The Heart

Question 1

2 circuits related to the heart?

Answer 1

Pulmonary = heart-lungs
Systemic = heart-body

Question 2

Blood flow?

Answer 2

vena cava, right atrium, AV valve, right ventricle, semi-lunar valve, pulmonary arteries (no O2), lungs
pulmonary veins (O2), left atrium, AV valve, left ventricle, aorta, body

Question 3

Function and type of connective tissue of fibrous skeleton?

Answer 3

attachment site for valves and cardiomyocytes
electrical insulator
- prevents electrical impulses between atria+ventricles
(dIRCT)

Question 4

4 Layers of pericardium?

Answer 4

Fibrous pericardium (dIRCT)
Parietal layer of Serous pericardium (simple squamous)
– adhered to fibrous
Pericardial cavity (fluid filled)
Visceral layer of Serous pericardium (simple squamous)
– adhered to heart

Question 5

3 Layers of the heart?

Answer 5

epicardium (simple squamous + loose CT)
myocardium (cardiac muscle)
endocardium
- subendocardial layer
- subendothelial layer
- endothelial cells

Question 6

Epicardium contains?

Answer 6

loose CT
- blood vessels
- adipocytes
- nerves

Question 7

Myocardium contains?

Answer 7

cardiac muscle surrounded by endomysium

Question 8

Ischemic Cardiomyopathy?

Answer 8

reduced blood flow to portion of heart = damage myocardium
- no striations, intercalated disks, smaller nuclei

Question 9

Subendocardial layer contains?

Answer 9

Purkinje fibers (cloud like appearance)
- modified cardiomyocytes filled with glycogen

Question 10

Subendothelial layer contains?

Answer 10

collagen fibers
elastic fibers
smooth muscle cells

Question 11

Conduction system - passage? spread?

Answer 11

sinoatrial node –> atrioventricular node delay
AV bundle of His = electrical signal passes to ventricles
electrical signal bottom to top (Purkinje fibers)

spread through gap junctions

Question 12

Systemic regulation from autonomic nervous system?

Answer 12

• modify action of SA/AV nodes

Parasympathetic – decrease HR
Sympathetic nerves – increase HR
- on cardiomyocytes (increase rate of contraction)
- on coronary arteries (increase width)

Question 13

Purpose of valves?

Answer 13

prevent backflow of blood

Question 14

Layers of AV valve? atria –> ventricle

Answer 14

Endothelium
Fibrosa (dIRCT with fibrous skeleton) – strength
Spongiosa (loose CT) – absorb shock when close
Ventricularis (dIRCT with elastic fibers)
Endothelium