Neuroanatomy Flashcards
1
Q
What are the 5 lobes of the brain?
A
Frontal Parietal Temporal Occipital Limbic
2
Q
What is the role of the frontal lobe?
A
Executive function - planning and decision making
Behavioural traits
Praxis - purposeful learned movement
Primary motor cortex - voluntary movements
Brocas area - speech (word formation and saying them)
3
Q
What is the role of the parietal lobe?
A
Sensory cortex - integrates sensory inputs
Object recognition
post central gyrus - conscious feelings of touch
4
Q
What is the role of the occipital lobe?
A
Vision, contains the visual cortex
5
Q
What is the role of the temporal lobe?
A
Primary auditory cortex (hearing)
emotions
learning and memory
6
Q
Where is the limbic lobe/ system located?
A
Deep to the temporal lobe
7
Q
What is the role of the limbic system?
A
Emotions
behaviour
smell
Associated with PTSD
8
Q
What is the role of the cerebellum?
A
Coordination and balance
9
Q
Longitudinal fissure
A
Separates the left and right hemispheres, stops at the corpus callosum
10
Q
What is a sensory homunculus
A
A pictorial representation of the primary somatosensory cortex
11
Q
Broca’s area
A
Speech formation
12
Q
Wernicke’s area
A
Speech understanding, located in the temporal lobe near the parietal lobe
13
Q
Where are the speech areas normally located?
A
Left hemisphere, but in some people they are in the right .
14
Q
What is dysphasia?
A
A deficiency in the formation / generation or comprehension of speech caused by a brain disease or damage. Receptive or expressive. Site of problem = speech centres - brocas or wernickes areas
15
Q
Broca’s dysphasia
A
Motor. expressive aphasia
inability to produce the words
limited effect on comprehension
16
Q
Wernicke’s dysphasia
A
Receptive/ sensory aphasia
speech is unaffected
speech is meaningless as they are unable to comprehend what they are being asked.
17
Q
Dysarthria
A
problems with the mechanical creation of words. Occurs in the motor neural pathway - upper/ lower or NMJ or pharyngeal muscles
18
Q
Dysphonia
A
Problems in production of sound for speech. Occurs in motor pathway or vocal cords .
19
Q
What is found within the brainstem?
A
Respiratory, cardiovascular and vomiting centres
Nuclei involved in motor control, sleep, respiration and bladder control
20
Q
What are the 3 parts of the brainstem?
A
Midbrain
Pons
Medulla
21
Q
What is the cardiovascular centre?
A
Responsible for regulation of heart rate, found in the medulla oblongata
22
Q
Respiratory centre
A
made up of 3 major groups - 2 in medulla and one in pons. Its main function is to control the rate of involuntary respiration
For voluntary respiration the motor cortex controls it. Voluntary respiration can be overridden by involuntary
23
Q
Pons
A
Contains nerve tracts - ascending and descending. Nerves of different pathways cross over at the medulla .
24
Q
Medullary pyramids
A
2 pyramid shaped swellings on the medulla oblongata, on either side of the ventral midline.
25
What are the 2 paired arteries that supply the brain?
Vertebral and Internal carotid
26
What do the vertebral and internal carotid arteries form?
Circle of Willis
27
What is the blood supply to the midbrain?
Basilar superior cerebellar
28
What is the blood supply to the pons?
Pontine
29
What is the blood supply to the medulla?
Anterior spinal artery
30
Regional blood supply
Anterior cerebral supplies the very front of the frontal cortex. The middle cerebral artery supplies the majority of the cerebral cortex. The posterior cerebral artery supplies the posterior of the parietal, occipital and inferior of the temporal lobes.
Anterior cerebral supplies all the centre of the brain up to corpus callosum and posterior cerebral supplies the posterior section.
31
Which artery is stroke most common in?
Middle cerebral - affects speech
32
Arteries supplying the spinal cord
3 - 1 anterior and 2 posterior.
33
Where does the anterior spinal artery originate?
Branches off the vertebral arteries
34
Where do the posterior spinal arteries originate?
Vertebral or posteroinferior cerebellar artery
35
Venous drainage of spinal cord
Anterior and posterior spinal veins drain into the internal and external vertebral plexuses
36
What are the 2 types of stroke?
Haemorrhagic and ischaemic
37
Ischaemic stroke
Obstruction within the blood vessel supplying the brain due to atherosclerosis
38
Haemorrhagic stroke
weakened blood vessel ruptures and bleeds into the brain. Blood accumulates and compresses the brain tissue
39
How to treat haemorrhagic stroke
Reverse existing anticoagulant treatment
| Give clotting factors and vitamin K
40
How to treat ischaemic stroke
Thrombolytics e.g. altepase injection
41
How to differentiate between the 2 types of stroke?
CT scan
42
management of stroke
aspirin for life
43
What is a TIA
Transient Ischaemic attack - mini stroke
44
What are the signs of a stroke
Facial weakness
Arm weakness
speech problems
45
What are the cranial nerves?
```
olfactory
optic
oculomotor
trochlear
trigeminal
abducens
facial
vestibulocochlear
glossopharyngeal
vagus
accessory
hypoglossal
```
46
How many branches does the trigeminal nerve have and what are they
3
Opthalmic
Maxillary
mandibular
47
What nerves do through the cribriform plate?
Olfactory
48
What nerves go through the optic canal
optic
49
What nerves go through the superior orbital fissure
Occulomotor
Trochlear
V1 - opthalmic
Abducens
50
What goes through the foramen rotundum?
V2 - maxillary
51
What goes through the foramen ovale?
V3 - mandibular
52
What goes through the foramen lacerum?
arteries, no nerves
53
What goes through the foramen spinosum?
Middle meningeal artery
54
What goes through the internal acoustic/ auditory meatus?
Vestibulocochlear and facial nerves
55
What does through the jugular foramen
Glossopharyngeal
vagus
accessory
nerves
56
Venous drainage of the brain
Drained by sinues that are hollow cavities in the skull where deoxygenated blood drains into. They are like veins but do not have valves
57
Main sinuses of the brain
```
Superior sagittal sinus
Inferior sagittal sinus
Straight sinus
Transverse sinus
Sigmoid sinus
```
58
What is found at the back of the head?
Confluence of the sinuses, where the sinuses all connect
59
Where do the sinuses drain into?
The internal jugular vein
60
What are the layers that cover the brain?
Dura mater
Arachnoid mater
Pia mater
61
what is the dural sinus
hollow spaces that collect pools of blood and drain into the internal jugular vein
62
Where are dural sinuses found?
Between the layers of the dura mater - periosteal and meningeal layers
63
How many sinuses are there?
11
64
Route through sinuses
Converge at confluence of sinuses > transverse sinus > sigmoid sinus > Internal jugular vein
65
Where are the straight, superior and inferior sagittal sinuses found?
Falx cerebri of dura mater
66
Straight sinus
A continuation of the great cerebral vein and inferior sagittal sinus
67
What does the cavernous sinus drain?
drains the ophthalmic veins and can be found either side of the sella turcica
68
What goes through the hypoglossal canal
Hypoglossal nerve
69
What is a cerebral venous sinus thrombosis
The presence of a thrombus within one of the dural venous sinuses. Venous return is occluded through the sinuses and causes an accumulation of deoxygenated blood and cerebrospinal fluid which can no longer drain .
70
How is cerebral venous sinus thrombosis treated?
Anticoagulation
71
What can accumulation of blood and cerebrospinal fluid cause?
Venous infarction
72
What are the symptoms of venous infarction?
Headache, nausea and vomiting
| neurological defects
73
How is venous infarction diagnosed?
CT or MRI scan
74
What innervates the meningeal layers?
Middle meningeal artery and trigeminal nerve
75
If there was pain due to stretching of the meningeal layers as a result of a haemorrhage where would the pain be referred to?
Face and forehead
76
What innervates the dura mater below the tentorium
Cervical plexus, so pain is referred to the back of the head and neck
77
Arachnoid mater
No innervations
beneath the arachnoid is the subarachnoid space - where the CSF is contained. Arachnoid granulations reabsorb CSF from the dural sinuses
78
Dura mater
Has no innervations and is avascular
| has 2 layers periosteal and meningeal
79
Pia mater
Underneath the subarachnoid space
tightly adhered to the surface of the brain - follows the gyri and fissures
Highly vascularised - vessels which supply the underlying neural tissue
80
Spinal meningeal layers
Dura mater - periosteal and meningeal layers join together
Arachnoid mater
Pia mater
81
What are the extensions of the dura mater that divide the brain?
Falx cerebri
Tentorium cerebelli
Falx cerebelli
Tentorial notch
82
Falx cerebri
In the longitudinal fissure between the cerebral hemispheres
83
Tentorium cerebelli
Separates the cerebellum from the occipital lobes
84
Falx cerebelli
Separates the 2 cerebellar hemispheres
85
Tentorial notch
An opening that is bounded by the anterior border of the tentorium cerebelli
86
Intracranial haemorrhage
Increases intracranial pressure
87
What are the types of Intracranial haemorrhage?
Epidural hematoma
Subdural hematoma
Subarachnoid hemorrhage
Intracerebral hemorrhage
88
Epidural hematoma
Blood accumulates between the skull and periosteal layer of the dura
89
Subdural hematoma
Subdural space blood collects between the dura and arachnoid mater - damage to cerebral veins
90
Subarachnoid hemorrhage
Bleeding into the subarachnoid space
91
Intracerebral hemorrhage
Bleeding inside your brain
92
Hematoma
Contained blood - clotted. Can result from an injury to any type of blood vessel.
93
Hemorrhage
Ongoing bleeding out of a structure
94
Meningitis
Inflammation of the meninges. Most commonly caused by Neisseria meningitidis and Streptococcus pneumoniae
95
Streptococcus pneumoniae
Gram positive spheres
| causes meningitis in the very young and elderly
96
Neisseria meningitidis
Gram negative spheres causing meningitis in the young adults and middle aged people .
97
What causes the symptoms of meningitis?
The immune response to the infection causes cerebral oedema which raises intracranial pressure. Complications of this can cause death
98
Effects of meningitis
Raised ICP causes part of the brain to be forced into the cranial cavity - cranial herniation. Systemic hypotension - dilation of blood vessels because of toxins. Raised intracranial pressure reduces cerebral perfusion.
99
Treatment for meningitis
Antibiotics - Penicillins, aminoglycosides - Gentamicin, Cefotaxime
100
Effect of meningitis on spinal cord
Infection spreads down the meningeal layers, which is why meningitis can be diagnosed by a lumbar puncture.
101
what are the parts of the spinal vertebrae?
```
Spinous process
Spinal canal
Transverse process
Articular process
Vertebral body
Lamina
Pedicle
Intervertebral foramen
```
102
How to distinguish between different types of vertebrae?
They get larger, lumbar is larger due to need for weight bearing lower down the spine .
103
Where does the spinal nerve emerge?
Intervertebral foramen
104
How many cervical vertebrae and nerves are there?
7 vertebrae and 8 nerves
105
How many thoracic nerves and vertebrae are there?
12
106
How many lumbar nerves and vertebrae are there?
5
107
How many sacral nerves and vertebrae are there?
4
108
Where is the lumbar puncture done?
L3/4
109
Where is an epidural done?
L3/4
110
What do you collect in a lumbar puncture?
CSF
111
Spina bifida
Malformation of spine, meaning there is no bone covering the spinal cord
112
Cauda Equina
w
113
Why do you get a headache after a lumbar puncture?
If CSF escapes from the site there is reduced intracranial pressure which causes the brain to sag and pulls on the meningeal attachments - worse on sitting/ standing
114
Cerebrospinal fluid
75ml in brain and 75ml in spine
115
where is CSF produced?
Choroid plexus by ependymal cells in the lateral and 3rd ventricles.
116
Route of CSF
Flows from lateral to 3rd ventricle via foramina of Monro and then through aqueduct of Sylvius into 4th ventricle
Flows over surface of brain and spinal cord
117
What reabsorbs CSF
Arachnoid granulations
118
What is the function of CSF?
cushions brain
regulated ICP
acts as a transfer medium for nutrients, elimination of metabolic products and circulates neurotransmitters
119
Intracranial pressure normal
<10mmhg
120
Raised ICP
Will compromise the cerebral perfusion pressure and cause a lack of perfusion through the brain. Compensation can occur quickly - more CSF will move into the spinal space and lower it. This may not be enough
121
How is ICP regulated long term?
Variation in reabsorption of CSF as production is constant
122
What is in CSF?
Glucose
Protein
Ions
123
Hydrocephalus
CSF blockage leading to a build up of CSF causing raised ICP.
124
Types of hydrocephalus
Communicating - still circulating not being reabsorbed
| Non-communicating - blockage
125
Treatment for hydrocephalus
Temporarily relieved by shunt
126
Common causes of hydrocephalus
Tumours
Hemorrhage
Aqueduct blockage
127
Symptoms of Hydrocephalus
Enlarged head in babies
| prominence of the veins of forehead
128
What is grey matter?
Cell bodies
129
What is white matter?
Axons
130
White and grey matter in brain
White is in the centre and grey outside
131
White and grey matter in spinal cord
White matter is on the outside and grey in the centre
132
What are the types of cortical fibres?
Association
Commissural
Projection
133
Projection fibres
Run between the cerebral cortex and subcortical structures - diencephalon, brainstem and basal ganglia
134
Association fibres
Connect cortical sites in one hemisphere
135
Commissural fibres
Run between the 2 cerebral hemispheres via corpus callosum
136
What is myelin?
White, lipid rich wrapping layer that surrounds an axon
137
Function of myelin
Provides electrical insulation and prevents current loss/ ion leakage and causes saltatory conduction
138
What are the types of myelination?
Schwann cells
| Oligodendrocytes
139
Schwann cells
PNS
whole cell wraps around axon
applied to single neuron
140
Oligodendrocyte
CNS
| process from cell wrap around axon and are applied to multiple neurones
141
Input and output to spinal cord
Sensory input comes into the dorsal horn and motor output from the ventral horn
142
Where does the spinocerebellar tracts get their inputs from?
Muscle spindles
| Golgi tendon organs
143
What are the somatosensory pathways?
Dorsal columns
| Spinothalamic tracts
144
What do the dorsal columns provide input on?
Proprioception, pressure, vibration and fine touch
145
What do the spinothalamic tracts provide input on?
Pain, temperature and crude touch
146
Fine touch
Sense and localisation of touch
147
Crude/ coarse touch
Sense of touch but cannot localise
148
Somatosensory pathways
Involves 3 neurons and the thalamus is the relay station
149
Thalamus
Large mass of grey matter that relays sensory signals and motor signals to the cerebral cortex. Can screen out irrelevant information. Specific nuclei for certain functions. Extensive CNS connections
150
Somatic body senses
```
Pain sharp vs dull
touch fine vs coarse
pressure
temperature
proprioception
vibration
```
151
Special senses
```
Vision
Hearing
Taste
Smell
Balance
```
152
Lateral spinothalamic tract
1st order neurone enters via dorsal root and synapses in dorsal horn
crosses at spinal level
pain and temperature
153
Anterior spinothalamic tract
crude touch
synapses at thalamus so ascends to the contralateral side of stimulus
crosses at spinal level
154
Dorsal columns
1st order neurone enters via dorsal root and ascends ipsilaterally
synapses and crosses in medulla - 2nd order neurone to thalamus
3rd order neurone to cortex
155
Motor pathways?
Lateral and anterior corticospinal tracts
| only 2 neurons in each pathway - upper and lower motor neurones
156
Lateral corticospinal tract
Crosses at medullary pyramids and synapses at ventral horn
157
Upper and lower motor neurones
Upper = within CNS
Lower = from CNS to periphery
Cranial nerves = lower
158
Anterior corticospinal tract
Descends ipsilaterally and decussates at spinal cord level . Synapses at ventral horn
159
Upper motor neurone lesion
```
Increased muscle tone
No change in muscle bulk
Increased reflexes
Clonus
Babinskis reflex - upgoing
No fasciculations
```
160
Lower motor neurone lesions
```
Decreased muscle tone
Reduced muscle bulk - wasting
Decreased or absent reflexes
Babinskis reflex is normal
Fasciculations
```
161
Sensory lesions
Paraesthesia / numbness
162
Motor lesion
weakness/ paralysis
163
Brown sequard syndrome
spinal lesion that causes weakness or paralysis on one side of the body and a loss of sensation on the opposite side
164
Hemiparaplegia
one sided weakness/ paralysis
165
Hemianesthesia
loss of sensation on one side of the body
166
Syringomyelia
Development of a fluid filled cyst within the central spinal cord. Loss of pain, temperature and coarse touch and bilateral weakness due to damage to crossing fibres of spinothalamic
167
Spondylosis
refers to degenerative changes in the spine - bone spurs and degenerating intervertebral discs
168
Lesions
Loss always occurs below the lesion
169
Poliomyelitis
Lower motor neuron lesions due to destruction of ventral horns - flaccid paralysis
170
Multiple Sclerosis
Mostly white matter of cervical region, random and asymmetric lesions due to demyelination. Scanning speech, intention tremor and nystagmus
171
ALS
combined upper motor and lower motor neuron deficits
172
Tertiary Syphilis
Degeneration of dorsal roots and dorsal columns, impaired proprioception and locomotor ataxia
173
Vitamin B12 neuropathy
demyelination of dorsal columns, lateral corticospinal tracts and spinocerebellar tracts - ataxic gait, hyperreflexia, impaired position and vibration
174
Are the cranial nerves motor or sensory?
```
Sensory
Sensory
Motor
Motor
Both
Motor
Brother
Sensory
Both
Both
Motor
Motor
```
175
Where does the olfactory nerve come from?
cerebrum
176
Role of olfactory nerve
Smell
177
Where does the optic nerve come from?
cerebrum
178
Where does the trochlear nerve come from?
Midbrain
179
Where does the oculomotor nerve come from?
midbrain-pontine junction
180
Where does the trigeminal nerve come from?
pons
181
Where does the abducens nerve come from?
pontine-medulla junction
182
Where does the facial nerve come from?
pontine-medulla junction
183
Where does the vestibulocochlear nerve come from?
pontine-medulla junction
184
Where does the glossopharyngeal nerve come from?
medulla
185
Where does the vagus nerve come from?
medulla
186
Where does the accessory nerve come from?
medulla
187
Where does the hypoglossal nerve come from?
medulla
188
Role of optic nerve
sensory
| transmits visual info to brain
189
Role of oculomotor nerve
all muscles except superior oblique and lateral rectus
190
role of inferior oblique muscle
moves eye up and in
191
Role of superior oblique muscle
moves eye down and in
192
Role of trochlear
Innervates superior oblique
193
Trochlear nerve palsy
```
normal = when head tilts to the left both eyes rotate in opposite direction
palsy = compensatory head tilt on opposite side
```
194
What happens when superior oblique is paralysed?
slight drift of pupil upwards and difficulty looking down
vertical diplopia in affected eye
patient presents with a head tilt to compensate for vertical diplopia
195
Role of opthalmic branch of trigeminal
sensation to forehead and scalp and upper part of face
196
Role of maxillary branch
sensation to cheeks and nasal cavity and upper lip
197
Role of mandibular
sensation of tongue and innervates and muscles of mastication
198
Trigeminal Neuralgia
Chronic pain disorder affecting trigeminal nerve
| caused by idiopathic - relating to compression of nerve or loss of myelin
199
signs and symptoms of trigeminal neuralgia
intense facial pain - electric shock and burning sharp pain
pain lasts minutes and comes on in bouts
triggered by eating, wind, shaving, talking, brushing teeth
200
Investigations for trigeminal neuralgia
usually none/ MRI
201
Treatment of trigeminal neuralgia
carbameazepine
| decompression or destruction of nerve
202
Role of abducens nerve
innervates lateral rectus
| purely motor
203
Clinical features of abducens nerve palsy
Nasal shoot
diplopia
adduction of eye - unopposed activity of medial rectus
patient may compensate by rotating their head to look sideways
204
Role of facial nerve
Sensory and motor functions
innervates muscles of facial expression and taste to anterior 2/3 of tongue
innervates to lacrimal gland and submandibular and sublingual salivary glands
205
Branches of facial nerve
```
temporal
zygomatic
buccal
marginal mandibular
cervical
```
206
Bell's palsy
palsy of facial nerve
similar presentation to stroke
entire half of face paralysed, in stroke forehead is spared
limb movement and strength is preserved in bell's palsy
207
Salivary glands and innervations
Submandibular- facial
sublingual - facial
parotid - glossopharyngeal
208
Parotidectomy
can damage facial nerve as it runs through but does not innervate the parotid gland
209
Role of vestibulocochlear
sensory
| hearing and balance
210
Vestibular schwannoma/ acoustic neuroma
benign primary intracranial tumour of myelin forming cells of the vestibulocochlear nerve
occurs in middle aged people
unknown cause
211
Signs/ symptoms and diagnosis and treatment of vestibular schwannoma
```
hearing loss
tinnitus
balance affected
facial weakness
taste affected
MRI
radiotherapy and surgery
```
212
Role of glossopharyngeal nerve
sensory
taste to posterior 1/3 of tongue
gag reflex
innervates parotid gland
213
Role of vagus nerve
innervates:
1. skin of external acoustic meatus
2. larynx
3. visceral sensation to heart and abdomen
4. provides taste sensation to the epiglottis and root of tongue
5. muscles of pharynx, soft palate and larynx
6. parasympathetic innervation of smooth muscle of trachea, bronchi and gastro-intestinal tract
7. regulates heart rhythm
214
Injury to vagus to nerve
normally uvula is in midline
if one side of the vagus nerve is damaged the uvula elevates asymmetrically and deviates towards the strong side and away from the side of tumour/ injury
215
Role of accessory nerve
innervates the sternocleidomastoid
216
Role of hypoglossal nerve
innervates intrinsic and extrinsic muscles of tongue
| tongue movements, speech and swallowing
217
Palsy of hypoglossal
tongue deviates to one side - toward affected side
218
Ramsay Hunt syndrome
shingles affecting facial nerve which causes facial paralysis and hearing loss
219
treatment for ramsay hunt syndrome/ shingles/ HSV/ Herpes virus
valacyclovir
220
What causes a thunderclap headache?
Subarachnoid hemorrhage
221
What is hypercarbia?
Raised carbon dioxide levels
222
autonomic innervation of blood vessels of cerebral cortex
none
