Brainscape's Knowledge GenomeTM

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


See full index

SAM Module C Neurology > Neuro anatomy > Flashcards

Neuro anatomy Flashcards

1
Q

What are the main divisions of the brain

A 
Forebrain
 Cerebral cortex
 Diencephalon
Brainstem
 Midbrain
 Pons
 Medulla oblongata
Cerebellum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the main divisions of the spine?

A 
 functionally divided in 4 segments:
C1-C5; C6-T2; T3-L3; L4-S3
 peripheral white matter
   nerve tracts
• motor (efferent)
• sensory (afferent)
 central grey matter (the H)
 interneurons and motor neurons that innervate muscles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Outline the components of the peripheral nervous system

A

Axons of spinal (36 pairs) and cranial nerves (12 pairs) and their receptors and effector organs
 nerves may be motor, sensory or both
 motor neuron cell body is usually in ventral horn SC or GM brainstem
 sensory axons have cell body within dorsal root ganglion of SC or ganglia for CN
 myelination through Schwann cells, no BBB
Neuromuscular junction:
 axon terminal
 synaptic cleft
 endplate of skeletal muscle

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

Compare the sympathetic and parasympathetic nervous system

A 
 Sympathetic
thoracolumbar
fight or flight (rapid responses)
 Parasympathetic
craniosacral
rest and digest
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Outline the autonomic nervous system’s control of the bladder (filling)

A

detrusor muscle relaxes and sphincter tone increases

as bladder gets bigger, messages go to pons until a critical size is reached and bladder is ready to empty

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

Outline the autonomic nervous system’s control of the bladder voiding

A

 detrusor muscle contracts, under control of parasympathetic system in sacral SC.
 sphincters relax, due to reduced activity in motor neurons in sacral SC (external sphincter) and sympathetic neurons (internal sphincter)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where would you expect a lesion to be if the bladder cannot fill?

A

L4-L6 as sphincters cannot be controlled

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

What is an UMN bladder?

A

 lesions cranial to sacral SC

 distended bladder difficult to express (loss of inhibitory pathways to sympathetic and somatic efferents)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a LMN bladder?

A
  • lesions in sacral SC and/or sacral spinal nerves

* distended bladder, that overflows and dribbles (only internal sphincter working)

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

Outline the autonomic nervous system’s innervation of the eye

A

 1st order neuron - starts in brainstem and courses caudally in cervical SC
 2nd order neuron - leaves SC at T1-T3 using brachial plexus, courses rostrally through neck in vagosympathetic trunk; synapse at cranial cervical ganglion ventromedial to the tympanic bulla
 3rd order neuron – courses rostrally towards the eye

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

What does the ANS supply in the eye?

A

 smooth dilator of the pupil
 orbitalis muscle (smooth muscle in periorbita and eyelids, including 3rd eyelid)
 smooth ciliaris muscle
 smooth muscle of blood vessels and sweat glands of head

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

Compare the white and grey matter

A

Grey Matter
 contains cell bodies
 in surface of brain and in centre (H) of spinal cord
 processes information, “computer”

White Matter
 mostly contains myelinated axon tracts
 deep parts of brain and superficial parts of spinal cord
 connects, “network cables”

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

What are the layers of the meniges

A

 Dura mater – thick, outer layer
 Arachnoid – thin layer
 subarachnoid space – CSF, blood vessels, nerve roots
 Pia mater – thin, inner layer

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

Outline the pathways of CSF

A
  1. lateral ventricles
  2. interventricular foramen
  3. 3rd ventricle
  4. mesencephalic aqueduct
  5. 4th ventricle
  6. lateral apertures
  7. subarachnoid space
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where should you collect CSF?

A

Caudal to the lesion

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

Outline cranial nerve I

Olfactory

A

 involved in conscious perception of smell
 cell bodies in olfactory epithelium rather than on a ganglion
 axons pass through cribiform plate and synapse in olfactory bulb (then to piriform lobe)

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

Outline CN II

Optic

A

 not a true nerve but an “extension of brain” (myelinated by oligodendrocytes, surrounded by meninges)
 1st neuron in bipolar cells of retina receiving information from rods and cones
 axons course caudally and enter skull through optic canal, then join at optic chiasm

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

Outline CN III

Oculomotor

A

 ipsilateral dorsal, ventral and medial recti. and ventral oblique extraocular m.
 levator palpebrae superioris - elevation of upper eyelid
 parasympathetic component controls pupillary constriction
 nucleus in midbrain, axons exit skull through orbital fissure

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

Outline CN IV

Trochlear

A

 contralateral dorsal oblique m.

 nucleus in caudal midbrain, axons exit skull through orbital fissure

20
Q

Outline CN V

Trigeminal

A

 sensory innervation of face
 motor innervation of masticatory muscles
 3 branches:
 Ophthalmic (S) – cornea, medial canthus of eye, nasal mucosa (orbital fissure)
 Maxillary (S) – lat canthus of eye, cheek, muzzle, palate, nasopharynx (round foramen)
 Mandibular (S & M) – mandibular portion of face, oral cavity (oval foramen)
 motor nuclei in pons; sensory nuclei extend through brainstem
If bilateral problem cannot close mouth

21
Q

Outline CN VI

Abducens

A

 ipsilateral lateral rectus and retractor bulbi m.
 nucleus in rostral medulla
 axons exit skull through orbital fissure
issue = medial strabismus

22
Q

Outline CN VII

Facial

A

 motor innervation to muscles of facial expression
 sensory innervation to rostral 2/3 of tongue and palate
 parasympathetic innervation to lacrimal, mandibular & sublingual glands
 nucleus in rostral medulla, axons pass internal acoustic meatus, exit skull through stylomastoid foramen (then middle ear)
 parasympathetic fibres separate at middle ear

23
Q

Outline CN VIII

Vestibulocochlear

A

 hearing and vestibular function
 receptors in inner ear, pass internal acoustic meatus to get to medulla
 vestibular nuclei in medulla (CNs eye movement, spinal tracts and cerebellum)
 cochlear nucleus in medulla

24
Q

Outline CN IX

Glossopharyngeal

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 nuclei with X in caudal medulla

25
Q

Outline CN X

Vagus

A

 motor innervation larynx, pharynx and oesophagus
 sensory innervation of larynx, pharynx and thoracic and abdominal viscera
 parasympathetic innervation to all thoracic and abdominal viscera (except pelvic region)
 shares nuclei with IX in caudal
medulla

26
Q

Outline CN XI

Accessory

A

 trapezius and part of sternocephalicus and brachiocephalicus m.
 nucleus in caudal medulla

27
Q

Outline CN XII

A

 motor innervation to tongue

 nucleus in caudal medulla, axons exit through hypoglossal foramen

28
Q

Which CNs are easy to see on MRI

A

2,5,7,8

29
Q

How does a reflex occur in the LMN?

A
  1. stimulus – dendritic zone (receptor) in sensory nerve in skin or muscle
  2. sensory PN, dorsal root, enters SC; telodendron on dendritic zone of other neuron in GM (usually dorsal column)
  3. directly (monosynaptic - patellar) or through interneuron (polysynaptic - withdrawal)
  4. exit SC, ventral root, motor PN, telodendron in muscle
30
Q

Which reflexes test which nerves?

A 
Flexor -  all thoracic limb PNs - C6-T2
Biceps - musculocutaneous - C6-C8
Triceps - radial - C7-T2
Ext carpi rad - radial -  C7-T2
Flexor - sciatic - L6-S1
Patellar - femoral -  L4-L6
Gastrocnemius - tibial - L7-S1
31
Q

Outline the main pain pathways

A

 dendritic zone mainly in surface of body (receptors
stimulated by mechanical, thermal and chemical stimuli)
 axons in PN - dorsal roots - enter spinal cord where
course cranially and caudally for short distance
 some axons synapse on interneurons in GM that will then synapse in motor neurons, activating local reflexes
 other axons course medially in SC (spinothalamic tract) – brainstem – thalamus – sensory cerebral cortex
 diffusely distributed through SC – big lesion necessary to completely interrupt nociception

32
Q

Outline the UMN system

A

 confined to 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 and passing through pyramids in brainstem
 Extrapyramidal
• most start in brainstem, do not pass through pyramids
• provide tonic mechanisms for support of body against gravity and recruit spinal reflexes for initiation of voluntary movement

33
Q

Outline the pathways of proprioception

A

 Unconscious proprioception
 spinocerebellar tracts – proprioceptive information mostly to ipsilateral cerebellum
 Conscious proprioception
 spinal tracts – cross to contralateral side in medulla –
thalamus – proprioceptive information to contralateral
sensory cerebral cortex (parietal lobe)

34
Q

What is the aim of thee vestibular system?

A

 Sensory system that:

  1. maintains balance
  2. maintains normal orientation relative to the gravitational field
  3. maintains position of eyes, neck, trunk and limbs relative to the position and movement of the head
35
Q

Outline the peripheral vestibular system

A

 Inner ear
 3 ducts oriented at right angles to each other – rotation of head makes endolymph flow within one or more ducts
 semicircular ducts (crista ampularis) →utriculus (macula) →saccule (macula) →cochlea
 Vestibulocochlear nerve
 dendritic zone in connection with hair cells of crista ampullaris and maculae
 movement of fluid in semicircular ducts causes deflection of cupula or otoliths bending hair cells – nerve impulse

peripheral = collecting information

36
Q

Outline the central nervous system

A

 Vestibular nuclei - 4 in either side of brainstem receive information from CnVIII & project to:
 spinal cord
• facilitatory to ipsilateral extensor m., inhibitory to ipsilateral flexors m. and inhibitory to contralateral extensor m.
 cerebellum • inhibitory action
 medial longitudinal fasciculus (MLF) • nuclei of CNs III, IV & VI for coordination of eye movement with movement of head
 forebrain
• conscious perception of balance
 reticular formation
• vomiting centre (motion sickness)

37
Q

How does raised ICP affec the MLF

A

MLF runs along the base of the brain. When ICP raised, this is affected. Normally seen as eyes not moving wtih head when the head is being turned

38
Q

What are the functions of the cerebellum?

A

control of motor activity – regulator (not initiator)
• receives GP information from spinocerebellar tracts
• coordinates and smoothes out movement induced by UMN system
 maintenance of balance (through connections with
vestibular nuclei)

39
Q

What is involved in the control of walking?

A

 UMNs initiate voluntary movement and modulate activity of LMNs
 LMNs connect the CNS with the muscles: execute UMN plan!
 need GP to know where body parts are
 need cerebellum to coordinate the movement
(range, strength)
 need vestibular system to maintain balance

40
Q

What is the pathway for vision?

Up to chiasm

A

 Retina – 10 layers with 3 types of neurons:
rods – low level light (night vision)
cones – high level light (day vision) and colour vision
 Optic disc
beginning of optic nerve, ventrolateral position
 Optic nerve
in fact a tract of CNS, covered by meninges & subarachnoid space
enter skull through optic canal and joins other side at optic chiasm
 Optic chiasm and tract
majority of axons crosses to other side in optic tract
birds/fish – all; horse/cow – 80-90%; dog – 75%; cat – 65%; primates – 50%

41
Q

What is the concious pathway for vision (past optic chiasm)

A

 lateral geniculate n. (thalamus)
 optic radiation
 contralateral cerebral cortex (occipital lobe)

e.g. menace

42
Q

What is the reflex pathway for vision (e.g. PLR)

A

 lateral geniculate n. (thalamus)
 optic radiation
 contralateral cerebral cortex (occipital lobe)

43
Q

How can a combination of PLR and menace help you localise the lesion?

A

Both absent - In the eye/ optic nerve/ chiasm

Absent menace, normal PLR - contralateral forebrain

44
Q

Outline the function of the forebrain

A

 cerebral cortex and diencephalon (brain rostral
to tentorium cerebelli)
 behaviour, decision making
 conscious perception for all sensory systems
 some motor functions (pyramidal system)
 thalamus is mainly a relay station (collects all information and passes it to cerebral cortex; also rostral part of ARAS

45
Q

What is the Ascending Reticular Activating system (ARAS)

A

 receives information from all conscious projection pathways of sensory systems
 information courses through brainstem to thalamus and then project to cerebral cortex through thalamic association system
 functions:
 arouse cortex
 awake brain to a conscious level
 prepare brain to receive sensory information
 it has role in behaviour, Alzheimer’s disease, and ADD/ADHD

46
Q

What are the types of paresis

A

Paresis is defined as a loss of ability to support

weight (lower motor neuron disease) or inability to generate a gait (upper motor neuron disease).

SAM Module C Neurology (14 decks)

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