Lecture 3 - Anatomy of the Heart Part 2

Question 1

AV valves

1. What’s their function?
2. Right side - how many cusps? And name?
3. Left side - how many cusps? And name?

Answer 1

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Question 2

1. What’re the chordae tendinae?

2. What’re the papillary muscles?

Answer 2

1. Cord-like structures that attach to the free edges of the cusps of the AV valvles to the interior walls of the vent via the papillary muscles. These chords are like parachute chords and prevent the back folding of the cusps.
2. Finger-like projections of the ventricular myocardium attached at one end to the vent surface and other end to the chordae tedineae

Question 3

SL valves:

1. What’s their function?
2. What’re the two valves names?
3. What dos back flow aid?
4. The aorta sits posterior or anterior to the pulmonary artery?

Answer 3

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Question 4

1. Coronary arteries - what and travel where?
2. Name the 4 main coronary arteries and where they at
3. Name the 3 main cardiac veins

Answer 4

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Question 5

Cardiac Muscle:

1. Yeah, describe the appearance
2. Capillaries
3. Tell me about the tight junctions in the endo cells
4. Actually, there is a list of 5 things
   - shape
   - nuclei
   - nucleus shape
   - poles
   - unique feature for cardiac

Answer 5

1. Striated, z-z and between cells are capillaries with RBCs in a single file.
2. They’re endothelial cells that form the wall of the capillaries and have nucleus and thin cytoplasm so RBC can be up against the side and small diffusion distance
3. They form tight junctions with themselves to seal into a tube so this cap is just an endo cell forming tube
4. -

Question 6

How much percentage of cells are mitochondria?

Also, irregular branched _____?

Answer 6

-

Sarcomeres

Question 7

What three things are in the intercalated discs? What do they link and what portion etc

Answer 7

A - Adhesion belts; link actin to actin - vertical portion (when one cell contracts then actin of other tagged so contracts too)
B - Desmosomes; link cytokeratin with cytokeratin (keeps cells together when contract)
C - Gap junctions; electrochemical communication - horizontal portion (allows chemical propagation. A allows physical).

Question 8

Conduction system of the heart

1. It’s actions greatly increase what?
2. This system is responsible for what?
3. Autonomic nerves alter the rate of what?

Answer 8

1. Increase efficiency of heart pumping
2. Responsible for co-ordination of heart contraction and of AV valves action (by altering tone of cap muscles that are attached to chordae tendineae)
3. Alter the rate of conduction impulse generation

Question 9

1. What are conduction pathways

Answer 9

Not nervous tissue - modified cardiac muscle

Question 10

Autonomic nerves alter rate of conduction node impulse generation

1. What decreases heart rate?
2. What increases heart rate?

Answer 10

1. Vagus (parasympathetic)

2. T1 - T4 spinal nerves (sympathetic)

Question 11

What’re Purkinje cells? What 5 things do they contain?

Answer 11

1. They’re cardiac but not contractile cells - conduction cells

Contain

• (some) peripheral myofibrils
• Central nucleus
• Mitochondria (heaps)
• Glycogen
• ICD’s and lots of gap junction