Exam 3 Nervous System (focused) Flashcards
What is the prosencephalon?
the forebrain
what are the two subdivisions of the prosencephalon?
telencephalon and diencephalon
what is the telencephalon composed of?
cerebrum
what is the diencephalon composed of?
epithalamus, thalamus, hypothalamus
what is the mesencephalon?
midbrain
what is the mesencephalon composed of?
tectum and tegmentum
what is the rhombencephalon?
hindbrain
what are the two subdivisions of the rhombencephalon?
metencephalon and myelencephalon
what is the metencephalon composed of?
pons, cerebellum
what is the myelencephalon composed of?
medulla oblongata
T/F? reptiles have a pons
false, only in mammals
what does gray matter consist of?
neuronal cell bodies
what does white matter consist of?
myelinated axons from ascending sensory and descending motor tracts.
what does the dorsal horn contain?
cell bodies of 2nd-order sensory neurons that receive terminations of 1st-order sensory neurons associated with receptors.
where are the cell bodies of 1st-order sensory neurons located? sensory or motor? somatic, visceral, or both?
dorsal root ganglia, both sensory
what does the ventral horn contain? somatic, visceral, or both?
cell bodies of lower motor neurons, somatic sensory
what does the lateral horn contain? motor or sensory? visceral, somatic, somatic or both?
cell bodies involved with the sympathetic division of ANS, visceral motor
where is the lateral horn located?
between T1 and L2
how do neurons exit the lateral horn?
through the ventral root
is the spinothalamic tract ascending or descending?
ascending
what is the function of the spinothalamic tract?
transmits information to the brain about pain, temperature, pressure, and crude touch
how does the spinothalamic tract function?
1st order sensory neuron axons from skin receptors enter dorsal root and synapse with 2nd order sensory neurons in the dorsal horn
What do axons of the spinothalamic tract do?
decussate to other side of the spinal cord, travel up the brainstem as tract to the thalamus then on to the sensory cortex via 3rd order neurons
is the corticospinal tract ascending or descending?
descending
what is the function of the corticospinal tract?
innervate voluntary muscles
how does the corticospinal tract fucntion?
neuronal cell bodies in the motor cortex (upper motor neurons) send axons down through the brain stem and spinal cord and synapse in the ventral horn with lower motor neurons
what do axons of the corticospinal tract do?
decussate to the opposite side in the medulla, axons of lower motor neurons innervate striated (voluntary) muscles
what type of muscles does the dorsal rami innervate?
epaxial
what type of muscles dot he ventral rami innervate?
hypaxial
What are the dorsal and ventral rami?
spinal nerves that divide to innervate different muscle groups
T/F, explain why? spinal cord exhibits cervical and lumbar enlargements
true, large number of cell bodies to innervate forelimb and hindlimb