Spinal Cord Organization Flashcards
CNS originates from ___________
The neural tube
The lumen of the neurotube becomes the ______________and____________filled with cerebral spinal fluid (CSF)
central canal of the cord; ventricles of the CNS
Alar plate = __________(dorsal/ventral)
Dorsal
Basal plate= ___________(dorsal/ventral)
Ventral
Syringomyelia
a rare disorder in which a cyst forms within your spinal cord. As this fluid-filled cyst, or syrinx, expands and lengthens over time, it compresses and damages part of your spinal cord from its center outward.
Metamerism
the phenomenon of having a linear series of body segments fundamentally similar in structure, though not all such structures are entirely alike in any single life form because some of them perform special functions
*The developing embryo show metamerism
Somites give rise to _______, ___________, and _________.
Sclerotomes, dermatomes, and myotomes
Which nerve fibers play a role in flexing hip during the “ swing phase of walking”?
L2, L3
Which nerve fibers play a role in extending the knee during the “ swing phase of walking”?
L3, L4
Which nerve fibers play a role in extending the ankle during the “ swing phase of walking”?
L4, L5
What type of neurons are found in the spinal cord?
Motor neurons
Interneurons
Projection Neurons
What are the two major functions of interneurons?
Excitatory
Inhibitory
What are the two types of Interneurons?
- intrasegmental interneurons (Renhsaw cell)
- propriospinal interneurons
a. short (3 segments, unilateral)
b. intermediate
c. long (entire length of cord, bilateral)
Cervical enlargement
C5-T1
Surrounding the neural tube you have the __________. This gives rise to________
Neural epithelium gives rise to the alar and basal plates
*Note: Even in a developing neural tube, you see a dorsal-ventral dichotomy separation
What can be found in the lumen of the CNS?
Cerebral spinal fluid
What is the general organization of the spinal cord?
A lumen surrounded by gray matter surrounded by white matter
What is the first structure that forms in the trilaminar embryo? What is it’s importance?
The notochord.
The notochord stimulates formation of the neural tube which comes from the ectoderm.
Lumbosacral enlargement
L1-S4
The intial effect of syringomyelia is on__________ (sensory/motor) function.
Sensory
What is metamerism?
Blocks of cells that begin at cranial region and extend down to the caudal region
During the first 3-4 weeks, what happens with the neuroepithelial of the neural tube?
The cells begin to differientiate forming neurons. These neurons will send out growth codes that inenrvate the dermis cells that will be becoming dermatomes and myotomes.
The dorsal have of spinal cord will innervate the ___________, which the ventral half of the spinal cord will innervate the ___________.
Dermatome; myotome
What’s the difference between the developing neural tube and the adult spinal cord?
In the neural tube, the central canal is large. The central canal is smaller the adult spinal cord