Brainstem Flashcards
describe the organization of Motor nuclei in the brainstem
- Cranial nerve nuclei (GSE) are located in the MIDLINE of brainstem levels
- Cranial nerve nuclei III, IV, VI and XII
describe the organization of Mixed sensory nuclei
- Cranial nuclei (SVA, GVA, SVE, GVE) are INTERMEDIATE columns throughout the PONS and MEDULLA of the brainstem
- Cranial nerve nuclei = V, VII, IX, X
describe the organization of Sensory nuclei in brainstem
- Cranial nerve VIII is the only PURE SENSORY nucleus and nerve (SSA) in brainstem
–> located DORSOLATERALLY in caudal pons and rostral medulla
- Cranial nerve V (GSA) is an EXCEPTION to pure sensory cranial nerve as it is mixed nerve
–> GSA nuclei (spinal, principal and mesencephalic nuclei) are located MOST LATERALLY in brainstem
Describe the Cranial nerve, modality and location
- Olfactory - sensory (some) - cerebrum
- Optic = sensory (say) = diencephalon
- Oculomotor = motor (money) = midbrain
- Trochlear = motor (matters) = midbrain
- Trigeminal = both (but) = pons
- Abducens = motor (my) = pons
- Facial = both (brother) = pons
- vestibulocochlear = sensory (says) = pons, medulla
- Glossopharyngeal = both (big) = medulla
- Vagus = both (boobs) = medulla
- accessory = motor (matter) = medulla, spinal cord
- Hypoglassal = motor (most) = medulla
define sulcus limitans
- embryologic line that separates Motor (GSE, GVE, SVE) and Sensory (SVA, GVA, SSA, GSA)
- landmark inside ventricular system then the tegmentum of the brainstem
- divides sensory nuclei, dorsally located, from motor nuclei ventrally located
embyology of spinal cord
Alar plate (dorsal) gives rise to sensory function
–> dorsal horns
Basal plate (ventral) gives rise to motor function
–> ventral horns
describe the embrylogy of the brainstem in relation to sensory/motor nuclei
- in the brainstem the alar plate is dorsolaterally
–> gives rise to somatic afferet, special visceral afferent, general visceral afferent nuclei (laterally to medial)
- in brainstem the basal plate is more medial along 4th ventricle
–> gives rise to general visceral efferent, special visceral efferent (Ix, X, XI) and somatic efferent (XII) (laterally to medial)
describe the medial zone of the closed caudal medulla
- Corticospinal tract and decussation
- Internal arcuate fibers forming medial lemniscus
- ventral trigeminothalamic tract = second order neurons of FACE (pain and temp pathway)
- Motor cranial nerve = HYPOGLOSSAL NUCLEUS (GSE)
Describe dorsal zone of closed caudal medulla
- Posterior column-medial lemniscus system
–> gracile fasciculus/gracile nucleus
–> cuneat fasciculus/cuneate nucleus
Describe the lateral zone of the closed caudal medulla
- SPinothalamic (ALS) tract
- Spinal trigeminal nucelus (GSA)
- Spinal trigeminal tract
describe the intermediate zone of the closed caudal medulla
- Dorsal motor nucleus of vagus (GVE) = preganglionic PARASYMPATHETICS to Visceral
- Nucleus ambiguus (SVE) = motor to muscle of laynx and pharynx (CN IX, X, XI)
- Nucleus Solitarius = SVA, GVA = taste and visceral sensation (CN IX and X)
describe the medial zone of open rostral medulla
- corticospinal tract
- corticonuclear tract
- medial lemniscus and ventral trigeminothalamic tract
- medial longitudinal fasciculus (MLF)
- Hypoglossal nucleus (GSE)
describe the dorsolateral zone of the open rostral medulla
–> due to 4th ventricle
- spinothalamic tract
- spinal trigeminal nucleus (CN V; GSA) = pain/temp orofacial region
- spinal trigeminal tract
- Vestiular and Cochlear nuclei (SSA) = seen in MOST ROSTRAL MEDULLA and CAUDAL PONS
describe the intermediate zone of the open rostral medulla
- Dorsal motor nucleus of vagus nerve (GVE) = parasympathetics to viscera
- inferior salivatory nucleus (GVE) = parasympathetics to parotid gland (CN IX)
- nucleus ambiguus (SVE) = motor to muscles of larynx and pharaynx (CN IX, X)
- Nucleus solitarius = SVA, GVA = taste and visceral sensation (CN IX, X)
describe the medial zone of the pons
- corticospinal tract
- corticonuclear tract
- medial lemniscus with ventral trigeminothalamic tracts
- BASIS PONTIS ( pontine nuclei)
- Abducens nuclei
- medial longitudinal fasciculus (MLF)
describe the dosolateral zone of the pons
- spinothalamic tract
- spinal trigeminal nucleus
- spinal trigeminal tract
- Vestibular and choclear nulcei (CAUDAL PONS)
describe intermediate zone of the pons
- Facial nucleus (SVE) = genu of nerve forms facial colliculus
- Principal (MAIN) sensory nucleus of CN V (GSA) = discriminitive touch orofacial region
- Mesencephalic nucleus of CN V (GSA) = rostral pons and caudal midbrian = proprioceptive nucleus for muscles of the head
- Motor nucleus of CN V (SVE) = motor fibers to muscles of mastication
- Superior salivatory nucleus (GVE) = parasympathetics to sublingual, submandibular, palatine glands (CN VII)
- nucleus solitarius (SVA) = taste, CN VII
describe the medial zone of the midbrain
- corticospinal tract
- corticobulbar tract
- substantia nigra
- red nucleus
- decussation of SCP
- TROCHLEAR nucleus (GSE)
- Oculomotor nuclear compelx (GSE and GVE) - Edinger-westphal nucleus
- medial longitudinal fasciculus (MLF)
describe the dorsal zone of the midbrain
- periqueductal gray (PAG)
- Tectum-sensory relay
–> superior colliculi - vision
–> inferior colliculi - auditory
describe the lateral zone of midbrain
- spinothalamic tract
- medial lemniscus
describe the intermediate zone of the midbrain
- Mesencephalic nulceus of CN V (GSA)
–> rostral pons enters the caudal midbrain, hence the name mesencephalic (pertaining to midbrain)
–> proprioceptive nucleus for muscles of the head
