Spinal cord Flashcards
Composed o the brain and spinal cord
Central Nervous system
Composed of spin nerves (31) and Cranial Nerves (12)
Peripheral nervous system
Transmits information from periphery to the cns. contains receptors (DORSAL)
Sensory (afferent) divison
Transmits information from the CNS to the rest of the body. Sends motor information to effectors (VENTRAL)
Motor (efferent) divison
Voluntary- skeletal muscle, sensation (pain, pressure, touch, temperature, proprioception)
Somatic nervous system
Involuntary- Smooth muscle, glands, and internal organs
Autonomic nervous system
Produces myelin protein for myelinated axons. Major glial cell in PNS
Schwann cell
Point at which one neuron communicates with one or more neurons
Synapse
Cell bodies
Gray matter
Axons (nerve fibers)
White matter
Where does the spinal cord end
L1-2
Automatic unconscious response to stimuli
Reflex
Initiates in the spinal cord, bypasses the brain right to the muscles
Spinal reflex
Why does the cervical cross section have more white?
Because of brachial plexus (more nerves running through or information)
Most superficial layer of meninges? Tough
Dura mater “hard mother”
Intermediate layer of meninges? Delicate avascular
Arachnoid Mater “spider mother”
Innermost layer of meninges? delicated
Pia mater “Delicated mother”
Non-excitable cells
They support, insulate, and nourish neurons
Glial cells (Neuroglia)
A shwann cell is a like a what in the CNS?
Oligodendryte
Structure and functional unit of the nervous system
Specialized for rapid communication
Neuron
A component of a neuron that carries impulses to the neuron cell body
Dendrites
A component of a neuron that carries impulses away from the body
Axons
Increases the velocity of the impulse transmission from neuron to neuron
Forms a sheath around some axons
Myelin
Nucleus- Gray matter, collection of neuron bodies
Tract- white matter, collection of nerve fibers, connects nuclei
CNS
Ganglion- collection of nerve cell bodies
Peripheral nerve- collection of nerve fibers, connect CNS with peripheral structuresn
Spinal OR cranial
PNS
What is the primary function of the spinal cord?
To transmit signals to and from brain to peripheral structures
Cell bodies of sympathetic nervous system are in what part of the spinal cord?
This has a lateral horn
Thoracic
Dura mater forms what
Spinal dural sac
What anchors the Spinal dural sac to the coccyx
Filum terminale
The arachnoid mater encloses what
Cerebrospinal fluid
Cushions the cord, clear odorless fluid, low in protein and cellular content
CSF
Sheets of pia mater that anchor the cord to the dural sac Separates anterior(ventral) and posterior (dorsal) nerve roots Run longitudinally along the cord
Denticulate ligaments
Cervical spinal nerves exit where
Exit intervertebral foramina above named segment
Thoracic spinal nerves exit where
Below named segment
Lumbar spinal nerves exit where
Below named segment
What are the 3 connective tissue coverings of the Peripheral nerve structure
Epineurium
Perineurium
Endoneurium
Encloses bundle of fascicles
Includes fat, blood vessels, and lymphatics
Epineurium
Dense tissue around a fascicle
Protection againt foreign substances
Perineurium
Delicate sheath surrounding neurolemma and cells
Endoneurium
Formed by the Lumbar and sacral nerve roots
L1-S5
Innervates lower extremity
Lumbosacral plexus
Enlargement of subarachnoid space to accomodate cauda equina
Lumbar cistern
3 longitudinal arteries run from the brainstem to conus medullaris and supply superior cord what are they?
Anterior spinal artery (from branches of the vertebral artery)
2 posterior spinal arteries (From vertebral or posterior inferior cerebellar artery)
Segmental medullary and radicular arteries do what
What reinforces circulation to 2/3 of cord
supply most of the cord
Great anterior segmental medullary
Run longitudinally and communicate freely with each other
Drained by 12 Ant/Post medullary and radicular veins
Join the internal vertebral venous plexus in epidural space which communicates with dural venous sinuses and vein in cranium
Anterior/ Posterior spinal veins
Somatic nervous system is a division of what?
Sensory (afferent)
Autonomic nervous system is a division of what?
Motor (efferent)
1 shwann cell can encase how many unmyelinated axons?
10
What neurotransmitters facilitate communication in the synapse?
Acetylcholine
Norepinephrine
Dopamine
GABA
The spinal cord starts where?
The medulla oblongata
Cell bodies of sympathetic nervous system are where?
Thoracic
Where does the spinal dural sac end?
S1,2
Pia mater continues as what?
Filum terminale
The filum terminale takes what with it?
Arachnoid and dura mater
Dorsal and ventral roots run in what space covered by what?
Subarachnoid space
Pia mater
Cervical enlargment runs from where to where?
C3-T1
Lumbosacral enlargement runs from where to where?
L1-S2
