Back Anatomy
1. What is the spinal cord, where is it located? Spinal cord= major conduction pathway b/w the body + barain slightly flatend anterioly/posteriorly Begin at Medula oblungada is located in Vertebral canal/cavity
2. Describe the structure, key features/subdivisions, and function(s) of the spinal cord
a. Cervical enlargement --Extends from C4 to T1 Pectoral girdle+upper limbs
b. Lumbar enlargement--Extends from L1 to S3 Pelvis +lower limbs
c. Conus medullaris-- End of Spincal cord
d. Filum Terminale internum-- Fibrous tissue that extends from conus medullaris, it consists primarily of pia matter and decends through spinal nerve roots in the caudia equina, later it becomes Filum Terminale externum and attaches to coccyx posteriorly
e. Cauda equine--Bundle of spinal nerve roots running inferior to spinal cord through the lumbar cistern (subarachnoid space) Resembles a horse tail
f. Spinal Nerves--Are points where Posterior/Anterior nerve roots unite at points of exit from vertebral canal Posterior (Sensory) Anterior (Motor) Presynaptic autonomic fibers
3. Describe the structure, key features/subdivisions, and function(s) of the spinal meninges
a. Dura mater-- Though mother outer layer of spincal cord
b. Arachnoid-- 2nd layer of spinal cord not attached to Dura but pressed against it from CSF pressure, Encloses the CSF
c. Cerebrospinal fluid-- Derived from blood between Arachnoid and Pia, provides cussion that protecs delicate tissue of spinal cord, also involved in exchange of nutrients b/w blood and neurons
d. Pia Mater-- Lines the spinal cord “Delicate” Covers the roots of spinal nerves+blood vessels, becomes filum terminale
e. Epidural Space – Space above the dura mater b/w wall of vertebral canal and dura mater, composed mostly of fat What is a “spinal tap”--obtain a sample/test for infection of CSF What is an epidural injection- drugs to numb the area
4. Be able to describe the key structures of the internal spinal cord transverse cross section
a. Grey matter-- H shaped in the spinal cord, mainly cell bodies and branching dendrites
b. White matter--surounds gray matter, nerve fibers with myelin sheaths
c. Nerve root – the initial segment of a nerve leaving the CNS
d. Axonal (motor) and dendritic (sensory) pathways – in the front, sensory in the back
e. Why the various ratios of white to grey matter in various levels of the spinal cord?
5. What is a dermatome?--Area of skin suported by a single spinal nerve
a. What is herpes zoster and how does the clinical presentation relate to anatomy?
6. Muscles of the Back
a. Describe the general function of the Extrinsic (superficial and intermediate) and Intrinsic back musculature Extrinsic superficial--control limb to trunk. Intermediate--repiratory movements Intrinsic (deep) back musculature--muscles that move vertebral column, and maintaining posture
b. Identify and Describe the structure and key features of the Extrinsic Intermediate Back Muscles--Levator Costorum C7-T11 (Insparation) attached to transverse process, Sarratus posterior superior C7-T4 elavates ribs (insparation), Sarratus posterior inferior T11-L2 depresses ribs (exparation) spinous process
c. Identify and Describe the structure and key features of the Intrinsic (superficial, intermediate and deep) Back Muscles--Extend from carnium to pelvis enclosed by thoracolumbar fasia, Splenious capitilis, Splenious cervicis thick and fat (bandage) rotate and extend, laterally flex
Intermediate m.--b/w spinous process, spinalis medial, Longissimus intermidiate, ilicostalis lateral, all extend laterally flex
Deep m.--from transverse process to transverse process, -Occupy “gutter” arise lateraly insert medialy
Components- semispinalis, Multifidus, Rotatores
d. Describe the general function of the Suboccipital muscles Rock, tilt the head into extension, assist into rotation of the head, play role in stabilization and fine mevement control of the cranium on