First Aid: Cardiovascular

Question 1

Explain what does the following structures form:

1. Truncus arteriosus
2. Bulbus cordis Endocardial cushion
3. Primitive atrium
4. Primitive ventricle
5. Primitive pulmonary vein Left horn of sinus venosus Right horn of sinus venosus
6. Right common cardinal vein and right anterior cardinal vein

Answer 1

Question 2

Explain cardiac looping.

Answer 2

Question 3

Explain septation of the chambers.

Answer 3

Question 4

Explain development of ventricles

Answer 4

Question 5

Explain development of outflow tract and valve formation.

Answer 5

Question 6

Explain fetal circulation

Answer 6

Question 7

Explain what the following fetal structures form:

AllantoisŽ

Ductus arteriosus

Ductus venosus

Foramen ovale

Notochord

UmbiLical arteries

Umbilical vein

Answer 7

Question 8

Explain the anatomy of the heart.

Answer 8

1. SA and AV nodes are usually supplied by RCA. Infarct may cause nodal dysfunction (bradycardia or heart block).
2. Right-dominant circulation (85%) = PDA arises from RCA.
3. Left-dominant circulation (8%) = PDA arises from LCX.
4. Codominant circulation (7%) = PDA arises from both LCX and RCA.
5. Coronary artery occlusion most commonly occurs in the LAD.
6. Coronary blood flow peaks in early diastole.
7. The most posterior part of the heart is the left atrium; enlargement can cause dysphagia (due to compression of the esophagus) or hoarseness (due to compression of the left recurrent laryngeal nerve, a branch of the vagus).
8. Pericardium consists of 3 layers (from outer to inner):
   
   1. Fibrous pericardium
   2. Parietal layer of serous pericardium
   3. Visceral layer of serous pericardium Pericardial cavity lies between parietal and visceral layers.

Question 9

CO = ?

MAP = ? (2) equations

What is fick’s law?

Answer 9

CO = stroke volume (SV) × heart rate (HR)

Fick principle:
CO = rate of O2 consumption / (arterial O2 content − venous O2 content)

Mean arterial pressure (MAP) = CO × total peripheral resistance (TPR)

MAP = 2 ⁄3 diastolic pressure + 1⁄3 systolic pressure

Question 10

Explain pulse pressure and SV.

Answer 10

Pulse pressure = systolic pressure – diastolic pressure pulse pressure in hyperthyroidism, aortic

Pulse pressure is proportional to SV, inversely proportional to arterial compliance.

SV = end-diastolic volume (EDV) − end-systolic volume (ESV)

Question 11

A few notes on cardiac output.

Answer 11

Question 12

Stroke volume

Answer 12

Question 13

Contractibility

Answer 13

Question 14

Myocardial oxygen demand

Answer 14

Question 15

Preload, afterload and ejection fraction

Answer 15

Question 16

Starling curve

Answer 16

Question 17

Resistance, pressure and flow

Answer 17

Question 18

Cardiac, vascular and function curves

Answer 18