Extrapyramidal Tracts Flashcards
Afferent connection to tectospinal tract (2)
- IL lat geniculate body (visual) to sup colliculus
2. Lat lemniscus (auditory) to sup/inf colliculus
Where does the tectospinal tract project to
axons project into lamina 5+6, 7+8 (cervical lvls)
What is the patheay of the tectospinal tract
From sup colliculus will cross midline at decussion of tectospinal tract (cranial midbrain). Descend next to midline and in spinal cord occupies ant white column
What is the function of the tectospinal tract
helps w automatic movements of head and neck based on unexpected visual/auditory stims
What is the special collateral the tectospinal tract has
some collaterals leave at the lvl of the pons and go to facial nerve and cause automatic contraction (eg. close eyes when there is a loud sound
Afferent and center of rubrospinal tract
- BL corticoreticular fibres
- CL cerebellum (dentorubral fibres)
center- Red nucleus (midbrain)
Efferent connection of rubrospinal tract
CL laminae 7,8,9 (mostly cerv+UL)
pathway of rubrospinal tract
Cross midline at ant tegmental decussian
descend thru lat portion of brainstem and keeps same pos when entering spinal cord
Function of rubrospinal tract
Faculitates flexors of UL (+ neck)
Afferent and efferent of medial reticulospinal tract
BL corticoreticular to pontine reticular nucleus for IL medial reticuospinal tract
IL lamina of 5/6,7,8,9 at every level
Function of medial reticulospinal tract
Excitatory to extensor motor neurons an for axial mm
(inhibits flexors)
-essential for autonomic posture
Afferent and efferent of lateral reticulospinal tract
BL corticoreticular firbes to medullary reticular nuc
BL lamina 5/6,7,8 of all lvls
function of lateral reticulospinal tract
inhibitory to extensor motor neurons (+ axial mm)
excitatory to flexors
afferent and efferent of medial vestibulospinal tract
IL cerebellum, IL vestibulococlear n to medial vestibular nuc
Efferent-medial vestibulospinal tract BL laminae 7,8,9 of cerv
Function of medial vestibulospinal tract
Controls pos of head, neck, shoulders`
afferent and efferent of lateral vestibulospinal tract
IL cerbellum and inner ear to lat vestibular nucleus
efferent- Il laminae 7,8,9 at all sc lvls
function of lateral vestibulospinal tract
Excitatory to all extensor neurons for the neck, upper limb, trunk, lower limb
Decorticate pos- how does it present
-elbows, wrists and fingers flexed, legs extended and rot in
Decorticate pos- what is likely affected
lesion above red nucleus
-it becomes unopposed and rubrospinal tract becomes hyperactive
decerebrate pos- presentation and what is likely affected
everything extended
- lesion below red nucles but above vestibular + pontine nuclei
vestibular nuclei become unsupressed and fires at higher rate and puts everything into ext
Where is benedikt syndrome located and functions it affects
Midbrain tumor
- Passage of CNIII- IL CNIII palsy
- Red nucleus- CL involuntary mvmts of limbs
- Medial + spinal lemnisucs- CL hemianesthesia
