Unit 1: Lecture 9 Flashcards
The spinal cord is a collection of…
- neuron cell bodies
- axons
- glial cells
Segments mark point of…
exit for the spinal nerves
How many spinal segments?
31
Split up the 31 spinal segments:
Cervical - 8 Thoracic - 12 Lumbar - 5 Sacral - 5 Coccyx - 1
How many pairs of spinal nerves?
31
Spinal nerve is comprised of…
a DORSAL root and a VENTRAL root
What nerves are formed immediately after the spinal nerve is formed?
Peripheral nerves
Groupings of peripheral nerves are called…
Plexi
Four different plexi that are formed directly from spinal nerves:
- Cervical plexus (C1 - C4)
- Brachial plexus (C5 - T1)
- Lumbrosacral plexus (L1 - S4)
- Coccygeal plexus (S4, S5, and 1st Coccygeal)
How long is adult spinal cord?
58-60 cm
23-24 in
~ 2 ft
Where does spinal cord begin and end?
Begins at foramen magnum and ends are conus medullaris
Where is conus medullaris found?
At the L1-L2 intervertebral disc
While the spinal cord doesn’t run the length of the vertebral column, the _________ ends at S2 and contains __________
Dura mater; cerebrospinal fluid
Cervical enlargement
- C5 - T1
- Brachial plexus found here
Lumbosacral enlargement
- L1 - S4
- Lumbrosacral plexus found here
- Cauda equine formed from rootlets of lumbrosacral plexus
Filum terminale
Ligamentous structure that anchors inferior tip of spinal cord to the coccyx
Filum terminal composed of…
glial cells and pia mater
Meninges (deep to superficial)
Pia mater
- Denticulate ligaments (21 pairs)
Arachnoid layer
- Subarachnoid Space (between arachnoid and pia)
Dura mater
- Epidural space (between Dura and vertebral canal)
White matter
- Myelinated axons
- makes up EXTERNAL portion of spinal cord
Gray matter
- composed of neuron cell bodies
- forms “butterfly”
Sulci/fissures
Splits in the spinal cord (dorsal median sulcus & ventral median fissure)
Dorsal root ganglia are located in the…
intervertebral foramina of the vertebral column
Posterior spinal arteries
Paired, derived from vertebral arteries, running posteriorly.
Supply 1/3 of spinal cord
Anterior spinal artery
Singular, derived from vertebral arteries, runs anteriorly (anterior median fissure)
Larger than either of the posterior spinal arteries
Supplies lower 2/3
Feeder arteries
Segmental spinal arteries on either side of spinal cord.
Each divides into an anterior & posterior radicular artery, which joins the anterior and posterior spinal artery, respectively.
Great Anterior Medullary Artery of Adamkiewicz
Unilateral artery, generally entering the spinal cord from the left side in the lower thoracic region
Dermatome
Area of skin supplied by a single spinal cord segment
