Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Year 3 MOD > Neurology: Clinical Neuroanatomy, Neurolocalisation > Flashcards

Neurology: Clinical Neuroanatomy, Neurolocalisation Flashcards

1
Q

What are the main CNS divisions of the brain?

How is the spine divided into 4 segments?

A

Forebrain- cerebral cortex, diencephalon

Brainstem- midbrain, Pons, Medulla oblongata

Cerebellum

C1-C5, C6-T2, T3-L3, L4-S3
Neck, forelimb, trunk, hindlimb- ish

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How does the spine matter appear what do the different matters do?

A

Peripheral white matter-
nerve tracts- motor going down, sensory going up

Central gray matter- butterfly
interneurons and motor neurons that innervate muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What makes up the PNS?

A

Nerves, NM junctions, Muscles

  • Axons of spinal (36) and cranial nerves (12) and their receptors and effector organs
  • Nerves may be motor, sensory or both
  • Motor neuron cell body is in ventral horn of SC
  • Myelination through schwaan cells, no BBB
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the function of the ANS?

What are the different parts?

A

Involuntary, controls visceral functions

Sympathetic- thoracolumbar- fight or flight

Parasympathetic- craniosacral- rest and digest

Antagonistic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How is the ANS involved in filling and emptying of the bladder?

A

Filling-
detrusor muscle relaxed and sphincter tone increases
as bladder gets bigger, messages go to pons until a critical size is reached and bladder is ready and empty

Emptying-
detrusor muscle contracts under parasympathetic control in sacral SC
Sphincters relax due to reduced activity in motor neurons and sympathetic neurones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the ANS- sympathetic supply to the eye

What does it innervate?

How does dysfunction present?

A
  1. 1st order neuron- starts at the brain stem and courses caudally in cervical spinal cord
  2. 2nd order neuron- leaves the spinal cord at T1-T3 through brachial plexus, courses rostrally through neck in vagosympathetic trunk
  3. Synapses at cranial cervical ganglion ventromedial to tympanic bulla
  4. 3rd neuron towards eye

Innervates- smooth dilator of pupil, orbitalis muscle, smooth ciliaris muscle, smooth muscle BVs and sweat glands of head

Dysfunction- Horner’s syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
  1. What does grey and white matter contain?
  2. What are the layer of the meninges?
  3. How are cranial nerves named?
  4. Describe the CSF pathway
A
  1. Grey- contains cell bodies, surface of brain or centre of spinal cord, process information
    White- myelinated axon tracts, deep part of brain, superficial SC, connects everything
  2. Dura mater- thick outer,
    Arachnoid- thin
    Subarachnoid space- CSF, blood vessels, nerve roots
    Pia mater- thin, inner layer
  3. Named I to XII from most rostral to most caudal
  4. Lateral ventricle to intraventricular foramen to 3rd ventricle to mesencephalic aqueduct to 4th ventricle to lateral apertures to subarachnoid space

CSF covers all surface of brain and SC- flows in pulsatoins of blood in choroid plexus, caudally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

List the cranial nerves

A
  • Olfactory
  • Optic
  • Occulomotor
  • Trochlear
  • Trigeminal
  • Abducens
  • Facial
  • Vestibulochlear
  • Glossopharyngeal
  • Vagus
  • Accessory
  • Hypoglossal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the CN I involved in?

Where are its cell bodies found?

What do axons pass through?

A

Olfactory- conscious perception of smell

Cell bodies in olfactory epithelium rather then on a ganglion

Axons pass through cribform plate and synapse in olfactory bulb

Rarely see dysfunction- responsible for too much in the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is CN II involved in?

Where do its axons travel?

Why is dysfunction ‘easy’ to diagnose?

What myelinates it?

A

Optic- vision

  • 1st neuron in bipolar cells of retina recivieing information from rods and cones
  • Axons couse caudally and enter skull through optic canal then join at optic chiasm

Easy to diagnose dysfunction- either eye, then nerve, then brain process

Myelinates by olidodendrocytes, surrounded by BBB- ‘extension or the brain’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What muscles does CN III innervate?

What does the parasympathetic component innervate?

Where is the nucleus, how do axons travel?

How can dysfunction be diagnosed?

A

Occulomotor- ipsilateral dorsal, ventral and medial rectus, ventral oblique extraocular muscles
Levator palpebrae superioris- elevation of eyelid

Parasympathetic controls pupillary contraction

Nucleus in midbrain, axons through orbital fissue

Pupillary contraction or lateral strabismus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does cranial nerve IV innervate?

Where is the nucleus and axon route?

A

Trochlear- contralateral dorsal oblique

Nucleus in caudal midbrain, axons exit through orbital fissure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the function of CN V?

What are the three branches?

Where are its nuceli?

A

Sensory innervation of the face
Motor innervation of the masticatory muscles

Opthalmic- sensory
Maxillary- sensory
Mandibular- sensory and motor

Motor nuceli in Pons, Sensory nuclei extend through brain stem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does CN VI innervate?

Where is its nucelus and the axon routes?

A

Abducens- ipsilateral rectus and retractor bulbi muscle

Nucleus in rostral medulla, axons exit skull through orbital fissure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does CN VII innervate?

A

Facial nerve

Motor innervation to muscles of facial expression

Sensory innervation to rostral 2/3 of tongue and palate

Parasympathetic innervation to lacrimal, mandibular and sublingual glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the function of CN VIII?

Where are its nuclei?

A

Vestibulochlear- Hearing and vestibular function

Receptors in inner ear pass internal acoustic meatus to get to medulla

Vestibular nuclei in medulla
Cochlear nucleus in medullar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the function of CN IX?

What nerve does it share is nuclei with?

A

Motor innervation of pharynx and palate
Sensory innervation of caudal 1/3 of tongue and pharynx

Parasympathetic innervation of parotid and zygomatic glands

Shares nuceli with CN X in caudal medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the function of CN X?

Where is its nucleus?

A

Vagus- Motor innervation of larynx, pharynx and oesophagus
Sensory innervation of larynx, pharynx, thoracic and abdominal viscera

Parasympathetic innervation to all thoracic and abdominal viscera

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the function of CN XI, where is its nucleus?

What is the function of CN XII, where is its nucleus?

A

Accessory- trapezius and part of sternocephalicus and brachiocephalicus
Nucleus in caudal medulla

Hypoglossal- motor innervation of the tongue
Nucleus in caudal medulla, axons exit through hypoglossal foramen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How can autonomic nervous system diseases cause incontinence?

What drugs can be used to treat this?

A

Upper motor neurone- sphincters tighten
Lesions cranial to sacral spinal cord, bladder difficult to express, loss of inhibitory pathway to sympathetic and somatic efferent

Lower motor neurone bladder- lesions in sacral spinal cord and/or sacral spinal nerves
Distended bladder overflows and dribbles, only internal sphincter works

Increase detrusor contraction- bethanecol, cisapride
Decrease detrusor hyperreflexia- propantheline bromide, oxybutin chloride
Increase urethral tone- phenylbenzamnine, Diazepam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe the route of sympathetic innervation to the eye?

A
  • 1st order neuron starts in brain stem, courses causally in cervical spinal cord
  • 2nd order neuron- leaves spinal cord at T1-T3 through brachial plexus, courses rostrally through neck in vagosympathetic trunk, synapse at cranial cervical ganglion venteromedial to the tympanic bulla
  • 3rd order neuron- courses rostrally to the eye

Innervates- smooth dilator of pupil, orbitalis muscle, smooth ciliaris muscle, smooth muscle of blood vessels and sweat gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What controls the lower motor neurone system?

A
  • Efferent neurons of the PNS
  • Connect CNS with muscle to be innervated
    CNS function is manifested through the LMN
  • Neuronal cell bodies in ventral GM of spinal cord
  • Axon leaves spinal cord through ventral root and travels as PN into muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe the process of a reflex?

A
  • Stimulus- dendritic zone is sensory nerve or muscle
  • Sensory peripheral nerve, dorsal root, enters spinal cord, synapses with other neuron in grey matter
  • Directly or through interneuron
  • Exits spinal cord- ventral root, motor peripheral nerve, neuromuscular junction, muscle contraction
24
Q

What forelimb peripheral nerves are responsbile for a forelimb flexor response?

What spinal cord segments do the nerves originate from?

A

All forelimb peripheral nerves- musculocut, radial

C6-T2

25
Q

What is the difference between pain and a reflex?

A

Local reflex- localised to spinal segment

Conscious perception of pain- projection to forebrain, important prognastic factor

26
Q

Describe the process of nociception

A
  • Dendritic zone mainly in surface of body- receptor stimulated by mechanical, thermal, chemical
  • Axons in PN- dorsal roots- enter spinal cord and course cranially and caudally for short distance
  • Some axons synapse on interneurons in GM activating local reflex, other course medially
  • Axons coursing medially in SC to brainstem to thalamus to sensory cerebral cortex
  • Diffusely distributes through SC- big lesion neccessary to completely interrupt
27
Q

What is the upper motor neurone system?

What are its functions?

How is movements seperated?

A

Confined to the CNS, axons organised in tracts in white matter that synapse with LMNs in SC grey matter

Functions- initiation of voluntary movement, maintenance of muscle tone for support against gravity

Pyramidal- skilled movement- poorly developed in animals, start in cerebral cortex through pyramids in brainstem

Extrapyramidal- most start in brainstem, dont pass throug pyramids

28
Q

How is general proprioception transmitted?

What is unconscious and conscious proprioception?

A

Detects position and movement of muscles and joints

GP afferent neuron- dendritic zone in muscle, tendon or joint- axons in PN- cell body in dorsal root ganglion

Unconscious proprioception- spinocerebellar tracts to ipsilateral cerebellum

Conscious proprioception- spinal tracts- cross to contralateral side in medulla to thalamus to contralateral sensory cerebral cortex

29
Q

What does LMN or UMN dysfunction lead to?

What causes ataxia?

A

Paresis or paralysis

Dysfunction of either general proprioception, cerebellum or vestibular system

30
Q

Describe the miracle of vision from the retina to optic chiasm

A
  1. Retina- 10 layers with 3 types of neurons
  2. Optic disc- begining of optic nerve
  3. Optic nerve- enters skull through optic canal and joins other side at optic chiasm
  4. Optic chiasm and tract- majority of axons crosses to other side in optic tract
31
Q

What is the conscious and reflex pathway of vision?

How can you test for these pathways?

A

Conscious- conscious perception of vision
Eye, CN II, crosses at optic chiasm
lateral geniculate nerve, optic radiation, contralateral cerebral cortex

Reflex pathway- pupil constriction
Eye, CNII, crosses at optic chism
brainstem, parasympathetic occulomotor, bilateral response

Menace response- conscious
Pupillary light reflex- reflex
Lack of both must be CNII

32
Q

What makes up the forebrain?

What is it responsible for?

A

Cerebral cortex and diencephalon

Behaviour, decision making, conscious perception for all sensory systems, some motor functions

Thalamus- relay station

Hypothalamus- autonomic centre

33
Q

What is ARAS?

A

Ascending reticular activating system

Recieves all information from sensory systems

Information courses through the brainstem to thalamus and then projects to cerebral cortex

Functoins- arouse cortex, awake and prepare brain

Role in alzheimers and ADHD

34
Q

What is the vesticular system?

What are the 2 disisions?

A

Sensory system- maintains balence, normal orientation, positon of eyes, neck, trunk and limbs relative to head

Peripheral and Central

35
Q

How does the peripheral vestibular system function?

A

Inner ear-
3 ducts orientated at right angles to each other- rotation makes endolymph flow within 1 or more ducts
Semicircular ducts leads to crista ampularis and macula
Drunk alters viscosity

Vestibulochlear nerve-
Dendritic zone in connection with hair cells of crista ampularis and maculae
Movement of fluid in semicircular ducts causes deflection of cupula bending hairs- nerve impulse

36
Q

How does the central vestibular system function?

A

Vestibular nuclei- 4 either side of brainstem recieve information from CN VIII and project to:

  • Spinal cord- facilitatory to ipsilateral extensor, inhibitory to ipsilateral flexors, inhibitory to contralateral extensor
  • Cerebellum- inhibitory
  • Medial longitudinal fasiculus- nuceli of CN III, IV, VI
  • Forebrain- perception of balance
  • Reticular formation- vomiting centre
37
Q

What are the functions of the cerebellum?

A

Control of motor activity- regulator
Recieves GP information from spinocerebellar tracts
Coordinated and smoothes out movements induced by UMN

Maintentance of balance- through connections with vestibular nuclei

Rare projections to LMNs in spinal cord- control of motor activity through influence on UMNs

38
Q

How is neurolocalisation initially divided?

A

Brain-
forebrain, brainstem, cerebellar vestibular
Each shows different neurological signs depending on function

Spinal cord-
further divided C1-C5, C6-T2, T3-L3, L4-S3
Dysfunction and reflexes allow localisation

Neuromuscular-
Peripheral nerve, NMJ, Muscle

39
Q

What are the overal functions of the forebrain?

A

Thinking

Behaviour

Vision

Hearing

Consciour perception of touch, pain, temperature, body position

Fine motor activity

40
Q

What are the potential complications of forebrain dysfunction?

A
  • Disorientation, depression
  • Contralateral blindness
  • Normal gait
  • Circuling, head turn, head pressing, pacing
  • Decrease in postural response in contralateral limbs
  • Seizures (always forebrain), behaviour change
41
Q

What are the functions of the brainstem?

What are the complications of dysfunction?

A

Functions- Basic functions for life, ARAS, regulation centres for resp and CV, CN III-XII, all sensory and motor tracts pass through, vestibular nuclei

Dysfunction

  • Depression, stupor coma,
  • CN defecits (III- XII)
  • Vestibular signs
  • Paresis or ipsilateral limbs
  • Decerebrare rigidity- weakness
  • Decreased postural responses
  • Resp and CV abnormalities
42
Q

What is the function of the cerebellum and what is seen with dysfunction?

A

Control motor activity, Regulator- not initiator
Coordinated and smoothes out movement induced by UMN system- spinal cord function and postural tonus, skilled movement
Inhibits vestibular system

Dysfunction-
Normal mentation
Ipsilateral abnormal menace with normal vision and PLR
Vestibular signs
Ataxia, broad stance, hypermetria [overshooting]
decerebellate rigidity
delayed initiation and then often hypermetric postural responses

43
Q

What is the function of the vestibular system?

What signs do both regions show with dysfunction?

A

Maintain balance
Position of eyes, neck, trunk and limbs relative to position and head movement

Both regions dysfunction show:

  • Head tilt- ipsilateral usually, contralateral in cerebellar, head sway
  • Nystagmus- horizontal, rotatory or vertical
  • Ataxia with leaning and falling
  • Positional strabismus
44
Q

How can peripheral and central vestibular lesions be distinguished?

A

Paresis possible with central, not in peripheral

Proprioceptive defecits possible with central, not with peripheral

Mentation with central may be affected, alert with peripheral

CN defecits- V-XII with central, VII with peripheral

Nystagmus:
Central- vertical, horizontal or rotatory
Peripheral- horizontal or rotatory

45
Q

What is and causes a paradoxical head tilt?

A

Head tilt contralateral to lesion

Lesion on flocculonodular lobe or caudal cerebellar peduncle

Cerebellim inhibits ipsilateral vestibular nuclei causing desinhibition

Leads to inhibition of ipsilateral extensors and facilitation of contralateral extensors- tilts head

46
Q

What is the difference between upper motor neurons and lower motor neurones?

Where do lower motor neurones originate from the SC?

A

UMN- efferent neuron that originates in the brain and synapses with a LMN modulating its activity

LMN- efferent also but from CNS to effector organ (muscle or gland), cell body is in the SC grey matter or nucleus of cranial nerve and axons become PN

LMNs for forelimbs- C6-T2, Hindlimbs L4-S3

47
Q

How are reflexes used to location lesions using limbs?

If all 4 limbs affected

If only hindlimbs are affected

Affected = ataxia, paresis, paralysis

A

If all 4 limbs are affected- C1-T2

  • But thoracic reflexes normal, lesion must be C1-C5- above brachial plexus
  • But reflexes in thoracic limbs reduced lesion must be C6-T2

If hindlimbs affected- T3-S3

  • Reflexes in HL normal must be T3-L3
  • If reflexes in pelvic limbs reduced must be L4-S3
48
Q

What are the possible symptoms of lesions in the following regions?:

C1-C5

C6-T2

T3-L3

L4-S3

The attached picture may help- try without?

A

C1-C5-
Tetra or hemiparesis/plegia, normal spinal reflexes in all limbs
Horners syndrome, respiratory difficulties, urinary retention

C6-T2-
Tetra or hemiparesis/plegia- possible mono
Reduced spinal reflexes in thoracic limbs- muscle tone atrophy
Possibly reduced/absent cutaneous trunci reflex
Nerve root signature, Horners, resp difficulties, urinary retention

T3-L3-
Paraparesis/plegia, normal muscle tone/no atrophy
Normal spinal reflexes in all limbs
Possibly reduced/absent cut trunci lesion, urinary retention

L4- S3-
paraparesis/plegia- possible mono
Reduced spinal reflex in HL, reduced anal tone/perineal reflex in more caudal lesions
Nerve root signature, reduced tail tone, urinary retention, incontience in caudal lesions

49
Q

What needs to be considered when interpreting reflexes?

A
  1. Pain can cause withdrawal of reflex to be reduced
  2. If lesion is subtle- just spinal pain- may not be severe enough to affect reflex pathway
  3. Patella reflex can be reduced in old age
  4. Spinal shock in acute cases
50
Q

What is spinal shock?

A

Flaccid paralysis with loss of spinal reflexes caudal to lesion in acute spinal cord lesions

Temporary- hours
Anal sphincter reflex 15 min
Patella reflex between 30 min and 2h
Flexor withdrawal upto 12 hours

Loss of descending facilitatory inpus causing hyperpolarization of spinal motor neurons and reduction in their exitability

51
Q

How are spinal cord lesions graded?

A

Grade 1- no defecits, just spinal pain

Grade 2- ambulatory paresis

Grade 3- non-ambulatory paresis

Grade 4- paralysis- 80% of walking without surgery

Grade 5- paralysis and loss of pain sensation- without surgery 5% chance of walking

52
Q

What are neuropathies, junctionopathies, and myopathies of the neuromuscular system?

A

Neuropathies- peripheral nerve

Junctionopathies- NMJ

Myopathies- muscle

DISEASE

53
Q

What can nerves can neuromuscular neuropathies affect?

How can it present differently?

How can it effect region size differ?

A

12 pairs of CNs and 36 pairs of spinal nerves

flaccid paralysis and reduced tone and muscle atrophy- Motor
May have proprioceptive deficits, decreases sensation and paraesthenia (self-mutilation)- Sensory
Reduced spinal or cranial nerve reflexes

Can affect 1 nerve- trigeminal tumour, facial paralysis
Can affect a group of nerves- brachial plexus tumour
Most/all nerves- polyneuropathy

54
Q

What are the components of a NMJ?

What are the three junctionopathies?

A

NMJ- axon terminal, synaptic cleft, endplate of skeletal muscle

Pre-synaptic- botulism

Post-synaptic- myasthenia gravis

Enzymatic- organophosphates

MG- blockage of ACH receptors, walks ok then collapses

55
Q

What are the symptoms of myopathies?

What is generalised and focal myopathies?

A

Generalised weakness and/or excercise intollerance- stiff gait
No propriceptive defects, normal spinal reflects

Generalised-
inherited/degen, inflam/infectious, metabolic

Focal-
one muscle- masticatory myositis

Year 3 MOD (42 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions