The Human Heart Structure

Question 1

Where is the heart located in the body?

Answer 1

In the thoracic cavity, behind the sternum (breastbone)

Question 2

Outline the human heart structure

Answer 2

1. Aorta
2. Left pulmonary artery
3. Left pulmonary veins
4. Semilunar valves (tricuspid valves)
5. Atrioventricular valves (biscuspid valves)
6. Septum
7. Cavity of the left ventricle
8. Thick muscular wall of the left ventricle
9. Superior vena cava
10. Right pulmonary artery
11. Right atrioventricular valves
12. Inferior vena cava

Question 3

What is the heart made out of and what provides the heart with oxygenated blood?

Answer 3

Cardiac muscle, coronary arteries

Question 4

What are the two unique properties of the cardiac muscle?

Answer 4

Cardiac muscle is myogenic and does not fatigue

Question 5

What is meant when it is said the cardiac muscle is “myogenic”?

(cntrct./rlx/ wtht/ stmltn.)

Answer 5

This means the cardiac muscle can contract/relax without nervous/hormonal stimulation

Question 6

What is meant when it is said the cardiac muscle “does not fatigue”?

(lng. - sply. o2 + glc. - nvr. ftge.)

Answer 6

This means as long as the cardiac muscle has a supply of oxygen and glucose, it will never fatigue

Question 7

What happens when the coronary arteries become blocked?

(blckge. crnry. atrs. - cse. myocrdl. infctrn. - bce. prt. mscle. dprve. oxygn.)

Answer 7

A blockage in the coronary arteries can cause a myocardial infarction (heart attack), because part of the cardiac muscle is deprived of oxygen

Question 8

Why can a blockage in the coronary arteries cause a myocardial infarction (heart attack)?

(crnry. A bcme. blckd. - cnt. rce. O - unble A rspr. - clls. D - ldng. mycrdl. infrtn.)

Answer 8

When coronary arteries become blocked, they cannot receive oxygen, making them unable to respire so the cells die, leading to a myocardial infarction (heart attack)

Question 9

What are the two main causes of a myocardial infarction?

Answer 9

The blockage of coronary arteries (fat build up/blood clots) or coronary artery rupturing

Question 10

What are the four chamber of the human heart?

Answer 10

The right atrium
The right ventricle
The left ventricle
The left atrium

Question 11

What are the two main structural features of the atria, and explain why they have these features

(thin - dnt. nd. cntrct. hrd. - nt. bng. too. fr; elastic; wlls. stcth. + mke. soce. whn. bld. entrs.)

Answer 11

The atria have thin muscular walls, that are elastic.

Thin: because atria do not need to contract as hard as blood is not being pumped far (only to ventricles)

Elastic: the walls need to stretch and make space when the blood enters

Question 12

Why does the ventricle have a much thicker muscular wall than the atrium?

(cntrct. strngly. pmp. bld. grtr. dstnc.)

Answer 12

It needs to contract strongly to pump blood a greater distance - to the lungs or the rest of the body

Question 13

What is the function of the vena cava?

(crs. deox. bld. frm. bdy. - rght. atrm.)

Answer 13

It carries deoxygenated blood from the body into the right atrium

Question 14

What is the function of the pulmonary vein?

(cry. ox. bld. frm. lngs. - lft. atrm.)

Answer 14

Carries oxygenated blood from the lungs to the left atrium

Question 15

What is the function of the pulmonary artery?

(crs. dox. bld. frm. ght. vntrlc. - lngs.))

Answer 15

Carries deoxygenated blood from the right ventricle to the lungs to become oxygenated

Question 16

What is the function of the aorta?

(crs. ox. bld. frm. lft. vntrlc. - rst. bdy.)

Answer 16

Carries oxygenated blood from the left ventricle to the rests of the body to become oxygenated

Question 17

Why does the left ventricle have a thicker muscular wall than the right ventricle?

(lft. pmps. bld. - entre. bdy. - lrgr. cntrncs. - mscle. gen. hghr. prsre.)

Answer 17

The left ventricle pumps blood to the entire body, so it must have larger contractions of the muscle to generate a high pressure

Question 18

How do valves open and close?

(open - prsr. hghr. bhnd. vlve. + clse. whn. prsre. hghr. frnt. vlve.)

Answer 18

Valves open when the pressure is higher, behind the valve and then proceed to close when pressure is higher, in front of the valve, preventing backflow of blood

Question 19

What are the two key valves in the heart, which is bicuspid/tricuspid?

Answer 19

The semilunar valves (bicuspid) and the atrioventricular valves (tricuspid)

Question 20

Where are the semi - lunar valves found?
Where are the atrioventricular valves found?

Answer 20

Semi lunar valves: In aorta and the pulmonary artery

Atrioventricular valves: Between the atria and the ventricles

Question 21

Why must oxygenated and deoxygenated blood be kept separate?

(mntn. ox. lvls. bld. bng. pmpd. bdy. - max. ox. dlvry. tses.)

Answer 21

To maintain high oxygen levels in the blood being pumped to the body, maximizing oxygen delivery to tissues

Question 22

What is the function of the septum?

(seprts. ox. + dox bld.)

Answer 22

The septum separates oxygenated and deoxygenated blood, ensuring oxygenated blood is not diluted by deoxygenated blood.

Question 23

Why is the function of the septum important?

(mnnt. conc. grdnt. - enbls. difss. amgst rsprng. clls.)

Answer 23

The septum ensures oxygenated blood is kept separate from deoxygenated blood, to maintain a concentration gradient which enables diffusion amongst respiring cells