lab 19 - axons, nerves, funiculus

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soma of motor neuron; contains nucleus and nissl body

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nucleus of motor neuron

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dendrite; receives signals from other neurons or special sensory cells

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nucleus of glial cell

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nucleus of motor neuron (inside soma)

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axon hillick; beginning of the axon and is the site of action potential initiation

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axon; is light gray in color and is known as axolemma

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dendrites

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telodendria

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axon terminals; the ends of telodendria that synapse with the soma/dendrites of another neuron and release neurotransmitters upon it

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myelin sheath; wraps around axon and protects/electrically insulates it and also increases the speed of the action potential

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nucleus of schwann cell

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gaps between neughboring schwann cells called nodes of ranvier that are essential to action potential propagation

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endoneurium; connective tissue that encloses the axon and schwann cells; binds neighboring axons to each other

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anterior median fissure

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cervical enlargement of the spinal cord

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phrenic nerve; takes motor signals to the diaphragm

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lumbosacral enlargement of the spinal cord

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conus medullaris; found at level of L1 vertebra

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filium terminale; strand of pia mater than anchors conus medullaris to the posterior coccyx

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cauda equina; collection of lumbar and sacral spinal nerves

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obturator nerve; takes motor/sensory signals to/from the medial thigh

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sciatic nerve; takes motor signals to hamstring muscles and carries sensory info from much of the posterior thigh/leg and the plantar foot

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spinal dura mater

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arachnoid mater

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subarachnoid space; continuous with 4th ventricle and contains CSF

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pia mater

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posterior median sulcus

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posterior funiculus; contains white matter that contains a group of myelinated axons that convey info from the body to the brain

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lateral funiculus; contains myelinated axons involved in taking sensory signals to cerebellum/thalamus and also motor commands from the cortex/brainstem

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anterior funiculus; contains myelinated axons involved in taking sensory signals to the thalamus and motor commands involved in balance/coordination

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ventral horn of spinal cord

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dorsal horn of spinal cord

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gray commissure

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central canal of spinal cord; contains CSF and is continuous with 4th ventricle

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dorsal root; contains sensory axons bringing sensory info into dorsal horn

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dorsal root ganglion; contains cell bodies of sensory neurons that bring sensory info into the spinal cord

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ventral root; contains axons of ventral horn motor neurons that travel to skeletal muscles

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spinal nerve; contains both sensory and motor axons from dorsal and ventral roots; is a mixed nerve