L10: Heart Anatomy & Development

Question 1

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When does the heart develop in the embryo?

Answer 1

Weeks 3-8

Question 2

3 germ layers

Answer 2

1) Ectoderm
2) Mesoderm
3) Endoderm

Question 3

Timeline of heart development

Describe Day 15 (1)

Answer 3

Cardiogenic precursors formed a crescent

Question 4

Timeline of heart development

Describe Day 21 (2)

Answer 4

2 arms of crescent fuse along middle to give a linear heart tube, elongates & is patterned with regions & chambers

Question 5

Timeline of heart development

Describe Day 28 (3)

Answer 5

After looping, regions are disposed in their final positions

Question 6

Timeline of heart development

Describe Day 50 (4)

Answer 6

Formation of valves

Question 7

Where and why is the heart enclosed?

Answer 7

Enclosed in a connective tissue sheath (pericardium) to ensure it maintains its position in the thorax, friction free

Question 8

3 pericardium layers

Answer 8

1) Outer fibrous layer
2) Inner layers
3) Visceral layer

Question 9

Where and why is there a small fluid filled space in the pericardium?

Answer 9

Separates the visceral & parietal pericardia lubricating & reducing friction between surfaces

Question 10

Functions of fibrous skeleton of the heart

Answer 10

• Dense connective tissue separating atria from ventricle
• Provides support
• Separates flow of electrical impulses

Question 11

5 stages to the Cardiac Conduction System

Answer 11

1. Excitation signal in SA node, wave of excitation spreads across atria & contracts
2. Reseaches AV node, delayed signal
3. Conducted into AV bundle
4. Down left & right bundle branches
5. Wave pulses spread along ventricles to contract

Question 12

2 main arteries supplying the heart

Answer 12

Right & Left Coronary Artery

Question 13

2 types of AV valves

Answer 13

1) Tricuspid
2) Bicuspid

Question 14

3 elements to AV valves

Answer 14

1) The Papillary Muscles
2) The Chordae Tendineae
3) The Cusps of the Valves

Question 15

2 types of semilunar valves

Answer 15

1. pulmonary valve
2. aortic valve

Question 16

Where is the pulmonary valve located?

Answer 16

Between the RV & pulmonary trunk

Question 17

Where is the aortic valve located?

Answer 17

Between LV & ascending aorta

Question 18

What happens to AV & SL valves during diastole?

Answer 18

AV: OPEN
SL: CLOSE

Question 19

What happens to AV & SL valves during systole?

Answer 19

AV: CLOSE
SL: OPEN

Question 20

5 vessels that enter & leave the heart

Answer 20

1) Superior & inferior vena cava

2) Pulmonary artery

3) Pulmonary vein

4) Aorta

Question 21

Role of superior & inferior vena cava

Answer 21

Return deoxygenated blood from circulation in the body & empty it in RA

Question 22

Role of pulmonary artery in the heart

Answer 22

Carries deoxygenated blood from RV into lungs

Question 23

Role of pulmonary vein in the heart

Answer 23

Carries oxygenated blood from lungs to LA

Question 24

Role of aorta in the heart

Answer 24

Carries oxygenated blood from LV into systemic circulation