Body system physiology

Question 1

What is systemic systolic arterial blood pressure?

Answer 1

The pressure exerted the blood on the walls of the aorta and systemic arteries when the heart contracts (

Question 2

What is systemic diastolic arterial blood pressure?

Answer 2

The pressure exerted by the blood on the walls of the aorta and systemic arteries when the heart relaxed (normally

Question 3

What is Mean Arterial Blood Pressure (MAP)?

Answer 3

The average arterial blood pressure during a single cardiac cycle, which involves contraction and relaxation of the heart (70 - 105 mmHg)

Question 4

Equations to calculate MAP?

Answer 4

MAP = (2 x diastolic) + systolic / 3

MAP = DBP + 0,5(SBP - DBP)

Question 5

Where are baroreceptors?

Answer 5

Aortic arch

Carotid sinus

Question 6

Which nerve takes the signal from the carotid receptors?

Answer 6

Glossolharyngeal nerve (CNIX)

Question 7

Which nerve takes the signals from the aortic receptors?

Answer 7

Vagus nerve (CNX)

Question 8

How does the cardiovascular control centre process the signal?

Answer 8

Recipes afferent information
NTS is site of first synapse for all CVS afferent in the medulla
NTS relays info to other areas of the brain
Generates vagal outflow to the heart
Regulates spinal sympathetic neurones

Question 9

What is total peripheral resistance?

Answer 9

The sum of resistance of all peripheral vasculature in the systemic circulation

Question 10

What 3 factors when regulated control BP?

Answer 10

Heart rate
Stroke volume
TPR

Question 11

How is heart rate increased?

Answer 11

Noradrenaline acts on B1 receptors

Question 12

How is heart rate slowed?

Answer 12

Acetylcholine acts on muscarinic receptors

Question 13

How is stroke volume controlled?

Answer 13

Frank-Starling mechanism

Question 14

What is the frank starling law?

Answer 14

The more the ventricle is filled with blood during diastole the greater the volume of ejected blood will be during the resulting systolic contraction

Question 15

What is TPR regulated by?

Answer 15

Vascular smooth muscle

Question 16

What is vasomotor tone?

Answer 16

Vascular smooth muscles are partially constricted at rest due to continuous release of noradrenaline

Question 17

What nerves supply vascular smooth muscle?

Answer 17

Sympathetic nerve fibres

Neurotransmitter is noradrenaline

Question 18

What 5 hormones are involved in controlling glucose?

Answer 18

Insulin (pancreas) 
Glucagon (pancreas) 
Adrenaline (adrenal gland) - in emergencies 
Cortisol (adrenal) 
Growth hormone (pituitary)

Question 19

What cells are in the pancreas?

Answer 19

Exocrine (digestive & absorptive enzymes)

Endocrine (clustered into islets of Langerhans)

Question 20

What do alpha cells in the pancreas release?

Answer 20

Glucagon

Question 21

What do beta cells in the pancreas release?

Answer 21

Insulin

Question 22

What do delta cells in the pancreas release?

Answer 22

Somatostatin

Question 23

What does aldosterone do?

Answer 23

Regulates salt levels

Question 24

What does cortisol do?

Answer 24

Stress hormone

Question 25

What does insulin do?

Answer 25

``` Favours anabolism Stimulates conversion of - glucose to glycogen - fatty acids to triglycerides - amino acids to proteins ``` Hormone of the fed state

Question 26

What does glucagon do?

Answer 26

Favours catabolism Stimulates conversion of - glycogen to glucose - triglycerides to fatty acids Hormone of the hungry state

Question 27

What happens when glucose increase?

Answer 27

Insulin increases | Glucagon decreases

Question 28

What happens when glucose decreases?

Answer 28

Insulin decreases | Glucagon increases

Question 29

How does insulin promote glucose uptake into muscle and fat?

Answer 29

GLUT4 into plasma membrane

Question 30

What causes diabetes mellitus?

Answer 30

Lack of insulin or impaired cellular responses to insulin

Question 31

How is diabetes detected?

Answer 31

Oral glucose tolerance test

Question 32

What is type 1 diabetes?

Answer 32

``` Childhood onset Little/no insulin secretion Defect in B cell function ketones develops (if untreated) Insulin injections for treatment Symptoms develop rapidly ```

Question 33

What is type 2 diabetes?

Answer 33

``` Adult onset Insulin may be normal or exceed normal Defect in insulin sensitivity Ketones ramen Diet/exercise + oral drugs for treatment Symptoms develop slowly ```

Question 34

How does glucagon increase glucose?

Answer 34

Increasing liver glycogenolysis Inhibits liver glycogen synthesis Promotes liver gluconeogenesis Also promotors lipgloss in liver and adipose tissue

Question 35

What rhythm does cortisol secrete in?

Answer 35

Diurnal

Question 36

How does cortisol raise glucose?

Answer 36

Stimulates protein catabolism Stimulates gluconeogenesis Stimulates lipolysis

Question 37

How does growth hormone increase glucose?

Answer 37

Mobilises glucose from livers | Promotes lipolysis in fat cells

Question 38

How does the baroreceptor reflex work?

Answer 38

``` BP change Sensed by baroreceptors Sent to cardiovascular control centre in the medulla of the brain Heart rate & stroke volume change TPR changes BP normal ```

Question 39

What damaging effects can increased body temperature cause?

Answer 39

``` Speeds up cellular metabolism Protein denaturation Nerve malfunction Convulsions Death ```

Question 40

What harmful effects can decreased body temperature cause?

Answer 40

Slows down cellular reactions | May fatally slow down metabolism

Question 41

Sites from monitoring body temperature

Answer 41

Ear drum Rectal Oral

Question 42

How is heat gained in the body?

Answer 42

Metabolic heat Radiation Convection Conduction

Question 43

How is heat lost from the body?

Answer 43

Convection Conduction Radiation Evaporation

Question 44

What is BMR?

Answer 44

The minimum amount of energy required to sustain vital Boyd functions which leads to a basic level of heat production

Question 45

How does the body know there is a change in heat?

Answer 45

Thermoreceptors (Central & peripheral)

Question 46

Which part of the brain controls heat?

Answer 46

Hypothalamus Posterior - cold Anterior - hot

Question 47

What is the effector responses to cold exposure?

Answer 47

Vasoconstriction Increased muscle tone (shivering) Postural changes Warm clothing

Question 48

Effector responses to heat exposure?

Answer 48

``` Vasodilation Sweating Decreased muscle tone Decreased voluntary movement Cool clothing ```

Question 49

What is a pyrogen?

Answer 49

A substance which produces fever

Question 50

Why do we get a fever?

Answer 50

Endogenous pyrogen (e.g. IL from white blood cells) stimulate the release of prostaglandins in the hypothalamus Prostaglandins act to reset the thermostat at a higher temperature The hypothalamus initiates cold response (shivering etc.) Body temp increases to new set point = fever