Cardiac Flashcards
(94 cards)
1
Q
Percentage of blood in systemic
A
84%
2
Q
Percentage of blood in pulmonary
A
9%
3
Q
What does S.V.C and I.V.C stand for
A
Superior vena cava
4
Q
Where does blood in svc/ivc come from
A
Inferior vena cava
5
Q
Midline of heart is called
A
Interventricular sulcus
6
Q
Right atrial pressure
A
5mmHg
7
Q
Right ventricle pressure
A
27mmHg
8
Q
Left atrial pressure
A
8mmHg
9
Q
Left ventricle pressure
A
120mmHg
10
Q
Left inlet valve
A
Mitral/bicuspid
11
Q
Left outlet valve
A
Aortic valve
12
Q
Right inlet valve
A
Tricuspid valve
13
Q
Right outlet valve
A
Pulmonary outlet valve
14
Q
Features of bicuspid/mitral value
A
Two cusps, Chordae tendineae, papillary muscles
15
Q
Ventricular pressure ratio
A
5:1
16
Q
Ventricular wall ratio
A
3:1 (12-15mm/4-5mm)
17
Q
Right border comprised of
A
Right atrium
18
Q
Inferior border comprised of
A
Right ventricle
19
Q
Apex orrientation
A
Inferior, left, anterior
20
Q
Left border comprised of
A
Left ventricle
21
Q
Cardio thorasic ratio
A
Normally 50%, heart width:chest width
22
Q
Rheumatic fever diagnosis: Issue and symptoms
A
Streptococcal infection, attacks/damages aortic valve, poor healing of valve (irregular, cusps fused at aortic wall). Aortic stinosus, left ventricle works harder, left ventricular hypertrophy, impeded blood supply to coronary arteries, stiff heart, small lumen volume.
23
Q
Serous membrane around heart
A
Pericardium
24
Q
Layers of pericardium and myocardium
A
Outside, fibrous, parietal, pericardial space (serous fluid), visceral/epicardium, myocardium, endocardium, lumen
25
Function and association of fibrous skeleton
Structure & support of valves, insulate electrical activity, associated with all valves other than pulmonary.
26
Path of action potentials in heart contraction
Sinoatrial node, myocardium muscle, atrioventricular node, bundle of his, purkinje fibres
27
Relative speeds of nodes/action potentials in reagards to heart conduction system
SA -> Atrial muscle (slow, 0.5m/s)
AV (Very slow, 0.055m/s)
AV bundle --> purkinje fibres (fast, 5m/s)
28
How long is the delay between SA and AV node action potential propagation and what is the purpose of this?
100ms, to allow for organised contraction (atrium then ventricle)
29
What are the stages of the cardiac cycle?
1. Ventricular filling
2. Atrial contraction
3. isovolumetric ventricular contraction
4. Ventricular ejection
5. Isovolumetric ventricular relaxation
30
Types of vessels
1. Elastic arteries
2. Muscular arteries
3. Arterioles
4. Capillaries
5. Venule
6. Vein
7. Coronary arteries
(Even Mum Acts Carefully, Very Very Carefully)
31
Structure/Function/location of elastic arteries
```
Thin sheets of elastin in middle tunic
Aorta/pulmonary arteries
Stretches to accommodate volume
Elastic recoil maintains blood flow
Absorb pressure pulse
```
32
Structure/Function/location of muscular arteries
Layer of smooth muscle in middle tunic, externa, media, interna tunics
Found in lungs and around body
Distribute blood, flow is proportional to radius 4th power
33
Structure/Function/Location of Arterioles
Areas of great pressure drops, and resistance.
1-3 layers of smooth muscle, thicker muscles wall relative to lumen (very strong)
Controls blood flow into capillary beds
CONSTRICTION DETERMINES:
total peripheral resistance which impacts mean arterial blood pressure
34
Structure/Function/Location of Capillaries
Located at muscle sites and everywhere
Small, thin walled, one blood cell thick, single layer endothelium, no muscle or CT
Leaky, allow gas exchange and nutrient/waste exchange
35
Structure/Function/Location of Venules
Small, CT & one layer of endothelium, sometimes a layer of smooth muscle
Drain capillary beds, low pressure, white blood cell migration
36
Structure/Function/Location of Veins
similar to muscular artery, thinner, back-flow valves also
Returns blood back to right atrium when it is compressed by neighboring muscles, acts also as volume reserve (64% total blood volume)
37
Structure/Function/Location of Coronary arteries
Located at the ascending aorta
Supplies myocardium with oxygenated blood, cardiac veins drain deoxygenated blood back to R.A.
Simple small muscular arteries
38
Average cardiac output at rest
5L/min
39
How to calculate cardiac output
L.V. volume * H.R.
40
Max cardiac output
20L/min
41
Cardiac reserve
Difference between resting CO and Maximal CO
42
CO formula
CO = HR x SV
43
Factors of stroke volume
Pre-load
Inotropy (contractility)\
After load
44
Define pre-load
The pressure provided by pulmonary circuit into left ventricle, causing stretch
45
Define inotropy
Forcefulness of contraction
46
Define after load
Pressure in arteries needed to overcome in order to achieve ventricular ejection
47
Frank-Starling Law 1920s
More blood in --> More blood out
48
Define positive inotropy agent and provide an example
Increases contractility of the heart via promoting inflow of CU ions into myocardium i.e. Sympathetic Nervous System
49
Define negative inotropy agent and provide an example
Decreases contractility of the heart via increasing potassium ions and therefore hyperpolaristion
50
Calculate stroke volume
difference between volume prior to ventricular filling and volume after atrial contraction
51
Ejection fraction
Percentage of volume pumped out of heart (60-70%)
52
At what ejection fraction will heart failure occur
50%
53
Normal and dangerous levels of BP
over 90mmHg diastolic, over 140mmHg systolic
54
ECG definition and function
Electrocaridogram, detects sum of electrical activity in the heart
55
Intrinsic rhythm of sinoatrial node
90-100bpm
56
Intrinsic rhythm of atrialventricular node
~50bpm
57
Fibrilation
Disordered/random coordination of contraction due to loss of rhythm of action potential propogation
58
Duration of cardiac action potential compared to standard neuron action potential
300ms vs 1-2ms
59
How come tetani of myocardium does not occur?
Action potential duration exceeds contraction dutration
60
P wave ECG graph
Depolarization of atria
61
R wave ECG graph
Depolarization of ventricle
62
T wave ECG graph
Repolarization of ventricle
63
P-Q & Q-T represents
Time delay between contraction of atria and ventricle
64
CNS involvement in heart
Cardiovascular centre in medulla
65
Facets of ANS
Sympathetic & Parasympathetic
66
Sympathetic NS on heart
Impacts SA node via spine, noreadrenaline increases heart rate and stroke volume
67
Parasympathetic NS on heart
Vagus nerve in neck, acetylcholine, decreases heart rate
68
Parasympathetic or sympathetic, which is faster acting on heart?
Parasympathetic. Sympathetic takes 3-4 seconds
69
Function and location of baroreceptors
Detects stretch/blood pressure increase of elastic arteries (pulmonary & aortic artery), sends information to the brain to activate SNS to increase heart rate.
Located on the arteries
70
Function of the heart
Supply
71
How do we change/stabilize BP
Change HR, SV or TPR
72
What vessels alter BP
Arterioles
73
Mean BP
Average blood pressure, MBP = CO x TPR
74
Systolic BP
High blood pressure (ventricular ejection)
75
Distolic BP
Lower blood pressure (ventricular filling)
76
At what vessel level does gas exchange occur
Capillary beds
77
What blood pressure do we measure with a pressure bag?
Arterial blood pressure, systolic/distolic
78
Order blood distribution from highest volume to lowest
Venules/veins, systemic arteries/arterioles, pulmonary circuit, heart, capillaries
79
Vascular tone at arteriole level is governed by
smooth muscle varying radius
80
TPR
Total peripheral resistance
81
Filtration pressures
Blood hydrostatic pressure, interstitial fluid osmotic pressure
82
Absorption pressures
Blood collide osmotic pressure, interstitial hydrostatic pressure
83
BHP
Blood hydrostatic pressure
84
IFOP
Interstitial fluid osmotic pressure
85
BCOP
Blood collide osmotic pressure
86
IFHP
Interstitial hydrostatic pressure
87
NFP definition & formulae
Net filtration pressure --> NFP = (BHP+IFOP)-(BCOP+IFHP)
88
Arterial pressure, A.K.A
Net filtration pressure
89
Venous pressure, A.K.A
Net reabsorption pressure
90
NFP-NAP
Net filtration pressure - Net absorption pressure. This will be a positive value, as more
91
CNS monitoring the blood pressure...
Baroreceptors, located on ascending arterial arch. Increased firing for high BP, decreased firing for low BP. Baroreceptors sned to cardiovascular center, then pack to ANS.
92
Functions of ANS on cardiovascular system
SNS--> noreadreniline increases HR, constricts arterioles
| PSNS--> Vagus nerve to heart, acetylcholine decreases heart rate
93
What receptors are on the arterioles
Alpha and beta receptors
94
Alcohol and heat cause
vasodilation, decreased heart rate
