Cerebellum, third and fourth ventricle Flashcards
why is cerebellum the largest part of the hindbrain?
- it accounts for 10% of the brain’s volume
- consists of most the neurons
what is the function of cerebellum?
coordination of movement and balance
what is the function of vermis?
it joins the two ovoid hemisphere in the midline of the cerebellum
what are the peduncles?
it attached the brainstem to each side of cerebellum
what is the function of cerebral aqueduct?
it runs through the midbrain and connects the third and fourth ventricles
how do you identify these structures?
red nucleus
substantia nigra
red nucleus - a circular mass of grey matter that is ventro lateral to the cerebral aqueduct
substantia nigra - a black band of nerve cells overlying the crus cerebri, ventrolateral to the red nucleus on each side
how would you identify the tonsil on cerebellum?
a prominent rounded swelling on cerebellum anteriorly and medially on either side of the vermis
what is the significance of flocculo-nodular lobe?
- flocculus (laterally) connected to nodule (medially, below vermis) is called floccular nodular lobe
- it is essential because it concerned with vestibular formation (which is associated with equilibrium)
which parts of the BS does the superior, middle and inferior cerebellar peduncles connect with?
superior cerebellar peduncle - connects the cerebellum to midbrain
middle cerebellar peduncle - connects the cerebellum to pons
inferior cerebellar peduncle - connects the cerebellum to medulla oblongata
what is the function of spinocerebellar tracts?
spinocerebellar - sensory input for balance and position;
- 2 types: dorsal and ventral
- dorsal spinocerebellar tract - ipsilateral: travels to inferior cerebellar peduncle
- ventral spinocerebellar tract - contralateral: travels to superior cerebellar peduncle
what is the function of vestibulocerebellar and corticopontocerebellar tracts?
vestibulocerebellar tract - vestibular impulses from labyrinth directly - travels to the inferior cerebellar peduncle
corticopontocerebellar (rubrothalamic) tract - information from motor cortex of motor plan, the same information goes to spine - travels to the middle cerebellar peduncles
which is the largest cerebellar nuclei and what is its function?
- dentate nucleus: most lateral of deep cerebellar nuclei
- zig-zag edged oval mass
- major fibres pass into the superior cerebellar peduncle
what is the rhomboid fossa?
it is diamond shaped floor of IVth ventricle limited laterally by cerebral peduncles and posteriorly by gracile and cuneate tubercles
what is the function of median sulcus on the floor of IVth ventricle?
divides the rhomboid fossa into triangular left and right halves
where to find the following with the respect to the cranial nucleus?
- vestibular trigone
- vagal trigone
- hypoglossal trigone
- facial collucli
- vestibular trigone - lateral triangular area overlying the CN8 nucleus
- vagal trigone - intermediate triangular area overlying the overlying the CN10 nucleus
- hypoglossal trigone - medial triangular area overlying the CN12 nucleus
- facial collucli - rounded swelling on pons, the facial nerves passes over it but has the facial nerve nuclei
where can you find the obex?
at the inferior apex of rhomboid fossa
what is the area posterma? and why is it important?
- a small tongue shaped area anterior-lateral to the obex
- associated with nausea control, a chemoreceptive trigger zone for emetic (vomiting) response
what is the function of the following sulcus?
- central sulcus
- parieto-occipital sulcus
- calacrine sulcus
- central sulcus - separates the frontal and parietal lobe
- parieto-occipital sulcus - separates the parietal and occipital lobe
- calcarine sulcus - separates the occipital and temporal lobe
what is the function of interventricular foramen?
- allows the CSF flow from lateral ventricles to 3rd ventricle
- it is filled filled with choroid plexus
what is corpus callosum? what is the function of corpus callosum?
- it is a broad arched band of white matter
- the largest of fibre bundles connecting the two halves of the brain
what are the four main regions of corpus callosum?
- genu - the anterior curved of CC
- rostrum - below the genu
- body - the central part of CC
- splenium - the posterior rounded end of CC
what is fornix and what is its function?
- a bundle of white fibres under the corpus callosum
- connects the hippocampus with the diencephalon and pre-commisural fibres
where is thalamus? what is its function?
- at the dorsal part of diencephalon
- major subcortical relay station for information ascending to the cerebral cortex
where is hypothalamus?
- at the ventral part of diencephalon
- contributes to the body homeostasis, control the autonomic nervous and neuroendocrine systems