Lecture 18: The Cardiavascular System Part 1

Question 1

Pericardium. What are the 3 layers of the pericardium? What is each of their functions?

Answer 1

Superficial fibrous pericardium
-protects, anchors, and prevents overfilling
Deep two-layered serous pericardium
-parietal layer- lines the internal surface of the fibrous pericardium
-visceral layer- (epicardium) on external surface of the heart
-separated by fluid-filled pericardial cavity (decreases friction)
Refer to slide 7 for picture

Question 2

What are the 3 layers of the heart wall?

Answer 2

1. Epicardium-visceral layer of the serous pericardium
2. Myocardium
   - spiral bundles of cardiac muscle cells
   - fibrous skeleton of the heart: crisscrossing, interlacing layer of connective tissue
   
   • anchors cardiac muscle fibres
   • supports great muscles and valves
   • limits spread of action potentials to specific paths
3. Endocardium
   - is continuous with the endothelial lining of blood vessels

Be able to label it!

Question 3

Chambers

Answer 3

Two atria:
-separated internally by the interatrial septum
-coronary sulcus (atrioventricular groove) encircles the junction if the atria and ventricles
-auricles increase atrial volume
Two ventricles:
-separated by interventricular septum

Question 4

Be able to label the heart on slide 11

Answer 4

Do it!

Question 5

Atria: the receiving chambers
What vessels enter the right atrium?
What vessels enter the left atrium?

Answer 5

Right:

• superior vena cava
• inferior vena cava
• coronary sinus

Left:
-right and left pulmonary veins

Question 6

Ventricles: the discharging chamber
What are the vessels leaving each ventricle?
What is the muscle called which projects into the ventricular cavities
Walls are rigid by?

Answer 6

-Walls are rigid by trabeculae carneae
-Papillary muscle projects into ventricular cavities
Vessels leaving right atrium:
Pulmonary trunk
Vessels leaving the left trunk:
Aorta

Question 7

Pathway of blood through the heart

Answer 7

Right atrium-tricuspid valve-right ventricle- pulmonary semilunar valve- pulmonary trunk -pulmonary arteries-lungs-pulmonary veins-left atrium- bicuspid valve- left ventricle- aortic semilunar valve- aorta- systemic circulation

Question 8

Equal volumes of blood are pumped to the pulmonary and systemic circuits
-pulmonary circuit is short, low pressure circulation
-anatomy of the ventricles:
Left wall is thicker

Answer 8

Husk

Question 9

Coronary circulation:

Answer 9

Arteries
-right and left coronary (in atrioventricular groove)
Veins:
-small cardiac, anterior cardiac, and great cardiac veins

Question 10

Be able to label the blood vessels of the heart.

Slide 23

Answer 10

Do it!

Question 11

Homeostatic imbalances

Answer 11

Angina pectoris: thoracic pain caused by a deficiency in blood delivery to the myocardium
Myocardial infarction: (heart attack)
-prolonged coronary blockage
-areas of cell death are repaired with non contractile scar tissue

Question 12

Heart valves:
Name them all and what are they for
What is the tendon thingo that anchors the AV valve cusps to papillary muscle?

Answer 12

Ensure unidirectional blood flow through heart
Atrioventricular valves:
-prevent backfow into the atria when ventricles contract
-tricuspid valve (right)
-Bicuspid valve (left)
Chordae tendinae anchor AV valve cusps to papillary muscles

Semilunar: 
-prevents backfow into ventricles when ventricles relax
-aortic semilunar valve 
-pulmonary semilunar valve
Lebel them slide 29