Lab 17

The spinal cord consists of ____ segments.

31

The spinal cord conveys ____ to the brain.

Action potentials

The ____ is the thin, web like middle layer of the meninges; lacks blood vessels.

Arachnoid mater

Curtain nerves arise from the conus medullaris and extend downward to form the

Cause equina

Grey mater consists of ...?

Cell bodies, dendrites, and unmyelinated axons of neurons.

A thickening of the spinal cord in the neck region, called the ___, gives rise to nerves that supply the upper limbs.

Cervical enlargement

The spinal cord ends near the intervertebral disk between the first and second lumbar vertebrae, forming a conical structure called the ____.

Conus medullaris

The brain occupies the ____.

Cranial cavity

The brain then processes the incoming information, and responds by sending action potentials ___ the spinal cord toward ____ such as ____ or ____.

Down, effectors, muscles, glands

The ____ is the outer most layer of the meninges.

Dura mater

____ is comprised of tough fibrous connective tissue with an extensive blood supply.

Dura mater

The spinal cord is connected to the brain at the level of the ____.

Foramen magnum

The ____ consist of cell bodies, dendrites and unmyelinated axons of neurons.

Gray matter

A cross section of the spinal cord reveals a core of ____ surrounded by ____.

Grey matter, white matter

Where does the spinal cord end?

L1-L2

A thickening in the spinal cord in the lower back, called the ____, give rise to nerves that supply the lower limbs.

Lumbar enlargement

The soft tissue of the brain and spinal cord are surrounded by three layers of protective membranes called the ____.

Meninges

The anterior root contains only axons of ____ neurons, which conduct nerve impulses to ____ and ____.

Motor, muscles, glands

The ____ is the innermost transparent layer of the meninges which adheres to the surface of the brain and spinal cord.

Pia mater

The upper and lower "wings" of gray matter are called ____ and ____, respectively.

Posterior and anterior gray horns

An enlargement called the ____ contains the cell bodies of sensory neurons.

Posterior root ganglion

Each spinal nerve is formed from the union of a ____ and ____ root that arises from the spinal cord.

Posterior, anterior

Spinal nerves are mixed nerves, containing axons of both ____ and ____ neurons.

Sensory, motor

The posterior root contains only axons of ____ neurons, which conduct nerve impulses from ____ receptors into the ____.

Sensory, sensory, spinal cord

The ____ conveys action potentials to the brain.

Spinal cord

Each of the 31 spinal cord segments gives rise to a pair of ____.

Spinal nerves

____ are mixed nerves, containing axons of both sensory and motor neurons.

Spinal nerves

What separates the arachnoid mater from the pia mater? What does it contain?

Subarachnoid space, cerebrospinal fluid

The ____ resembles the

Wings of a butterfly

The central nervous system is composed of the ____ and ____.

brain and spinal cord

The _____ is composed of the brain and spinal cord

central nervous system

The white matter contains ____.

myelinated axons

What separates the dura mater and the arachnoid mater? What does it contain?

subdural space, interstitial fluid

Spinal cord occupies the ____.

vertebral canal

The ____ contains of myelinated axons.

white matter