Flashcards in Exam #1: Lab 2 Deck (54):
What is the cervical enlargement?
Roots of the brachial plexus coming off the cervical spinal cord= larger cord
What do the ventral primary rami become in the thoracic spinal cord?
What is the lumbar enlargement?
Area of the cord that innervates the lower limb
What is the conus medullaris? Where is the conus medullaris?
~L1 the end of the spinal cord
What is the filuman terminale?
Pia mater anchor for the spinal dura at the end of the spinal cord
Where is the gray matter?
“Butterfly” in the middle of the cord; this is the unmyelinated neuronal cell bodies, axons & dendrites
Where is the white matter/
Outside of the butterfly
How does the white:gray matter ratio of the cervical cord compare to other regions? Why?
In the cervical cord there is much more white matter b/c this is the ascending & descending tracts of myelinated axons & dendrites from all of the body
Where is the anterior horn on the cross-section of the spinal cord? What does the anterior horn contain?
Anterior horn= bottom of the butterfly that contains motonuerons
Where is the dorsal horn on the cross-section of the spinal cord? What does the dorsal horn contain?
Wing-tips of the butterfly that contain sensory neurons
Where is the lateral horn on the cross-section of the spinal cord? What does the lateral horn contain?
Preganglionic cell bodies of the SNS—T1-L2
What is the ventral median fissure?
Wide/ deep groove that is specific for the ventral aspect of the spinal cord
What is the dorsal median sulcus?
Shallow groove in the dorsal part of the spinal cord
What is & where is the dorsal faniculus/ posterior faniculus?
This is the white matter between the two dorsal/ posterior horns i.e. the wingtips of the butterfly
What is & where is the lateral faniculus?
This is the white matter lateral to the two dorsal/ posterior horns i.e. the wingtips of the butterfly
What is & where is the anterior faniculus?
This is the white matter anterior to the ventral horns i.e. the body of the butterfly
How does the white:gray matter ratio change in the lumbar spinal cord? Why?
Less white & more gray matter b/c the descending motor tracts have “left” gone to the upper body & sensory tracts only contain information from the lower limb
What is the anterior horn?
Body of the butterfly that contains cell bodies of the lower motoneurons
How is the posterior/ dorsal horn of the gray matter divided?
The posterior horn is divided into “Rexed’s Lamina”
What are the major division of the posterior horn that we are responsible for? What is their function?
Substantia gelatinosa—”Rexed’s Lamina II” = pain & temperature
Nucleus proprius= pain & temperature
What is Lissauer’s Tract?
- This is a white matter tract that sits just outside of the posterior horn; it is also called the “dorsolateral tract”
- This bundle of myelinated axons comes from cell bodies of sensory neurons located in the dorsal root ganglion (DRG)
Where are the DRG in relation to Lissaruer’s Tract?
DRG sits outside of the cord in the proximal spinal nerve. Axons of the DRG exit the spinal nerve & enter the spinal cord to form “Lissauer’s Tract.”
What is the function of Lissauer’s Tract?
Crude touch fibers
How does the pons appear on gross dissection?
Swollen portion of the brainstem
What forms the pons?
Tracts that leave the cerebellar hemispheres, especially the middle cerebellar peduncle
*Note that the pons is called the “basis pedunculi” b/c is the structure that bridges the two cerebellar hemispheres
What is the anterior median fissure?
Ventral fissure that continues from the cord into the brain
What are the pyramids?
Columns of white matter that sit just lateral to the ventral fissure in the medulla
What is the olive?
Hallmark of the medulla that sits just lateral to the pyramids
What are the pre & post-olivary sulci?
These are the sulci adjacent to the olive
- Pre= between olive & the pyraminds medially
- Post= lateral to the olive
What are the cerebral peduncles?
Columns of white matter coming down into the midbrain from the cerebrum
What is the Corpora Quadrigemina?
“Four bodies” that indicate that you’re in the midbrain or “tectum (roof) of the midbrain”
What are the superior colliculi?
- Two superior nuceli of the Corpora Quadrigemina
- Function in vision
What are the inferior colliculi?
- Two inferior nuceli of the Corpora Quadrigemina
- Function in hearing
What is the name of the sulcus visualized of the brainstem from the dorsal view?
Dorsal median sulcus
Where does the 4th ventricle sit relative to the dorsal brainstem?
Superior to the dorsal brainstem, between the pons & the medulla
What is the MCP or Middle Cerebellar Peducle?
White matter tract from the cerebellum to the pons
What is the ICP or Inferior Cerebellar Peduncle?
White matter tract connecting the cerebellum to the medulla
What is the SCP?
White matter from cerebral cortex to the midbrain
What EOM is specific to CN III (oculomotor)?
Where is the root of CN V(trigeminal) in relation to the ventral brain?
What is the name of CN CN VI? What EOM does it specifically innervate?
“Abducens” Lateral rectus
Where is CN VI (Abducens) in relation to the ventral brain?
Ponto-medullary junction, medially
Where are CN VII & CN VIIII in relation to the ventral brain?
Lateral ponto-medullary junction
What is the landmark for CN IX, X & XI?
Olive; specifically, the post-olivary sulcus
What is the landmark for CN XII?
Olive; specifically, the pre-olivary sulcus
Where does CN IV leave the brain?
What forms the basilar pons?
This is a swelling formed by the middle cerebellar peduncle
What is the tegmentum? What does the tegmentum contain?
“Floor” of the midbrain & pons that contains cranial nerve nuclei
What divides the tectum & tegmentum?
What is the Crus Cerebri?
This is a collection of descending white matter tracts from cerebral cortex into the midbrain; it is on the anterior aspect of the midbrain
What is the white wavy structure that is deep to the olive seen on cross-sectional view?
“Inferior olivary nucleus”
What is the hallmark that tells you that you’re in the rostal midbrain?
What are the three parts of the cerebral peduncle?
1) Crus cerebri
2) Substania Nigra
3) Tegmentum of the midbrain