Lecture 4: Spinal Cord, PNS & Meninges	Lab 4. Deep Back & Laminectomy
Lecture 5: Org. UE & Joints; Shoulder	Lab 5: Shoulder, Scapula, and Post. Axillary Wall
Lecture6 & 7: Imaging Techniques. The Axilla	Lab 6. Ant. Axillary Wall and Axilla
Quiz #1

SPINAL CORD AND PERIPHERAL NERVOUS SYSTEM

James H. Baker, Ph.D.
Blair H. Turner, Ph.D.
Robert J. Cowie, Ph.D.

Objectives:

The student should be able to:

Describe the anatomical and functional divisions of the nervous system.

1. Describe the neuron and the structure and functions of its three principal components.
2. Describe the cellular and connective tissue coverings associated with the axon.
3. Identify and discuss the components of spinal nerves including the afferent and efferent components.
4. Describe the anatomical and functional features of the coverings of the spinal cord.
5. Describe the clinical significance of dermatomes.
6. Describe the various spinal nerve plexuses and their formation from ventral primary rami.

  OUTLINE:

9. Organization of the nervous system

1. Anatomical
2. 1. Central Nervous System

a. Brain

b. Spinal cord

2. Peripheral Nervous System

a. Peripheral nerves

b. Ganglia

B. Functional

1. Somatic

2. Autonomic

2. Neuron-Functional unit of the nervous system

Neuron: a cell specialized for rapid communication. It receives information in the form of electrochemical signals from one neuron and relays it to the next in a sequence.

A. Parts

1. Dendrites: receive electrochemical information from a previous neuron in a chain of relays.

2. Nerve cell body (soma): contains the metabolic machinery of the cell.

3. Axon: relays information transmitted through its soma and to the next neuron in the relay system.

B. Some different types of neurons

C. Synapses: the site at which one neuron chemically influences the next neuron in a chain or pathway of neurons.

D. Axonal coverings

1. Axolemma

2. Neurolemma

3. Node of Ranvier

III. Nerves

1. Associated connective tissue

1. Epineurium

2. Perineurium

3. Endoneurium

B.Functional divisions

1. Sensory fibers

a. General somatic afferent

b. General visceral afferent

2. Motor fibers

a General somatic efferent

b. General visceral efferent

c. Association (internuncial)

IV. Spinal cord (31 pairs of spinal nerves)

1. Location
2. Enlargements
3. Growth
4. D. Cauda equina
5. Conus medullaris
6. Cross section of spinal cord
7. Coverings of spinal cord

1. Dura

2. Arachnoid

3. Pia

V. Spinal Nerve

A. Diagram

B. Number of spinal nerves

C. Divisions

1. Dorsal root: contains sensory axons only. Their cell bodies are in the dorsal root ganglion.

2. Ventral root: contains motor axons and supplies effector organs. Their cell bodies are in the intermediate and ventral gray matter of the spinal cord.

3. Mixed spinal nerve: contains both sensory and motor axons.

4. Dorsal primary ramus: a dorsal (posterior) division of a mixed spinal nerve supplies the "true back" between the angles of the ribs.

a. Lateral division

b. Medial division

5. Ventral primary ramus: a ventral (anterior) division of a mixed spinal nerve the remainder of the body wall and the extremities. Ventral primary rami join to form nerve plexuses.

a. Muscular

b. Lateral cutaneous

c. Anterior cutaneous

d. White ramus communicans: contains general visceral afferents and general visceral efferents (preganglionic sympathetic axons).

e. Gray ramus communicans: contains postganglionic sympathetic axons.

D.Definitions

1. Dermatome: the area of skin innervated by sensory axons of a single dorsal root.

2. Myotome: all the muscles innervated by motor neurons of a single ventral root.

3. Plexus: a network of nerves (ventral primary rami)

4. Referred pain

5. Spinal punctures

Copyright©1996-99 B. Turner. All rights reserved.