Week 3 Flashcards
(92 cards)
1
Q
describe the fibrous pericardium
A
- touch and inelastic
- rests on/attached to diaphragm
- open end fused with great vessels
2
Q
describe the serous pericardium
A
- parietal layer fused to fibrous pericardium
- visceral layer continuous/part of epicardium-pericardial cavity space
- between parietal and visceral layers contain pericardial fluid
3
Q
what are the three layers of the heart wall
A
outer - epicardium - visceral serous pericardium
middle - myocardium - cardiac muscle
inner - endocardium - continuous with endothelium of large vessels of heart
4
Q
describe the fossa ovalis
A
remnant of opening between atria
-allowing blood to bypass lungs during embryonic development
5
Q
describe the crista terminalis
A
the boundary of the right atrium
smooth wall sinus venarum posteriorly
rough wall pectinate muscles anteriorly
6
Q
what are trabeculae carneae
A
muscular ridges in wall of ventricle
prevent walls suctioning together
7
Q
what are the papillary muscles
A
contract to prevent cusps reverting into atria during systole
8
Q
what are chordae tendineae
A
attach cusps to papillary muscles
9
Q
arterial pressure in the pulmonary circuit
A
10-25mmHg
10
Q
arterial pressure in the systemic circuit
A
110/70mmHG
11
Q
describe foetal circulation
A
Oxygenated blood enters through the umbilical vein
Some enters liver, rest enters ductus venosus to bypass liver -> IVC
IVC enters right atrium and most blood goes through foramen ovale to left atrium, ventricle and aorta
blood entering right atrium via SVC is poorly oxygenated
This passes through ductus arteriosus and reduces oxygenation of blood in the aorta
12
Q
what is the annulus fibrosis
A
ring of tissue across the AV valves that acts as an electrical insulator
13
Q
P wave
A
Atrial depolarisation
(Atrial Contraction)
Initiated by the SA node
14
Q
PQ Segment
A
Atrial depolarisation complete
Impulse is delayed at AV node
15
Q
QRS complex
A
Ventricular depolarisation begins at apex.
Ventricular contraction
Atrial repolarisation occurs
16
Q
ST segment
A
Ventricular depolarisation complete
17
Q
T wave
A
Ventricular repolarisation begins at apex
18
Q
TP segment
A
Ventricular repolarisation is complete
19
Q
Time for ventricular filling
A
0.5seconds
20
Q
Isovolumetric contraction time
A
0.05seconds
21
Q
Ejection timing
A
0.3seconds
22
Q
Isovolumetric relaxation time
A
0.08seconds
23
Q
Aim end diastolic volume
A
120ml
24
Q
Describe isovolumetric contraction
A
NO volume change
All valves are shut
Increase in pressure
25
Describe parasympathetic control of HR
vagal motor nuclei in medulla - vagus nerve
Right side - SA node
Left side - AV node
NT= acetylcholine
Binds to muscarinic receptors
Decreases rate of SA node depolarisation by making membrane hyperpolarised (more negative)
26
Describe sympathetic control of HR
Cardiac sympathetic fibres exit spinal cord at T1-T5
Long nerve fibres that run along the great vessels
Right supply atria
Left supply ventricles
NT = noradrenaline
B1 adrenoceptors
1) increase AV conduction velocity
2) Decrease myocyte AP length
3) Increase rate of relaxation
4) Increase contractile force (increase SV)
27
What is seen on an ECG with no flow due to coronary blockage
STEMI
28
What is seen on an ECG with persistent flow but a partial coronary blockage
NSTEMI
29
Pros and cons of ECG
Cheap
Available
Portable
No radiation
Requires good acoustic window
User dependent
30
What does a B line on a lung ultrasound indicate
Congestion
31
What do you see in a CMR short axis view
Right and Left ventricles
32
What do you see in a CMR horizontal long axis view
All four chambers
33
Why is gadolinium injected when doing an MRI
Shows contrast
Its enhancement is indicative of fibrosis
34
Pros and cons of CMR
Gold standard for anatomy, volumes and function
Reproducible
No radiation
Cost
Availability
Claustrophobia
Pacemakers
35
Pros and cons of coronary angiography
Gold standard
Option for intervention during same procedure
Availability
Invasive
RAdiation
Risks - stroke, MI, contrast reaction, bleeding, death
36
Pros and cons of nuclear perfusion imaging
Availability
Radiation
No structural assessment
37
Pros and cons of Cardiac CT
Good rule out for CAD
Low risk
Radiation
Requires low heart rate
No functional assessment of ischaemia
38
What 4 places do you place the probe in an echocardiogram
1. Parasternal/Sternum
2. Apical/Apex
3. Subcostal/Below rib cage
4. Suprasternal/ Above sternum
39
What does a bubble contrast echo show
If there is a hole within the interatrial septum
40
WHat does ECG-gating in echocardiography determine
Systole and diastole
41
What can be seen in a parasternal long axis view
Either the entire left or right side
Eg, In Left PLAX
Left atrium
Mitral Valve
Left ventricle
Left ventricular outflow tract
Aortic valve
Aortic arch
42
WHat can you see in a parasternal short axis view
Depends what focus is on
If Left ventricle
Left ventricle
Papillary muscles
Chordae tendineae
Right ventricle (but off centred)
43
How to calculate LV ejection fraction
LVEF = (LV stroke volume) / LVEDV
44
How to calculate LV stroke volume
LVEDV - LVESV
45
Describe echo doppler
Can be used to asses valve flow
46
Describe how aortic stenosis severity is assessed
Qualitative (visual) assessment
Quantitative assessment with Doppler (peak velocity, peak gradient, mean gradient), aortic valve area, continuity ratio, dimensionless index
47
what is aortic stenosis
when the valve has narrowed and doesnt open fully
48
what is regurgitation
when the valves don't function properly and you get blood flowing backwards from the ventricles to the atria
49
what is a doppler ultrasound
Doppler ultrasound is a noninvasive test that can be used to measure the blood flow through your blood vessels. It works by bouncing high-frequency sound waves off red blood cells that are circulating in the bloodstream. A regular ultrasound uses sound waves to produce images, but can't show blood flow.
50
What is the 4D approach to prescribing inhalers
EITHER
Drug + dose + duration + De-escalation
OR
Diagnosis + Drug, Doe and device + Disease control + Disposal of device
51
Describe the brown inhlaer
Anti-Inflammatory
Inhaled corticosteroids
Preventer treatment
(low adherence issues)
52
Describe the blue inhaler
Bronchodilators
Short acting Beta 2 agonist (SABA)
Rescue/Reliever
Long acting Beta 2 agonists ?
53
Describe the pink/brown/purple inhaler
Combination
ICS (low or high dose) + LABA (Slow or fast acting)
AIR of MART approach
54
What is AIR therapy
Anti-inflammatory reliver
55
What is MART therapy
MAintenance and Reliever treatment
56
recommended therapy for mild asthma
Low dose AIR therapy as needed for relief, step up if use > twice a week
57
Recommended therapy for moderate asthma
Step up to MART therapy, regularly for maintenance treatment but also as needed for relief
58
Where does right lymphatic duct empty
Junction of right internal jugular and right subclavian veins
59
Where does thoracic duct empty
Junction of left internal jugular and left subclavian veins
60
What is the cisterna chyli
Most inferior part of the thoracic duct
61
What is virchow's node most commonly enlarged as a result of
Stomach tumour (70%)
62
What is the vasovagal reaction/Syncope
Fainting
Brain is insufficiently perfused and so you faint in order to redirect blood flow to the brain
(Gravity)
63
What is a hiatus hernia
Stomach has moved upwards into the chest
64
nerve roots of the phrenic nerve
C3, 4, 5
65
Where does the left recurrent laryngeal nerve loop around
Aortic arch
66
Where does the right recurrent laryngeal nerve loop around
Right Subclavian artery
67
What does the recurrent laryngeal nerves innervate
Vocal cords - larynx
68
Symptoms of Horner's syndrome (Pancoast tumour)
Drooping upper eyelid (ptosis)
Constricted pupil (miosis)
Dry skin
69
partial pressure of oxygen in the lung
100+-2mmHg
70
Partial pressure of carbon dioxide in the lung
40mmHg
71
how to calculate partial pressure of gas
fraction of gas in gas mixture x barometric pressure
72
what is barometric pressure
sea level atmospheric pressure
760mmHg
73
partial pressure of oxygen in capillaries
40mmHg
74
partial pressure of carbon dioxide in capillaries
45mmHg
75
describe how to calculate the amount of oxygen dissolved in blood
amount of dissolved O2 in blood is proportional to its partial pressure
For each mmHg of PO2 there is 0.003ml O2/100ml
76
Describe the relationship between pH and Hb saturation
The lower the pH, the lower the percentage Hb saturation
Takes longer to reach 100%
Dissociation curve shifts to the right with a lower body pH
77
Describe the relationship between temperature and Hb saturation
The lower the temperature, the higher the percentage Hb saturation
Takes less time to reach 100%
Dissociation curve shifts to the right with a higher body temp
78
How much oxygen can bind to Haemoglobin
Four O2 atoms can bind to each Hb molecule
1g Hb combines with 1.39ml O2
79
What is the respiratory exchange ratio
Ratio of expired CO2 to O2 uptake
In normal condition, respiratory exchange ratio = 0.8
(80 CO2 to 100 O2)
80
In what 3 forms is CO2 carried in blood
7% dissolved
23% bound to Hb
70% converted to bicarbonate
81
What is the V/Q ratio
Ratio of ventilation to blood flow
Single alveolus: alveolar ventilation divided by capillary flow
Lung: total alveolar ventilation divided by cardiac output
82
function of chemoreceptors
sensory receptors that detect chemical changes in the surrounding environment
provide feedback on blood PO2, PCO2 and pH
83
describe mechanoreceptors
provide feedback on mechanical status of lungs, chest wall and airways
littered around respiratory tree
84
describe peripheral chemoreceptors
small, highly vascularised bodies in region of aortic arch and carotid sinuses
85
how are signals from mechanoreceptors and peripheral chemoreceptors sent
via the glossopharyngeal and vagus nerves to the nucleus in brainstem called NTS
nucleus tractus solitarius
86
describe central chemoreceptors
clusters of neurones in the brainstem that are activated when PCO2 is increased of pH is decreased
87
pathophysiology of asthma
inflammatory disease of the medium sized airway
- loss of airway epithelium
- thickening of the basement membrane
- hypertrophy of the smooth muscle layer
88
most common asthma triggers
Viral infections, systemic infections - neutrophilic inflammation
Airborne allergies, exercise - CATS, mast cell degranulation, histamine, IgE mediated
89
Describe mechanism of Beta 2 agonists
Binds to beta-2 adrenergic receptor which activates G protein.
Cyclic AMP second messenger
Relaxes smooth muscle widening the airway
90
Describe anti-leukotriene receptor drugs
Add on treatment for resistant inflammation. Targets only leukotriene D4 in the airway. Direct effect on mast cells and smooth muscle. Good in exercise asthma
91
describe corticosteroids
Mainstay of treatment prevents and treats inflammation non selectively. Reduces airway twitchiness and reduces exhaled nitric oxide.
92
