Class Notes (839,327)
Canada (511,270)
BIOB32H3 (80)
Lecture

spinal cord and spinal nerves.docx

4 Pages
83 Views

Department
Biological Sciences
Course Code
BIOB32H3
Professor
Kenneth Welch

This preview shows page 1. Sign up to view the full 4 pages of the document.
Description
The Spinal Cord and Spinal Nerves General Organization of the Nervous System Divisions of the Nervous System • CNS • Brain and spinal cord • In the white matter, axons arranged in tracts and columns • PNS • Remainder of nervous tissue Gross Anatomy of the Spinal Cord Adult spinal cord • Localized enlargements provide innervation to limbs • 31 segments • each segment has a pair of dorsal roots and a pair of ventral roots • Filum terminale • Conus medularis • Spinal nerves extend off cord • Mixed nerves Spinal meninges • Provide physical stability and shock absorption • Three layers • Dura mater • Arachnoid • Pia mater Dura mater • Covers spinal cord • Tapers to coccygeal ligament • Epidural space separates dura mater from walls of vertebral canal Arachnoid • Interior to dura mater are the subdural space, the arachnoid and the subarachnoid space • Subarachnoid space contains CSF Pia mater • Meshwork of elastin and collagen fibers • Innermost meningeal layer • Denticulate ligaments extend from pia mater to dura mater Sectional anatomy of the spinal cord • White matter is myelinated and unmyelinated axons • Gray matter is cell bodies, unmyelinated axons and neuroglia • Projections of gray matter toward outer surface of cord are horns Horns of spinal cord • Posterior gray horn contains somatic and visceral sensory nuclei • Anterior gray horns deal with somatic motor control • Lateral gray horns contain visceral motor neurons • Gray commissures contain axons that cross from one side to the other White matter • Divided into six columns (funiculi) containing tracts • Ascending tracts relay information from the spinal cord to the brain • Descending tracts carry information from the brain to the spinal cord Spinal Nerves 31 pairs of spinal nerves • Nerves consist of: • Epineurium • Perineurium • Endoneurium Spinal nerves • White ramus (myelinated axons) • Gray ramus (unmyelinated axons that innervate glands and smooth muscle) • Dorsal ramus (sensory and motor innervation to the skin and muscles of the back) • Ventral ramus (supplying ventrolateral body surface, body wall and limbs) • Each pair of nerves monitors one dermatome Nerve plexus • Complex interwoven network of nerves • Four large plexuses • Cervical plexus • Brachial plexus • Lumbar plexus • Sacral plexus Principles of Functional Organization General organization • Sensory neurons • Deliver information to CNS • Motor neurons • Distribute commands to peripheral effectors • Interneurons • Interpret information and coordinate responses Neuronal pools • Functional group of int
More Less
Unlock Document

Only page 1 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit