CVS Basics Flashcards
(138 cards)
1
Q
Functions of the CVS (5)
A
O2 and CO2 Transport Nutrients Metabolites Hormones Heat
2
Q
Heart pumps are in series because
A
output must be equal
3
Q
Most vascular beds are in parallel because
A
All tissues get oxygenated blood
Regional redirection of blood
4
Q
Flow = change in ?
A
pressure / resistance
5
Q
Flow is controlled by
A
radius of arterioles (selectively redirects flow)
6
Q
Arterioles act as
A
taps controlling the resistance (therefore flow) to each vascular bed
7
Q
The aorta is an
A
elastic artery
8
Q
The aorta has
A
wide lumen
elastic wall
damp pressure variations
9
Q
Arteries are
A
muscular
10
Q
Arteries have
A
wide lumen
strong non-elastic wall
low resistance conduit
11
Q
Arterioles act as
A
resistance vessels, so control resistance and flow
12
Q
Arterioles have
A
narrow lumen
thick contractile wall
(allow regional redirection of blood)
13
Q
Capillaries act as
A
exchange vessels
14
Q
Capillaries have
A
narrow lumen
thin wall
15
Q
Venules and veins act as
A
capacitance vessels
so allow fractional distribution of blood between veins and rest of circulation
16
Q
Venules/veins have
A
wide lumen
distensible wall
17
Q
The left heart contains what valves?
A
mitral valve
aortic valve
18
Q
The right heart contain what valves?
A
tricuspid valve
pulmonary valve
19
Q
Describe the function of the heart, arteries, veins and capillaries (respectively)
A
Heart = a pump Arteries = distribute blood from heart Capillaries = exchange nutrients Veins = collect and return blood to heart
20
Q
Function of the lymphatics is to
A
drain excess extracellular fluid from tissues
21
Q
The heart lies in the
A
mediastinum
22
Q
The mediastinum is
A
an area of the thoracic cavity between pleural sacs
23
Q
In relation to the sternum, the heart lies
A
1/3rd to the right, 2/3rd to the left
24
Q
The apex beat can be found at
A
the 5th intercostal space, midclavicular line
25
Anterior relations of the heart are
sternum and costal cartilages 4 - 7
anterior edges of lungs and pleurae
thymic remnants
26
When does the thymus disappear?
After adolescence
27
Posterior relations of the heart are
Oesophagus
Descending aorta
Thoracic vertebrae 5 - 8
28
Lateral relations of the heart are
the lungs
| the phrenic nerve(s)
29
Inferior relations of the heart are
central tendon of diaphragm
30
Situs Inversus is when
everything is the opposite way round to normal
31
The three layers of the heart wall are
Endocardium (innermost)
Myocardium (middle)
Epicardium (outermost)
32
The endocardium is made up of (in order)
epithelium
basement membrane
connective tissues
33
The myocardium is made up of
muscle
34
The epicardium is made up of (in order)
connective tissue
basement membrane
epithelium
35
Functions of endocardium
lines heart chambers
| forms valves
36
The endocardium
is simple squamous
| sits on connective tissue
37
The myocardium
closes down chamber lumens
has rich capillary bed
has lots of mitochondria
38
The myocardium contains
cardiac muscle (myocytes) which are connected by intercalated discs
39
Intercalated discs are
complex junctions that connect myocytes
40
Desmosomes...
connect at horizontal interface
| bind myocytes together
41
Gap Junctions...
connect vertically
are for electrical communication
essential to co-ord cardiac cycle
42
Epicardium is the
outer layer of the heart wall
43
The epicardium epithelium is the same layer as
the visceral layer of serous pericardium
44
The epicardium contains
main branches of coronary arteries
| may be fatty
45
Name the four heart chambers
right atrium
right ventricle
left atrium
left ventricle
46
Functions of heart valves
control direction of blood flow
work passively
create heart sounds
47
Chordae terminae and papillary muscles prevent
valve failure
48
Valve abnormalities include narrowing (______) and widening (______)
Also, infection called _______
stenosis
incompetence
bacterial endocarditis
49
aortic and pulmonary valves are _____ valves with ___ cusps
semilunar
| 3
50
The mitral valve is also known as the
bicuspid valve (2 cusps)
51
The tricuspid and bicuspid valves are also known as
atrio-ventricular valves
52
Aortic stenosis =
| Causes =
failure of aortic valve to close
| back flow of blood into left ventricle
53
Electrical insulation in the heart
atria from ventricles
myocardium from great vessels
purlinje fibres
54
Describe the coronary arteries during systole
openings in aortic sinuses shielded by aortic valve cusps
55
Describe the coronary arteries during diastole
elastic recoil of aorta closes aortic valve, blood enter coronary arteries
56
At diastole, when myocardium relaxes
blood can flow into capillaries
57
The heart hangs by the ________ within the __________________
great vessels
| fibrous pericardium
58
Attachments of the heart include
central tendon of diaphragm
sternum
roots of great vessels
59
The serous pericardium contains
```
epithelium
pericardial fluid (lubricant)
```
60
The visceral layer is bound to
the heart
61
The parietal layer is bound to
the fibrous pericardium
62
Visceral and parietal layers are continuous so give
a closed bag for the heart
| freedom to move during cardiac cycle
63
In the non-pacemaker potential, the RMP has
high resting K+
64
In the non-pacemaker potential, the initial depolarisation causes an
increase in Na+
65
The plateau in the non-pacemaker potential is caused by
an increase in Ca2+
| a decrease in K+
66
The depolarisation in the non-pacemaker potential is caused by
decrease in Ca2+
| increase in K+
67
In the pace-maker potential, an increase in Ca2+ causes
an action potential
68
Three changes to cause pacemaker potential =
gradual decrease in K+
early increase in Na+
late increase in Ca2+
69
Two drugs that effect contraction force of the heart are
Ca2+ channel blockers
| Cardiac glycosides
70
Ca2+ channel blockers
decrease force of contraction
71
Cardiac glycosides
increase force of contraction
72
Temperature increases
about 10 beats/min/degreeC
73
Hyperkalemia (high plasma K+) causes
fibrillation
| heart block
74
Hypokalemia (low plasma K+) causes
```
fibrillation
heart block (anomalous)
```
75
Hypercalemia (high plasma Ca2+) causes
increased HR
| increase force of contraction
76
Hypocalemia (low plasma Ca2+) causes
decreased HR
| decreased force of contraction
77
The senatorial node acts as the
pacemaker
78
The atrioventricular node acts as the
delay box
79
Purkinje fibres do what, and are where?
Rapid conduction to ventricles
| Spread from node to rest of heart (ventricles, IV septum etc)
80
The action potential in a single myocyte evokes what?
A very small extracellular electrical potential
81
The P wave corresponds to
atrial depolarisation
82
The QRS complex corresponds to
ventricular depolarisation
| (
83
The T wave corresponds to
ventricular repolarisation
84
The U wave (sometimes heard) is the
depolarisation of Purkinje fibres (and other specialised cells)
85
The PR interval is what, and takes how long?
time taken from atrial depol to ventricular depol
| 0.12 - 0.2 seconds (3 to 5 small boxes on ECG strip)
86
The QT interval is the
time spent in ventricular depolarisation and depolarisation
| maximum 0.42 seconds
87
The settings on an ECG should be
paper speed: 25mm/sec
| calibration: 1mV = 1 cm
88
```
The following ECG leads show be placed where:
Red
Yellow
Green
Black
```
right wrist
left wrist
left ankle
right ankle
89
The C1 lead goes
4th ic space, right sternal edge
90
The C2 leads goes
4th ic space, left sternal edge
91
The C4 lead goes
5th left ic space, midclavicular line (apex)
92
The C3 lead goes
midway between C2 and C4
93
C5 goes
in line with C4
| anterior midaxillary line
94
C6 goes
in line with C4
| midaxillary line
95
What is essential for a good ECG recording?
```
Patient comfortable, skin exposed
Not shivering (no movements)
Dry skin (no sweat)
```
96
Compare the action potentials or cardiac muscle, to skeletal muscle
Cardiac had longer action potential than skeletal
97
The RMP of cardiac muscle =
leak of K+
98
The initial depolarisation =
increased Na+ permeability
99
The plateau is due to
Increased Ca2+
| Decreased K+ permeability
100
The depolarisation =
decreased Ca2+
| increase K+ permeability
101
Standard limb leads look at
events in vertical/frontal plane
102
Precordial (chest) leads look at
events in the horizontal/transverse plane
103
30 large squares on a rhythm strip =
6 seconds
104
1 large (5mm) square =
0.2 seconds
105
STEMI stands for
ST Elevated Myocardial Infarction
106
NSTEMI stands for
Non ST Elevated Myocardial Infarction
107
Which is worse, a STEMI or a NSTEMI?
a STEMI
108
What is happening to the atria during a P wave?
depolarisation
contraction
increased pressure
atrial systole
109
The P wave goes on to cause
an increase in ventricular volume
110
During the QRS complex, what is happening?
ventricular depolarisation
ventricles contract
ventricular systole begins
111
What opens the semi-lunar valve (opens aortic valve)?
Enough pressure in ventricles pushing valve open
112
When the valves open:
| ventricular volume ________ and blood leaves when they _________
decreases
| contract
113
During the T wave
repol. of ventricles
ventricles relax
drop in pressure
114
What causes the 1st heart sound, the 'lub'?
Closing of atrioventricular valves (mitral, tricuspid)
115
What causes the 2nd heart sound, the 'dub'?
Semi-lunar valves close (aortia, pulmonary)
116
What does the SA node do and where is it found?
Pace-maker, automatically makes impulses
| Right atrium
117
SA node stands for
sinoatrial node
118
AV node stands for
atrioventricular node
119
The Av node in between
the atria and the ventricles
| makes automatic impulses
120
The Purkinje fibres
extend from nodes
| spread signals to rest of ventricle
121
Afterload =
load against which muscle tries to contract
122
What effect does the parasympathetic system have on SV?
Little effect on contraction strength or SV
123
Starlings Law states that
energy of contraction is proportional to initial length of the cardiac muscle fibre
124
Sympathetic nerves release ___________ that act on ___________, which ___________ contractility
nor(adrenaline)
B1-receptors on myocytes
increase
125
CO (cardiac output) =
HR x SV
126
Heart rate
Symp supply =
Parasymp supple =
increases HR
| decreases HR
127
Preload increases
SV
128
Afterload decreases
SV
129
SV increased by
preload
| symp supply
130
Measure arterial pressure by
auscultation of Korotkoff sounds using stethoscope and sphygmomanometer
131
Pressure in veins is _______ so change in P driving blood back to heart is _______
low
| low
132
Does gravity effect driving pressure from arteries to veins?
No
133
Height of jugular collapse = 0 - 5 = ?
confusion
134
Height of jugular collapse = 20 = ?
anger
135
venomotor tone =
state of contraction of smooth muscle
136
central venous pressure can be estimated by
jugular collapse
137
venous pressure and return are influenced by
gravity
skeletal muscle & resp pump
venomotor tone
systemic filling P
138
Darcy's Law states that flow is
equal to change in pressure / resistance
