Neuroanatomy Flashcards
What forms the floor of the 4th ventricle?
Rhomboid Fossa
What makes up the dorsal brainstem?
Tectum, rhomboid fossa, gracile and cuneate nuclei and medulla oblongata
What seperates the gracile and cuneate tubercles
posterior median sulcus
What makes up the tectum
the superior and inferior colliculi
What makes up the diencephalon?
hypothalamus, thalamus, epithalamus (dorsal to thalamus) , subthalamus (ventral to thalamus) and the 3rd ventricle
What joins each side of the thalami?
interthalamic adhesion
Where does the anterior nuclear group receive fibres from and project fibres to?
Mammillary bodies (limbic) –> cingulate cortex
Where does the medial nuclear group receive fibres from and project fibres to?
Hypothalamus, amygdala (limbic) –> prefrontal cortex
Where does the ventral anterior nucleus receive fibres from and project fibres to?
Basal ganglia –> premotor cortex
Where does the ventral lateral nucleus receive fibres from and project fibres to?
Globus pallidus, substantia nigra, cerebellum –> primary motor cortex (frontal)
Where does the ventral posterior nucleus (lateral) receive fibres from and project fibres to?
somatic afferent fibres from body –> somatosensory cortex (parietal)
Where does the ventral posterior nucleus (medial) receive fibres from and project fibres to?
somatic afferent fibres from head –> somatosensory cortex (parietal)
Where does the medial geniculate nucleus receive fibres from and project fibres to?
inferior collicus –> auditory cortex (temporal)
Where does the lateral geniculate nucleus receive fibres from and project fibres to?
optic tract and superior collicus –> visual cortex (occipital)
Where does the pulvinar nucleus receive fibres from and project fibres to?
Extensive connections with association cortices of parietal, temporal and occipital lobes.
What does the epithalamus contain?
Habenula (stalk and connected nerve fibres of the pineal gland) and the pineal gland
What is the pineal body?
An endocrine gland synthesising hormones including melatonin. May have an effect on circadian rhythyms.
What is the lentiform nucleus made up of?
putamen and globus pallidus
What is the striatum made up if?
Caudate and Putamen
Where is the primary somatosensory cortex?
Postcentral gyrus on the parietal love
Where is the secondary somatosensory cortex?
Adjacent to the head region of the primary SS cortex
Where does C4 innervate?
Shoulder tip
Where does T4 innervate?
Nipples
Where does T10 innervate?
Belly Button
Where does L1 innervate?
Inguinal ligament
What is the spinothalamic tract responsible for?
Coarse touch, pain, temperature
What is the dorsal column pathway responsible for?
Proprioception, vibration, fine touch
What is the spinocerebellar pathway responsible for?
proprioception
What is Brown-Sequard synfrom
hemisection of spinal cord, ipsilateral loss of vibration, fine touch + contralateral loss of temp, pain and coarse touch.
What is the motor cortex made up of?
Primary motor cortex, paracentral lobule, premotor cortex, supplementary motor area
Describe the cortico-spinal fibres
Pyramidal tract, desc motor pathway from cerebral cortex, fibres run to contralateral ventral and dorsal horns of spinal cord
Describe the cortio-nuclear fibres
Descend with cortico-spinal fibres, terminate in motor nuclei of cranial nerves of pons and medulla
Describe the cortico-pontine fibres
First order fibres in cortico-pontine-cerebellar pathway, terminate ipsilaterally in pontine nuclei
What are medullary pyramids?
Eminences marking position of underlying fibres, 80% fibres decussate here
What are the medullary olives?
Swellings lateral to pyramids on each side, contain inferior olivary nuclei.
What are the inferior olivary nuclei?
Have connection with contralateral cerebellar circuits
Lateral corticospinal tract (in spinal cord)
already decussated and mainly controls distal muscles
Ventral corticospinal tract (in spinal cord)
hasn’t decussated and mainly controls trunk muscles- balance
Rubrospinal tract (in spinal cord)
function in humans unclear- fine finger movement/proximal trunk?
Reticulospinal tract (in spinal cord)
influences muscle tone and responsiveness
Vestibulospinal tract (in spinal cord)
balance
Tectospinal tract (in spinal cord)
reflexes
What are substantia nigra?
Black, dopamine producing, visible superior to cerebral peduncle?
In what condition to substantia nigra die?
Parkinson’s
What are the red nucei?
Imaginary on cadaver, give rise to rubrospinal tract from above.
What can a raised ICP cause?
herniation of cerebellar tonsils –> foramen magnum and brainstem compression
Where foes the floccular lobe lie?
Mediun surface of where 4th ventricle protrudes into base of cerebellum
What does the floccular lobe do?
Concerned with vestibular information
What happens in Huntingdon’s?
atrophy of caudate nucleus, leads to hyperkinetic movement
What happens in Parkinson’s?
inhibits too many movements, hard to initiate movement
What motor fibres synapse at the genu?
V, VII, IX, X, XI, XII
What can cause cerebellar dysfunction?
alcohol, ischaemia/stroke, thiamin deficiency, demyelination
What signs are there of cerebellar dysfunction?
Dysdiadokinesis Ataxia Nystagmus Intention tremor Slurred speech Hypotonia Past pointing
Olfactory Nerve
Special sensory
Olfaction. No brainstem nuceli.
Direct projection to reach limbic and olfactory cortex structures, passes through cribiform plate.
Optic Nerve
Special sensory
Sight and pupillary reflex. Originates in thalamus, passes through optic canal. Retina–> LGN.
Oculomotor Nerve
Motor Eye movement (not lateral) and levator paplebrae. Edinger-Westphal nucleus. Roots emerge from medial surface of each crus cerebi into the interpenduncular fossa --> cavernous sinus --> superior orbital fissure
Trochlear Nerve
Motor
Eye movement- superior oblique. Emegres dorsally and curves around lateral peduncle –> interpeduncular fossa. `Through cavernous sinus to superior orbital fissure.
Trigeminal Nerve
Both
Sensation of touch on face, mastication, taste. Emerges through middle cerebellar peduncle lateral to pons. Goes through superior orbital fissure (V1), foramen rotundum (V2) and foramen ovale (V3)
Abducens Nerve
Motor
Eye movement- lateral oblique. Emerges either side of the midline and passes rostrally over the ventral pontine surface. Exits through superior orbital fissure. Long intracranial course and may be stretched with abnormalities (including raised ICP)
Facial Nerve
Both
Muscles of facial expression, salivation, tear secretion. Emerges medially at lateral margin of medullary-pontine angle. Leaves through internal auditory meatus –> stylomastoid foramen
Vestibulocochlear Nerve
Sensory
Hearing and balance. Emerges laterally at margin of medullary-pontine angle. Leaves through auditory meatus.
Glossopharyngeal Nerve
Both
Taste, salivation and swallowing. Slender rootlets found in venterolateral sulcus at posterolateral margin of the olive of the medulla- lying across cerebellar flocculus. Exits skull through jugular foramen.