Chapter 13: The Spinal Cord, Spinal Nerves, and Spinal Reflexes

Flashcards created from lecture notes on the spinal cord, spinal nerves, and spinal reflexes to assist in exam preparation.

What are the two main components of the nervous system?

Central nervous system and peripheral nervous system.

What are the three meningeal layers that surround the spinal cord?

Dura mater, arachnoid mater, and pia mater.

What is the primary role of the spinal cord?

To carry sensory and motor information between the brain and the rest of the body.

What is a spinal reflex?

A quick, automatic nerve response triggered by specific stimuli, controlled by the spinal cord only.

What is the significance of gray matter in the spinal cord?

Gray matter contains cell bodies of neurons and neuroglia, involved in processing and relaying information.

What is the role of white matter in the spinal cord?

White matter contains myelinated axons that relay sensory and motor information.

Define a reflex arc and its components.

A reflex arc consists of a sensory receptor, sensory neuron, information processing in the CNS, motor neuron, and an effector.

What is the functional organization of the anterior horns of gray matter?

Anterior horns contain somatic motor nuclei which send outgoing motor commands.

What does the posterior median sulcus do?

It is a groove that divides the spinal cord into left and right.

What is the name for the enlargement of the spinal cord that supplies nerves to the lower limbs?

Lumbar enlargement.

What is the cauda equina?

A bundle of spinal nerves and spinal nerve roots located at the lower end of the vertebral canal.

How are spinal nerves named?

Spinal nerves are designated by their vertebral region and number.

What is a nerve plexus?

Complex networks of interwoven nerve fibers that allow multiple spinal nerves to supply the same structures.

What are the major components of the cervical plexus?

Includes anterior rami of spinal nerves C1-C5 and innervates the neck, scalp behind the ear, and diaphragm.

Which spinal nerves are included in the brachial plexus?

C5 to T1 spinal nerves.

What do ascending tracts in white matter do?

Transmit sensory information up toward the brain.

What do descending tracts in white matter do?

Transmit motor commands down to the spinal cord.

What are the five components of a reflex arc?

Sensory receptor, sensory neuron, information processing in CNS, motor neuron, and effector.

What type of information processing occurs in spinal reflexes?

Processing occurs in the spinal cord.

What is meningitis?

An infection of the meninges that can be viral or bacterial.

What occurs during the plantaris reflex in adults?

Curling of the toes when the lateral sole is stroked.

What is the difference between the Babinski reflex and the plantar reflex?

The Babinski reflex is normal in infants and indicates CNS damage in adults; the plantar reflex is normal in adults.

What part of the spinal cord contains the central canal?

The central canal is located in the center of the spinal cord and contains cerebrospinal fluid.

What role do autonomic ganglia play in the nervous system?

They serve as relay points for autonomic signals from the CNS to the target organs.

What is the function of the pia mater?

The pia mater is the innermost layer that directly covers the spinal cord and provides support and protection.

What do sensory neurons do?

Sensory neurons bring information into the CNS.

What is an example of a spinal reflex activity?

Dropping a hot pan and releasing it before the pain is perceived.

How does higher brain function modify reflexes?

Higher brain centers can control and modify reflex responses based on sensory information and context.

What distinguishes anterior white columns from posterior white columns?

Anterior white columns are located between the anterior horns and the anterior median fissure, while posterior white columns are between the posterior horns and the posterior median sulcus.

How many pairs of spinal nerves are there?

There are 31 pairs of spinal nerves.

What is the function of the gyri and sulci in the spinal cord?

They increase the surface area for processing information within the spinal cord.