Cardiovascular system 2

Question 1

What is the name of the valves between the atria and ventricle

Answer 1

Atrioventricular valves (AV)

Question 2

What type of AV valve is on the right side of the heart

Answer 2

Tricuspid valve

Question 3

What type of AV valve is on the left side of the heart

Answer 3

Bicuspid (mitral) valve

Question 4

What is the purpose of valves in the heart

Answer 4

To stop blood from flowing back where it just came (prevent backflow)

Question 5

How do the valves work

Answer 5

When the pressure of one area is great than the other the valves open or close in response (pushed open against walls or closed together)

Question 6

Describe the diastole phase

Answer 6

Filling phase (relaxed/resting) -of ventricles with blood- of the cardiac cycle 
AV valves open

Question 7

Describe the Systole phase

Answer 7

Emptying phase - Muscles contracting to pump blood - AV valves closed. When pressure in heart exceeds pressure in arteries semilunar valves

Question 8

What do semilunar valves do

Answer 8

Prevent blood from returning to ventricles during diastole (filling)

Question 9

What type of semilunar valve is on the left side of the heart

Answer 9

Aortic valve - 3 cusps (flaps)

Question 10

What type of semilunar valve is on the right side of the heart

Answer 10

Pulmonary valve - 3 cusps (flaps)

Question 11

How do the AV valves not prolapse

Answer 11

Chordae tendineae and papillary muscles help control the closing of the leaflets

Question 12

How does the heart get blood to its tissue/muscles

Answer 12

Through coronary, circumflex and anterior interventricular arteries
Start at left side of heart and runs through coronary grove then over surface of heart to the right side

Question 13

How does the heart get deoxygenated blood from its tissue/muscles

Answer 13

Through coronary sinus, great and small cardiac veins.
Left side mostly drained by great cardiac vein
Right ride mostly by small cardiac vein.
Gathers into coronary sinus and drained into right atrium through Venus sinus

Question 14

What is a capillary

Answer 14

Epithelial cell that forms junctions with itself and neighbouring cell

Question 15

Why are capillaries only wide enough for one red blood cell to travel through at a time

Answer 15

So the red blood cell is as close to the walls as possible to allow easier diffusion (of gases)

Question 16

Describe Cardiac muscle cell structure

Answer 16

Cardiomyocyte 
Striated 
Short 
Branched
One (occasionally 2), central nuclei
Organelles packed at poles of nucleus 
Interconnected with neighbours via Intercalated disks (ICD)

Question 17

What aspects of Cardiac muscle cells are similar to smooth and skeletal

Answer 17

Smooth - short, num. of nuclei, nuclei position

Skeletal - Striated appearance

Question 18

What makes up 20% of cardiac muscle cells cytoplasm

Answer 18

Mitochondria

2% in skeletal

Question 19

Why do cardiac muscle cells have large amounts of mitochondria

Answer 19

Very energy dependant. Shifts metabolism to oxygen dependant (rather than food) so it can become a more flexible process

Question 20

What are the three types of junctions (ICD) between cardiac muscle cells

Answer 20

Adhesion belts
Desmosomes
Gap junctions

Question 21

Describe the purpose of adhesion belt junctions

Answer 21

Links actin from one cells to the actin from neighbouring cell. When one muscle contracts its actin pulls on it’s neighbours and forces it to contract as well (Physical propagation)

Question 22

Describe the purpose of desmosome junctions

Answer 22

Tight, anchoring junctions - spot welding. Stops the cells from pulling apart when they contact

Question 23

Describe the purpose of Gap junctions

Answer 23

Electrochemical communication between cells by allowing small molecules through - mostly calcium

Question 24

What does the conduction system of the heart do

Answer 24

Ensures the right part of the heart beats at the right time
Increases efficiency
Controls closing of AV valves
Modified cardiac cells (Purkinje)

Question 25

What can alter the rate of conduction impulse

Answer 25

Autonomic nerves