Topic 4 - Circulation and The Heart

Question 1

Whats tendenous fibrous

Answer 1

prevent atroventricular valves turning inside out

Question 2

Why would the atrioventricular valves turn inside out?

Answer 2

due to the pressure when the heart contacts

Question 3

what are coronary arteries

Answer 3

theyre wrapped around the heart to supply blood to cardiac muscle of the heart

Question 4

What is cardiac muscle and where is it thicker and why?

Answer 4

• thicker muscle of the heart. Makes up the thick middle layer of the heart.

thicker LHS bc of higher blood pressure is needed to pump blood further to alll the tissues of the body

Question 5

3 types of muscle in the heart

Answer 5

• myocardium (cardiac muscle)
• skeletal
• smooth muscle

Question 6

another name for cardiac muscle?

Answer 6

• myocardium

Question 7

what are the semi lunar valves

Answer 7

• aortic valve
• pulmonary valve

Question 8

what are the atrioventricular valves

Answer 8

• tricuspid
• bicuspid

Question 9

4 types ofcirculatory systems:

Answer 9

• open and closed systems
• single or double

Question 10

whats a closed system

Answer 10

blood confined to blood vessels only

Question 11

circulation and the heart

what’s a single system?

in the body

Answer 11

• blood is only pumped once around the whole system

Question 12

circulation and the heart

what’s a double system?

in the body

Answer 12

where blood is pumped twice

humans have this

Question 13

4 advantages to a double circulatory system?

pressure, conc. , organisms

Answer 13

• conc. gradient maintained, as deocygenated blood and oxygenated blood dont mix.
• blood pressure to body tissue is higher
• blood pressure to lungs is lower, avoids damaging the capillaries in lungs and increases time for gas exchange
• organisms can develop larger bodies

Question 14

myogenic meaning

Answer 14

• originating in muscle tissue (rather than nerve impulses).

Question 15

the hearts ability to initiate its own contraction is referred to as …..?

Answer 15

myogenic

Question 16

depolarisation of the heart meaning

Answer 16

to trigger its contraction

Question 17

where does depolarisation oif the heart begin?

Answer 17

Sinoatrial Node

Question 18

Depolarisation spreads through atria causing ….?

Answer 18

• atrial systole

Question 19

non conductive tissue of the heart is called?

Answer 19

annulus fibrous

Question 20

what does the annulus fibrous stimulate

Answer 20

• another region of conducting tissue called Atrioventricular Node

Question 21

what conduction fibres does the AVN pass the depolarisation onto?

Answer 21

Bundle of His

Question 22

what does the Bundle of His split into?
and what does this cause?

Answer 22

• two branches called Purkinje fibres
• causes ventricular systole

Question 23

explain how depolarisation of the heart is carried out
including systole and diastole

Answer 23

• SAN
• Atrial systole
• Annulus fibrous
• AVN
• atrial diastole
• into Bundle of His
• Apex
• Bundle of His splits into two branches - Purkinje Fibres
• causing ventricular systole

Question 24

What are the 3 stages of cardiac cycle

Answer 24

• atrial systole
• ventricular systole
• cardiac diastole

Question 25

whats atrial systole

Answer 25

- atrial contract - forces atrioventricular valves to open amd blood flows into ventricles

Question 26

whats ventricular systole

Answer 26

- ventricles contract - causing atrioventricular valves to open, allowing blood to leave LV through aorta and RV through Pulmonary Artery

Question 27

whats cardiac diastole

Answer 27

- atria and ventricles relax, pressure inside heart chambers decrease. - This causes semi-lunar valves to relax in aorta and P.A to close, preventing backflow

Question 28

what is the blood made up of?

Answer 28

- Plasma - Erythrocytes (RBC) - Leukocytes (WBC) - Platelets

Question 29

3 functions of the blood:

Answer 29

- transport - formation of lymph - tissue fluid - defense against pathogens

Question 30

plasma what it does?

Answer 30

- transports digested food products (e.g glucose, amino acids), nutrient molecules, hormones, excretory products (e.g CO2, urea) - Transfers heat around the body

Question 31

another name for RBC

Answer 31

Erythrocytes

Question 32

Erythrocytes (RBC) what they do and their adaptation?

Answer 32

- transports O2 and some CO2 - adapt via their bioconcave shape and lack of nucleus + contains heamoglobin | no nucleas means more surface area for O2 biconcaveshape = easy moving

Question 33

another name WBC

Answer 33

Leukocytes

Question 34

2 types of leukocytes

Answer 34

- Granulocytes - Agranulocytes

Question 35

# leukocytes what are the cells that come under granulocytes and function

Answer 35

- eutrophils (phagocytosis) - Basophils (histamines - inflamation/allergic response) - Eosinophils (response to parasites, allergic reactions, inflamation, immunity)

Question 36

what are the cells that come under Agraulocytes and function

Answer 36

- Monocytes ( call on other white blood cells to help treat injury and prevent infection.) - lymphocytes (involved in specific immune response)

Question 37

Platelets what they are and do?

Answer 37

- Fragments of megakaryocytes (large cell that has a lobulated nucleus, is counf especially in bone marrow, is the source of blood platelets) - involved in blood clotting

Question 38

what are Megakaryocytes

Answer 38

large cell that has a lobulated nucleus, is counf especially in bone marrow, is the source of blood platelets