CARDIOVASCULAR Flashcards
1
Q
what is plasma
A
translucent liquid component of the blood that holds the cellular components of blood in a suspension
about 90% water, 7% carrier proteins and the rest is electrolytes, hormones gases and nutrients
2
Q
what is serum
A
plasma without the clotting factors
3
Q
what are red blood cells
A
they are erythrocytes, which are anuclear, and are important for the carrying of oxygen around the body
4
Q
what is the lifespan of a RBC
A
about 120 days
5
Q
what are the different types of leukocytes and their groupings
A
monocytes, lymphocytes, basophils, eosinophils, neutrophils
monocytes and lymphocytes are agranular and basophils, eosinophils and neutrophils are granular
6
Q
what are the granulocytes
A
neutrophils, eosinophils and basophils
7
Q
what is the most abundant leukocyte
A
neutrophils
8
Q
what are neutrophils function
A
they are the first line of defense and phagocytose pathogens, they are part of the innate immune response
9
Q
what is the function of eosinophils
A
combats parasite infections and neutralises histamine
10
Q
what is the basophil function
A
they produce histamine - responsible for anaphylaxis
11
Q
what are the agranulocytes
A
monocytes and lymphocytes
12
Q
what is the function of monocytes
A
monocytes in the blood and macrophages in the tissue. they phagocytose foreign material - examples are kupfer cells, microglial cells
13
Q
what is the function of lymphocytes
A
they are part of the adaptive immune system, T cells, B cells and natural killer cells. they produce antibodies and attack cells, as well as activating other parts of the immune system
14
Q
what are platelets
A
they are anucleate cells that become spiculated which they are activated. they form a platelet plug to prevent damage to underlying cells during vessel wall damage
15
Q
what is hemostasis
A
process to prevent and stop bleeding
16
Q
what happens during vessel injury
A
in vessel injury there is endothelium exposure and endothelin release. this causes vasoconstriction. you then get adhesion of platelets to the subendothelial collagen via vWF using receptor GP1B. once the platlets bind there is activation inducing a shape change. the platelets release their alpha and dense granules containing vWF, thromboxane A2, fibrinogen and fibrin stabilizing factor, and ADP, CA2+ and serotonin respectively. this release causes aggregation of further platelets
17
Q
what are the different parts of the coagulation cascade
A
there is an intrinsic and extrinsic pathway, with the most important aspect being fibrin
18
Q
how does the common pathway work
A
fibrinogen is in the blood and in the inactive form. it requires thrombin to be active. through the coagulation cascade prothrombin is converted to thrombin. this then converts fibrinogen into fibrin
19
Q
what are important factors in the coagulation cascade
A
IIa (thrombin), Ia(fibrin), XIIIa (fibrin stabilizing factor), IV (Ca2+)
20
Q
what are the vitamin K dependent factors
A
X, IX, VII, II
21
Q
what does warfarin do
A
warfarin inhibits the vitamin K dependent clotting factors
22
Q
what is the fibrinolytic pathway
A
this is plasmin mediated fibrin breakdown. plasminogen is activated into plasmin by factor X. this then degrades fibrin
23
Q
what is required before a blood transfusion occurs
A
cross matching to see if the donors blood is safe for the recipient
24
Q
what are the 4 main blood groups
A
A, B, AB and O
25
how is membrane potential in a cardiac myocyte maintained
it is maintained by the sodium potassium pump (as well as smaller diffusion channels)
26
what is the cardiac myocyte cycle
in depolarisation there is an influx of sodium into the cell, and this causes the membrane potential to increase. once it reaches -60mV this causes depolarisation and more sodium channels to open. at 30mV sodium channels close and there is partial repolarisation. there is then the plateau phase as L type calcium channels are open and allow for influx of calcium into the cell, which balances to potassium efflux. there is then repolarisation, as the calcium channels close and there is a net movement of potassium out of the cell
27
what is the absolute refractory period
the cell can not be excited again no matter the stimulus
28
what is the relative refractory period
where the threshold potential is higher, but you can cause depolarisation with a strong stimulus
29
what is pacemaker potential
the pacemaker potential is responsible for the automaticity of the heart, which is generated by nodal cells. the primary pacemaker is the SAN
30
what happens when there is sympathetic stimulation of the SAN
noradrenaline increases the calcium channel opening, which causes a steeper depolarisation, increasing the heart rate and the force of contration
31
what happens when there is parasympathetic activity on the SAN
this is via the vagus nerve, this decreases the heart rate. Ach activated the potassium channels which hyperpolarises the membrane
32
what is excitation-contraction coupling
this is when calcium moving into the cell binds onto the ryanodine receptor on the SR and releases more intracellular calcium. this calcium binds onto troponin on the myofilaments which uncovers the binding site for actin on the tropomyosin strand.
33
in an ECG, what is a lead
a lead is the plane in which you are looking at the heart
34
in ECG what is an electrode
an electrode is what you place on a body to pick up electrical signals
35
in EGC where is lead 2 placed
from the right arm to the left leg
36
how many leads are looked at on an ECG
12
37
what is lead 1 placed in ECG
from the right arm to the left arm
38
where is lead 3 placed in an ECG
left arm to the left leg
39
what are the three unipolar leads in ECG
aVR, aVL and aVF
40
where are the 6 chest leads places
lead V1 - 4th intercostal space to the right of the sternal border
lead V2 - the 4th intercostal space to the left of the sternal border
lead V3 - midway between V2 and V4
lead V4 - 5th intercostal space, midclavicular line
lead V5 - anterior axillary line at the same level as V4
lead V6 - mid axillary line at the same level as V4 and 5
41
what does the initial two heart tubes develop from
the visceral mesoderm
42
then do the 2 primitive heart tubes fuse
during lateral folding
43
what are the primitive heart tube divisions
the truncus arteriosus, the bulbus cordis, the primitive ventricle, the primitive atrium and the sinus venosus
44
what does the truncus arteriosus become
the ascending aorta and the pulmonary trunk
45
what does the bulbus cordis become
the smooth parts of the left and right ventricles
46
what does the primitive ventricle become
forms the majority of the ventricles
47
what does the primitive atrium become
the entire left atrium and the anterior part of the right atrium
48
what does the sinus venosus become
the smooth part of the right atrium, the venal canal and the coronary sinus
49
what is the process of septation in embryology
the formation of the left and the right heart
| the tube folds and pinches
50
what does the first aortic arch become
becomes the maxillary artery
51
what does the second aortic arch become
becomes the stapedial and hyoid artery
52
what does the third aortic arch become
the common carotid - part of the internal carotids
53
what does the fourth aortic arch become
branches. the left becomes the aortic arch and the right becomes the right subclavian
54
what happens to the fifth aortic arch
it regresses and doesnt become anything
55
what happens to the sixth aortic arch
it becomes the pulmonary arteries, and the left becomes the ductus arteriosus
56
when does the heart appear in utero, and when does it start beating
it appears in the third week and begins beating on day 23
57
describe the cardiac cycle
starts with ventricular systole. there is isovolumetric contraction where the ventricles contract, with all valves closed and the pressure increases. the pressure continues to increase until it is above the aortic pressure. the aortic valve opens and the blood is forced into the aorta. as this happens the ventricular pressure reduces, eventually below the aortic and the valve will shut. this again causes a closed system. the atria fills with blood and contracts, its pressure rising above ventricular pressure. this causes the atrioventricular valve to open and blood to flow into the ventricle and the cycle starts again
58
what is the end diastolic volume
this is the volume of blood in the ventricles before contraction
59
what is the stroke volume
the amount of blood that is pumped out during ventricular systole (~70%)
60
what is the ejection fraction
ejection fraction is the stroke volume divided by the end diastolic volume
61
what factors effect stroke volume
preload, afterload and contractility
62
what is preload
preload is the same as the end diastolic volume. the larger the preload the larger the stroke volume
63
what factors can effect preload
atrial contractility, venous return, ventricular compliance, valvular resistance and the heart rate
64
what is contractility
the force of contraction that the heart beats with. can increase contractility via the sympathetic nervous system
65
what is afterload
afterload is the amount of pressure that the heart needs to exert to eject the blood during ventricular contraction. it is affected by valvular disease, aortic pressure and resistance
66
what is resistance to blood flow related to
its directly proportional to the viscosity and the length, and inversely proportional to the radius of the vessel to the 4th power
67
what is intrinsic control of resistance
myogenic autoregulation. an arteriole regulates its own blood pressure based on stretch. there are local mediators which can vasoconstrict and dilate.
constrictor - endothelin
dilators - prostacyclin, hypoxia, tissue factor, nitric oxide
68
what is extrinsic control or resistance
hormones
vasoconstrictors = adrenaline acting on alpha receptors, angiotensin II and vasopressin.
Vasodilators = adrenaline actin on beta 2 receptors
69
what are baroreceptors
the detect pressure changes
70
where do baroreceptors talk to
they feed impulses via CN 9 and 10 to the medulla oblongata
71
what are the separations of the mediastinum
divided into superior and inferior by the sternal angle. the inferior is then separated into the anterior, middle and posterior
72
what structures are present in the muddle mediastinum section
the heart, aorta, vena cava, trachea, vagus and phrenic nerve
73
what is the pericardium
the pericardium is a fibro serous sac that surround the heart.
the outermost layer is fibrous, the serous layer is divided into the parietal and visceral layer.
the visceral layer contains vessels and nerves.
74
what are the borders of the heart
right - right atrium
the inferior - left and right ventricle
left - the left atria and some of the left ventricle
superior - left and right atria and great vessels
75
how does the heart receive a blood supply
when the aortic valve closes the cusps fill with blood when then supplies the left and right carotid arteries. the heart gets perfused during diastole
76
what are the divisions of the right coronary artery
the right coronary has two branches the right marginal and the right posterior interventricular artery.
77
what does the right marginal artery supply
the right marginal supplies the right ventricle including the SAN
78
what does the posterior interventricular artery supply
the posterior 1/3 of the interventricular septum and the AVN (in 60% of people)
79
what does the left coronary artery divide into
the left anterior descending, the left marginal and the circumflex.
80
what does the left anterior descending artery supply
the LAD supplies 2/3 of the interventricular septum and the right and left ventricle
81
what does the left marginal artery supply
the left ventricle
82
what does the circumflex artery supply
it supplies the left atrium and the left ventricle
83
what does carotid artery dominance mean
this is where the posterior interventricular artery gets its supply from. in 70% of people it is from the right only, in 10% of people it is from the left only and in 20% of people it is from both
84
where is the apex of the heart found
the midclavicular line in the 5th intercostal space
85
where on surface anatomy are the aortic and pulmonary valves found
the second intercostal space
86
what are the aortic arch and pulmonary trunk connected by
the ligamentum arteriosum
87
what are the 4 parts of the aorta
ascending, arch, thoracic/descending and abdominal
88
where does the aorta end
T4
89
what are the three main branches found at the aortic arch
the subclavian, the common carotid and the brachiocephalic
90
what are the three main branches found at the aortic arch
the subclavian, the common carotid and the brachiocephalic
91
what are the nerves found in the thorax
phrenic and vagus
92
what is the right and left phrenic nerve route
the right phrenic nerve descends anteriorly along the right lung root. it travels along the pericardium to the right atrium and passes through the diaphragm at the IVC opening at T8.
the left phrenic nerve ascends anterior to the left lung root and crosses the aortic arch bypassing the vagus. it travels along the pericardium of the left ventricle and through the diaphragm
93
what does the phrenic nerve innervate
the diaphragm - c3,4,5 keeps the diaphragm alive
94
what is the vagus nerve route
similar to the phrenic, but it passes behind the lung roots, and passes through the diaphragm at T10
95
what are the three main structures that go through the diaphragm
the vena cava (T8), the aorta (T12) and the oesophagus (T10)
96
what are the layers of a blood vessel from outer to inner
Adventitia, external elastic lamina, tunica media, internal elastic lamina, intima and the basement membrane (endothelial cells)
97
where is most of the resistance in the circulation
in the arterioles
98
what factors effect cardiac output
exercise, emotion, pregnancy, posture, sweating, age, gender
99
what factors effect stroke volume
preload, afterload, contractility and heart rate
100
what is tachycardia and bradycardia
tachycardia - high heart rate
| bradycardia - low heart rate
101
what is frank starling's law
the force of contraction is directly proportional to the initial length of the muscle fibre within physiological limits
102
what is the pathway of cardiac impulses during a cardiac cycle
starts at the SAN, travels to the AVN, then to the bundle of his and finally the perkinje fibres
103
describe the pacemaker potential
phase 0 - opening of voltage gated calcium channels and depolarisation
phase 3 - closure of the calcium channels and opening of voltage gated potassium channels causing repolarisation
phase 4 - closure of the potassium channels and sodium moves into the cell via HCN channels and calcium moves in via T type channels.
technically there is no resting membrane potential
104
how does sympathetic activity act on the heart
it increases the heart rate and force of contraction by noradrenaline acting on beta 1 receptors, increasing calcium channel opening
105
how does parasympathetic activity act on the heart
decreases the heart rate, by Ach acting on the muscarinic 2 receptors which activates potassium channels and causes hyperpolarization of the membrane
106
what is the mean arterial pressure
average pressure during a cardiac cycle
107
how do you calculate mean arterial pressure
```
diastolic + (1/3 X systolic)
OR
2/3 diastolic + 1/3 systolic
OR
CO X TPR
```
108
how long does systole and diastole last
systole lasts for 0.3 seconds
| diastole lasts for 0.5 seconds
109
what insulates the atria from the ventricles
fibro granular rings around the AV valve
110
where is the apex of the heart found
In the fifth intercostal space in the midclavicular line
111
where are the sulci of the heart
coronary sinus runs transversely on the heart and separates atria and ventricles
the anterior and posterior interventricular sulci can be found running vertically on their retrospective sides and represent the wall separating of the ventricles
112
where is the apex of the heart found
in the fifth intercostal space in the midclavicular line
113
how is the heart muscle supplied with blood
when the aortic valve closes, there is a backflow of blood, which then allows the blood to enter the coronary vessels
114
what are the main cardiac veins
the great cardiac vein, the small cardiac vein, the middle cardiac vein and the posterior cardiac vein
115
what is the path of the great cardiac vein
it originates from the apex of the heart and ascends in the anterior interventricular groove
116
what is the endocardium
it is the innermost layer of the cardiac wall
117
what is the endocardium composed of
loose connective tissue and simple squamous epithelium
118
what is the subendothelial layer
it lies between the endocardium and the myocardium. it consists of a fibrous tissue which contains the vessels and nerves
119
what is the myocardium
it is composed of cardiac muscle and involuntary striates muscle = contraction of the heart
120
what are the two types of myocardial infarction
Nstemi (non S-T elevated myocardial infarction - coronary artery partially blocked) and stemi (S-T elevated myocardial infection - coronary artery blocked fully)
121
what is the epicardium, and what is it composed of
it is the outermost layer of the heart and is formed by the visceral layer of the pericardium, made of connective tissue and fat
122
what is the interior surface of the right atrium like
the interior surface can be divided into two parts, which is separated by a muscular ridge called the crista terminalis. the two portions are
- the sinus venarum, posterior to the crista terminalis, smooth walls and receives blood from superior and inferior vena cava
- the atria proper which is anterior to the crista terminalis and includes the right auricle. it has a rough muscular wall formed by the pectinate muscles
123
what is the interatrial septum
it separates the two atria and is where the fossa ovalis is - remnant of the foramen ovale
124
what is the interior of the left atrium like
inflow portion - receives blood, with a smooth surface
| outflow portion - anteriorly and includes the left auricle, it is lined by the pectinate muscles
125
what is the inflow and outflow portions of the right ventricle separated by
a muscular ridge called the supraventricular crest
126
what is the inflow portion of the right ventricle like?
it is covered with irregular muscular elevations called trabeculae carnage which can be divided into ridges, bridges and pillars which are anchored at their base to the ventricle
127
what are the papillary muscles in the ventricle attached to
they are attaches to the fibrous cords called chordae tendineae which are in turn attached to the three tricuspid valves
128
what is the outflow portion of the right ventricle like
it has smooth walls and no trabeculae carinae, it is derived from the bulbus cordis
129
what is the inflow portion of the left ventricle like
it is lines with trabeculae carneae, there are papillary muscles present which attach to the cusps of the mitral valve
130
what is the outflow portion of the left ventricle like
this is also known as the aortic vestibule, it is smooth walled and no trabeculae carneae
131
where is the tricuspid valve located
between the right atrium and ventricle, it consists of three cusps (anterior, posterior and septal) with the base of each being bound to a fibrous ring that surrounds the opening
132
where is the mitral valve located
this is located between the left atrium and ventricle, this is known as the bicuspid valve as it has only two cusps (anterior and posterior)
133
how many papillary muscles are there in total
there are three in the right ventricle and two in the left
134
describe the flow of electricity in the cardiac conduction system
excitation signal created in the SAN, and a wave of excitation spreads across the atria causing contraction. Upon reaching the AVN the signal is delayed. It is then conducted into the bundle of His, and spreads down the interventricular septum. The bundle of His and Purkinje fibres spread the wave impulses along the ventricles
135
What nerve innervates the pericardium
the phrenic nerve
136
what is the parasympathetic relationship between BP and systemic vascular resistance
parasympathetic nerves do not have a major influence on peripheral blood vessel diameter - they don't have parasympathetic innervation
137
occlusion of what coronary artery is most likely to result in a fatal heart attack
the left main coronary artery
138
what is the equation of cardiac output
Heart rate X stroke volume
139
what is the normal conduction pathway in the heart
SAN, contraction of atria, AVN, Bundle of His, Purkinje fibres, contraction of ventricles
140
increase in what pressure indicates left heart failure
left ventricular end diastolic pressure
141
increase in what pressure indicated a mitral valve stenosis
left atrial end systolic pressure - an increased resistance to blood flow across the valve therefore a higher pressure is required to force blood from atrium to ventricle
142
what does shortness of breath, severe peripheral oedema and ascites after a heart attack indicate
biventricular failure
143
what is the relationship between systemic vascular resistance and blood pressure with regards to the sympathetic nervous system
Sympathetic nerves decrease peripheral blood vessel diameter thereby increasing systemic vascular resistance and increasing blood pressure.
144
what is pulmonary oedema in the presence of a normal central venous pressure a sign of
Left sided heart failure causes an increase in pulmonary pressure leading to pulmonary oedema.
145
what is a raised central venous pressure a reflection of
right sided heart failure
146
severe pulmonary hypertension is a cause of what
Right heart failure
Severe pulmonary hypertension means the right ventricle has to work harder to pump blood through the pulmonary artery. Ultimately the right ventricle is unable to generate sufficient pressure and therefore starts to fail.
147
What is the purpose of the Ductus Arteriosus in the foetal cardiovascular system?
allow blood to bypass the foetal lungs by shunting it from the Pulmonary Artery to the Aorta
148
Which artery most frequently supplies the Atrio Ventricular Node?
Right coronary artery
The RCA supplies the area above including both SA & AV nodes.
The LAD supplies most of the area below the AV conducting system, the His-Purkinje system
149
what does the right coronary artery split into
the right marginal and the right posterior interventricular artery
150
what does the left coronary artery branch into
the left anterior descending, the circumflex and the marginal
151
what is the venous drainage of the heart
it is the coronary veins which drain into the right atrium via the coronary sinus
there is the small, middle and great cardiac vein
152
at what spinal level does the aorta end
L4
153
where does the aortic arch begin and end
it begins at the level of the second sternocostal joint and ends at the level of the T4 vertebrae
154
what are the three main branches off of the aortic arch
the brachiocephalic, the left common carotid and the left subclavian
155
what are the two divisions in the right atria
smooth atrium, and trabeculated atrium
156
what does the circumflex artery divide into
the obtuse marginal arteries
157
where does the circumflex artery travel to in the heart
in 70% of people it finishes before the posterior interventricular groove. in 30% of people it runs into the groove.
158
where is the SAN present in the heart
in the ridge of tissue called the crista terminalis
159
when does the blood flow to the myocardium occur
during diastole
160
oxygen saturation in the coronary venous blood is very low (compared to other veins). Why is this
oxygen extraction by the heart is very high
161
what does the right coronary artery supply
the inferior surface of the heart
162
what is responsible for synthesizing coagulation factors and fibrinogen
the liver
163
what is the precursor to the enzyme that lyses clots
plasminogen
164
what cleaves fibrinogen to make fibrin
thrombin
165
where do you find the apex beat of the heart
left 5th intercostal space in the midclavicular line
166
what prevents backflow of blood into the left atrium during ventricular systole
the mitral valve
167
what prevents high pressures developing in the jugular veins during ventricular systole
the tricuspid valve
168
on an ECG what wave represents ventricular repolarisation
T wave
169
what is the normal duration of the PR interval on an EGC
120 - 200 ms
170
what heart leads assesses the electrical activity within the lateral myocardial territory
Leads I, aVL, V5 and V6
171
what leads assesses the electrical activity within the inferior myocardial territory
leads II, III and aVF
172
how long does QRS take
should be less than 120 ms
173
what spinal level does the pulmonary trunk split into the right and left pulmonary arteries
T5 - T6
174
how many surfaces does the heart have
5
175
what is the anterior surface of the heart (sternocostal)
the right ventricle
176
what is the posterior surface of the heart (base)
left atrium
177
what is the inferior surface of the heart (diaphragmatic)
left and right ventricles
178
what is the right pulmonary surface of the heart
the right atrium
179
what is the left pulmonary surface of the heart
the left ventricle
180
what is the oblique pericardial pathway
a blind ending passageway located on the posterior surface of the heart
181
what is the transverse pericardial sinus
found superiorly on the heart
182
where is the right auricle and where is it found
it is in the right atrium and is a muscular pouch that acts to increase the capacity o the atrium
183
what are the two embryological origins of the right atrium
the sinus venosus - this becomes the smooth part of the atrium
the primitive atrium - becomes the rough muscular wall
184
what are the two embryological origins of the left atrium
inflow portion - derived from the pulmonary veins
| outflow portion - lined by pectinate muscles and derived from the embryonic atrium
185
what separates the right ventricular inflow and outflow portions
the supraventricular crest
186
what are the three main types of trabeculae carnae found in the right ventricle
ridges - entire length on one side of the ventricle
bridges - attaches the ventricle at both ends but free in the middle (moderator band)
pillars (papillary muscle) - attach the tricuspid valve via their chordae tendineae
187
what is the embryological origin of the outflow portion of the right ventricle
the bulbus cordis
188
how many papillary muscles are there attached to the left mitral valve
2
189
what is the embryological origin of the left ventricular outflow portion
the bulbus cordis
190
what are the three layers of the heart
endocardium, myocardium and epicardium
191
what is the structure of endocardium
it is the innermost layer - loose connective tissue and simple squamous epithelial tissue
192
what layer are the purkinje fibres located in
the subendothelial layer
193
what is found in the subendocardial layer
vessels and nerves of the conducting system of the heart
194
what is the myocardium composed of
cardiac muscle (involuntary striated muscle)
195
what is the structure of epicardium
outermost layer - composed of connective tissue and fat, formed by the visceral layer of the pericardium
196
what is the pericardium
fibro-serous, fluid filled sack that surrounds the muscular body of the heart and the roots of the great vessels
197
what are the two main layers of pericardium
tough fibrous pericardium
| thin serous pericardium
198
what are the two divisions of the serous pericardium
parietal (outer) and visceral (inner)
199
what are the functions of the pericardium
fixes the heart, prevents overfilling, lubrication and protection from infection
200
what artery of the heart does the left circumflex contribute to in 20-25% of people
the posterior interventricular artery
201
what does the right coronary artery supply
right atrium the SA and AV nodes and the posterior part of the interventricular septum
202
what does the right marginal artery supply
the right ventricle apex
203
what does the posterior interventricular artery supply
the right and left ventricle and the posterior 1/3 of the interventricular septum
204
what does the left coronary artery supply
the ;eft atrium and ventricle, the interventricular septum and the AV bundles
205
what does the left anterior descending artery supply
the right and left ventricle and the anterior 2/3 of the interventricular septum
206
what does the left marginal artery supply
the left ventricle
207
what does the circumflex artery supply
the left atrium and ventricle
