cardiovascular system - structure and function of heart

Question 1

what is cardiac

Answer 1

Hardest working muscle of all

Question 2

what is cardiology

Answer 2

Study of heart & associated diseases

Question 3

describe the direction of blood flow of the human heart

Answer 3

oxygenated blood exits the lungs from the top and enters the lower half of the heart, heart the processes this and send the deoxygenated blood out the top of the heart vessels to the lower half of the lungs

Question 4

explain the pericardium

Answer 4

Double-walled sac enclosing heart

To isolate & give room for expansion

Resists compression

Pericardial space/cavity
- Fluid filled

Question 5

what is Cardiac Tamponade

Answer 5

Compression of heart
by abnormal accumulation of fluid on pericardial cavity

e.g., pericarditis
due to viral infection or cancer etc.,

Question 6

name the 3 layers of the heart wall

Answer 6

Outer: EPICARDIUM
Middle: MYOCARDIUM
Inner: ENDOCARDIUM

Question 7

explain the Outer: EPICARDIUM layer of the heart wall

Answer 7

same layer as visceral pericardium, simple squamous epithelium

Question 8

explain the Middle: MYOCARDIUM layer of the heart wall

Answer 8

thickest layer, cardiac muscle

Question 9

explain the inner endocardium layer of the heart wall

Answer 9

simple squamous
epithelium, forms inner lining of chamber

Question 10

explain the divisions of the pericardium layer which is the outer layer of the heart wall

Answer 10

most outer layer to most inner layer:

fibrous pericardium

parietal layer of serous pericardium

pericardial cavity

visceral layer of serous pericardium (epicardium)

Question 11

what is the fibrous skeleton of the heart made up of

Answer 11

Dense connective tissue surrounding valves

Question 12

what does the Fibrous Skeleton of the Heart form and do

Answer 12

Forms foundation to which heart valves attached

Point of insertion for cardiac muscle fibres

Prevents overstretching of valves

Electrical insulator

Question 13

name the Fibrous Skeleton parts of the Heart

Answer 13

in order from posterior to anterior

right fibrous anulus
left fibrous anulus
right fibrous trigone
left fibrous trigone
fibrous ring of aortic valve
tendon of conus
fibrous ring of pulmonary ring

Question 14

name the 4 chambers of the heart

Answer 14

left atrium
right artium
left ventricle
right ventricle

Question 15

explain the right atrium of the heart

Answer 15

Receives deoxygenated blood from the body

blood enters it via 3 veins:
- superior vena cava
- inferior vena cava
- coronary sinus

Question 16

explain the left atrium

Answer 16

Receives oxygenated blood from the lungs
- Via L&R pulmonary veins

Blood pumped to left ventricle then back into systemic circulation

Question 17

right and left atria function to do what

Answer 17

to promote continuous venous flow

• No atrial inlet valves
• Contact incompletely
• Contractions are mild
• Relax before ventricular contraction starts

Question 18

what is septal defect

Answer 18

‘hole in the heart’

when interatrial septum which is between left and right atrium has an atrial septal defect

Question 19

explain the right and left ventricles

Answer 19

Large chambers at bottom of the heart
Collect and expel blood

RV —–> pulmonary circulation

LV ——> systemic circulation

Question 20

explain what direction blood flows and via what

Answer 20

right atrium to right ventricle

via tricuspid valve
(= R atrioventricular valve)

Question 21

explain the process of blood flow from the right ventricle

Answer 21

RV blood leaves through pulmonary semilunar valve

to

pulmonary trunk (large artery)

to either

Left Pulmonary Artery
or
right Pulmonary Artery

Question 22

explain the flow of blood from the left atrium

Answer 22

LA receives blood from 4 pulmonary veins via bicuspid (Mitral) valve (=L atrioventricular valve)

to

left ventricle, where,
blood leaves through Aortic Semilunar Valve

to

AORTA (largest artery of body)

to either

coronary arteries
or
arch of aorta, then to body

Question 23

describe the operation of heart valves

Answer 23

Ensure one-way flow of blood

Question 24

explain AV valves

Answer 24

AV valves involve:

• Chordae tendineae (strings of connective tissue)
• Papillary muscle

Question 25

explain SL valves

Answer 25

Pocket-like cusps

Question 26

when heart is pumping what happens to alternate valves

Answer 26

they close

ex :
if pulmonary and aortic valve closed then bicuspid and tricuspid valves open

and vice versa

Question 27

name the 4 heart valves

Answer 27

pulmonary valve
aortic valve
bicuspid valve (left AV)
tricuspid valves (right AV)

Question 28

explain bioengineered heart valves

Answer 28

Current options for paediatric patients:

• bioprosthetic valves made from chemically treated animal tissues.
• These generally calcify and do not grow with the child.

2021

• bioengineered heart valves implanted into lambs have been shown to grow with the recipient.

Prospect for humans?

• Long-lasting product for paediatric heart surgery.