Exam 3 Lecture 1 Flashcards
A Bundle of Axons within the CNS is called?
Tract
What is the 2nd Main Motor Descending Pathway?
*Percentage
*Full Pathway
Anterior Corticospinal Tracts [17%]
SAME as Lateral Corticospinal Tracts, EXCEPT XOVER IS AT SPINAL CORD where the signal actually meets the motor neuron [if leg wants to move, XOVER at motor neuron of moving leg]
Random Part of the Thalamus to Know per lecture
Ventrobasal Complex
What is the 3rd Motor Descending Pathway?
* Percentage
Uncrossed Lateral Corticospinal Tract; NO XOVER [2%]; stays on the same side
Lamina 1–>6 contain what types of receptors, per lecture
Mechanoreceptors
What parts do sensory and motor go through that are the same?
Internal Capsule, Medulla, Spinal Cord?
What does Decussation mean?
Place where something crosses over
What is the Fasciculus Cuneatus?
Part of the DCML; sensory signals from the upper parts of the body
Lamina 8
*What is located here?
*Where is it
*How is it turned on, What can it stimulate
Large Motor Neurons in the Anterior Grey Matter Horn
*Turned on by signal from brain or reflex arc
*can stimulate action potentials
Where do the Spinocerebellar Tracts transmit sensory information?
Spinal Cord to the Cerebellum
The higher you get in the cord, what happens to the dorsal columns?
They become larger/wider
What 2 Main Tracts makeup the Motor Descending Pathway?
Pyramidal Tract and Extrapyramidal Tract
What are the 2 main parts of the Pyramidal Motor Descending Pathway
Lateral Corticospinal Tract
Anterior Corticospinal Tract
What 2 routes do touch sensations take?
Gray Matter or up to Brain via Dorsal Column
What is the Main Sensory Ascending Pathway called
*where is it
*What fibers and subtypes
* 2 main parts
Dorsal Column Medial Lemniscus System [DCML]
*dorsal columns in back of spinal cord
*A fibers, all subtypes (a,b,g,d)
*Fasciculus Gracilis, Fasciculus Cuneatus
What is the Main Motor Descending Pathway?
* Percentage
* Full Pathway
Lateral Corticospinal Tracts [80%]
Motor Cortex in FL - Internal Capsule - Pyramids of Medulla [X] - Lateral Corticospinal Tracts - Activation of Motor Neuron @ Anterior Horn of Grey Matter in Spinal Cord
Lamina 7 (never mentioned but on ppt)
*another name and location
Intermediolateral Nucleus; Lateral Gray Horn
Lamina 2 and 3
*another name
*what kind of pain signals and fibers
*myelinated or non
*what other lamina can be roped in with these 2?
Substantia Gelatinosa
*Slow pain - C fibers, non-myelinated
*Lamina 5 can also get slow pain
A bundle of Axons outside the CNS is called?
Nerves
Where does the Anterior Spinothalamic Tract transmit Sensory Pain Information?
Spinal Cord –> Thalamus –> Parietal Lobe
What is the Difference between the Main and the 2nd Main Motor Descending Pathway?
X-OVER in Main is Pyramidal Decussation on Pyramids of Medulla
X-OVER in 2nd is Spinal Cord at where motor neuron meets
Main - Lateral side of cord
2nd - Anterior side of cord
What is the Fasciculus Gracilis?
Part of the DCML; sensory signals from lower parts of the body
Lamina 1
*Another name for it
*What kind of Pain signals and fibers
*myelinated or non
Most Dorsal Lamina; called Lamina Marginalis
*Sharp Pain - A delta Fibers, myelinated nociceptors
Post-Central Gyrus Portions [anterior to posterior]
Lower extremity, trunk, upper extremity, face
How many Lamina are in Rexed’s Laminae?
*How are they labeled
*What part of the cord are they located
10 Lamina
*Labeled most Dorsal to Ventral
*Gray Matter
Which is Bigger: Sensory or Motor areas for transmission?
Sensory
What is the Extrapyramidal Tract?
Outside of pyramidal tracts that are accessory motor pathways to coordinate complex tasks
What is the XOVER for the Lateral Corticospinal Pathway [primary]?
Pyramidal Decussation of the Medulla
What is the XOVER for the DCML Pathway?
Medulla [lower part] - Lemniscal Decussation
What is the XOVER for the Anterior Corticospinal Pathway [2nd]?
Spinal Cord where it meets the motor neuron
Lamina 10
*What is it used for
*What is the white portion surrounding it
Cross-Talk between both sides of spinal cord; located on middle body of gray butterfly
*Anterior White Commissure (AWC)
DCML Sensory Pathway
Dorsal Root - Dorsal Root Ganglia - Dorsal Column [fasciculus gracilis] - Upper extremities to brain via fasciculus gracilis - XOVER at Medulla - Medial Lemniscus - Thalamus [Ventrobasal Complex] - Internal Capsule - Parietal Lobe
Is the Sensory Ascending Pathway Afferent or Efferent?
Afferent
Is the Motor Descending Pathway Afferent or Efferent?
Efferent
What is a Homunculus?
Creepy drawing on ppt
What 2 specific portions of the body have a higher number of sensors?
*how does this compare to part of brain size, per lecture
Face, Hands - Large part of the brain, b/c more sensors
How many total spinal tracts do we have?
5
