Anatomy of the heart

Question 1

How many vales

Answer 1

4 valves; 2 pairs
The 2 atrioventricular valves between atrium and ventricle

The two semilunar valves between the ventricles and pulmonary arteries/veins

Question 2

Right AV valve

Answer 2

Tricuspid valve

Question 3

Left AV valve

Answer 3

Biscuspid (mitral) valve

Question 4

Function of the AV valve

Answer 4

To contract when P builds up in the ventricles to prevent the backflow of blood into the atrium

Question 5

Diastole (filling phase)

Answer 5

When blood moves from atrium to ventricles
- AV valves are open
- Semilunar valves are closed to prevent backflow of blood in the pulm art/vs

Question 6

Systole (contractile phase)

Answer 6

P builds in ventricles
- AV valves close
- When P is built, semilun vales open

Question 7

Semilunar valves function

Answer 7

Prevent blood returning to ventricles during
filling (diastole)

Question 8

Semilun valves

Answer 8

Right side - Pulmonary (semilunar) valve, 3 cusps.
Left side - Aortic (semilunar) valve, 3 cusps.

Question 9

What seperates the RHS and LHS of the heart?

Answer 9

The intraventricular septum

Question 10

What happens during Sytole?

Answer 10

The papillary muscle pull on the chordae tendineae

Question 11

Function of the chordae tendineae

Answer 11

To gently pull the large AV flaps when the pap muscle first contracts to prevent the valves from folding back into the atrium during V systole pressure

Question 12

What is the first branch of Systemic circulation

Answer 12

To the myocardium tissue, branches from the Aorta called cardiac circulation

Question 13

Right coronary artery

Answer 13

Branches from the ascending Aorta, runs in a groove between the Right atrium and Ventricle in the epicardial layer, to the pos, it branches into smaller that run into myocardial layer

• Supply mostly ventricles

Question 14

How does the left coronary artery run

Answer 14

Behind the pulm artery and branches into two other arteries
- Circumflex artery and Anterior interventricular artery

Question 15

Where does the circumflex artery run

Answer 15

Towards the back

Question 16

Where does the interventricular artery run?

Answer 16

Between the interven septum anteriorly

Question 17

What drains the blood from the right coronary artery?

Answer 17

The small cardiac vein

Question 18

What drains the blood from the left coronary arteries?

Answer 18

Great cardiac vein

Question 19

Where does the small and great Cardiac veins drain?

Answer 19

In the coronary sinus (a chamber) which empties directly in the right atrium

Question 20

How many RBCs can pass through a capillary wall

Answer 20

One cell at a time in single file

Question 21

What kind of muscle is cardiac muscle?

Answer 21

Striated

Question 22

Why is the cytoplamsm of a cap wall thin?

Answer 22

To allow gas exchange over the shortest distance possible

Question 23

Features of the cardiac muscle

Answer 23

Features of both smooth & skeletal muscle as well as cardiac muscle specific specialisations.

Question 24

Structure of the cardiac muscle cell

Answer 24

Striated
* Short, branched cells.
* 0ne (or occasionally 2) nuclei / cell.
* Central (oval shaped), nucleus.
* Cytoplasmic organelles packed at the poles
of nucleus.
* Interconnected with neighboring cells via intercalated disks (ICDs).

Question 25

Adhesion belts

Answer 25

(linking actin to actin) ~Vertical portion, transmits force allowing other cells to contract

Question 26

Desmosomes

Answer 26

(linking cytokeratin with cytokeratin). As the cells contract, the sarcomeres move away from each other so the desmosomes anchor them together

Question 27

Gap junctions

Answer 27

(electrochemical communication) ~ Horizontal portion, layer fused and Ca2+ together, release of Ca2+ which travels from cells to cell through junctions and innervates other cells

Question 28

What does the conduction system of the heart do?

Answer 28

Ensures that the heart beats in its set rhythm

Question 29

Features of conduction system

Answer 29

Its actions greatly increase the efficiency of heart pumping.
* This system is responsible for the co-ordination of heart
contraction and of atrioventricular valve action eg pathway to the pap to contract chordae to prep for P build
* Autonomic nerves alter the rate of conduction impulse
generation eg sym and parasym activity of modifies muscle cells

Question 30

Conduction system pathway

Answer 30

Sinoatrial node (SA node) –> internodal pathways –> atrioventricular bundle –> R + L bundle branches –> purkinje fibres that terminate in the capillary walls

Question 31

What activates the SA node

Answer 31

If no input from nerves, then it activates through its own tone

Question 32

Where are the internodal pathways found

Answer 32

Across the right and left atriums

Question 33

What does the AV node do

Answer 33

Allow completion of filling phase

Question 34

What does the AV bundle split into

Answer 34

R + L bundles

Question 35

Features of the conduction cells

Answer 35

(some) Peripheral myofibrils.
Central nucleus,
mitochondria, glycogen
lots of gap junctions
some desmosomes & few adhesion belts.
1% of cardiac cells