of circulating blood
lifestyle factors
genetics
```
179
when is the myocardium perfused
in heart relaxation (diastole)
180
during cardiac cycle theres a greater flow of blood through which coronary arteries
left in most people
181
what are the consequences of a LAD occlusion
myocardial infarction in front/bottom of LV and front of septum
nausea, shortness of breath, pain in head/jaw/neck
induces cardiac arrest
182
what are the consequences of a RCA occlusion
RCA supplies SAN/AVN
chest pain, shortness of breath
leads to ischaemic myocardium and conduction abnormalities
183
are RBC precursors found in the blood
no, this is a sign of leukemia
184
what is myogenic autoregulation
when blood flow increase smooth muscle constricts until diameter is normalised/slightly reduced.
when blood flow decrease smooth muscle relaxes and dilates in response.
185
what is intrinsic autoregulation
when arterioles either vasoconstrict or vasodilate in response to changes in resistance seemingly automatically to maintain constant blood flow
186
what is hyperaemia
increase in blood flow
187
what is active hyperaemia
increase in blood flow when metabolic activity is increased
188
what is reactive hyperaemia
transient increase in organ blood flow that occurs following a brief period of ischaemia
189
what happens at the P wave
atrial depolarisation
| 0.08-0.11s
190
what happens at PR interval
time taken for atria to depolarise and electrical activation to reach AVN
0.12-0.2s
191
what happens at the QRS complex
ventricular depolarisation
| 0.06-0.1s
192
what happens at ST segment
interval between depolarisation and repolarisation
| 0.005-0.150s
193
what happens at the T wave
ventricular repolarisation
194
what happens at QT segments and how long does it take
ventricular depolarisation then repolarisation
| 0.2-0.4s
195
what is the conduction pathway
SAN
AVN
bundle of His
Purkinje fibres
196
how is the His-Purkinje system specialised (4)
rapid conduction
large fibres
high permeability at gap junctions
spreads from endocardium to pericardium
197
what does an ECG show
changes in voltage over time
198
p waves are positive in every lead apart from
aVR
199
t waves are positive in every lead apart from
aVR/sometimes V1/V2
200
what is anaemia
reduction in haemoglobin in the blood
201
what is the normal Hb levels
12.5-15.5g/dl
202
what is iron deficiency anaemia
iron needed for Hb production
| lack of iron result in reduced production of small red cells
203
what is MCV
mean corpuscular volume
| = average size of RBC
204
how does vitamin B12/folate deficiency lead to anaemia
B12/folate needed for DNA synthesis
| deficiency = RBCs cannot be made in bone marrow = less are released = anaemia
205
what is haemolysis
normal/increased RBC production but decreased life span (<30 days)
206
how is a delay created at AVN
has less gap junctions
207
what happens at day 19 heart development
2 endocardial tubes form
208
what happens at day 22 heart development
embryo undergoes lateral folding
| 2 endocardial heart tubes fuse to form single tube
209
what develops from the bulbus cordis
proximal 1/3 = muscular RV
| conus cordis = smooth outflow portion of LV/RV
210
what develops from the truncus cordis/arteriosus
proximal aorta and pulmonary trunk
211
what develops from the primary ventricle
left ventricle
212
what develops from the primary atrium
anterior RA
entire LA
L/R auricles
213
what develops from the sinus venosus
part of RA/VC/coronary sinus
214
where is the CVS embryologically derived from
mostly the mesoderm
| some contribution from neural crest cells from ectoderm
215
what occurs in cardiac looping
1. bulbus cordis and primary ventricle grow
2. BC moves inferiorly, anteriorly and right
PV moves to left
3. PA, SV move superiorly and posteriorly
truncus arteriosum form
216
what are the stages of cardiac embryological development
1. heart tube fuse
2. cardiac looping
3. cardiac septation = 4th - 5th week
217
what is vasculogenesis
angioblasts from mesoderm coalesce to form angioplasties cords throughout embryonic disc
= migrate to form the aorta
218
what is angiogenesis
driven by growth factors = adds to vasculogenesis through proliferation and sprouting
219
what does 3rd aortic arch develop into
L/R common/internal/external carotid arteries
220
what does 4th aortic arch develop into
```
Left = part of aortic arch
Right = part of right subclavian artery
```
221
what does 6th aortic arch develop into
```
left = L pulmonary artery and ductus arteriosus
right = R pulmonary artery
```
222
foetal circulation
1. oxygenated from placenta via umbilical vein
2. bypass liver via ductus venosus = combine with deoxy in IVC
3. join with blood from SVC and enter RA
4. RA shunted to LA
5. blood to aorta via ductus arteriosus
6. deoxy to placenta via umbilical arteries
223
what occurs after birth
1. increased alveolar O2 = vasodilation of pulmonary vessels
| 2. increased LA pressure/decrease RA pressure = foramen ovale close
224
what happens to the foramen ovale after it closes
becomes the fossa ovalis
225
3 granulocytes
neutrophils
eosinophils
basophils
226
2 agranulocytes
lymphocytes
| monocytes
227
the heart is mainly composed of
myocardium
228
what are the heart valves composed of
fibro-elastic connective tissue
229
what is the surface of the heart valves covered by
endocardium
| includes a layer of endothelial cells
230
what is the surface of the heart covered by
mesothelial cells that form the visceral pericardium
231
what does the medial layer of blood vessels contain
smooth muscle
elastic
collagen
232
what does the adventitia layer of blood vessels contain
densely packed collagen and elastic fibres
233
how does cardiac muscle differ from skeletal muscle
```
structurally = branched, central mononuclear, no stem cells
physiological = contract/relax without rest, secrete hormones
```
234
what hormone does cardiac muscle secrete and what does it do
ANP
| when stretched excessively = increase water/K+/Na+ excretion and inhibit RAAS
235
what is the role of gap junctions
allow ion transfer between cardiac smooth muscle = electrochemical coupling
236
what colour do purkinje fibres stain with PAS
magenta
237
purjinke fibres histology characteristics
large vacuoles
pale H&E bc few myofibrils
stores glycogen
238
histology of valves
thick collagen occasional elastic tissue
both surfaces have endothelial cellss
fibrous chordae tendinae
239
what is the pericardium made up of
single layer of mesothelial cells on BM with thin loose elastic and fibrous tissue
240
what is the endocardium made up of
endothelial cells on BM with thin loose elastic and fibrous tissue
241
what are the colours of an elastic artery with mallorys stain
```
elastic = red
collagen/muscle = blue
```
242
capillary diameter is same as
RBC
243
what are the 4 functions of endothelial cells
1. AT across membrane
2. influence muscle tone
3. coagulation
4. produce cell adhesion molecules to influence lymphocyte/neutrophil migration
244
what type of muscle do large veins have in their medial layer
smooth muscle
245
what colour do lymph vessels stain
blood plasma and valves stain pink
246
what are reticulocytes
immature RBC with some visible ribosomes = dark staining granules
247
why can muscular arteries reduce their diameter
have smooth muscle in media
248
elastic tissue van gieson with iron haemotoxylin counter stain
elastic = black
smooth muscle = mushroom
collagen = pink
249
name 2 hormonal vasodilators
atrial natriuretic peptide
| adrenaline
