LAB 6: SPINAL CORD AND REFLEXES

Meninges

Three protective layers surrounding the spinal cord: Dura Mater, Arachnoid Mater, Pia Mater.

Dura mater

The tough, outermost membrane protecting the spinal cord.

Epidural space

The area between the dura mater and the vertebrae, containing fat and blood vessels.

Arachnoid mater

The middle layer of the meninges, containing cerebrospinal fluid (CSF).

Subarachnoid space

The area beneath the arachnoid mater, filled with CSF to cushion the spinal cord.

Cerebrospinal fluid

A clear liquid that protects and nourishes the spinal cord and brain.

Pia mater

The thin, innermost layer of the meninges that directly covers and protects the spinal cord.

Dendrite

The branched extensions of a neuron that receive signals from other neurons.

Cell Body

The main part of a neuron that contains the nucleus and organelles necessary for cell function.

Axon

A long, thin structure that transmits electrical impulses away from the cell body.

Synaptic Knob

The terminal end of an axon where neurotransmitters are released to send signals.

Myelin

A fatty substance that surrounds and insulates axons for faster electrical signal transmission.

Node of Ranvier

Small gaps in the myelin sheath where the axon is exposed, speeding up conduction.

Sensory receptor

A specialized structure that detects changes in the environment (stimuli).

Sensory/afferent neuron

A neuron that carries sensory information from the receptor to the spinal cord.

Integration center

The part of the spinal cord or brain where sensory input is processed.

Motor neuron

A neuron that carries commands from the central nervous system to muscles or glands.

Effector

The muscle or gland that responds to the motor neuron signal.

Patellar reflex

A simple stretch reflex that causes the leg to extend when the patellar tendon is tapped.

Flexor reflex

A reflex that causes an automatic withdrawal of a body part in response to a painful stimulus.

Crossed-extensor reflex

A reflex occurring in the opposite limb to help maintain balance when withdrawal reflex is activated.

Anterior median fissure

A deep groove on the anterior side of the spinal cord that partially divides it into two halves.

Central canal

A small, fluid-filled channel running through the center of the spinal cord.

Gray matter

The butterfly-shaped inner region of the spinal cord that contains neuron cell bodies.

Posterior horn

The part of the gray matter that receives sensory input from the body.

Lateral horn

A section of gray matter present only in the thoracic and upper lumbar spinal cord.

Anterior horn

The part of the gray matter that contains motor neurons.

White matter

The outer layer of the spinal cord that contains nerve fibers transmitting signals.

Anterior column

A section of white matter that carries motor signals from the brain to the spinal cord.

Posterior column

A section of white matter that carries sensory information to the brain.

Lateral column

A region of white matter that carries both motor and sensory information.

Posterior (dorsal) root

The part of a spinal nerve that carries sensory signals from the body to the spinal cord.

Posterior (dorsal) root ganglion

A cluster of sensory neuron cell bodies located on the dorsal root of the spinal nerve.

Anterior (ventral) root

The part of a spinal nerve that carries motor signals from the spinal cord to muscles.