BB Lecture 1 Flashcards
Corpus Callosum
a large white matter tract that acts as the main “highway” of neuronal cables which connects the two hemispheres
What is the significance of Shh in the development of the neural tube?
Shh acts as a morphogen that patterns neural tube
Where is sonic hedghog expressed during neurulation?
In the notochord and the floor plate (basal layer as opposed to alar plate) of the neural tube
Reticular formation
a region in the brainstem that is involved in multiple tasks such as regulating the sleep-wake cycle and filtering incoming stimuli to discriminate irrelevant background stimuli.
Nerve Roots are
EITHER motor OR sensory
Ventral root
contains the cell bodies of motor axons
Dorsal root
contains cell bodies to which the axons of sensory neurons synapse with
Ganglion
an encapsulated collection of nerve-cell bodies and their synapses; usually located outside the brain and spinal cord
Where does the dorsal root ganglion reside?
After preganglionic sensory axons leave the spinal nerve and before the postganglionic axons synapse with cells in the dorsal root of the spinal cord
ventral and dorsal rami contain
a mixture of BOTH motor AND sensory axons
A spinal nerve is formed by
the joining of a ventral root and a dorsal root
Peripheral nervous system
consists of the nerves and ganglia outside of the brain and spinal cord
Where do rami come from?
They are branches of spinal nerves
What do spinal nerves branch into?
ventral and dorsal rami
Autonomic Nervous System
divided into sympathetic and parasympathetic nervous system
How many synapses are required for nerves of the ANS to carry out its function?
2 synapses required (one in ganglion and one in target cell)
Sympathetic subdivisions come from which spinal nerves?
T1 - L2
What is a white ramus?
the preganglionic neuron of sympathetic from spinal nerve
What is a gray ramus?
postganglionic neuron of sympathetic from spinal nerve
What is a splanchnic nerve?
It is simply the name given to a what ramus that passes the paravertebral ganglia and heads to prevertebral ganglia
What are paravertebral ganglia?
They are the sits of synapse of sympathetic neurons and they supply body wall and throacic viscera
What are prevertebral ganglia?
They are located closer to the target organ/cell and they are the sites of synapse of splanchnic nerves (from sympathetics); usually supplies abdominopelvic viscera
Are paravertebral and prevertebral ganglia associated with the parasympathetic nervous system?
Hell no motherfucker
