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Flashcards in Brain and Behaviour Deck (223):
1

Anterior cranial fossa bones and contents

Bones = frontal, ethmoid, sphenoid
Contents = frontal lobes

2

Middle cranial fossa bones and contents

Bones = sphenoid, temporal
Contents = temporal lobes, pituitary gland

3

Posterior cranial fossa bones and contents

Bones = sphenoid, temporal, parietal, occipital
Contents = brainstem, cerebellum

4

Accessory nerve innervation

SCM and trapezius

5

Foramen spinosum

Middle meningeal artery

6

What the sympathetic nerve can do once it has entered the sympathetic trunk

Synapse
Ascend or descend
Leave

7

Conus medullaris

End of the spinal cord at L2

8

Where is a lumbar puncture performed?

Between L3&4 or L4&5

9

Rexed laminae I-II

Pain

10

Rexed laminae III-IV

Exteroception

11

Rexed laminae V-VI

Proprioception

12

Circulation of aqueous humour

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

Vitreous chamber function

Helps to preserve the shape of the eyeball to maintain focussing precision

14

Orbicularis occult innervation

CN VII

15

Superior rectus action

Elevation, adduction

16

Inferior rectus action

Depression, adduction

17

Superior oblique

Depression, abduction, intorsion

18

Inferior rectus

Elevation, abduction, extorsion

19

Papilloedema

Swelling of the optic disc
Sign of raised ICP

20

Partial optic nerve lesion

Ipsilateral scotoma

21

Optic nerve lesion

Monocular blindness

22

Optic chiasm lesion

Bitemporal hemianopia

23

Optic tract lesion

Homonymous hemianopia

24

Meyer's loop lesion

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