Chapter 14 Anatomy

Gray commissure

Connects left and right side of the brain (functional/informationally), axons of interneurons

Spinal meninges

Specialized membrane that protects, stabilizes, and absorbs shock

Dura, arachnoid, pia

The 3 meningeal layers of the spinal cord from superficial to deep

Spinal cord

The epidural space can be found in the…

Subarachnoid space

Area of the spinal cord containing CSF (and therefore ependymal cells which make CSF)

Denticulate ligaments

Pia mater structures, stabilizes spinal cord within spinal canal

Gray matter

Surrounds central canal in spinal cord, contains cell bodies, glial, cells, and groups of nuclei (sensory or motor) with specific functions

Posterior gray horns

Part of gray matter that is dorsal, contains somatic and visceral sensory nuclei

Anterior gray horns

Part of gray matter that is ventral, contains somatic motor nuclei

Lateral gray horns

Part of gray matter that is on the side, contains visceral motor neurons

T1-L2

The vertebral numbers where the lateral horns can be found in the gray matter of the spinal cord

White matter

The myelinated portion of the spinal cord, divided into 6 columns with tracts

Ascending tracts

White matter tracts that relay information from spinal cord to brain

Descending tracts

White matter tracts that carry information from the brain to the spinal cord

Epineurium

Covers the whole peripheral nerve

Perineurium

Covers a nerve fascicle

Endoneurium

Covers a nerve cell

ASK ABOUT BRACHIAL PLEXUS NERVES

ASK ABOUT BRACHIAL PLEXUS NERVES

Reflex

Immediate involuntary response to a specific stimulus

Reflex arc

The neural “writing” of a single reflex

Steps of reflex (including brain)

1) Arrival of stimulus

2) Sensory neuron activation, travels through dorsal root to relay sensation to brain

3) Information processed

4) Travels back down to spinal cord and through ventral root, activates motor neuron

5) Effector responds

Steps of stretch reflex (only spinal cord)

1) Stimulus, stretch of muscle stimulates muscle spindles

2) Sensory neuron is activated and travels into spinal cord

3) Information is processed at motor neuron

4) Motor neuron is activated

5) Response, muscle contracts