Neuroanatomy Flashcards
what does the brainstem consist of?
Midbrain, Pons and Medulla Oblongata
what does the diencephalon consist of?
Thalamus, Hypothalamus
Name the 4 types of glial cell and their functions
Astrocytes- Support, Communicate with endothelial cells to maintain blood brain barrier
Oligodendrocytes- Produce Myelin (found in CNS, Schwann cells found in PNS)
Microglial Cells- Macrophages
Ependymal Cells- Lines cavities, Ciliated
what is the term for a deep groove, shallow groove and lump on the brain and cerebellum?
fissure,
Sulcus
Gyrus- Brain
Folium- Cerebellum
calcarine sulcus- vision
cingulate sulcus- suffering
what are the landmarks demarcating the frontal lobe?
the central and lateral sulci
what’s the name of the 5th lobe and what is its function?
Insular lobe or insula
Co-ordinates and pain
what is the enteric nervous system called?
myenteric plexus
where are the cavernous sinuses located?
Lateral to the sella turcica
what are the two different types of neuron and what is the difference between them?
Multipolar (ANS and Motor)- cell body found in CNS- multiple proccesses
Unipolar (sensory)- cell body found in PNS (dorsal route ganglion)
where are spinal nerves located?
only within the intervertebral foramina
describe the dermatomes
name the 4 plexi, where they inervate and what spinal nerves contribute to them
- Cervical plexus
- C1-C4 anterior rami
- Posterior scalp, neck wall …..and diaphragm
- Brachial plexus
- C5-T1 anterior rami
- Upper limb
- Lumbar plexus
- L1-L4 anterior rami
- Lower limb
- Sacral plexus
- L5-S4 anterior rami
- Lower limb, gluteal region and perineum
which spinal nerves make up the sympathetic chain?
T1-L2
how would you recognise a segment of the spinal cord running from T1 to L2
Lateral horns
describe the sympathetic outflow via the paravertebral ganglion
describe how sympathetic outflow reaches organs
for heart and lungs spinal presynaptic axons synapse at paravertebral ganglions. Postsynaptic axons continue in cordiopulmonary spanchnic nerves
For abdominal organs. presynaptic axons synapse in prevertebral ganglia.
For adrenal medulla the presynaptic axons synapse directly to it
what are the facial signs and causes of horner’s syndrome?
-Facial signs include:
- ipsilateral ptosis: drooping of the upper eyelid
due to lack of sympathetic innervation of the
smooth muscle within levator palpebrae
superioris
- ipsilateral miosis (pinpoint pupil) due to lack of
sympathetic innervation of the dilator pupillae
- reduced sweating of the ipsilateral facial skin
due to lack of sympathetic innervation of skin
sweat glands
- Causes of compression of the cervical parts of the sympathetic trunk:
- root of neck trauma (transection or haematoma)
- arch of aorta dissection
- internal jugular vein engorgement
- goitre
- deep cervical node metastases
- direct spread from lung apex malignancy
(pancoast tumour)
describe parasympathetic outflow
-Parasympathetic ganglia in head – to lacrimal gland (facial nerve) and salivary glands (parotid glossopharyngeal and facial for other 2)
-
-Vagus nerve supplies organs of the neck, chest and abdomen as far as the mid-gut
-
-Sacral spinal nerves ‘carry’ parasympathetic axons to the hindgut, pelvis and perineum
-
The spinal cord terminates in a tapered cone-shape called the …… which in turn, continues as a thin connective tissue cord called the …… which is anchored to the dorsum of the coccyx.
conus medullaris
filum terminale
The spinal cord is suspended in the canal by a ribbon of tissue on the lateral aspects of the cord called the ……. This ligament is formed of pial and arachnoid tissue and attaches to the dura at points along the length of the cord.
denticulate ligament
name the four comlumns in the spinal cord
lateral, posterior and anterior
name the sulcus and fissure found on the spinal cord
dorsal median sulcus and septum
ventral median fissure
describe the arterial supply of the spine
A. Three major longitudinal arteries: one anterior and two posterior that originate from the vertebral arteries. These run the length of the cord.
B. Segmental arteries derived from vertebral, intercostal and lumbar arteries.
C. Radicular arteries that travel along the dorsal and ventral roots.
Unlike the dura in the cranial cavity, which is attached to the periosteum, in the spinal canal there is a space between the dura and the bone, termed the ….., which contains adipose tissue and the anterior and posterior epidural venus plexuses. This space is utilized in epidural anaesethesia.
epidural space
where is the primary somatosensory cortex located?
just posterior to the central sulcus in the parietal lobe
post central gyrus
What is the name of the system that supplies fine touch and concious proprioception (particularly from the upper limb)
Dorsal Column/ Medial Lemniscus Sytem
how many nerves are there in the dorsal column/medial lemniscus system? Where do they synapse? Where do they cross?
what are the two components of the dorsal column (dorsal funiculus)?
Fasciculus Gracilis (fine touch and concious proprioception from leg)
Fasciculus Cuneatus (from upper limb)
what is the name of the tract that carries pain, temperature and deep pressure?
where does it cross
spinothalamic tract
crosses segmentally
where is the primary motor cortex?
precentral gyrus
Which tract allows fine, precise movement, particularly of distal limb muscles (e.g. digits).
Corticospinal tract
Tract forms visible ridges referred to as the ‘pyramids’ on the anterior surface of the medulla, so also called the pyramidal tract. About 85% of fibres cross in the caudal medulla at the decussation of the pyramids.
Crossed fibres form the Lateral CST.
Uncrossed fibres form the Ventral CST, which cross segmentally.
what is docorticate posturing and what causes it?
hyperflexion of the upper limbs caused by a CVA in internal capsule resulting in a lack of descending control
There are a number of motor systems outside of the pyramidal tract and these are often referred to collectively as the……
“extrapyramidal system”
The reticulospinal tract has variety of functions including infuencing volantary movements.
where is the reticular formation found?
Where are fibres influencing extension and flexion located?
Core of brainstem
In general: Fibres originating in pons facilitate extensor movements and inhibit flexor movements, while those originating in the medulla do the opposite.
which tract is involved in the process of stopping a fall
vestibulo spinal tract
input into “antigravity muscles”
fibres originate vestibular nuclei of pons and medulla, which in turn recieve inout from vestibular apparatus and cerebellum
The ….. is thought to play an important role in patients exhibiting decerebrate rigidity and paraplegia in extension. Lesions of the brainstem at or below the midbrain can result in a lack of descending cortical control of this tract (plus others). This leads to domination of extensor muscle tone and hyperextended spastic paralysis.
vestibulospinal tract
give a definition for the back
a part of the soma (body wall)
anatomically it is:
the posterior aspect of the trunk
(trunk = chest + abdomen + pelvis + back)
lies inferior to the neck
lies superior to the gluteal region
is attached to the upper limbs
is attached to the lower limbs
composed mainly of skeletal muscle &
bone
name the two main groups of intrinsic back muscles
Erector spinae (superficial)
Transversospinalis (deep)
which are the only vertebrae not to have discs?
-between all vertebrae except C1-C2 and the fused sacrum/coccyx
Fescribe all the ligaments attatched to the spinal cord
Ligamentum flavum
-short
-connect adjacent laminae posterior to spinal cord
-
-posterior longitudinal ligament
-narrow, weak
-attaches to posterior aspects of all vertebral bodies and intervertebral discs
-less support for disc
-prevents over-flexion of spine-anterior longitudinal ligament
-broad, strong
-attaches to anterior aspects of all vertebral bodies and intervertebral discs
-stronger support for disc
-prevents over-extension of spine
-
- supraspinous ligament
- short
- connects tips of spinous processes
- strong, fibrous-
- interspinous ligament
- short
- connect superior and inferior surfaces of adjacent spinous processes
- weak, membranous
what feature is unique to cervical vertibrae?
- All have a foramen in each transverse process
- transverse foramen
- passage of vertebral arteries
which joints main movementes are nodding and shaking the head?
nodding- atlanto-occipital join
shaking- atlanto-axial joint
in caudal anaesthesia local anaesthetic is injected into the …… to anaesthetise the sacral spinal nerve roots of the cauda equina
sacral hiatus
at what level does the spinal cord end?
L2
Outline the points at which you examine the spinal nerves dermatomes
C2 – back of scalp & Adam’s apple
C3 – back of neck & jugular notch
C4 – clavicle & shoulder tip
C5 – “badge patch”
C6 - thumb
C7 – middle finger
C8 – little finger
T1 – medial forearm
T2 – medial arm & sternal angle
T3
T4 – male nipple
T5
T6
T7
T8 – xiphoid process
T9
T10 - umbilicus
T11
T12 – pubic symphysis
L1 – groin (“hands in pockets”)
L2 – anterior thigh
L3 – anterior knee
L4 – medial malleolus
L5 – dorsum of foot
S1 - heel
S2 – posterior knee
S3 - buttock
S4 - perineum
S5 – perianal skin
outline the lobes of the cerebellum
The cerebellar cortex is divided into 3 layers. Name them
The cerebellar cortex is divided into 3 layers:
Molecular layer (outer)
Purkinje cell layer (middle)
Granular layer (inner)
From all three lobes of the cerebellum: the only output is via the axons of ….. cells which mainly synapse on neurons of the deep ……. and subsequently contribute to coordinating the functions all of the motor tracts of the brainstem and spinal cord (corticospinal, vestibulospinal, rubrospinal tracts).
Most efferent axons of the deep cerebellar nuclei cross the midline and synapse in the thalamus. The thalamus in turn sends fibres to the motor cortex.
Purkinje
cerebellar nuclei
Cerebellar hemispheres influence the …… side of the body
Bilateral cerebellar dysfunction: Results in ……
ipsilateral
slowed, slurred speech (dysarthria), bilateral incoordination of the arms and a staggering, wide based gait (cerebellar ataxia).
Functions of the Basal Ganglia
facilitates ourposeful movement
inhibits unwanted movements
Somewhat like the accelarator and breaks of a car
role in posture and muscle tone
name the basal ganglia
where is the substantia nigra found?
photo shows axial section of midbrain
out of the direct and indirect pathways which enhance/inhibits signals?
Direct pathway enhances
indirect inhibits
lesions in the basal ganglia cause….
changes in muscle tone
dyskinesias (abnormal, involuntary movements) including:
tremor (sinusoidal movements),
chorea (rapid, asymmetrical movements usually affecting distal limb musculature)
myoclonus (muscle jerks).
(lesions affect the contralateral side of the body)
what is the cause and signs of Parkinson’s Disease
Parkinson’s Disease
Pathology: degeneration of dopaminergic neurons of the substantia nigra
Signs: akinesia, rigidity and resting tremor
what is the cause, signs and genetics of Huntington’s Disease?
Genetics: autosomal dominant disorder
Pathology: progressive degeneration of the basal ganglia and cerebral cortex
Signs: chorea and progressive dementia
highlight the key sensory points
what are the named nerves of cutaneous innervation of the neck?
what is the named nerve cutaneous innervation of the trunk?
describe the named nerve cutaneous innervation of the back
describe the named nerve cutaneous innervation of the skin
describe the named nerve cutaneous innervation of the lower limb
muscles of facial expression …….
muscles of mastication…….
muscles of the tongue ……………
muscles of the soft palate ……………
muscles of facial expression (CN VII)
muscles of mastication (CN V)
muscles of the tongue (CN XII)
muscles of the soft palate (CN X/pharyngeal plexus)
neck postural muscles …………
strap muscles ………..
diaphragm ………….
sternocleidomastoid & trapezius …………
muscles of the pharynx …………….
intrinsic muscles of the larynx………….
neck postural muscles (posterior rami of cervical spinal nerves)
strap muscles (cervical plexus)
diaphragm (phrenic nerve: C3,4,5 – from the cervical plexus)
sternocleidomastoid & trapezius (CN XI)
muscles of the pharynx (mainly CN X)
intrinsic muscles of the larynx (CN X)
intercostal muscles ………….
anterolateral abdominal wall muscles …………….
intercostal muscles (intercostal nerves)
anterolateral abdominal wall muscles (thoracoabdominal nerves)
axillary nerve: nerve roots…………
innervates ……&…….
axillary nerve: C5,6
deltoid & teres minor
musculocutaneous nerve: roots……………
innervates …………………..
musculocutaneous nerve: C5,6,7
ALL of the anterior compartment of arm
biceps brachii
coracobrachialis
brachialis
median nerve: roots………….
innervates……………..
median nerve: C6,7,8,T1
muscles of the anterior compartment of forearm:
the pronator muscles (teres & quadratus)
flexor carpi radialis
palmaris longus
flexor digitorum superficialis
lateral half of flexor digitorum profundus
flexor pollicis longus
muscles of the hand:
thenar muscles
lumbricals 1&2
radial nerve: roots………..
innervates………….
radial nerve: C6,7,8
muscle of the posterior compartment of arm: triceps brachii
muscles of the posterior compartment of forearm: brachioradialis
supinator
ALL the extensors of the carpus & digits
abductor pollicis longus
ulnar nerve: roots……………
innervates……………
ulnar nerve: C(7),8,T1
muscles of the anterior compartment of forearm: flexor carpi ulnaris
medial half of flexor pollicis longus
adductor pollicis
muscles of the hand:
hypothenar muscles, lumbricals 3&4
& ALL the interossei (dorsal & palmar)
femoral nerve: roots………..
innervates………….
femoral nerve: L2,3,4
quadriceps femoris, sartorius & pectineus
sciatic nerve (roots…….) -
tibial part: roots…..
innervates……
sciatic nerve (L4-S3) -
tibial part: L4-S3
muscles of the posterior compartment of leg:
true hamstrings -
semimembranosus
semitendinosus
long head of biceps femoris
muscles of the posterior compartment of leg:
gastrocnemius
soleus
plantaris
popliteus
tibialis posterior
muscles of the sole of the foot:
flexors of the digits (digitorum & hallucis longus)
ALL intrinsic muscles of the sole of the foot
obturator nerve: roots……
innervates…….
obturator nerve: L2,3,4
ALL of the medial compartment of thigh
ALL adductors (brevis/longus/magnus) & gracilis
sciatic nerve – (roots….)
common fibular part: roots……
innervates…….
sciatic nerve – (L4-S3)
common fibular part: L4-S2
short head of biceps femoris
common fibular nerve -
superficial fibular branch: roots
innervates…….
common fibular nerve -
superficial fibular branch: L4-S2
muscles of the lateral compartment of leg:
fibularis longus & brevis
common fibular nerve -
deep fibular branch: roots…..
innervates……
common fibular nerve -
deep fibular branch: L4-S2
muscles of the anterior compartment of leg:
fibularis longus & brevis
muscles of the dorsum of the foot:
extensor digitorum brevis (EDB)
extensor hallucis brevis (EHB)
all cranial nerves exit anteriorly with the excepetion of…..
IV Trochlear
which is the only sensory modality that does not synapse in the thalamus prior to reaching the cortex.
olfactory nerve
where is the primary olfactory area?
name the motor nerves
III, IV, VI, XI, XII
where are the motor and sensory areas within the brainstem?
where are the inf/sup colliculus?
the middle cerebellar peduncle?
and the floor of the 4th ventricle?
what are the functions of the trigeminal nerve?
- Somatosensation of face: discriminative touch, vibration sense, pain, temperature
- Proprioception associated with chewing (TMJ, muscles of mastication, teeth
- Motor control: muscles of mastication, tensor tympani, mylohyoid, ant. belly of digastric, tensor veli palatini
what would happen if there was a lesion haff way down the spinal nucleus on the left hand side?
loss of pain and temp sensation on left face with perioral sparing
what is the purpose of the Pontine Trigeminal nucleus (Principal nucleus)?
discriminative touch, vibration
what is the function of the Mesencephalic nucleus?
(proprioception info from chewing muscles)
what is the function of the facial nerve?
- Motor (muscles of facial expression, stapedius).
- Parasymp. innervation to pterygopalatine and submandibular ganglia.
- Taste (anterior 2/3 of tongue via c. tympani).
What is the function of the glossopharyngeal nerve?
- Tactile sense, pain and temperature sense from the posterior tongue pharyngotympanic tube and upper pharynx.
- Taste (posterior 1/3 of the tongue).
- Parasympathetic fibres to the otic ganglion (parotid gland).
- Motor (one muscle: stylopharyngeus)
what is the function of the vagus nerve?
- Tactile sense, pain and temperature sense from the pharynx, larynx, trachea, oesophagus and thoracic and abdominal viscera.
- Taste (epiglottis)
- Parasympathetic innervation to ganglia serving thoracic and abdominal viscera.
- Motor (striated muscle of the pharynx and larynx) (cranial accessory contributes to this function).
describe the solitary nucleus
which nerves originate from it?
what are the two segments?
what is the most destinctive feature of the medulla?
the olivary nucleus
what is the corticobulbar tract?
The corticobulbar tract is the part of the pyramidal tract that is motor to cranial nerves.
describe the path that fibres take after leaving the cochlea
input is bilateral
Superior olivary nucleus and nucleus of lateral lemniscus are important in sound localization and as relays for stapedial and tensor tympany reflexes.
Name: Q,N,L,F,H,G
Q = CN VIII
N = 4th Ventricle
L= Middle cerebellar peduncle
F = Inferior colliculus
H = Medial geniculate nucleus
G = Inferior brachium
where is Broca’s Area?
Wernicke’s Area?
and the primary auditory cortex?
what does damage to Broca’s/ Wernicke’s area cause?
Broca’s, motor or expressive aphasia.
Wernicke’s, sensory or receptive aphasia.
describe the visual pathway
where is the primary visual cortex?
where do the visual fields lie in the visual cortex?
Fibres of the geniculocalcarine tract initially form part of the internal capsule. Those carrying visual information from the upper half of the visual field first loop anteriorly around the temporal part of the lateral ventricle in …… ending below the calcarine sulcus.
Meyer’s loop
Tracking movements tend to be smooth, while movements of command tend to be “jumpy” (saccadic). Why is this?
The frontal eye fields control “movements of command”, that is movements that are independent of moving visual stimuli.
In general the visual cortex provides for movements in response to visual stimuli, for example tracking moving objects.
through which foramen do the branches of the trigeminal nerve pass?
CN V1- superior orbital fissure
CN V2- foramen rotundum
CN V3- foramen ovale
outline the different regions of trigeminal nerve innervation
describe the trigeminal nerve’s motor innervation
where does the facial nerve exit the skull
stylomastoid foramen
after intering internal acoustic meatus and passing through facial canal
what is the function and composition of the lingual nerve?
supplies somatic sensory and taste to anterior 2/3rds of tongue and parasympatherti innervation to submadidibular and sunligual salivary glands
Branch of V3 but includes fibres from facial nerve (chorda tympani) which provide taste and parasympatheic innervation
name 4 important muscles of facial expression
-orbicularis oculi
-
-elevators of lips
-
-orbicularis oris
list the functions of the glossopharyngeal nerve
describe the route of the thoracic vagus nerves
- both pass posterior to lung root and onto oesophagus
- both pass through diaphragm with oesophagus
what are the origins and insertions of the spinal accessory nerve
by what foramen does XII exit the skull
hypoglossal canal
what are the 5 layers of the scalp?
- S = Skin
- C = Connective tissue
- A = Aponeurosis
- L = Loose connective tissue
- P= Pericranium
what bones form the pterion?
what lies under the pterion?
sphenoid, frontal, parietal, temporal
middle meningeal artery
where does the vertebral artery originate?
subclavian artery
describe the arteries that form the circle of willis
where is CSF produced, reabsorbed
choroid plexus of the ventricles
- reabsorbed into the dural venous sinuses
- via arachnoid granulations
CSF circulates from the right & left lateral ventricles to the 3rd ventricle via the right and left …….
foraminae of Monro
describe the different types of bleeding within the cranial cavity
what are the two main types of herniation caused by raised ICP?
Supratentorial and Infratentorial
If vision is lost in the same visual field in both eyes it is termed ‘……..’. The opposite is ‘………’.
homonymous
heteronymous
