Brain and Behaviour Flashcards
1
Q
Anterior cranial fossa bones and contents
A
Bones = frontal, ethmoid, sphenoid Contents = frontal lobes
2
Q
Middle cranial fossa bones and contents
A
Bones = sphenoid, temporal Contents = temporal lobes, pituitary gland
3
Q
Posterior cranial fossa bones and contents
A
Bones = sphenoid, temporal, parietal, occipital Contents = brainstem, cerebellum
4
Q
Accessory nerve innervation
A
SCM and trapezius
5
Q
Foramen spinosum
A
Middle meningeal artery
6
Q
What the sympathetic nerve can do once it has entered the sympathetic trunk
A
Synapse
Ascend or descend
Leave
7
Q
Conus medullaris
A
End of the spinal cord at L2
8
Q
Where is a lumbar puncture performed?
A
Between L3&4 or L4&5
9
Q
Rexed laminae I-II
A
Pain
10
Q
Rexed laminae III-IV
A
Exteroception
11
Q
Rexed laminae V-VI
A
Proprioception
12
Q
Circulation of aqueous humour
A
Produced in ciliary body
Passes out of posterior chamber through the pupil and into the anterior chamber
Drains out the canal of Schlemm (scleral venous sinus)
13
Q
Vitreous chamber function
A
Helps to preserve the shape of the eyeball to maintain focussing precision
14
Q
Orbicularis occult innervation
A
CN VII
15
Q
Superior rectus action
A
Elevation, adduction
16
Q
Inferior rectus action
A
Depression, adduction
17
Q
Superior oblique
A
Depression, abduction, intorsion
18
Q
Inferior rectus
A
Elevation, abduction, extorsion
19
Q
Papilloedema
A
Swelling of the optic disc
Sign of raised ICP
20
Q
Partial optic nerve lesion
A
Ipsilateral scotoma
21
Q
Optic nerve lesion
A
Monocular blindness
22
Q
Optic chiasm lesion
A
Bitemporal hemianopia
23
Q
Optic tract lesion
A
Homonymous hemianopia
24
Q
Meyer’s loop lesion
A
Homonymous upper quadrant hemianopia
25
Optic radiation lesion
Homonymous hemianopia with macular sparing
26
Parasympathetic innervation of CN III
Sphincter pupillae
| Ciliary muscle
27
Parasympathetic innervation of CN VII
Lacrimal glands
Mucosal glands of the nasal and oral cavities
Submandibular and sublingual glands
28
Parasympathetic innervation of CN IX
Parotid gland
29
Horner syndrome symptoms
Miosis - contraction of the pupil
Ptosis - eyelid droop
Anhydrous - lack of sweating on face and neck
Exophthalmos - sinking of the eye
30
Dural venous sinus location
Between periosteal and meningeal dural layers
31
What is found in the cereal ventricles that is responsible for producing CSF?
Choroid plexus
32
Path from lateral ventricles --> subarachnoid space
Lateral ventricles
Interventricular foramen
Third ventricle
Cerebral aqueduct
Fourth ventricle
Then either central canal --> film terminal --> subarachnoid space
Or cisterna magna --> median and lateral aperatures --> subarachnoid space
33
CSF function
Buoyancy
Protection from trauma
Brain nourishment
34
How is CSF absorbed into the venous system
Via subarachnoid granulations that project into the superior sagittal sinus and other dural venous sinuses
35
Where is the fourth ventricle found?
Between the brainstem and cerebellum
36
What forms the lateral borders of the third ventricle?
Thalamus on either side
37
What is found superior to the third ventricle?
Corpus callosum
38
Where are the 3 horns of the lateral ventricles found?
```
Anterior = frontal lobes
Inferior = temporal lobes
Posterior = occipital lobes
```
39
What is the condition in which there is an excessive accumulation of CSF?
Hydrocephalus
40
Anterior cerebral artery supplies...
Midline of the brain
41
Middle cerebral artery supplies...
Lateral 2/3 of the brain
| Including Broca's and Wernicke's areas and the auditory cortex
42
Posterior cerebral artery supplies...
Bottom of the brain
| Mainly occipital lobes and including visual cortex
43
Borders of the posterior triangle of the neck
Posterior border of SCM
Anterior border of trapezius
Middle 1/3 of clavicle
44
Contents of the posterior triangle of the neck
```
Spinal accessory nerve
External jugular vein
Subclavian artery
Brachial and cervical plexuses
Lymph nodes
```
45
Borders of the submandibular triangle
Mandible
Anterior belly of digastric
Posterior belly of digastric
46
Submandibular triangle contents
Submandibular gland
Hypoglossal nerve
Facial artery and vein
47
Carotid triangle borders
SCM
Posterior belly of digastric
Omohyoid
48
Carotid triangle contents
```
ICA
CN X, XI, XII
IJV
Carotid body and sinus
Ansa cervicalis
```
49
Muscular triangle borders
Hyoid
Omohyoid
Midline of the neck
SCM
50
Muscular triangle contents
Infrahyoid muscles
Thyroid gland
Parathyroid glands
51
Submental triangle borders
Hyoid
Anterior belly of digastric
Midline of the neck
52
Submental triangle contents
Mylohyoid
53
Carotid sheath contents
```
Common carotid artery
ICA
IJV
Vagus nerve
Ansa cervicalis
Sympathetic trunk
```
54
Muscles of the pharynx
3 constrictor muscles - superior, muddle and inferior
Palatopharyngeus
Salpingopharyngeus
Stylopharyngeus
55
Innervation of the pharyngeal muscles
Pharyngeal plexus of vagus nerve
| Except stylopharyngeus which is supplied by the glossopharyngeal nerve
56
Internal laryngeal nerve
Sensory to larynx above vocal folds
| Lesion damages cough reflex
57
External laryngeal nerve
Motor to cricothyroid
| Lesion produced monotonous voice
58
Recurrent laryngeal nerve
Motor to all muscles of the pharynx except cricothyroid
Sensory to larynx below vocal folds
Lesion produces dysphonia
59
Bones of the orbit
Maxillary, frontal, zygomatic, sphenoid, ethmoid, lacrimal
60
Orbital foramina
Optic canal = optic nerve and ophthalmic artery
| Superior orbital fissure = CN III, IV, VI, VI
61
MCA stroke
Global aphasia if dominant hemipshere
Sensorimotor loss on contralateral face, upper limbs and trunk
neglect syndrome if non-dominant side
62
ACA stroke
Contralateral sensorimotor loss below waist
Urinary incontinence
Personality defects
Split brain syndrome
63
PCA stroke
Contralateral homonymous hemianopia
Reading and writing deficits
Impaired memory
64
Lateral medullary syndrome
Affects PICA
Vertigo, nystagmus, nausea, dysphonia, dysphagia, loss of gag reflex
Horner syndrome
65
Diencephalon
= thalamus and hypothalamus
66
Mesenchaplon
= midbrain
67
Locus coeruleus
Pons
Noradrenaline
SNS control and pain inhibition
68
Raphe nuclei
Throughout the brainstem
Serotonin
Arousal, cognition, mood
Damage --> OCD, depression, anxiety
69
Substantia nigra
Midbrain
Dopamine
Control of movement initiation and switching
Damage --> Parkinson's disease
70
Ventral tegmental aera
Midbrain
Dopamine
Organising behaviours, reward, attention, motivation
Damage --> schizophrenia, addiction
71
Pedunculopontine nucleus
Pons
| Acetylcholine
72
Types of brain herniation
Subfalcine - brain moves under falx cerebri
Uncal - temporal lobe moves down and compresses midbrain
Tonsillar - brainstem moves down through foramen magnum
73
CN III palsy
Eye in down and out position
Ptosis
Dilated pupil
74
CN IV palsy
Eye slightly elevated and adducted
Tilting of head due to loss of intorsion
Complain of neck pain and have problems walking down stairs
75
CN VI palsy
Abduction in affected eye not possible
76
Ependymal cells
Line the ventricles
Function in the circulation of CSF
Ciliated and appear like epithelial cells
77
Astrocytes
Most common glial cells
Provide structural and metabolic support to neurones
Help form the BBB
Forms scars in areas of damage
78
Microglia
Immune cells of the CNS - immune surveillance
| Small cells with long spiny processes
79
Oligodendrocytes
Myelinating cells of the CNS
| Each cell can myelinate up to 60 neurones
80
Schwann cells
Myelinating cells of the PNS
| Each cell can only myelinate one axon
81
Contents of the axoplasm
Mitochondria for energy
| Microtubules to maintain shape
82
Satellite cells
Supporting cells of the PNS
| Found in dorsal root ganglia
83
What sensory modalities are carried by the DCML pathway?
Conscious proprioception
| Discriminative touch - touch, pressure, vibration
84
What sensory modalities are carried by the spinothalamic tract?
Pain and temperature
| Crude touch and pressure
85
What sensory modalities are carried by the spinocerebellar tract?
Unconscious proprioception
86
What does the corticospinal tract convey?
Control of voluntary movement
87
Where does the DCML pathway decussate?
High in the medulla after the primary neurone has synapsed in the gracile/cuneate nucleus
88
Where does the spinothalamic tract decussate?
Low in the spinal cord, around 1-2 levels above where the nerve entered through the spinal root
It is the secondary afferent that decussates after the primary afferent synapses in the dorsal horn
89
Where does the spinocerebellar pathway decussate?
It doesn't --> ipsilateral cerebellum
90
Where does the corticospinal decussate?
At the spino-medullary junction
91
Superior colliculus function
Visual tracking and attention
92
Inferior colliculus function
Auditory reflexes
93
Inferior olivary nucleus
Nucleus found in the rostral medulla
| Important projection to the cerebellum
94
What is found dorsally in the brainstem?
Cranial nerve nuclei
Motor found medially
Sensnory found laterally
95
What is found down the middle of the brainstem?
Ascending pathways
| Reticular formation
96
What is found ventrally in the brainstem?
Descending pathways
97
Reticular formation roles
Arousal responses
Autonomic nervous system control
Control fo muscle tone and reflexes
Pain modulation
98
MLF location and function
Throughout the brainstem, roughly in the middle
| Connects gaze centres and vestibular system
99
Periaqueductal grey location and function
Surrounding the cerebral aqueduct
Descending pain control
Regulation of autonomic functions
100
Substantia nigra location
Rostral midbrain
101
Where is the fourth ventricle at its widest point?
At the junction between the pons and medulla
102
Where is the spinal nucleus of the trigeminal nerve found and what is its function?
Rostral medulla
| Receives pain and temperature information from the head
103
Jaw jerk reflex
```
Afferent = CN V3
Efferent = CN V
```
104
Symptoms of Parkinson's disease
Tremor, rigidity, gait abnormalities, slurred speech
105
Where does the damage in Parkinson's disease occur?
Substantia nigra
106
Parkinson's disease treatment
Dopamine receptor agonists
| L-dopa + enzyme inhibitor of decarboxylase enzyme (so only converted in the brain)
107
Schizophrenia symptoms
Hallucination, delusions, social withdrawal, paranoia
108
Pathology of schizophrenia
Hyperactivity of ventral striatum
| Increased dopamine release
109
Treatment of schizophrenia
Dopamine receptor antagonists
110
Pathology of depression
Dysfunction of monoamine system in the brain
| Deficiency of serotonin and noradrenaline
111
Treatment of depression
Re-uptake inhibitors
112
How does ecstasy work?
Increases monoamine release
113
How does cocaine work?
Inhibits monoamine reuptake
114
How does heroin work?
Mu opoid receptor antagonist
115
How does ketamine work?
Glutamate receptor antagonist
116
How does nicotine work?
Nicotinic cholinergic receptor agonist
117
How is alcoholism treated?
Disulfiram
| Makes alcohol consumption unpleasant and painful
118
Where in the meninges are blood vessels found?
Within the dura and arachnoid
119
Epidural haemorrhage
Bleeding outside the dura
Usually arterial
No symptoms initially
Severe headache later as haematoma compresses brain
120
Subdural haemorrhage
Bleeding between the dura and arachnoid
Usually from bridging veins
Slow onset of symptoms
Imaging shows blood spread diffusely over brain surface
121
Subarachnoid haemorrhage
Bleeding into the subarachnoid space
Often from ruptured aneurysm
Sudden severe thundercap headache
122
CSF production rate
500ml/day
123
Common site of blockage in hydrocephalus
Cerebral aqueduct
124
What contributes to the BBB
Astrocyte end feet
| Tight junction system between endothelial cells of the cerebral capillaries
125
Broca's Broadmann area
44 and 45
126
Wernicke's Broadmann area
22
127
Broca's damage
Expressive aphasia
| Halting speech with disordered word order and grammar
128
Wernicke's damage
Receptive aphasia
| Fluent but meaningless speech
129
What connects Broca's and Wernicke's areas?
Arcuate fasciculus
130
Arcuate fasciculus damage?
Conduction aphasia
Difficulty repeating words
Difficulty reading aloud
131
Right Broca's equivalent damage
Aprosodia
Difficulty understanding the non-semantic aspects of speech such as intonation, emphasis and rhythm
Produce robotic and monotonous speech
132
Left vs right frontal lobes
Left focuses attention on one aspect
| Right maintains an overall vigilance of your surroundings
133
Left vs right hemispheres
Left good at deductive reasoning
| Right good at inductive and intuitive reasoning
134
Left inferotemporal cortex damage
Associative agnosia
| Cannot assign names to objects
135
Right inferotemporal cortex damage
Apperceptive agnosia
| Cannot recognise objects when in an unusual rotation or shadow
136
Fusiform gyrus damage
Prospoagnosia
| Cannot assign names to faces
137
Primary motor cortex Broadmann area
4
138
Primary somatosensory cortex Broadmann area
1,2,3
139
Primary visual cortex Broadmann area
17
140
Primary auditory cortex Broadmann area
41,42
141
Right posterior parietal cortex function
Separates what we see into the background and what is part of the object
142
Right posterior parietal cortex damage
Piecemeal perception - can only observe one object at a time
Constructional apraxia - difficulty building 3D objects
Optic apraxia - inaccuracies reaching for objects
Discalculia - difficulty counting
Contralateral disregard - ignores left side of the body
143
Balint's syndrome
Bilateral lesions of the posterior parietal cortex
Appear blind - bump into objects etc
Can describe a small area in great detail
Oculomotor apraxia and simultanagnosia
144
Where does recall from long term memory occur?
Parts of the temporal lobes
145
Orbitofrontal cortex
Control of acceptable behaviours and awareness of social norms
146
Hypothalamic outputs
Neural signals via the ANS
| Endocrine through the pituitary gland
147
Cavernous sinus contents
ICA, CN III, IV, V1, V2, VI
148
Hypothalamic nuclei involved in ADH release
Supraoptic
| Paraventricular
149
What does the posterior pituitary secrete?
ADH
| Oxytocin
150
What stimulates adrenocorticotrophic hormone release/
Corticotrophin releasing hormone
151
Types of nerve regeneration
Anterograde (Wallerian)
Retrograde (to the cell body)
Transneural
152
Where are sensory receptors found in the skin?
At the epidermal-dermal junction
153
alpha A neurones
Alpha motor neurones
1a muscle spindle afferernts
1b golgi tendon afferent
154
beta A neurones
General sensory afferents
155
gamma A neurones
Gamma motor neurones to muscle spindle
156
delta A neurones
Fast pain
| Thermoception
157
C fibre neurones
Slow pain
| Thermoception
158
Spatial vs temporal summation
```
Spatial = more than one EPSP at a time
Temporal = two EPSPs in close proximity to one another
```
159
Where is osmolaity detected?
Subfornical organ in the wall of the third ventricle
160
Where does the subfornical organ project to?
Medial preoptic nucleus to induce thirst sensation
| Paraventricular and supraoptic nuclei to induce ADH release
161
Effects of ADH
Additional aquaporins to move into the membrane of the collecting duct
Increases collecting duct permeability to urea
Stimulates sodium reabsorption in the thick ascending loop of Henle
162
Lateral vs medial hypothalamus in maintenance of body weight
```
Lateral = hunger centre
Medial = satiety centre
```
163
Which nucleus is the satiety centre?
Periventricular nucleus
164
Where are internal hunger/satiety cues detected?
Arcuate nucleus of the hypothalamus
165
Ghrelin
Hunger hormone
Released by cells in the fundus of the stomach
Acts on a GPCR and induces eating behaviours
Also stimulates the dopamine pathway responsible for the enjoyment of food
166
Leptin
Released from adipose tissue
Acts to reduce hunger
Gives the brain an overall idea of the total amount of adipose tissue in the body
Acts as a long-term regulator rather than a satiety signal
167
CCK
Released by duodenal cells in response to chyme from the stomach
Causes released of digestive enzymes and bile
Acts on the arcuate nucleus to induce satiety
168
GLP1
Glucagon like peptide 1
Released as a consequence of food in the gut
Induces satiety
Induces insulin secretion
169
In what nerves do the sympathetic efferents to the bladder travel?
Hypogastric nerve
170
Action of sympathetic efferents on the urinary system
Maintain tonic contraction of the internal urethral sphincter via alpha receptors
Tonically inhibit the contraction of the detrusor muscle via beta receptors
171
What happens when the bladder becomes stretched?
Activation of pelvic nerves
| Sense of bladder fullness via spinothalamic tract
172
What nerve controls the external urethral sphincter?
Pudendal
173
Where is the micturition centre?
Barrington's nucleus in the pons
174
Describe the micturition reflex
Descending fibres in the reticulospinal tract inhibit sympathetic and somatic outputs controlling the urethral sphincters
Activation of parasympathetic efferents which stimulate the contraction of the detrusor muscle via M3 receptors
175
Ano-rectal reflex
Activated by stretching of the rectal afferents
Inhibition of sympathetic nerves to cause relaxation of the internal anal sphincter
Pressure increases on external anal sphincter and triggers the urge to defecate
176
Process of defecation
Allow external anal sphincter to relax
Faeces moves down
Upper rectum contracts to propel the faeces out of the anal canal
177
Ready, steady, go in movement
```
Ready = posterior parietal cortex
Steady = association motor cortex
Go = primary motor cortex
```
178
3 parts of the cerebellum
```
Vestibulo = balance and posture
Spino = locomotion
Cerebro = skilled motor tasks
```
179
Cerebellum damage
Ataxia and hypotonia
180
Basal ganglia damage
Slowing or unwanted movements - hypo/hyperkinesia
181
Association motor cortex damage
Apraxia - unable to execute familiar, learned movements
182
Descending motor pathways damage
Spasticity and hypotonia
183
Spasticity vs rigidity
Both increase in muscle tone
Spasticity due to loss of inhibition of gamma motorneurones
Rigidity due to loss of inhibition of alpha motorneurones
184
Flaccidity
Occurs when LMNs or peripheral nerves are damaged
185
CNS excitatory NTs
ACh
| Glutamate
186
CNS inhibitory NTs
GABA - brain
| Glycine - spinal cord
187
Function of gamma motor neurones
Alter the sensitivity of the muscle spindles
188
Golgi tendon organ reflex arc
1b afferent
Glycinergic inhibitory interneurone
Alpha motorneurone
189
Flexion reflex arc
Delta A nocioceptor afferent
2-3 excitatory interneurones
Alpha motor neurone
190
Pacinian corpuscle
Vibration
191
Ruffini ending
Pressure or skin stretching
192
VPM vs VLP
```
VMP = information from the face
VPL = information from the limbs
```
193
What happens in the VPL?
Convergence of the DCML and anterior spinothalamic pathways
194
Where does the lateral spinothalamic tract project to?
Limbic system - pain and pleasure
Midbrain reticular formation - pain induced arousal
Intralaminar nuclei of the thalamus - focusing attention on pain
195
Blink reflex
```
Input = V1
Output = VII to orbicularis oculi
```
196
Pupillary light reflex
```
Input = CN II
Output = CN III parasympathetic portion to the pupillary constrictor muscle
```
197
What drug blocks the pupillary light reflex?
Atropine
198
Components of the accommodation reflex?
Pupillary constriction - improves focusing by increasing depth of field
Thickening of the lens - allows focusing on near objects
Convergence - simultaneous contraction of medial rectus muscles
199
Vestibulo-ocular reflex
```
Input = CN VIII
Output = CN III and CN VI
```
200
Contents of tears
Mucous
Antibodies
Lysozyme
201
Layers of the eye
```
Outer = sclera and cornea
Middle = iris, ciliary body and choroid
Inner = retina
```
202
What is the primary refractive surface of the eye?
Cornea
203
What is normal intra-ocular pressure?
10-21mmHg
204
Where is visual acuity the highest?
At the fovea
205
Circulation of aqueous humour
Ciliary body --> posterior chamber --> pupil --> anterior chamber --> canal of Schlemm
206
Glaucoma
Increase in intraocular pressure that damages the retina
207
Open angle glaucoma
Progressive condition
Trabecular meshwork over canal of Schlemm becomes gradually blocked
Angle between cornea and iris remains normal around 40 degrees
208
Primary angle glaucoma
Sudden blockage of canal of Schlemm
Rapid rise in pressure
Sudden loss of vision and extreme pain
Angle between cornea and iris is reduced
209
Glaucoma treatments
Prostaglandin analogs
Beta adrenergic receptor antagonists
Alpha-2 agonists
CA inhibitors
210
How do cataracts form?
Level of antioxidants is too low or too much UV exposure
| Lens becomes opaque
211
Protein found in rods
Rhodopsin
212
Protein found in cones
Iodopsin
213
How does light affect photoreceptors?
Light hyperpolarises the cell
| Stops the tonic glutamate release
214
Dual blood supply of the eye
Central ophthalmic artery
| Choroid network of capillaries from ophthalmic artery
215
From photoreceptor --> optic nerve
Photoreceptor --> bipolar cell --> ganglion cells --> optic nerve
216
Organ of Corti hair cells
3 rows of outer hair cells --> amplification of sound signals
1 row of inner hair cells --> auditory discrimination
217
Apex vs base of cochlea
Apex is thin and wide --> responds to low frequency sounds
| Base is thick and narrow --> responds to high frequency sounds
218
Impedance matching factors
Relative sizes of ear ossicles
| Tympanic membrane larger than oval window
219
Attenuation reflex
Activated by own voice or loud sounds
Contraction of muscles like stapedius to dampen middle ear transmission
50-100ms delay
220
Startle reflex
Defensive response against threatening stimuli
Involves facial nerve and reticular formation
Less than 10ms latency period
221
Rinne's test
Tuning fork on mastoid process then by ear canal
222
Weber's test
Tuning fork on forehead
223
Angular gyrus damage
Alexia and agraphia - can't read or write
