year 3 physiology

Question 1

main function of ependymal cells

Answer 1

production of CSF as part of the choriod plexus

Question 2

what cells degeneraet in MS

Answer 2

oligodendrocytes

Question 3

where is CSf contained

Answer 3

within subarachnoid space and the central canal of the spinal cord

Question 4

what cells form the blood cerebral spinal fluid barrier

Answer 4

ependymal

Question 5

what cells regualte the compostion of CSF

Answer 5

ependymal

Question 6

foramen from 4th venricle to subarahnoid space or central canal

Answer 6

luschka and megendie

Question 7

where does csf get drained to

Answer 7

superior saggital venous sinus through arachnoid villi

Question 8

communicating hydrocephalus is casued by

Answer 8

imbalance in csf production and absorption - most commonly inaqdeqaute reasbsorption into teh dural venous sinuses as the fucntion of teh arachnoid villi is impaired

Question 9

non communicating hydrocephalus is due to

Answer 9

obstruction of CSf outflow - most likely to occur at the foramens, cerebal aqueduct etc

Question 10

glutamate and GAba are what

Answer 10

amino acids

Question 11

acetylocholine plays a role in

Answer 11

attention

Question 12

what drugs can cause memory loss and have the potential to become addicitve hence they are only prescribed for short term use

Answer 12

Benzodiazepines

Question 13

what is a ganglion

Answer 13

collection of neuronal cell bodies in the PNS

Question 14

parasympathetic system only uses

Answer 14

acetylocholine where symapthetic used actelycholien and noraderenalien

Question 15

what ion has greates influence of the resting membrane potential

Answer 15

K

Question 16

what is not involved in the repolarisation process following an action potential

Answer 16

Na/K ATPase

Question 17

action potentials can only occur where

Answer 17

nodes of ranvier

Question 18

how does myelin sheath speed up conduction

Answer 18

increaseing the membrane resistance and reducing memebrane capacitance

Question 19

does dopamine exert an excitatory or inhibitoryy effect

Answer 19

both!

Question 20

glutamate and gaba both act on inotropic but gaba also works on what receptors

Answer 20

metabotropic

Question 21

electroencephalogram measure what in epilepsy

Answer 21

excitatory or inhibitory transmission

Question 22

schwan cell is ony able to myelinate

Answer 22

one single axon

Question 23

what has a high memebrane resistance and reduces teh capitance of the axon

Answer 23

myelin

Question 24

long term potentiation is also know as

Answer 24

tetanus - requires strong activity in both presynatpic and postsynaptic neurones

Question 25

induction of long term potenitation requires activation of

Answer 25

glutamate NMDA receptors

Question 26

abnormal synaptic plasticity can lead to

Answer 26

intellectual disability

Question 27

long term potentitatio is synapse...

Answer 27

specific

Question 28

acetlycholinsterase inhibitors eg pyridostigmine and donezpezil inhibit the activity of acetylocholinesterase so increases cholinergic transmission so more acetlycjoline is in the synaptic cleft for longer

Answer 28

- these drugs can cause side effects which activate the parasympathetic system eg bradycardia, excessive salivation, hypotension

Question 29

is dorsum column tract consious

Answer 29

yes

Question 30

what ascending tract is unconscious

Answer 30

spinocerebellar

Question 31

second order neurones from DCLM decussate where

Answer 31

medulla

Question 32

where are third order neurones

Answer 32

thalamus

Question 33

what spinothalamic tract carries pain and temperature

Answer 33

lateral

Question 34

second order neurones in the spinothalamic tract decussate where

Answer 34

within the spinal cord

Question 35

3rd order neurones carry signals from thalamus to where

Answer 35

ipsilateal primary sensory cortex of the brain

Question 36

if DCLM affected sensory loss will be

Answer 36

ipsilateral

Question 37

spinothlamic tract affected, the sensory loss will be

Answer 37

contralateral

Question 38

think decussation - spinothalamic decussates at

Answer 38

SPinal cord

Question 39

spinocerebellar pathway likely to be affected if what is injured

Answer 39

descending motor tracts

Question 40

main pathway for audiory

Answer 40

Lemniscal

Question 41

most hearing decussate at

Answer 41

superior olivary nuclei

Question 42

what sleep do you dream

Answer 42

Rem

Question 43

sympathetic innervation is more related to what sleep

Answer 43

REM and paraympathetic more linked to non rem remeber in rem you get rapid eye movement so think sympathetic

Question 44

what system is regulator for sleep wake cycle

Answer 44

RAS - reticular activating system

Question 45

hypocretin affects what sleep

Answer 45

REM

Question 46

nucleus thats major circaidan clock

Answer 46

suprachiasmatic nucleus

Question 47

levels of hypocretin becoem very low in what

Answer 47

narcolepsy

Question 48

what receptros respond do pressure, touch, vibration and stretch

Answer 48

mechanoreceptors

Question 49

what plays a key role in differentation textures

Answer 49

merkels discs

Question 50

what detects initial contact with objects

Answer 50

meissners corpuscles

Question 51

what is involved with proprioception

Answer 51

muscle spindles and golgi tendon organs

Question 52

finger tips have smaller receptive fields but larger density of free nerve endings - allows for greater acuiting in detectig a sensory stimulus

Question 53

smaller the receptive field, the greater the sensoryy acuity

Question 54

morphine and other opiods acts on what receptros

Answer 54

G protein coupled receptors

Question 55

lateral inhibition allows for better

Answer 55

sensory acuity

Question 56

smaller the receptive field the better the

Answer 56

sensory acuity

Question 57

lateral genicuale nucleus involved in

Answer 57

vision

Question 58

temporal lobe affects what quadrants

Answer 58

superior - lower optic radiations

Question 59

what tracts are responsible for voluntary control

Answer 59

pyramidal

Question 60

what tract is responsible for involunatry and autonomic control of musculature eg muscle tone, balance, posture and locomotion

Answer 60

extrapyramidal

Question 61

are there synapses in the desending tracts

Answer 61

no

Question 62

pyramidal tracts consist of

Answer 62

corticospinal and corticobulbar

Question 63

one of the first things the descending tract goes through is the

Answer 63

internal capsule - particualrly susceptible to compression from haemorrhagic bleeds

Question 64

what corticospinal tract remains ipsialteral

Answer 64

anterior

Question 65

upper motor neurones for what nerves dont innervate bilaterally

Answer 65

facial and hypoglossal

Question 66

lower quadrants of the face (below teh eyes) has what innervation from facial

Answer 66

contralateral

Question 67

upper motor neurones for what nerve only provide contralateral innervation

Answer 67

hypoglossal

Question 68

what extrapyramidal tracts provide contralateral innervatoon

Answer 68

rubrospinal and tectospinal

Question 69

what extrapydramidal tracts do not decussate and therefore provide ipsilateral innervation

Answer 69

vestibulospinal and reticulospinal

Question 70

what tract involved with balance and psoture by innervating anti gravity muscles

Answer 70

vestibulspinal

Question 71

what tract facilatates / inhibits voluntary movemtns

Answer 71

reticulospinal

Question 72

rubro spinal tract involves

Answer 72

fine control of hand movements - red nucleus

Question 73

tectospinal tract

Answer 73

coordinates head in relation to vision stimuli

Question 74

what pyramidal tract is susceptible to damage becasue tehy extend almsot the wholw length of teh CNS and pass through internal capsule - common site of cerebrovascular accidents

Answer 74

corticospinal

Question 75

corticospinal lesions affect what side

Answer 75

contralateral

Question 76

corticospinal lesions cause what symptoms

Answer 76

upper motor neurone eg hypertonia, hyperreflexia , clonus, babinski

Question 77

motor unit is

Answer 77

combination of the LMN and muscle fibres

Question 78

difference in roles between alpha and gamma (lmns)

Answer 78

alpha - contraction gamma- muscle tone and unconscious proprioception

Question 79

what is often described as having a bag of worms under the skin

Answer 79

fasciculations

Question 80

checking for reflexes uses what motor neurones

Answer 80

gamma

Question 81

UMN signs seen in the descending motor tracts eg

Answer 81

corticospinal and corticobulbar ( also side note: also seen in extrapyradminal)

Question 82

positive babinski - upper or lower motor neurone lesion

Answer 82

upper

Question 83

postive babinksi is normal if

Answer 83

under 2 as the corticospinal tracts are not fully developed yet

Question 84

clonus - rhymic movemtns as its as series of contractions

Question 85

most common cause of ischaemic strokes

Answer 85

atherothromboembolii from the carotids

Question 86

strokes cause what signs

Answer 86

UMNs

Question 87

after strokes can regain sme fucntion in limb due to what tract

Answer 87

rubrospinal tract - is able to compensate for the loss of corticospainl fibres to a certain extent