Physiology Cardio book

Question 1

Cardiovascular changes in pregnancy

Answer 1

Increase stroke rate 35%
Venous dilation 150%- due to increase plasma and
Red cell mass 20-30
Ventricular enlargement
Resting HR 15%

Question 2

Frank starling law

Answer 2

Stroke volume is a function of end diastolic volume

Greater volume entering heart at diastole - greater stretch and SV

Due to Ca affinity to troponin C

Question 3

BP in each area of heart and pulmonary circulation

Answer 3

Right atrium- 0-4
RIght ventricle- 25/0-4
Pulmonary artery-25/15
Left atrium- 5-10
Left ventricle- 120/0-10

Question 4

What can you use to measure pulmonary artery pressure and estimate left atrial pressure

Answer 4

Stanz ganz catheter

Question 5

Cause of third and fourth HS

Answer 5

3rd- rapid ventricular filling- dilatation

4th- ventricular hypertrophy/HF- due to forceful atrial contraction

Question 6

Normal central venous pressure

Answer 6

8-12

Question 7

Wnckebach phenomenon

Answer 7

PR interval becomes progressively more prolonged until QRS is missed

Question 8

Cause of high CO due to reduced peripheral resistance

Answer 8

Beriberi, AV fistula, hyperthyroidism, anaemia

Question 9

Factors aiding recovery from shock

Answer 9

Baroreceptors- sympathetic stimulation
Reverse stress relaxation- vasoconstriction
Angiotensin- kidneys

Question 10

Most important electrolyte in myocardial contracility

Answer 10

Intracellular Ca- bind to trop C activating actin-myosin

Question 11

Pressures in capillary beds and interstitial tissues

Answer 11

Arterial end- filtration highest
Oncotic pressure highest venous end

Question 12

% coronaries receive of CO

Answer 12

5%

Question 13

Coronary blood flow

Answer 13

70-80ml/min rest
300-400 per 100g of tissue

Question 14

O2 consumption of heart

Answer 14

8ml/100g at rest

Question 15

Fick principal

Answer 15

The Fick principle states that the uptake or release of oxygen by a tissue is the product of the amount of oxygen delivered to the tissue times the difference in oxygen content between the blood entering and leaving the tissue.

Question 16

Distribution of water in human body

Answer 16

2/3 of weight is water (66%)

Of that 2/3 intracellular (40%)
1/3 extracellular (20%)

Of which
2/3 Interstitial (13%)-between cells
Intravascular (6%)- blood
Transcellular (1%)- CSF, synovial fluid

Question 17

Factors affecting turbulence of blood flow

Answer 17

Velocity v
Diameter d
Density p
Viscosity n

vdp/n

So increased velocity, diameter, density increase turbulence
Decreased viscosity increases

Question 18

Where main site of RBC formation is in adults

Answer 18

Flat bones

Question 19

Types of shock and features

Answer 19

Cardiogenic- increased PVR due to low SV
Neurogenic- loss of autonomic- low PVR
Septic- low PVR, high CO

Question 20

Classification of shock

Answer 20

<15- <750ml- normal, slightly anxious, urine >30ml/hr

15-30- 750- 1500- HR >100, BP normal, urine 20-30

30-40- 1500-2000ml- BP low, urine 5-15, HR 120-140

> 40- >2000ml- BP low, urine neg, HR >140

Question 21

Effects of haemorrhage shock on physiology

Answer 21

Increase in HR
Reduced central venous pressure
Splanchnic vasoconstriction

Question 22

Waves of JVP and what causes them

Answer 22

a- atrial contraction
x descent- ventricle contraction
c wave- bulge in tricuspid
v wave- rapid atrial filling
y descent- opening of tricuspid passively

Question 23

Abnormalities seen on JVP waves

Answer 23

Cannon a - complete HB, as contracting against closed TV
Large a- RVH, pulmonary HTN
Absent a- AF

Large V- TR

Question 24

Features of cardiac cells

Answer 24

Have intercalated discs which join 2 together- z lines
Branched structure
Uninucleated
Involuntary striated muscle

Question 25

Septal vs anterolateral vs lateral st changes

Answer 25

Septal- V1-3 Anterolateral- V1-6 Lateral- V4-6, I, aVL

Question 26

Which organs contain which adrenoreceptors

Answer 26

a1- smooth muscle contraction- blood vessels, uterus, ureters, liver- gluconeogenesis and glycogenolysis a2- negative feedback b1- cardiac contractility b2- smooth muscle relaxation Bronchioles, GI, vessels Liver- glycogenolysis and gluconeogenesis

Question 27

Clotting cascade

Answer 27

Intrinsic- XII- XI- IX- VIII (activates X by IX) Extrinsic- VII, X, tissue factor Common X- II (thrombin)- I fibrin V required from thrombin activation Several stages require Ca

Question 28

What happens when you stand in the CVS

Answer 28

SV falls Increase in SVR Reduction in baroreceptor stimulation causing reduction in vagal stimulation and increasing sympathetic

Question 29

What causes stimulation of RBC production

Answer 29

High altitude Resp disease Haemorrhage Increased RBC segregation products

Question 30

Structure and properties of myoglobin

Answer 30

Single chain protein Contains haem Instant binding rather than cooperative Hyperbolic dissociation curve Store O2 in muscles- rapid release when needed

Question 31

Pulse pressure during shock, exercise and ACEi

Answer 31

Narrow in shock Increase in exercise ACEi effective treatment of reducing PP

Question 32

Types of haemoglobin

Answer 32

HbA- adults HbF- fetus- higher O2 dissociation HbS- sickle

Question 33

Uses of Central venous catheter

Answer 33

CVP monitoring TPN delivery Drug infusion Haemodialysis

Question 34

Location of SA node Blood supply Nerve supply

Answer 34

RA near the entrance of SVC RC blood supply T1-4 symptomatic, vagal para

Question 35

Normal EF

Answer 35

Around 60% Increases with exercise

Question 36

Baroreceptor location and properties

Answer 36

Wall of the heart Carotid and aorta Increase stimulation when stretched with more pressure - inhibits symp Afferent from carotid part of glossopharyngeal Aortic- vagus

Question 37

Where is renin produced

Answer 37

Juxtaglomerular apparatus om response to low BP, Na or symp

Question 38

Anrep and Bowditch effect

Answer 38

Anrep -Myocardial contractility increases with increase after load Bowditch- Increase in MC in response to increased HR

Question 39

When do papillary muscles contract

Answer 39

Prior to ventricular contraction To close mitral and TV

Question 40

Cardiac index

Answer 40

CI=CO/BSA (body SA)

Question 41

Types of lymphatic vessels and properties

Answer 41

Initial lymphatics- valveless, no smooth muscle, in smooth muscle and intestinal walled, fluid transported due to muscular contractions Collecting - valves, smooth muscle, contract via peristalsis

Question 42

What is oedema

Answer 42

Accumulation in extravascular space Nephrotic- transudate