Download Brainstem Anatomy and Function: Exam Questions and Answers and more Exams Advanced Education in PDF only on Docsity!
OPT 113 Brainstem Exam Questions And Correct Answers!!
What makes up the brainstem? midbrain and hindbrain (pons and medulla)
What cranial nerves arise from the midbrain? III and IV
What cranial nerves arise from the pons (metencephalon)? V, VI, VII
What cranial nerves arise from the medulla (myelencephalon)? VIII, IX, X, XI, XII
What is the tegmentum? area between substantia nigra and aqueduct; contains CN III and CN IV nuclei
What is the crus cerebri? part of the cerebral penduncles which contain descending tracts
What is the tectum? roof of the midbrain
Are there any special pathways in the brainstem?
no. special senses are only in cranium (no cranial nerve pathways in the spinal cord)
What GSE columns are located in the brainstem? -Striated muscle of orbit -striated muscle of tongue
What SVE columns are located in the brainstem -brachial arch striated musculature or face, jaws, palate, larynx, pharynx
visceral functions include food and air intake
What GVE columns are located in the brainstem -cranial parasympathetics
- head ganglia= ciliary, pterygopalatine, otic, submandibular
- thorax/abdomen= vagal
What GVA columns are located in the brainstem receives from visceral teritories of CN IX and X
What SVA columns are located in the brainstem receives from taste buds in endoderm lining brachial arches
What occurs in the corticospinal pathway of the brainstem -motor -corticol fibers descend through corona radiata and internal capsule to brainstem -fibers continue through crus of midbrain and basilar pons to form pyramid of medulla
What does the midbrain connect? pons and cerebellum with telencephalon
What does the Ventral surface of the midbrain contain?
- interpeduncular fossa bounded laterally by cerebral peduncles -optic tracts wind around midbrain at junction with diencephalon -CN III and IV emerge ventrally at caudal end
What does the lateral surface of the midbrain contain? -superior brachium -inferior brachium
What does the superior brachium connect? superior colliculus with the LGN of the thalamus and optic tract (10% OF GANGLION AXONS TRAVEL HERE)
What does the inferior brachium connect? inferior colliculus with the medial geniculate nucleus of the thalamus
What does the dorsal surface of the midbrain contain? -corpora quadrigemina ; collection of four areas of grey matter (colliculi)
What are superior colliculi responsible for? visual reflexes
What are inferior colliculi responsible for? auditory reflexes
What does the cerebral aqueduct do? runs through midbrain and is the route for CSP from 3rd to 4th ventricle
Central (periaqueductal) grey matter surrounds the aqueduct and... -trochlear nuclei are in the central gray at inferior level -oculomotor nucleus with edinger westphal (parasympathetic) nucleus
Where is the tectum located? dorsal to aqueduct in the midbrain
What is the near pupil response? signal from visual cortex from the frontal eye fields that detect movement through CN III motor nuclei; stimulates medial rectus muscles and allows for convergence
Where are pons located? ventral to cerebellum, caudal to midbrain and rostral to medulla
Basilar groove located on the ventral surface of the pons and lodges the basilar artery
What does the middle cerebellar peduncle do? connects brain stem to cerebellum
What is the dorsal surface of the pons covered by? cerebellum
facial colliculi floor of 4th ventricle formed by abducens nuclei and facial nerve fibers project ventrally
What is the trapezoid body? A collection of fibres in the pontine tegmentum. The fibres are a key part of the auditory pathway and arise from the ventral cochlear nucleus, heading to the superior olives (the superior olive is on the dorsal side of the trapezoid body)
Pontine tissue is ventral to the trapezoid body. what part of the pons does this make up? basal part of pons
Where do the pontine nuclei axons decussate? anterior surface of the pons and enter middle cerebellar peduncles. contains corticospinal and corticobulbar tracts
In the pontine nuclei, corticopontine fibers from the cerebral cortex terminate. where do they synapse? neurons of the pontine nuclei
Where is the tegmentem in relation to the pons? dorsal to the trapezoid body
Where is the facial nucleus located? posterior to the trapezoid bodies of the pons
inferior cerebellar peduncle connects the cerebellum to the medulla oblongata
Where are cuneate tubercles located? lateral to the superior parts of the gracile tubercles
What nuclei are located in the medulla oblongata? -Nucleus ambiguus -Solitary tract nucleus -Dorsal Nucleus/ Vagus
What is the nucleus ambiguus responsible for? CN IX, X, and XI control muscles of throat via many cranial nerves
What is the solitary tract nucleus responsible for? CN VII (ant 2/3), IX (post 1/3), X (throat) receives visceral sensation and taste from several cranial nerves
What is the dorsal nucleus responsible for? CN X controls parasympathetic functions of the vagus nerve throughout the body
What is the reticular formation? a diffuse network of nerve pathways in the brainstem connecting the spinal cord, cerebrum, and cerebellum, and mediating the overall level of consciousness.
What are the important functions of the reticular formation? -autonomic activities -reflex functions -limbic functions
Overview of reticular formation
- Median RF
- Paramedian RF
- Lateral RF
What is the paramedian RF? part of the reticular formation containing mainly efferent (motor) fibers. contains parapontine RF responsible for initiating lateral eye movements
What is the lateral RF? part of the reticular formation containing mainly afferent (sensory) fibers from all sensory pathways including special senses
What parts of the reticular formation are responsible for respiratory control? medullary chemosensitive areas and carotid chemoreceptors
What do reticular formations do to provide sleep and wakefulness functions? -arousal (caudal midbrain and rostral pons) -sleep inducing (hypothalamus) -Rem and non rem centers of the pons -ascending arousal system -flip flop switch for waking and sleeping
