Mrs H bio 4 The Heart

Question 1

what type of tissue is the heart made from?

Answer 1

cardiac muscle

Question 2

what happens to the size of the four chambers when the heart ‘beats’?

Answer 2

decreases

Question 3

what is the name of the blood vessel that supplies the heart with its own blood supply?

Answer 3

coronary artery

Question 4

what is pulmonary ventilation?

Answer 4

the blood passes the heart and is pumped t the lungs, returning back to the heart

Question 5

what is systemic circulation?

Answer 5

the blood passes through the heart a second time (the blood is re-pressurised) and pumped round the body organs before returning to the heart.

Question 6

which side of the heart is thickest and what does this mean?

Answer 6

left side meaning stronger contractions

Question 7

what and where does the vena cava transport?

Answer 7

deoxygenated blood returns from the body in the vena cava and enters the right atrium

Question 8

what are the 4 steps of blood flow through the heart?

Answer 8

1.deox blood vena cava and into right atrium
2.passes via atrio-ventricular valve into the right ventricle and out via the semi-lunar valve into the pulmonary artery
3. the blood passes through the lungs and returns to the left atrium via the pulmonary vein
4.the blood passes through 2nd atrio-ventricular valve into left ventricle and then through semi-lunar valve into aorta and then onto body tissues

Question 9

why is the left ventricle thicker?

Answer 9

right ventricle only pushes blood through pulmonary arteries, the left ventricle is pushing blood through a much larger no. of capillaries around body so requires more pressure so a thicker wall and more muscle fibres allow for a greater contraction force

Question 10

which blood vessel enters the right atrium and what does it do?

Answer 10

vena cava brings blood from the body

Question 11

which blood vessel is leaving the right ventricle and what does it do?

Answer 11

pulmonary artery and takes blood to the lungs

Question 12

which blood vessel enters the left atrium and what does it do?

Answer 12

pulmonary vein and brings blood from the lungs

Question 13

which blood vessel is leaving the left ventricle and what does it do?

Answer 13

aorta takes blood to the body

Question 14

what does systole mean?

Answer 14

contraction of the heart muscle

Question 15

what does diastole mean?

Answer 15

heart muscle relaxed

Question 16

why do valves open and close?

Answer 16

pressure changes on either side

Question 17

when do the atrio-ventricular valves open?

Answer 17

when the pressure in the atria increases above that in the ventricles

Question 18

when do the semi-lunar valves open?

Answer 18

when the pressure in the ventricle increases above that of the aorta

Question 19

how and why can valves only open on way?

Answer 19

due to tendons that anchor the valve to prevent back flow

Question 20

what is the equation for cardiac output?

Answer 20

stroke volume x heart rate

Question 21

what is stroke volume?

Answer 21

volume of blood expelled from the left ventricle in on heart beat

Question 22

draw a diagram of a heart

Answer 22

https://www.google.com/url?sa=i&url=https%3A%2F%2Fcommons.wikimedia.org%2Fwiki%2FFile%3ADiagram_of_the_human_heart.svg&psig=AOvVaw1wA-9SfyIGRzS1XtQkXRI7&ust=1702026580068000&source=images&cd=vfe&ved=0CBMQjhxqFwoTCLjojaD9_IIDFQAAAAAdAAAAABAE

Question 23

what is coronary heart disease?

Answer 23

any interference with the coronary arteries which supply blood to the heart muscle itself

Question 24

describe the process of an atheroma forming (atherosclerosis)

Answer 24

1. lumen of artery narrowed due to build up of fatty deposits and cholesterol underneath artery endothelium
2. muscle fibres and calcium salts accumulate + form uneven patches called plaque which bulges into artery lumen
   3.partial blockage= deprived muscle cells during exercise so lactic acid and pain.
3. if completely blocked then muscle cells= no O2 and die causing heart attack

Question 25

when does atherosclerosis usually occur?

Answer 25

damage occurred to the artery wall for some reason like high BP or bacterial toxins

Question 26

how does an atheroma increase the chances of an aneurysm?

Answer 26

when artery is blocked, blood flow restricted. BP builds up in front of blockage and presses on artery wall causing wall to weaken and bulge out known as an aneurysm

Question 27

how does an atheroma increase the chances of thrombosis?

Answer 27

the plaque may rupture and trigger blood clotting over the damaged area which builds up rapidly causing further blockage of artery known as a thrombus

Question 28

what could happen if a thrombus breaks up?

Answer 28

travel in the blood stream and cause blockage elsewhere (e.g. stroke)

Question 29

name the risk factors for CHD (6)

Answer 29

age, gender, genetic factors, smoking, stress, high lipid/cholesterol diet

Question 30

describe how blood cholesterol can lead to an atheroma

Answer 30

cholesterol is transported in the blood connected to LDL so a higher conc of LDL means Higher risk of CHD

Question 31

how can high blood LDL be treated?

Answer 31

statins

Question 32

describe how cigarette smoking can lead to an atheroma

Answer 32

• Nicotine increases blood pressure and damage to endothelium
  -increases cholesterol levels
  -chemicals increase chance of thrombosis

Question 33

describe how a student could investigate wether their heart rate when sitting down was similar to other people their age?

Answer 33

1. obtain pulse rated for a large number of students
   2.belonging to a variety of different groups like sex and ethnicity
   3.calculate mean and standard deviation
   4.see if their mean lies within the standard deviation

Question 34

explain 4 ways in which the aorta is adapted for its function

Answer 34

elastic tissue stretches and recoils maintaining pressure
elastic tissue stretches when ventricles contract and recoil when ventricles relax
muscle for contraction
thick wall withstands pressure
smooth endothelium reduces friction
aortic valve prevents backflow

Question 35

describe how blood is moved from the left ventricle of the heart to the body and back to the heart

Answer 35

1. left ventricle contracts
   2.increasing pressure so semi-lunar valve opens
   3.increased pressure shuts AV valves so no backflow
   4.blood leaves heart via aorta to body
   5.blood travels in arteries to capillaries to veins
   6.valves in veins prevent back flow
   7.blood drains into vena cava
   8.enters right atrium