phase 1 week 7

Question 1

What make up the central components of the ANS?

Answer 1

hypothalamus
brainstem
spinal cord

Question 2

What makes up the peripheral components of the ANS?

Answer 2

sympathetic nerves

parasympathetic nerves

Question 3

what are the main functions of the ANS?

Answer 3

mediate neuronal regulation of the internal environment
coordinate body function necessary for survival
regulate removal of waste products from the body
prepare the body for normal and life-threatening stress

Question 4

Describe activities of the sympathetic nervous system

Answer 4

accelerates heart rate
causes constriction of peripheral blood vessels
raises blood pressure
brings about redistribution of the blood - leaves areas of skin and intestine and becomes available to the brain, heart and skeletal muscles
Inhibits peristalsis of the intestinal tract and closes the sphincters

Question 5

What are the primary neurotransmitters?

Answer 5

Sympathetic - noradrenaline, adrenaline

Parasympathetic - Acetylcholine

Question 6

what does the ANS control?

Answer 6

cardiorespiratory function
digestion
genitourinary
sexual 
stress response
exercise ability

Question 7

Where is the origin of the sympathetic NS?

Answer 7

thoracolumbar

except cervical ganglia

Question 8

What is the neurotransmitter for the sympathetic NS?

Answer 8

Noradrenaline

except sweat glands and deep muscle vessels use ACH

Question 9

What do alpha 1 receptors control?

Answer 9

arteriole constriction

Question 10

What do alpha 2 receptors control?

Answer 10

venous and coronary vasoconstriction

Question 11

What do beta 1 receptors control?

Answer 11

mainly heart, adrenal glands and renal

Question 12

What do beta 2 receptors do?

Answer 12

lungs

Question 13

Where is the origin of the parasympathetic NS?

Answer 13

Craniosacral outflow

Question 14

Where are the parasympathetic ganglia?

Answer 14

diffuse near site of action

Question 15

What do muscarinic receptors do?

Answer 15

smooth muscle and salivary glands

Question 16

What do nicotinic receptors do?

Answer 16

on motor end plate (near skeletal muscles)

Question 17

What are the functions of the brain stem?

Answer 17

cranial nerve function
conduit function - spinothalamic, corticospinal
integrative functions - respiration, cardiovascular, sleep, arousal, conciousness

Question 18

What is the result of brain stem death?

Answer 18

paralysis and unconsciousness
apnoea
loss of cranial nerve function

Question 19

What is blood pressure?

Answer 19

the pressure exerted by circulating blood upon the walls of blood vessels.
BP usually refers to arterial pressure in the systemic circulation

Question 20

Which physical features affect blood pressure?

Answer 20

blood volume
resistance - radius, length and smoothness of vessels
viscosity of fluid

Question 21

Define pressure (in equation)

Answer 21

P = Q X R

Question 22

What is cardiac output?

Answer 22

stroke volume X heart rate

Question 23

What is MAP?

Answer 23

cardiac output X total peripheral resistance

Question 24

What are the physiological aspects of changes in BP?

Answer 24

gradual rise with age
greater rise in males
varies through the day - lowest when sleeping
increased transiently during physical or mental stress

Question 25

What is Poiseuille's equation?

Answer 25

Q = pressure X Pi X radius4 / 8nL

Question 26

What are baroreceptors?

Answer 26

stretch receptors found in carotid sinus and aorta changes in pressure lead to changes in heart rate and vasomotor control

Question 27

How can peripheral resistance be controlled?

Answer 27

vasomotor mechanism | vasoconstriction increases TPR and therefore BP

Question 28

Describe the mechanisms for the control of blood volume

Answer 28

ADH - increases water retained by kidneys Renin - secretion of aldosterone - increased Na+ retention- increased water retention angiotensin II - vasoconstriction anti-natriuretic hormone - increases Na+ loss, promotes vasodilation

Question 29

What is the neural mechanism of vasovagal syncope?

Answer 29

simultaneous vagal activation and sympathetic inhibition during fainting

Question 30

Why can emotional events evoke vasovagal fainting?

Answer 30

one of the neural pathways descends from the portico-hypothalamar centres to the medullary cardiovascular centres

Question 31

What is the cardioinhibitory response?

Answer 31

drop in heart rate (negative chronotropic effect) primarily from enhancement of parasympathetic tone

Question 32

What is the vasodepressor response?

Answer 32

vasodilation due to withdrawal of sympathetic nerve tone

Question 33

what are the functions of the cardiovascular system?

Answer 33

``` transport of nutrients, oxygen and waste products around the body transfer of heat buffers body pH transport of hormones assists in response to infection assists in formation of urine ```

Question 34

What is the first heart sound?

Answer 34

AV valves closing

Question 35

What is the second heart sound?

Answer 35

pulmonary and aortic valves closing

Question 36

what is EDV?

Answer 36

end diastolic volume | the amount of blood remaining in the ventricles after systole

Question 37

what is the normal cardiac output?

Answer 37

5 litres / minute

Question 38

Describe conduction and contraction of the heart

Answer 38

impulses generated in the SA node spread over the atria followed by the ventricles SA node has fastest intrinsic rate so determines heart rate AV node slows conduction and can act as a second pacemaker if required millions of purkinje fibres interdigitate with myocytes to spread the impulse across ventricles - excitation contraction coupling

Question 39

Describe an ECG

Answer 39

electrocardiogram | detects phasic changes in potential difference between two electrodes

Question 40

what is the p wave?

Answer 40

atrial depolarisation

Question 41

What is the QRS complex?

Answer 41

ventricular depolarisation

Question 42

What is the T wave?

Answer 42

ventricular depolarisation

Question 43

what is the PR interval?

Answer 43

delay through AV node

Question 44

what is the ST interval?

Answer 44

plateau phase of AP

Question 45

how is heart rate decreased?

Answer 45

increased K+ permeability means more time to threshold | action of ACh from vagal nerve

Question 46

how is heart rate increased?

Answer 46

``` Increased Ca2+ permeability means less time to threshold action of (Nor)adrenaline ```

Question 47

describe the factors affecting capillary transport

Answer 47

the blood in the capillaries experts a pressure on the capillary wall (hydrostatic pressure) this tends to favour movement of fluid out of the capillaries The plasma has intrinsic osmotic pressure due to plasma proteins (colloid pressure) This tends to favour movement of fluid into the capillaries

Question 48

what are the functions of the nervous system?

Answer 48

``` communication regulating internal events organising behaviour information storage sensations, perceptions, emotions ```

Question 49

Which cells from myelin in the CNS?

Answer 49

oligodendrocytes

Question 50

what cells form myelin in the PNS?

Answer 50

Shwann cells

Question 51

what do astrocytes do?

Answer 51

involved in nutrient supply to neurons on CNS

Question 52

What do ependymal cells do?

Answer 52

involved in production of CSF

Question 53

What do microglia do?

Answer 53

defence role - phagocytic

Question 54

what does the frontal lobe do?

Answer 54

"executive" functions, long term memory

Question 55

What does the parietal lobe do?

Answer 55

integration of sensory function

Question 56

what does the occipital lobe do?

Answer 56

visual processing

Question 57

what does the temporal lobe do?

Answer 57

primary auditory cortex

Question 58

what are dorsal roots?

Answer 58

sensory

Question 59

What are ventral roots?

Answer 59

motor

Question 60

what do dorsal root ganglia contain?

Answer 60

all cell bodies of primary sensory neurons

Question 61

what is a nerve plexus?

Answer 61

the peripheral nerves that supply particular body regions

Question 62

name the cranial nerves

Answer 62

1. olfactory 2. optic 3. oculomotor 4. trochlear 5. trigeminal 6. abducens 7. facial 8. vestibulocochlear 9. glossopharyngeal 10. vagus 11. spinal accessory 12. hypoglossal

Question 63

What are individual nerve fibres coated by?

Answer 63

endoneurium

Question 64

What are nerve fascicles coated by?

Answer 64

perineurium

Question 65

What are peripheral nerves coated by?

Answer 65

epineurium