Lecture 5: ANATOMY OF THE HEAT, PART 2

Question 1

What valves does each side of the heart have?

Answer 1

A semilunar valve and an atrioventricular valve

Question 2

Where is the atrioventricular valve found?

Answer 2

Between the atrium and the ventricle

Question 3

Where is the semilunar valve found?

Answer 3

Between the ventricle and the outflow artery

Question 4

What is the function of atrioventricular valves?

Answer 4

To prevent blood returning to the atria during ventricular contraction

Question 5

What is the AV valve on the right side?

Answer 5

The tricuspid valve

Question 6

How many leaflets/cusps does the tricuspid valve have?

Answer 6

3

Question 7

What is the AV valve on the left side?

Answer 7

The bicuspid (mitral) valve

Question 8

How many leaflets/cusps does the bicuspid valve have?

Answer 8

2

Question 9

What is the filling phase called?

Answer 9

Diastole

Question 10

What is the squeezing phase called?

Answer 10

(ventricular) systole

Question 11

How is theAV valve during diastole?

Answer 11

Open to allow blood to drain into the ventricle

Question 12

How is the semilunar valve during diastole?

Answer 12

Closed to prevent blood from leaving the ventricle

Question 13

How is the AV valve in (ventricular) systole?

Answer 13

Closed to prevent blood flowing back into the atrium

Question 14

How is the semilunar valve during (ventricular) systole?

Answer 14

Open to allow blood to exit the ventricle

Question 15

What is the function of semilunar valves?

Answer 15

To prevent blood returning to ventricles during filling (diastole)

Question 16

What is the semilunar valve on the right side?

Answer 16

The pulmonary (semilunar) valve

Question 17

How many cusps does the pulmonary (semilunar) valve have?

Answer 17

3

Question 18

What does the pulmonary (semilunar) valve control?

Answer 18

Flow into the pulmonary circulation

Question 19

What is the semilunar valve on the left side?

Answer 19

The aortic (semilunar) valve

Question 20

How many cusps does the aortic (semilunar) valve have?

Answer 20

3

Question 21

What does the aortic (semilunar) valve control?

Answer 21

Flow from the left ventricle to the aorta

Question 22

When are semilunar valves pushed open?

Answer 22

As blood flows out of the heart

Question 23

When do semilunar valves close?

Answer 23

As the blood starts to backflow

Question 24

What is the size comparison of AV and semilunar valves?

Answer 24

Semilunar valves are much smaller than AV valves

Question 25

How is the AV leaflet described?

Answer 25

Large and flappy

Question 26

What would the AV leaflet do if there was nothing preventing it shutting?

Answer 26

It would slam shut

Question 27

What are papillary muscles?

Answer 27

Finger-like projections of the ventricular wall

Question 28

What do papillary muscles do?

Answer 28

Tension early in systole

Question 29

What are chordous tendineae?

Answer 29

Tendonous chords which are attached to the tip of the papillary muscle and the AV leaflet

Question 30

Where is the tension in the papillary muscle transferred to?

Answer 30

The chord tneidneae

Question 31

What do the papillary muscles and chordous tendineae do?

Answer 31

Allow the AV leaflet to slowly move into place when closing

Question 32

Where does the first branch of the systemic circulation form the aorta go?

Answer 32

Straight to the heart (oxygenated blood)

Question 33

Where is the right coronary artery found?

Answer 33

Running in a groove in the epicardium between the right atrium and ventricle (oxygenated blood)

Question 34

Where does the left coronary artery run?

Answer 34

It runs a small distance and then branches into the circumflex artery and anterior inter ventricular artery (oxygenated blood)

Question 35

What is the right side of the heart drained by?

Answer 35

The small cardiac vein (deoxygenated blood)

Question 36

What is the left side of the heart drained by?

Answer 36

The great cardiac vein (deoxygenated blood)

Question 37

Where do the small cardiac vein and great cardiac vein join?

Answer 37

At the coronary sinus at the posterior of the heart

Question 38

What does the coronary sinus do?

Answer 38

Drain deoxygenated blood into the right atrium

Question 39

What is the width of a capillary?

Answer 39

About the width of a red blood cell so the distance for diffusing substances to travel is minimised

Question 40

What features does cardiac muscle have?

Answer 40

It has features of smooth and skeletal muscle as well as cardiac muscle specific specialisations

Question 41

What is the function of cardiac muscle?

Answer 41

Beating of the heart

Question 42

Is cardiac muscle striated?

Answer 42

Yes, just like skeletal muscle but not smooth muscle

Question 43

How are the cells of cardiac muscle described?

Answer 43

Short, branced

Question 44

How wide are cardiac muscle cells?

Answer 44

Approximately 25 micrometres

Question 45

How many nuclei in cardiac muscle cells?

Answer 45

One (or occasionally 2) which is the same as smooth muscle but not skeletal

Question 46

How is the nucleus in cardiac muscle described?

Answer 46

Centrally positioned and oval shaped (in skeletal muscle the nucleus is pushed to the outsides)

Question 47

Where are cytoplasmic organelles in cardiac muscle?

Answer 47

Packed at the poles of the nucleus

Question 48

How are cardiac muscle cells connected?

Answer 48

By intercalated discs which are only found in cardiac muscle

Question 49

What volume of a cardiac muscle cell is mitochondria?

Answer 49

20%

Question 50

How are the sarcomeres arranged in cardiac muscle?

Answer 50

Irregular and branched (not linearly arranged as in skeletal)

Question 51

What are intercalated discs?

Answer 51

Regions between cardiomyocytes (cardiac muscle cells)

Question 52

What are the 3 junctions in intercalated discs?

Answer 52

Adhesion belts, desmosomes and gap junctions

Question 53

What do adhesion belts link?

Answer 53

Actin to actin via trasnmembrane proteins

Question 54

Where are adhesion belts found?

Answer 54

In the vertical portion and transfer force between cells

Question 55

What do desmosomes link?

Answer 55

Cytokeratin with cytokeratin

Question 56

What do gap junctions allow?

Answer 56

Electrochemical communication

Question 57

Where are gap junctions placed?

Answer 57

Parallel to the force of contraction because they are delicate junctions

Question 58

What does the conduction system of the heart actions do?

Answer 58

Greatly increase the efficiency of heart pumping

Question 59

What is the conduction system of the heart responsible for?

Answer 59

The co-ordination of heart contraction and atrioventricular valve action

Question 60

What alters the rate of conduction impulse generation?

Answer 60

Autonomic nerves

Question 61

What type of tissue is the conduction system of the heart?

Answer 61

Modified cardiac tissue, not nervous tissue

Question 62

Where does the conduction pathway of the heart begin?

Answer 62

At the superior aspect of the right atrium where there is a cluster of cells called the sinoatrial node

Question 63

Where does the conduction pathway go after the sinoatrial node?

Answer 63

Through the atrial chamber by internodal pathways

Question 64

Where do the internodal pathways reunite?

Answer 64

At the AV node which is the gateway into the ventricular chambers

Question 65

What comes after the AV node?

Answer 65

The AV bundle which goes down the inter ventricular septum into the tight snd left bundle branches

Question 66

What is the last part of the conduction system?

Answer 66

Purkinje fibres

Question 67

Where do purkinje fibres go?

Answer 67

They run up into the papillary muscles

Question 68

What do purkinje cells have?

Answer 68

Some peripheral myofibrils, mitochondria and glycogen

Question 69

Where is the nucleus of purkinje cells?

Answer 69

Central

Question 70

What junctions are found in purkinje cells?

Answer 70

Lots of gap junctions because involved in communication, some desmosomes and a few adhesion belts

Question 71

What portion of cardiac cells are purkinje cells?

Answer 71

1%