Spinal Cord Flashcards
Where does the spinal cord start
Inferior to the medulla oblongata
Where does the spinal cord end?
Between L1 L2
Sulcus
Narrow groove
Fissure
Wider groove
Conus medullaris
Thin, conical spinal cord below L enlargement
Cauda Equina
Nerve root extending below the conus medullaris
Filum Terminae
Thin thread of Fibrous Tissue that attaches to the coccygeal ligament
Cervical Enlargement
Nerves for shoulders and limbs
Lumbar enlargement
Nerves for pelvis and lower limbs
Meninges
Membranes that isolate spinal cord from surroundings
Dura matter
The outer layer that is thick and durable and a thin cord
Arachnoid
Spider Webbed layer
Pia Mater
Inner most layer
What is meningitis
Bacteria in the meninges
Where is the epidural space
Between the Dura matter and walls of the vertebrae canal
Contains loose connective tissue and adipose tissue
Where is Cerebrospinal fluid
Circulates in subarachnoid space contains collagen and elastin fiber
Longitudty
Dura matter fuses with periosteum of occipital bone
Laterally
denticulate ligaments connect pia matter
Ventral roots
Contains Axons of Motor Nerves
Dorsal root
Contains axons of sensory nerves
Dorsal root ganglia
Big bulge on the dorsal root
What is Gray Matter made of
Cell bodies dendrites synapses
What is white matter made of
Myelin makes the color Axons of ascending sensory and descending
What are the sections of gray matter
The gray horn: Posterior- Somatic and Visceral sensory Nuclei Anterior- Somatic Motor Nuclei Lateral- Visceral Motor Gray Commissure: Axon crossing
The gray horn:
Posterior- Somatic and Visceral sensory Nuclei
Anterior- Somatic Motor Nuclei
Lateral- Visceral Motor
Gray Commissure:
Axon crossing
Epineurium
Outer layer
Perineurium
Middle, surrounds the facicle
Endoneurium
Entire individual axon
Permotormes
Each pair of spinal nerves motors a specific region of the body
Nerve plexus
Complex and woven networks of nerve fibers that controls skeletal muscles cervical muscles brachial muscles and lumbar sacral muscles
Cervical plexus
Consists of C1 through C5
Phrenic Nerve
Helps control breathing
Brachial plexus
C5 through T1
Lumbar plexus
T 12 through L4
Sacral plexus
L5 through S4
Sensory neurons
10 million and they deliver to the CNS
Motor neurons
I have 1 million delivers commands CNS to effectors
Interneurons
2 billion they do both
Divergence
Fast info
Convergence
Into 1
Serial processing
Move info
Parallel
One to many
Reverbratius
Positive feedback
What is a reflex
The automatic response coordinated with the CNS
Development Reflexes
Innate or required
Born or learned
Information processing Reflex
Spinal reflex or cranial reflex
Neural Circuitry
Monosynaptic polysynaptic neurons
Polysynaptic
More complicated includes includes Interneurons
Reciprocal inhibition
Action Potential in one inhibits the other
The Babinski Reflex
Normal in an infant but indicates CNS damage in adults