PHYSIOLOGY NOTES

Question 1

Cardiac Output (CO) =

Answer 1

Heart Rate (HR) x Stroke Volume (SV)

Question 2

Venous return

Answer 2

volume of blood returning to the heart from the vasculature every minute and is linked to cardiac output

Question 3

PRE-LOAD

Answer 3

Stretch on LV before it contracts. when the ventricle is filling, the pressure rises and this stretches the myocardial fibres, placing them under a degree of tension

Question 4

Starling’s Law

Answer 4

the energy of contraction of the ventricle is a function of the initial length of the muscle fibres comprising its walls

Question 5

CONTRACTILITY

Answer 5

Strength and rigour of the heart’s contraction during systole. The heart will eject a greater stroke volume at greater filling pressures

Question 6

AFTER LOAD

Answer 6

Afterload is the force or load against which the heart has to contract to eject the blood.

Question 7

HYPERTENSION

Answer 7

High blood pressure - if elevated this will mean your afterload will be high

Question 8

myocardium

Answer 8

creates the mechanical work of the pumping action of the heart

Question 9

Systole

Answer 9

Systolecauses the ejection of blood into the aorta and pulmonary trunk.

Question 10

Diastolic Reading

Answer 10

Thediastolicreading, or the bottom number, is the pressure in the arteries when the heart rests between beats. This is the time when the heart fills with blood and gets oxygen. A normaldiastolicblood pressure is lower than 80. A reading of 90 or higher means you have high blood pressure.

Question 11

Systolic Blood Pressure

Answer 11

Systolic blood pressure, the top number, measures the force your heart exerts on the walls of your arteries each time it beats.

Question 12

Cardiac cycle

Answer 12

includes all events associated with one heartbeat, forcing blood from areas of high pressure to areas of low pressure

Question 13

ECG

Answer 13

summation of all electrical activity spreading around the heart

Question 14

Potassium slows the HR

Answer 14

Flow of potassium in and out of heart cells helps regulate your heartbeat. Low blood potassium levels can alter this - heart palpatations

Question 15

Sodium/Potassium/Calcium

Answer 15

3 main parts for action potential in regulation of heart

Question 16

coronary heart disease

Answer 16

inability to supply blood to the heart

Question 17

Blood pressure stability is the…

Answer 17

most important thing!

Question 18

heart consists of specialised muscle cells called

Answer 18

cardiac myocytes

Question 19

contraction of these cells initiated by

Answer 19

action potentials

Question 20

SA Node

Answer 20

primary pacemaker of the heart. intiates all heart beats

Question 21

AV Node

Answer 21

electrical gateway to the ventricles. passes onto AV bundle or bundle of his

Question 22

depolarization

Answer 22

In biology, depolarization is a change within a cell, during which the cell undergoes a shift in electric charge distribution, resulting in less negative charge inside the cell.

Question 23

Repolarisation

Answer 23

restoration of the resting membrane potential after each deploarisation event

Question 24

P wave

Answer 24

atrial depolarisation

Question 25

QRS complex

Answer 25

onset of ventricular depolarisation

Question 26

T wave

Answer 26

ventricular repolarisation

Question 27

proprioceptors

Answer 27

monitor joint movements (e.g. when exercising)

Question 28

baroreceptors

Answer 28

monitor blood pressure

Question 29

chemoreceptors

Answer 29

monitor blood activity

Question 30

vagus nerve (parasympathetic)

Answer 30

heart - decreased rate | decreased rate of spontaneous depolarisation in SA node (and AV node) decreases heart rate

Question 31

cardiac accelerator nerves (sympathetic)

Answer 31

heart - increased rate and contractility. increased rate of spontaneous depolarisation in SA node (and AV node) increases heart rate. increased contractility of atria and ventricles increases stroke volume

Question 32

vasomotor nerves (sympathetic)

Answer 32

blood vessels - vasoconstriction

Question 33

sensory afferent neurons

Answer 33

to the body and CNS

Question 34

motor efferent neurons

Answer 34

exit the body

Question 35

Vagus nerves, parasympathetic travel to

Answer 35

the SA node

Question 36

impacts on increasing stroke volume

Answer 36

increased preload, increased contractility and decreased afterload

Question 37

mean arterial blood pressure

Answer 37

MAP, or mean arterial pressure, is defined as the average pressure in a patient's arteries during one cardiac cycle.

Question 38

blood pressure equation

Answer 38

BP = CO (cardiac output) x TPR (total periphery resistance)

Question 39

main resistance vessels

Answer 39

arterioles

Question 40

cardiovascular system is made up of

Answer 40

aorta, arteries, arterioles, capillaries, venules, vein, vena cavae

Question 41

cardiovascular system anatomically

Answer 41

is organised in parallel

Question 42

blood pressure is the same in

Answer 42

all organs

Question 43

capillaries are

Answer 43

where exchange takes place

Question 44

ADH

Answer 44

antidiuretic hormone