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MBChB1 Phase 1 > Week 12 > Flashcards

Week 12 Flashcards

1
Q

How many pairs of spinal nerves are there?

A

31
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal

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2
Q

How many pairs of cranial nerves are there?

A

12

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3
Q

Name each cranial nerve and function

A

Olfactory - smell
Optic - vision
Oculomotor - eye movements
Trochlear - eye movements
Trigeminal - motor to muscles of mastication and general sensory to face
Abducens - eye movements
Facial - muscles of facial expression
Vestibulocochlear - hearing and balance
Glossopharyngeal - swallowing, taste
Vagus - wandering nerve supplying, heart, lungs, gut
Spinal accessory - neck muscles
Hypoglossal - tongue muscles

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4
Q

What are the special senses?

A

Vision - optic nerve
Taste - glossopharangeal and facial
Hearing and balance – vestibulocohlear
Smell - olfactory

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5
Q

What is the sclera of the eye and composition? Function?

A

White of the eye/outer layer
Fibrous and elastic tissue
Determining where someone is looking

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6
Q

What is the iris of the eye? Function? Composition?

A

Coloured part of eye
Controls diameter of pupil
Smooth muscle

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7
Q

2 muscles in iris of eye?

A

spincter pupillae and dilator pupillae

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8
Q

when do pupils get wider?

A

in the dark

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9
Q

Most common structure for transplant? Why?

A

Cornea
Avascular
Less likely to reject tissue from someone else as no blood

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10
Q

When can the optic nerve of the eye been seen? What does it look like?

A

When using opthalmoscope
Performing fundoscopy
Solid white sturtcure in middle of retina

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11
Q

What is the optic nerve surrounded by? What happens to it when there is intercranial pressure?

A

Meningeal layers
Will be transmitted along nerve and cause bulging of optic disc

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12
Q

What is papillodema?

A

bulging of optic disc

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13
Q

when is intercranial pressure increased?

A

bleed or tumour

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14
Q

What is keratoconus?

A

thinning of cornea resulting in coning shape
causing blurring and double vision
surgery/cornea transplant required

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15
Q

what is jaundice? what can it indicate?

A

yellowing of eye/sclera
indicates blood disorders or liver problems

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16
Q

Main composition of eyes?

A

water and electrolytes

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17
Q

What is within anterior and posterior chambers of the eye? What is it made from? Circulation? Function?

A

Aqueous humour
ciliary bodies
circulates from anterior to posterior
maintains pressure in eye, provides nutrients to eye, protects eye

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18
Q

What is in vitreous chamber of eye? Composition?

A

Contains vitreous humor
gel between lens and retina
contains phagocytes to remove cell debris
mainly water and no blood vessels

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19
Q

Function of retina? What is contained here?

A

light sensitive layer of tissue
rods - black
cones - colour vision

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20
Q

Were does optic nerve take impusles from pupil?

A

pupil to vitreous humor
retina
optic nerves to optic tract
some info passes to other side by optic chiasm
then occipital lobe

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21
Q

Where are tears produced? Function?

A

lacrimal gland
- lubricates movement
- removes debris
- tears go from lateral to medial and drains into nose

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22
Q

function of nasolacrimal duct?

A

takes tears from lacrimal gland to nasal cavity
to opening under inferior nasal meatus

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23
Q

what is the canal containing nasolacrimal duct called?

A

nasolacrimal canal

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24
Q

Name parts of the eye

A
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25
Q

Name bones of the orbit

A
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26
Q

which orbit bone is one of the thinnest in the body?

A

lacrimal

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27
Q

why is the nose ,more anterior of the orbit?

A

allows wider lateral gaze of each eye in bony orbits

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28
Q

where are the paranasal sinuses?

A

maxillary - under eye
fronal - forehead
ethmoid and spenoid - posterior to nose

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29
Q

function of sinuses?

A

reduces weight of skull
allows circulation of mucous
resonance of sound

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30
Q

what happens when eyeball is herniated?

A

double vision/diplopia
eyeball passes into maxillary sinus

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31
Q

how many ethmoid sinuses are there?

A

30-40

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32
Q

what cavities have sinuses?

A

orbital
nasal
oral cavities

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33
Q

function of extraocular muscles?

A

corrects eyeball position to look straight ahead
eyes usually point laterally and superiorly

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34
Q

what cranial nerves control extra ocular muscles?

A

III
IV
VI

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35
Q

How many extra ocular musclea are there? functions?

A

7
movement of eye
keeps upper eyelid open

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36
Q

which types of extraocular muscles move the eyes?

A

recti and obliques

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37
Q

which types of extra ocular muscles keep eyelids open?

A

levator palpebrae superioris

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38
Q

Function of superior rectus?

A

elevation of eyeball

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39
Q

function of inferior rectus?

A

depression of eyeball

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40
Q

function of medial rectus?

A

adducts eyeball

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41
Q

function of lateral rectus?

A

abducts eyeball

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42
Q

funcions of superior oblique?

A

depresses eyeball
abduction
medial rotation

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43
Q

functions of inferior oblique?

A

elevation
abduction
rotation of eyeball

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44
Q

which nerve innervates most extraocular muscles?

A

oculomotor nerve III

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45
Q

what muscle does the trochlear nerve innervate?

A

superior oblique

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46
Q

what muscle does the abducent nerve innervate?

A

lateral rectus

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47
Q

functions of nasal cavity?

A

warms
humidifies
filters air

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48
Q

why is nasal cavity suited to its function?

A
  • rich, superficial blood supply (warmth)
  • mucous supplies moisture
  • mucous and hair traps particles
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49
Q

function of olfactory nerve? where is it found?

A
  • converts chemical info (smells) to electrical
  • superior surface of nasal cavity
  • defence mechanism (e.g. poisoning)
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50
Q

function of tongue?

A

moves food for mastication
swallowing
speech
taste (tongues upper surface)

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51
Q

2 parts of tongue?

A

oral part anteriorly
pharangeal part at back

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52
Q

function of sublingual gland?

A

mucous secreting salivary gland

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53
Q

name parts of the tongue

A
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54
Q

what is the buccal surface?

A

side of mouth where surface is at teeth

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55
Q

what is lingual surface?

A

surface that faces bottom of tongue

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56
Q

what is the floor of the mouth formed by?

A

mylohyoid muscle
overlying stratified squamous epithelium
U shaped

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57
Q

Name parts of mouth

A
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58
Q

What is the fungiform papillae?

A

mushroom like on front 2/3 of tongue

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59
Q

what is foliate papillae?

A

leaf like and vertical ridges on side of tongue

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60
Q

what are filiform papillae?

A

threadlike and serve as coating mechanism
creates rough and abrasive tecture for speaking and chewing

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61
Q

what are vallate papillae?

A

only a dozen
minor salivary glands
some taste buds

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62
Q

what are foramen caecum?

A

primitive tract where thyroglossal duct was
represents where thyroid gland was in embryological development

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63
Q

what is epiglottis?

A

elastic cartilage closes over trachea in swallowing

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64
Q

name parts of the tongue

A
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65
Q

what is the chorda tympani?

A

branch of facial nerve
carries taste fibres from front 2 thirds of tongue

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66
Q

where does chorda tympani run through? what does it join?

A

middle ear
lingual nerve from mandibular division of trigeminal nerve

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67
Q

function of mandibular division of trigeminal nerve?

A

carries sensory info from front 2/3 of tongue and lower 1/3 of face

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68
Q

what cranial nerves does lingual nerve carry axons from?

A

V3 and VII

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69
Q

function of glossopharangeal nerve in tongue?

A

taste and general sensation from posterior 1/3

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70
Q

function of hypoglossal nerve in tongue?

A

motor control of most tongue muscles

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71
Q

where does facial and vestibulocohelear nerve enter middle ear?

A

internal auditory meatus in temporal bone

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72
Q

2 parts of temporal bone?

A

squamous (flat part)
petrous (rocky)

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73
Q

function of ear ossicles?

A

transmit vibrations through middle ear

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74
Q

3 ear ossicles?

A

malleus
incus
stapes

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75
Q

what is malleus attached to?

A

tympanic membrane

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76
Q

what is on the lateral wall of tympanic cavity?

A

tympanic membrane aka ear drum

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77
Q

what is on the medial wall of tympanic cavity? what is it closed by?

A

vestibular window/oval window
opening into vestibule of ear
closed by base of stapes

cochlear/round window
opening into cochlea of inner ear

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78
Q

how do soundwaves get to brain?

A

enter through external auditory meatus
tympanic membrane vibrates
malleus, incus and stapes vibrate
oval window vibrates
fluid in scala vestibuli vibrates
vibration hits round window
stereocilia transmits info to vestibulocohlear nerve

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79
Q

function of cochlea?

A

sound amplification
converts vibration to electrical signal
signal transmitted to vestibulocochlear nerve

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80
Q

function of semicircular canals?

A

balance
vestibulocohlear nerve

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81
Q

what links pharynx to ear? function?

A

eustachian tube
maintains pressure in middle ear as same level as pharynx

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82
Q

why do childrens ears get infected more easily?

A

auditory tube in children is smaller
infection in throat can pass to middle ear
otitis media

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83
Q

Where can temperature be recorded? How?

A

axilla, rectum, ear
thermometer/electronic probe

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84
Q

Why is tympanic membrane / ear temperature usually recorded in hospitals?

A

minimally invasive
reflects core temperature: close to internal carotid artery and tympanic membrane blood supply

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85
Q

What is the instrument used to examine the ear? What studtucre does this show?

A

Otoscope
Tympanic membrane (pearly grey/translucent appearance)

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86
Q

What is otitis media? when is it common?

A

middle ear infection/inflammation, associated with collection of fluid
first year of life

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87
Q

clinical features of middle ear infection?

A

otalgia/earache
decreased hearing
fever, vomiting, irritability, tugging at ear, poor feeding

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88
Q

what is the shape and arrangement of steptococcus pneumoniae?

A

gram positive (blue) cocci in chains

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89
Q

what is sensorineural hearing loss?

A

disease of the cochlea/organ of corti/CN VIII or more CNS pathways

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90
Q

what is conductive hearing loss?

A

failure of conducting mechansims of outer and middle ear to transmit sound to fluids of inner ear

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91
Q

how are sound waves converted to electrical signals?

A
  • sound waves collected by pinna and travel down ear canal
  • tympanic membrane stretched across end of external auditory canal and air molecules vibrate at same frequency of sound wave
  • vibrations transmitted and amplified through ossicles to oval window
  • oval window to scala vestibuli and then scala media (cochlear duct)
  • pressure waves across cochlear duct vibrate basilar membrane where organ of corti located
  • stereocilia bend and open ion channels in plasma membrane of hair cell and depolarise it
  • receptor potential created, hair cells release exitatory neurotransmitted which excites afferent cochlear neurons
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92
Q

what does the prefix ot mean?

A

the ear

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93
Q

what is suppuration?

A

pus production

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94
Q

what embrological component makes up the mucosal surface of the anterior 2/3 of tongue?

A

first branchial arch endoderm

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95
Q

what does the first branchial arch endoderm form?

A

tuberculum impar (midline)
lateral lingual swellings

95
Q

what embrological component makes up the posterior 1/3 of tongue?

A

third branchial arch endoderm

96
Q

what does the third branchial arch endoderm form?

A

cupula

97
Q

what innervates the anterior 2/3 of tongue?

A

trigeminal nerve for touch and pain
facial nerve for taste

98
Q

what innervates the posterior 1/3 of tongue?

A

glossopharangeal nerve

99
Q

what forms the intrinsic and extrinsic muscles of the tongue?

A

mesoderm in upper neck (occipital somites)

100
Q

what innervates the tongue muscles?

A

hypoglossal nerve

101
Q

label the tongue

A
102
Q

function of intrinsic muscles in tongue?

A

change shape of tongue

103
Q

what muscle of the tongue is not inner vated by the hypoglossal nerve?

A

palatoglossus

104
Q

structure and function of lingual tonsils?

A

produce antibodies
lymphoid tissue

105
Q

what is the foramen caecum?

A

where thyroid gland developed in early life

106
Q

what is the circumvallate papillae? how many?

A

boundary between anterior and posterior tongue
12

107
Q

function of fungiform papillae?

A

taste buds here

108
Q

function of filiform papillae?

A

rough surface of manipulation of food

109
Q

5 primary tastes?

A

sour
salty
sweet
bitter
savoury/unami

110
Q

what is sour taste component?

A

acid, H+

111
Q

what is salty taste comonent?

A

sodium

112
Q

what is sweet taste component?

A

glucose

113
Q

what makes up bitter?

A

coffee
beer
blue cheese
olive

114
Q

what makes up savory/unami taste?

A

glutamate - ramen

115
Q

why is btterness most sensitive taste?

A

protects against poisoning

116
Q

why are sweet, salt, sacory and sour all associated with pleasure?

A

to incentivise nutrition

117
Q

how is taste carried to brain? anterior 2/3 of tongue

A

lingual nerve (first branch of trigeminal) then chorda tympani then facial nerve then brain stem

118
Q

how is taste carried to brain , posterior 1/3 of tongue?

A

glossopharangeal

119
Q

where do taste fibres synapse in brain?

A

solitary nucleus of medulla, thalamus, gustatory cortex

120
Q

how is pungency aka chilli mediated?

A

pain/temperature receptors

121
Q

how is collness/menthol mediated?

A

temperature receptors

122
Q

what does temperature of food enhance?

A

release of odorants to nose

123
Q

how can ear surgery damage to chorda tympani damage taste?

A

if bilateral, unpleasant metallic taste in mouth

124
Q

what happens if durgery to sublingual and submandibular salivary glands damages lingual nerve?

A

loss of taste unilaterally and loss of common sensation in floor of mouth and tongue

125
Q

what happens in quiet breathing?

A

laminar airflow over inferior intubate

126
Q

what happens when you sniff?

A

turbulence to mix air and send odorants to roof of nose

127
Q

where does olfactory mucosa lie? what is above?

A

below cribiform plate
olfactory bulbs

128
Q

where do odorant molecules in the air dissolve?

A

nasal mucus

129
Q

what is smell detected by?

A

detectors on dendrites of olfactory cells

130
Q

how many active smell genes in human?

A

400

131
Q

where does olfactory nerve project to in brain?

A

amygdala
hippocampus
parahippocampal gyrus

132
Q

what sensory modality doesnt relay primarily to thalamus?

A

smell
goes straight to limbic system instead

133
Q

what is kallmann syndrome?

A

congenital anosmia
congenital in children

134
Q

how can anosmia be acquired?

A

chronic rhinosinusitis
neurological disorders aka parkinsons
base of skull fracture
brain tumor
covid

135
Q

how can lack of smell risk health?

A

smoke alarm
off food

136
Q

how many taste receptord are there?

A

5

137
Q

what is majority of taste>

A

smell

138
Q

why has life expectancy increased?

A

improements in public health

139
Q

what does public health respond to?

A

societal health concerns
science, ethics

140
Q

definition of public health?

A

collective action for sustained population-wide health improvemetn

141
Q

what is in the first wave of public health? when was it?

A

1830-1900
public health interventions e.g. handwashing and wateer

142
Q

what was the miasma paradigm of disease? when was it?

A

first wave
disease was caused by bad air

143
Q

what was the second wave of public health? when?

A

1890-1950
germ theory
scientific rationalism

144
Q

what are the 3 components of germ theory?

A

host
vector - air, water
agent - viruses and bacteria

145
Q

what was the third wave of public health?

A

1940-1980
emergence of nhs
social housing

146
Q

what is health?

A

state of physical, mental and social well being

147
Q

what is the biophyscosocial model of health?

A

third wave
mental health at centre

148
Q

what is the forth wave of public health?

A

1960-2000
risk factors and life style central concern
social inequalities

149
Q

what are the health concerns of today?

A

health inequalities
obesity
population growth and ageing demographic
human impacts on planets life support systems
climate change

150
Q

what is health protection?

A

set of activities in public health
- ensuring safety and wuality of food/air/environent
- preventing transmission of communicable diseases
- managing outbreaks

151
Q

what exactly is sound?

A

vibration of medium
spreads out as wave of pressure
spreads outwards from a source

152
Q

what is hertz a measure of?

A

pitch

153
Q

what is herts exactly?

A

frequency in cycles per second

154
Q

what is range of human hearing?

A

20-20k

155
Q

how do you measure loudness of sound?

A

decibels

156
Q

what is 3db?

A

twice the sound energy

157
Q

what is 10db?

A

10x sound energy
twice perceived loudness

158
Q

what is thereshold in hearing?

A

quietest sound heard at each frequency

159
Q

what is sound pressure defined as?

A

db spl

160
Q

what is measuring sound pressure against hearing theresholds in young adults with normal hearing?

A

dB HL

161
Q

what medium is required for sound?

A

something thats particle vibrates
air, water, rock

162
Q

what is freuqency made from?

A

number of vibrations per second

163
Q

what is loudness of sound?

A

strength of vibrations

164
Q

what is the loudest sound you can hear?

A

100 trillion times energy of quietest

165
Q

what is an audiogram?

A

hearing test

166
Q

what is the outer ear made of?

A

pinna
ear canal

167
Q

what is the middle ear made of?

A

tympanic membrane
ossicles

168
Q

what is the inner ear made of?

A

cochlea
vestibule

169
Q

why do we have to ears? why?

A

localisation of sound - allows you to determine where sound is coming from
due to inter aural time difference, and difference in loudness

170
Q

function of pinna?

A

amplifies and filters incoming sounds
filtering at certain frequencies

171
Q

how long is the ear canal?

A

2.5cm

172
Q

how much do pinna and canal increase pressure by?

A

20dB

173
Q

why is frequecy filtering useful?

A

sound localisation in vertical and front back planes

174
Q

function of oval window?

A

amplifies sound by concentrating energy

175
Q

function of 3 ossicle system?

A

amplification
sensitivity to high-frequency sounds
stronger bite

176
Q

what is the first branchial arch form?

A

malleus and incus

177
Q

what does second branchial arch form?

A

stapes

178
Q

2 protective muscles in middle ear? function?

A

stapedius reflex
tensor tympani
protects against loud sounds

179
Q

what does eustachian tube connect?

A

connects nasopharync to middle ear

180
Q

functions of eustachian tube?

A

allows air to enter and leave middle ear
keeps air pressure in middle ear space same as ambient atmospheric pressure

181
Q

why is it important to have middle ear at same pressure as pharynx?

A

allows tympanic membraen to vibrate

182
Q

dysfunction of eustachian tube?

A

blocked feeling
poor hearing

183
Q

when is eustachian tbe open/closed?

A

open - swallowing
closed - rest

184
Q

what is conductive hearing loss caused by?

A

ear canal - wax, foreign body
tympanic membrane - perforation
ossicles - congenital fusion, damage in infection
middle ear space - fluid instead of air

185
Q

what is sensorineural hearing loss?

A

congenital and not acquired

186
Q

how can you get sound to inner ear alternatively?

A

cochlear impant

187
Q

how is sound amplified in the ear?

A

tympanic membrane has larger surface area than oval window

188
Q

function of vestibular apparatus?

A

contains sensory structures for balance and head movements

189
Q

function of cochlea?

A

sensory epithelium for hearing
organ of corti

190
Q

how does vibration get to the cochlea?

A

oval window faces into vestibule
vestiuble contains sensory epithelia
vestibule leads into scala vestibuli (upper cochlear duct)
pressure waves travel along scala vestibuli and back through scala tympani (lower part)
waves terminate at round window

191
Q

function of organ of corti?

A

sensory epithelium containing auditory hair cells

192
Q

function of stria vascularis?

A

regulates ionic and metabolic functions of scala media

193
Q

4 parts of organ of corti?

A

spiral ganglion
auditorynerve fibres
tectorial memvrane - above
basilar membrane - sits on

194
Q

when is frequency stiff and light?

A

high frequency
base of cochlea

195
Q

when is frequency flexible and heavy?

A

low frequency
apex of cochlea

196
Q

where do hair cells originate? what do they form and where?

A

epithelial origian - remeble cells lining stomach
stereocillia form bundle at apical pole of hair cell

197
Q

what membrane does the cochlea sit on?

A

basilar membrane

198
Q

how are stereocilia arranged?

A

shortest to tallest

199
Q

what happens when stereocilia are pushed towards the tallest?

A

depolarisation
potassoim channels open, potassium flows into cells from endolymph

200
Q

what happens when stereocilia are pushed towards shortest?

A

hyperpolarisation
potassium channels closed

201
Q

what are inner hair cells innervated by?

A

afferent
lateral efferent

202
Q

what are outer hair cells inervated by?

A

medial efferent

203
Q

what happens when outer hair cells are stimulated by movement of basilar membrane?

A

change shape and stiffness
reverse transduction
cochlear amplifier

204
Q

what is reverse transduction by outer hair cells?

A

feeding energy back into basilar membrane when stimulated

205
Q

how do outer hair cells act as a coclear amplifier?

A

increases amount of vibration on basilar membrane at point of macimal vibration

206
Q

other function of outer hair cells?

A

improves frequency selectivity

207
Q

what are are otoacoutic emmisions? when are these important?

A

outer hair cells move in response to noise, can measure this
screening test for hearing loss in babies

208
Q

what can hair cells in ear be sensitive to?

A

infection, ototoxins, noise
aging
sensorineural hearing loss

209
Q

what happens if you lose inner hair cells?

A

no signal to brain
can loss a lot of hearing

210
Q

what happens if outer hair cells are lost? how much hearing loss?

A

basilar vibration insufficiently amplified
approx 50 db loss in hearing
loss of sound discrimination

211
Q

how do hearing aids work?

A

microphone - amplifier - speaker
make everythign louder
corrects conductive hearing loss

212
Q

what do you lose with hearing aids?

A

lose discrimination of sound
lose dynamic range
central processing affects

213
Q

how is pitch encoded?

A

position of hair cells

214
Q

how do cochlear implants work?

A

stimulates spiral ganglion cells if severe hearing loss due to loss of hair cells

215
Q

what can solve hearing loss if auditory nerve lost? why would auditory nerve be lost?

A

can put hearing implant onto cochlear nucleus in brainstem
tumor on nerve
results arent great

216
Q

why doesnt stroke/cns damage cause hearing loss?

A

above cochlear nuclei representation is bilateral

217
Q

what is tonotopic map? where is this maintained to?

A

arrangement of frequencies
primary auditory cortex

218
Q

where is sound processed?

A

come from neurons in spinal ganglion of cochlea
travel in CN VIII
synapse in cochlear nuclei (junction of medulla and pons)

219
Q

how is impendance mismatch overcome?

A

The transmission of mechanical energy
from the air to the fluid of the cochlea by the middle ear.

220
Q

Which interleukin can reset the thermostat in the hypothalamus?

A

IL-2

221
Q

What is IL-2 involved in?

A

T cell proliferation/differentiation

222
Q

what protein in the organ of corti can cause deafness? where is it?

A

alpha tectorin
tectorial membrane

223
Q

Which molecule protects the stomach lining?

A

prostagandins made by cox-1

224
Q

which cochlear structure causes endolymph production (fluid in ear)?

A

stria vascularis

225
Q

organ of corti function?

A

vibrations converted to electrical signals

226
Q

which part of eye regulates amount of light taken to photoreceptor cells?

A

iris

227
Q

what activity do nsaids inhibit?

A

cyclooxygenase

228
Q

name 2 eicosanoids?

A

thromboxane
prostaglandins

229
Q

function of lipooxygenase?

A

produces leukotrienes

230
Q

leukotriene function?

A

inflammatory mediator

231
Q

what does cyclooxygenase produce?

A

eicosanoids

232
Q

which structure determines pitch?

A

bending of basilar membrane

233
Q

what does the stria vascularis line?

A

scala media

234
Q

What would indicate loss of hearing in an otoacoustic emmisions test?

A

reflected sound only - 1 recorded sound

235
Q

differences betwene inner and outer hair cells?

A

inner:
more afferent inputs
primary receptor
transducer
kidney bean shape

outer hair cells:
more efferent inputs
secondary receptor
amplifier
straight shape

MBChB1 Phase 1 (12 decks)

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