Anatomy Flashcards
Falx cerebrii formed by?
Meningeal layer of dura
Infants lumbar tap at which level?
Below L4 (column hasn’t outgrown cord yet)
Posterior grey column nuclei locations
Substantia gelatinosa group found though out the length of SC and receives pain, temperature, and touch.
Nucleus proprius found throughout the SC and receives proprioception and two-point discrimination information.
Nucleus dorsalis (clark’s column) extends from C8-L4 and receives unconscious proprioception.
Visceral afferent nucleus extend from T1-L3 receives visceral afferent information.
RECAP ALL TRACT IMAGES
WEEK ONE
Anulus weak points and neurovascular special characteristic
The anulus is thinner posteriorly and may be incomplete posteriorly in the
adult in the cervical region.
The anulus becomes decreasingly vascularized centrally, and only the
outer third of the anulus receives sensory innervation.
Nucleus Pulposus Vascularity
The nucleus pulposus is avascular; it receives its nourishment by diffusion from blood vessels at the periphery of the anulus fibrosus and vertebral body.
Lordosis Effect On Muscles
This abnormal extension deformity is often associated with weakened trunk musculature, especially the anterolateral abdominal muscles.
Recurrent Meningeal Nerve Extra-vertebral
Nerve fibers to the periosteum, anuli fibrosi, and ligaments supply pain receptors.
Those to the anuli fibrosi and ligaments also supply receptors for proprioception (the sense of one’s position).
Sympathetic fibers to the blood vessels stimulate vasoconstriction.
Recurrent Meningeal Nerves receive input from where?
Grey rami communicantes
Corticospinal Tract Synapse Points
Anterior corticospinal tracts end in upper cervical and thoracic segments
Large fibres synapse directly without interneurons
Tectospinal tract synapse point
Upper cervical segments
SC Injury Causes
Anterior cord syndrome - anterior artery ischaemia
Central cord syndrome - hyperextension of cervical region
Hemisection/Brown-Sequard syndrome - fracture dislocation of vertebral column
Syringomyelia - developmental abnormality in formation of central canal, most often in brain stem and cervical region
Hypoglossal and vagal trigone locations
Hypoglossal above
Vagal below
Vomiting centre
Area postrema and solitary tract nucleus
CN 9 Nucleus Ambiguus
Stylopharyngeus
CN 9 lesion causes
Jugular foramen syndrome, paraganglioma, etc can cause injury to the nerve
Which muscle is NOT supplied by the hypoglossal nerve?
Palatoglossus
Which muscle is controlled by only contralateral corticonuclear fibres?
Genioglossus
Trapezius paralysis
Trapezius paralysis causes brachial plexus neuralgia due to drooping of the upper limb which stretches the plexus
What forms the junction between the pons and the middle cerebellar peduncle?
Pons
Trigeminal nerve upper control
UMN damage has no significant impact on nerve functions, but bilateral UMN lesion results in loss of UMN control over both trigeminal nerves
Vestibular and cochlear ganglia cell types
Vestibular: pseudounipolar
Cochlear: bipolar
Lumbar Tap Position
between the spinous processes of the L3 and L4 (or L4 and L5) vertebrae.
Brainstem Blood Supplies
Recap the slides from the three week 2 Narayana notes
Midbrain Lesions
- Weber’s syndrome:
Structures affected: Oculomotor nerve and corticospinal fibres
Features: Contralateral hemiplegia and pupil pointing downward and laterally due to III CN injury - Benedikt’s syndrome: Most of tegmentum of midbrain is damaged Structures affected: medial leminiscus, red nucleus, superior cerebellar peduncle and III CN
Features: Loss of proprioception, pupil points downward and laterally, contralateral tremors and twitching due to damage to red nucleus and superior cerebellar peduncle - Perinaud’s syndrome:
Structure affected: superior colliculi
Features: Weakness of upward gaze and vertical nystagmus - Argyll Robertson pupil:
Structure affected: pretectal nucleus
Features: light reflex is affected, but accommodation reflex is retained
Interpenducular Fossa
A wide subarachnoid space with an arterial sulcus
Uncus Clinical Significance
If there is an increase in the intercranial pressure, the uncus can herniate to the tentorial nerve and compress the crus cerebri and the nerve related to that»_space;> oculomotor and trochlear nerve
Corpus Callosum Functions
Area 22, 39, 40, 44&45
Coordination of activities of 2 cerebral hemisphere
Transfer of learning process
Transfer of speech function
Betz cells
giant pyramidal cells, also known as Betz cells, whose cell bodies measure as much as 120 mm and are located in precentral gyrus.
Common haemorrhage sites
Most common sites of haemorrhage are the basal nuclei, followed by thalamus, cerebral hemispheres, brainstem and cerebellum.
Fate of the cranial accessory nerve
Cranial accessory nerve is now considered as a part of the vagus nerve
Glossopharyngeal Nerve Extra Innervations
Ventral Respiratory Group Carotid Sinus (Baroreceptors) Carotid Body (Chemoreceptors)
Which reflex is lost in lateral medullary syndrome and as part of which fibres? What is the other name of the syndrome specific to this finding?
Ciliospinal reflex
Horner’s syndrome
Trigeminal Neuralgia And Herpes Locations
Neuralgia: maxillary and mandibular
Herpes: mandible
Red nucelus afferents and efferents
Lies ventrally, receives afferents from the cerebellum, globus pallidus,
subthalamic nucleus and cerebral cortex. It projects to spinal cord (rubrospinal tract),
reticular formation, thalamus, inferior olivary nucleus and subthalamus. It inhibits
muscle tone
Argyll Robertson Syndrome
Structure affected: pretectal nucleus
Features: light reflex is affected, but accommodation reflex is retained
Costal facet articulates with?
Tubercle of rib
Rupturing the IV disc posteriorly without fracturing the vertebral body?
Chronic or sudden forcible hyperflexion of the cervical region, as might occur during a head-on collision or during illegal head blocking in football
Caudal epidural anaesthesia effect range
The agent spreads superiorly and extradurally, where it acts on the S2– Co1 spinal nerves of the cauda equina.
Muscle joint information from cerebellum sections
Ant. spinocerebellar - upper and lower limbs, also skin and superficial fascia information
Post. spinocerebellar - trunk and lower limbs
Cuneocerebellar - upper limb and upper part of the thorax
Transverse Sinus Supratentorial And Infratentorial Drainages
Supratentorial: occipital lobe
Infratentorial: superior cerebellar vein
Which part of the internal carotid artery is susceptible for aneurysm?
Cavernous part of the internal carotid artery is susceptible for aneurysm
Hippocampus development
Starts on medial surface then goes to lateral surface
Structures formed by alar plate with contribution from basal plate
Red nuclei and substantia nigra
Which part of the hippocampus is involved in neurogenesis?
Granular layer of dentate gyrus
What type of sensations or perceived in the thalamus and what is their magnitude?
crude sensations of pain and temperature and they are perceived portly
Thalamic pain syndrome (Dejerine-Roussy disease) artery affected (mainly)
Thalamogeniculate arteries
Directions of collateral and occipito-temporal sulci
Collateral: antero-posterior
Occipito-temporal: postero-anterior
What does the stem of the lateral sulcus lie on?
Lesser wing of sphenoid bone
What is the significance of the posterior commissure?
Bilateral pupillary light reflex - mediates consensual pupillary light reflex by connecting pretectal nuclei
What does the anterior commissure connect?
Middle and inferior temporal gyri - pain sensation especially sharp, acute pain as well as decussating fibres of olfactory tracts for smell and chemoreception
What is the only sensation that does not pass through the thalamus?
Olfactory
What is the pigment found in rods cells and what nutrient is required for this pigment?
Rhodopsin, needs vitamin A
What is the main refractive medium in the eye?
Cornea
Origin and path of ICA
The internal carotid arteries (ICA) originate at the bifurcation of the left and
right common carotid arteries, at the level of the fourth cervical vertebrae (C4).
They move superiorly within the carotid sheath, and enter the brain via the carotid
canal of the temporal bone.
Vessel rupture + type of haemorrhage
Rupture of cerebral arteries - Subarachnoid bleeding
Rupture of meningeal arteries – Extradural bleeding
Rupture of superior cerebral (bridging) veins – Subdural bleeding
Cerebellar efferent to vestibular pathway
Some Purkinje cell axons pass directly out of
the cerebellum to the lateral vestibular
nucleus
What separates structures in the cavernous sinus from the sinus?
Endothelial lining
Trigeminal area and back of the scalp/neck area
Trigeminal area - supratentorial innervation
Back of the scalp/neck area - infratentorial innervation
Role of claustrum?
Consciousness
brainstem striatal fibre neurotransmitter
Serotonin
Pallidothalamic fibres
Ansa lenticularis and lenticular fasciculus to form the thalamic fasciculis
Motor and associative/cognitive connections to BG
Motor: postcommissural putamen
Associative/cognitive: precommissural putamen (and caudste in general)
BG Cholinergic interneurons
These neurons do not leave the striatum
They synapse on GABAergic striatal neurons that project to the GPi and on the striatal neurons that project to the GPe
They inhibit striatal cells of the direct pathway and excite striatal cells of the indirect pathway (opposite of dopamine)
So they’re favoring the indirect pathway