cardiovascular 1

Question 1

Describe arteries

Answer 1

Thick walled high pressure vessels which conduct the blood from the heart to the tissues

Question 2

Describe veins

Answer 2

Thin walled lower pressure vessels returning blood to the heart

Question 3

describe the heart:

Answer 3

the LHS- oxygenated blood for systemic circulation
RHS: deoxygenated blood for pulmonary circulation

Question 4

what are the valves in the heart called

Answer 4

AV valves-between atria and ventricle
tricuspid valve- between the right atria and the right ventricle
mitral value- between left atria and left valve
pulmonary valve - pulmonary artery and RV
aortic value- aorta and the LV

Question 5

WHAT IS the purpose of valves

Answer 5

to stop blood flow back into the heart
they open in one direction and the papillary muscles contract to prevent valves opening in the wrong direction

Question 6

describe the cardiac cycle

Answer 6

diastole- the heart is relaxing and blood flows from A to V
systole- atria contract, AV valves close, atria refills, ventricles contract and Aortic and pulmonary valves open and blood flows out of ventricles

Question 7

what is the frank starling mechanisms

Answer 7

the greater the heart is stretched the stronger it contracts

Question 8

what is normal heart rate

Answer 8

60-100 BPM

Question 9

tachycardia is defined as

Answer 9

greater than 100 BPM

Question 10

what is bradycardia

Answer 10

less than 60 BPM

Question 11

what happens when the heart rate is too fast

Answer 11

impulses sent to the vagus nerve which lead to the SAN which slow down the heart rate via parasympathetic NS

Question 12

what causes increase of heart rate

Answer 12

increase of sympathetic NS- release of noradrenaline which act on beta cholinergic receptors increases firing of SAN and increases force of contraction and increased heart rate

Question 13

define cardiac output

Answer 13

the volume of blood that is pumped around the body in time
CO= HR X SV

Question 14

How do we increase BP

Answer 14

baroreceptors detect low blood pressure
kickstart SNS
increase hr
increase SV
constrict arterioles and veins

Question 15

define blood pressure

Answer 15

CO X TPR (TOTAL PERIPHERAL RESISTANCE)

Question 16

how to we lower BP

Answer 16

baroreceptors detect high BP
PSN kicks in
reduced HR
dilation of arterioles and veins

Question 17

in the long term how do we balance BP

Answer 17

renin- angiotensin system

Question 18

a low blood pressure long term can be managed by

Answer 18

arterial constriction and then reduction in blood flow to the kidneys
this reduces NA and water excretion
kidneys produce renin and converts angiotensin into angiotensin 1 which is in the blood
converted by ACE in the lungs into angiotensin II
THEN releases aldosterone which is released by adrenal Cortex and stimulates sodium and water resorption into the nephrons
leading to increase in BP