Anatomy and Cell Biology 3319 Lecture Notes - Lecture 14: Brachial Plexus, Cervical Plexus, Sacral Plexus
1 May 2018
School
Department
Professor
Lecture 014: Spinal Nerves and Brachial Plexus
Objectives
● Spinal Nerves
○ Understand the overall organization of the spinal nerves, and distinguish spinal
roots from rami
○ Differentiate between the type of information carried in the various components
● Brachial Plexus
● Correctly name and identify roots, trunks, divisions, cords and terminal branches
● Be able to accurately draw the brachial plexus
● Understand general areas of upper limb innervated by terminal branches
● Diagnose brachial plexus injuries based on symptoms
Vertebral Column
● Bony framework of the spinal cord
● Vertebrae surround the spinal cord
● Cervical, thoracic, lumbar, sacral and coccygeal
regions
○ What are the identifiable features of each?
Intervertebral Formation
● Two vertebrae articulate to create an
intervertebral foramen
● Spinal nerves exits the spinal canal through here
● Common site of nerve impingement ment
Spinal Nerves
● Peripheral nervous system
● Mixed nerves carrying motor and sensory
information between spinal cord and body
● 31 pairs of nerves
○ 1 LESS cervical vertebrae (7) than spinal
nerve (8)
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Nomenclature: Cervical Nerves vs Vertebrae
● Cervical nerves exit ABOVE the corresponding vertebrate
○ Spinal C8 is transition site (leaves below C7)
● All other exit BELOW the corresponding vertebrae
● Example:
○ what spinal nerve exits between C3 and C4?
■ C4
○ what spinal nerve exits between T7 and T8?
■ T7
Spinal Cord Anatomy
● Spinal cord:
○ Dorsal/Posterior (Sensory)
○ Ventral/Anterior (Motor)
● Dorsal Roots (splits into the dorsal rootlets)
○ Sensory
information enters
via the dorsal side
○ Dorsal root
ganglion
■ Cell bodies
of sensory
neurons
■ Outside of
the spinal
cord
● Ventral rootlets (join to
make the Ventral Roots)
○ Motor information
leaves via the
ventral side
○ Ventral horn of the
spinal cord has
the cell body of
the motor neuron
● Spinal nerve
○ Mixed information
○ Dorsal and ventral roots join
○ Leaves through the intervertebral foramen carrying both motor and sensory
information
■ Motor to muscle
■ Sensory from region (dermatome: specific skin regions)
○ Connected to the spinal cord via root/rootlets (depends on if its sensory or motor)
○ Afferent/IN/Dorsal/Sensory
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Understand the overall organization of the spinal nerves, and distinguish spinal roots from rami. Differentiate between the type of information carried in the various components. Correctly name and identify roots, trunks, divisions, cords and terminal branches. Be able to accurately draw the brachial plexus. Understand general areas of upper limb innervated by terminal branches. Diagnose brachial plexus injuries based on symptoms. Cervical, thoracic, lumbar, sacral and coccygeal regions. Two vertebrae articulate to create an intervertebral foramen. Spinal nerves exits the spinal canal through here. Mixed nerves carrying motor and sensory information between spinal cord and body. 1 less cervical vertebrae (7) than spinal nerve (8) Cervical nerves exit above the corresponding vertebrate. Spinal c8 is transition site (leaves below c7) All other exit below the corresponding vertebrae. Dorsal roots (splits into the dorsal rootlets) Sensory information enters via the dorsal side. Ventral rootlets (join to make the ventral roots) Motor information leaves via the ventral side.
