Human Anatomy - Spinal Cord Anatomy

Dura mater

forms a sac in continuation with dura mater of brain from foramen magnum to S2

Arachnoid mater

deep to dura mater and is continous with arachnoid mater of braine

Subdural space

Between dura mater and arachnoid mater, contains interstital fluid

Pia Mater

adhere to surface of brain and spinal cord, contain many blood vessels, subarachnoid space between matter and pia matter 

Denticulate ligaments

thickenings of pia mater that protect spinal cord against shock and sudden displacement

Cervical enlargment

C4-T1, nerves to and from upper limb

Lumbar enlargement

T4-T12, nerve to and from lower limbs

Conus medullaris

Inferior to lumbar enlargement , end at disc between L1 and L2

Filum terminate

extension of pia mater that extends inferily andanchor spinal cord to coccyx 

Peripheral nervous system

conveys impulses to and from brain or spinal cord

Mixed nerves

sensory and motor fiber

Afferent

carry impulses toward CNA

Efferent

carry impulses away from CNS

Mechanoreceptor

pressure touch vibration stretch

Thermoreceptor

change in temp

Nocreceptor

pain

Photoreceptor

vision

chemoreceptor

chemical stimuli, foods, orders

Autonomic nervous system

control involuntary internal function

Sympathetic nervous system

Fight or flight

Parasympathetic Nervous system

Digestion, urination, conserve energy

Cervical Plexus

consists of consists of spinal nerves C1-C5, branches innervate the muscles of the neck and extend into the thoracic cavity, where they control diaphragmatic muscles 

Brachial Plexus

Innervates the pectoral girdle and upper limb with contributions from the ventral of spinal nerves C5-T1

Lumbar Plexus and Sacral plexus 

arise from lumbar and sacral segments of spinal cord, respectively and innervate the plevic girdle and lower limbs

Musculocutaneous Nerve

C5-C7 root, lateral cord

Median Nerve

C5-TI, medial cord and lateral cord

Ulnar Nerve

C7-T1, medial cord

Radial Nerve

Origin C5-T1, arises from posterior cord

Sciatic nerve 

Originates from L4-S3 sciatic nerve compromised of tibial and common fibular nerves

Femoral Nerve

Originates from L2-L4

Tibial Nerve

descends in posterior compartment of leg passes posterior to medial malleolus 

Common fibular nerve

passes superficial to the neck of the fibula where it is subcutaneous and vulnerable to injury 

Deep fibular nerve

descends on the anterior surface of the innerosseous membrane