Week 1 - External Features Flashcards
What are the main parts of the brain?
Cerebrum, cerebellum and brainstem
Which cranial fossa does the brainstem lie in?
Posterior cranial fossa
Which 2 vesicles embryologically give rise to the brainstem?
Mesencephalon and Rhombencephalon
What are the parts of the brainstem?
Midbrain
Pons
Medulla
What are the cavities of the ventricular system which lie within the brainstem?
Cerebral aqueduct
4th ventricle
What is the groove which separates the pons from the medulla?
Pontomedullary junction
Which cranial nerves emerge from the pontomedullary junction?
VI - abducent
VII - facial
VIII - vestibulocochlear
What cranial nerves emerge from medulla?
IX - glossopharyngeal
X - vagus
XII - accessory
XII - hypoglossal
What is the function of the olives on medulla?
Protrusion formed by underlying inferior olivary complex of nuclei
Relays fibres from brain and spinal cord to cerebellum
What is the function of the pyramids on the medulla?
Control conscious voluntary movements
What is the function of the decussation of the pyramids?
Cerebrum controlling muscles on oppisite side of body
Contains motor fibres of tracts
What are the open and closed parts of the medulla?
Open - superior and on dorsal surface, formed by 4th ventricle
Closed - inferior, where 4th ventricle is narrowed at obex in caudal medulla
What foramen does the medulla pass to become spinal cord?
Foramen magnum
What cranial nerve emerge from lateral aspect of mid-pons?
Trigeminal nerve - CNV
What is the middle cerebellar peduncle made up of?
Projection fibres
What does the middle cerebellar peduncle connect?
Pons to cerebellum
What part of brain lies superior to midbrain?
Cerebrum
What lie inferior to the midbrain?
Cerebellum
What does superior cerebellar peduncle connect?
Cerebellum and midbrain
What are the projections on midbrain called?
Superior and inferior cuniculi
What makes up the diencephalon?
Thalamus, hypothalamus and epithalamus
Where does the diencephalon lie?
Between brainstem and cerebrum
What projections of hypothalamus called which are visible on surface?
Internal capsule
Where is the pineal gland?
Part of diencephalon
Above superior cuniculi
What is the function of the pineal gland?
Releases melatonin in response to darkness which helps the body clock
What is the midline structure connecting the 2 cerebellar hemispheres?
Vermis
What are the 3 lobes of the cerebellar hemisphere?
Anterior, posterior and flucculo-nodular lobe
Also have the cerebellar tonsils
What is the ventricular space anterior to cerebellum?
4th ventricle
What is cerebellar coning?
Sudden drop in intracranial pressure so cerebellar tonsils may herniate through this foramen
What are the different lobes of the cerebrum?
Frontal, parietal, frontal and temporal
What is the large fissure separating the two cerebral hemispheres?
Median longitudinal fissure
What connects the 2 cerebral hemispheres?
Corpus callosum
What fibres are most likely to be carried in the corpus callosum?
Commissural fibres
What fold of dura mater do the cerebral hemispheres sit on?
Tentorium cerebelli
Describe the lateral sylvian fissure
Separates the frontal and temporal lobes of cerebrum
What separates the parietal and occipital lobes?
Parieto-occipital sulcus
What does the calcarine sulcus separate?
Separates the occipital lobe into superior and inferior lobe
Describe the cingulate sulcus
Separates the frontal and parietal lobe
Is on medial surface of hemisphere
What does the central sulcus separate?
Precentral and post-central cortex
Where is the primary motor cortex?
Frontal lobe
Where is the primary visual cortex?
Occipital lobe
Where is the primary sensory cortex?
Parietal lobe
Where is the primary auditory cortex?
Temporal lobe
What muscles overlie the bony parts of vertebrae?
Erector spinae
What ligaments may be encountered when trying to reveal spinal canal?
Supraspinal, interspinal, ligamentum flavum, posterior longitudinal ligament
What vertebral level does spinal cord end?
L1-2 in adults
L3 in new born
A what vertebral level does the dura mater and arachnoid mater end?
S2
What happens to pia mater inferior to spinal cord?
Forms the filum terminale
What vertebral level is lumbar puncture performed?
L3-4 in adults
How many pairs of spinal nerves are there?
31
Where are upper motor neurons located?
Neurons found in cerebral cortex and brainstem
Where are lower motor neurons located?
Neurons in spinal cord and brainstem
What are upper motor neuron lesions characterised by?
Spasticity, increase in muscle tone, complex sensory syndromes
What are lower motor neuron lesions characterised by?
Global sensory changes, flaccid paralysis depending on nature of mixed peripheral nerves
