week 3 and 4 control Flashcards
what are the general functions of the brain stem?
conduit –> allows ascending and descending pathways to reach the thalamus and cerebellum from the spinal cord
integrative –> has a lot of functions –> respiratory, cardiovascular, consicousness
cranial nerve –> root
what structure is between the 3rd and 4th ventricle? What is a possible problem that could occur?
it is the cerebral aqueduct. It can become blocked and therefore CSF can build up in this space and can cause swelling of the brain. In kids the skull is flexible and can adapt to the growing brain but in adults the skull is fixed and therefore more of a problem.
what structure is the brain stem continous with caudally?
it is continous with the spinal cord at the level of the formamen magnum
what structure is the brain stem continous with rostrally?
it is continous with the diencephalon that contains the thalamus and hypothalamus
what structures make the brain stem?
pons, midbrain, medulla oblaganta and diencephalon
what structures are ventral and dorsal to the brain stem?
the clivus of the occipital bone is ventral to the brain stem.
Cerebellum is dorsal to the brain stem.
what type of fibres are on the ventral surface of the medulla?
motor fibres
what seperates the medulla from the pons?
pontomedulla junction
what is the structure that seperates the two pyramids
anterior median fissure
what type of fibers are within the pyramids?
motor fibers
what sulcus seperates the pyramid from the olive? what nerve is present here?
anterolateral sulcus seperates the 2. Olive contains nucleus
The hypoglossal nerve –> cranial nerve 12 is present here
at what sulcus does the vagus and glossopharyngeal nerve emerge?
the posterolateral sulcus that is dorsal to the olive
what do you have to do to view the dorsal surface of the brain stem?
have to remove the cerebellum
what structure is formed in the medulla. What does it do and how is it formed?
the central canal open up into the 4th ventricle at the point of the obex where CSF fluid is produced.
what are the two parts of the medulla fromed by the 4th ventricle?
the closed (caudual) --> central canal the open ( rostral) --> 4th ventricle
what is the name of the name of the floor of the 4th ventricle?
Rhomboid fossa –> grooves and elevation shows underlying nuclei
what is the name of the structures either side of the midline of the dorsal surface of the medulla?
gracile fascile which is axon bundles that transfer sensory information from the lower limbs. It moves rostrally to form gracile tubercle which contain cell bodies
what structure is formed laterally to the gracile fascile?
the cuneate which contain axons and transfer sensory information from the upper limbs. It travels rostrally to form the cuneate tubercle –> contains cell bodies
what pathway is the gracile and cuneate fascile part of?
they are part of the dorsal collumn pathway that transfers sensory information from the body to the brain
what structure bridges the two cerebral hemispheres?
the corpus callosum –> contain white matter
what is the junction between pons and midbrain?
the pontomesencephalic junction?
what nerves emerge from Cerebellopontine angle?
facial nerve and vestibucochlear nerve
what nerve emerges from the pontomedullar junction?
the abducens nerve
what pon connects the medulla to the cerebellum?
the inferior cerebellar peduncles
what two structures are connected by the superior cerebellar peduncles
the midbrain and cerebellum
what is the middle cerebellar peduncles
connect pons to cerebellum
what is a peduncle?
is a stalk that connects two structures and bundle of axons –> white matter
what is the roof of the 4th ventricle formed from?
superior cerebellar peduncles
what is the cerebral peduncle?
it connects the midbrain to the cerebellar
what structure is between the cerebral peduncle and what is its importnace?
it is the interpeduncle fossa and contains the occulomotor nerve
what is the superior and inferior colliculi associated with?
superior –> sight pathway
inferior –> auditory pathway
what is the only nerve to emergy from the dorsal aspect of the brain stem?
cranial nerve 4 –> troclear nerve
which two nerves come from the diecaphalon? are a outgrowth?
optic and olfactory nerves
in the mid brain what structure is the tectum?
the superior and inferior colliculi
what does the basal contain?
pons, midbrain and peduncles
what does the tegmentum contan?
contains cranial nerve nuclie and tracts –> some ascending and descending pathways. A lot of nucleis in which the cranial nerves synpase from come from the tegmentum. –> reticular formation
Damage to which part of the brain stem causes lock in syndrome?
the basal as it is most anterior and contains ascending and descending fibers from the cerebral cortex
what functions is the reticular formation involved in?
arousal, sleep wake cycle and modulate pain
what does the reticular formation contain?
a reticular nuclei that gives rise to descending motor pathways
vital autonomic centres such as cardiovascular and respiratory
Cells giving rise to Ascending Reticular Activating System – pass to the cortex and involved in consciousness (damage = coma
what seperates the middle cranial fossae from the posterior cranial fossae?
the middle ridge of the petrous part of the temporal bone
which sinus drains into the jugular foramen?
sigmoid sinus
what route does the olfactory nerves take to enter the nasal cavity?
it passes through a series of small holes in the cribiform plate
what two structures run along the optic canal to supply the eye?
the optic nerve and opthalmic artery
what nerves pass through the superior orbital fissure?
opthalmic division (V1) of trigeminal nerve occolumotor nerve --3 trochlear neve --4 abducens nerve --6 all there supply the extraocular muscles
what formane is posterior to the superior orbital fissurea and what structure passess through here?
the foramen rotundum and allows the maxillary divison of the trigeminal to pass through here
which foramen does the mandibular divison of the trigeminal to pass through?
the foramen ovale
what is the importane of foramen lacerum?
dry skull –> contains cartiladge not a lot goes through there however it is posterior to the carotid canal. The itnernal carotid artery passes superiorly over the foramen lacerum to form the circulis of willis
which formane allows the middle meningeal artery and vein to pass through?
the foramen spinous
what two structures run through the internal acoustic meatus?
the facial nerve –7
the vestibulocochlear nerve –> 8th
what foramen does cranial nerve 11 ,9 and 10 pass through?
the jugular foramen?
what sinus is the internal jugular vein continous with?
sigmoid sinus
what nerve runs through the hypoglossal canal?
hypoglossal nerve –> 12
what foramen allows the facial nerve to leave the skull?
stylomastoid foramen