Nervous System

brain and spinal cord

spinal and cranial nerves

What does the CNS include? PNS?

posterior longitudinal ligament (anterior prevents excessive extension)

what ligament prevents excessive flexion of the spine

intertransverse

what ligament prevents excessive lateral flexion and rotation

brain and spinal cord

what does the meninges surround

dura

arachnoid

pia

superficial to deep: meninges

dura mater in subdural space

where would an epidural get inserted

cerebrospinal fluid

what is inside the subarachnoid space in the arachnoid mater

more roots that go off to limbs

why is it called the cervical and lumbar enlargement

lumbar

the conus medullaris tapers the spinal cord in start of what region

cauda equina

“horse tail”

filum terminale

secures cauda to the coccyx and is an extension of the pia mater that anchors the spine in place

denticulate ligaments

extensions of pia mater that secure the spinal cord to the dura mater

nuclei

1

ganglia

2

tracts

3

nerves

4

used for integration and act as a control center

What is the function of the CNS?

back to the CNS (brain and spinal cord)

where does sensory input send information to

out to the PNS (brain to a muscle for voluntary contraction…somatic nervous system)

when the brain interrogates information, it will then send that info…

communication lines between the CNS and the rest of the body

What is the function of the PNS?

1. Sensory (afferent) division

2. Motor (efferent) division

What are the subdivisions of the PNS?

1. Sensory input

2. Integration

3. Motor output

What are the functional divisions of the nervous system?

Somatic sensory fibers and Visceral sensory fibers

What are the two types of fibers that would be found in the sensory division of the peripheral nervous system?

sensory, afferent, dorsalmotor, ventral, efferent

SAD MOVE acronym

Nervous Tissue

what is highly cellular with little extracellular space in the nervous system

1. neurons

2. neuroglia

What are the 2 principal cell types found in nervous tissue?

neurons

excitable cells that transmit/communicate electrical signals

neuroglia

small cells that surround and wrap delicate neurons

protect the neurons and make sure they survive (neurons do not heal well or reproduce quickly)

What is the function of neuroglia?

impulses

longevity

metabolic rate

neurons

- structural units of nervous system

- large highly specialized cells that conduct _____

- extreme _______

- high _________

- all have cell body and one or more processes

dendrites

What part of the neuron receives signals?

Cell body/soma

- biosynthetic center of the neuron

- synthesizes proteins, membranes, and other chemicals

axon

What part of the neuron sends signals?

Myelin Sheath

- protects and electrically insulates axon

- increases speed of nerve impulse transmission

axon hillock

the start of the axon where the incoming action potentials combine

Axon Terminal

end of neuron where neurotransmitters are secreted to another neuron or next function begins

nuclei

What would you call a collection of somas in the CNS?

ganglia

What would you call a collection of somas in the PNS?

tracts

What would you call a collection of axons in the CNS?

nerves

What would you call a collection of axons in the PNS?

1. Astrocytes

2. Microglial cells

3. Ependymal cells

4. Oligodendrocytes

5. Satellite cells

6. Schwann cells

6 glial cells

start- foramen magnum

end- L1 or L2 vertebrae

Where does the spinal cord start and end?

- provides two-way communication to and from brain and body

- major reflex center: reflexes are initiated and completed at the spinal cord

What are the functions of the spinal cord?

dura mater

thick, outermost layer of the meninges surrounding the spinal cord

subdural space

space between dura mater and arachnoid mater

arachnoid

web-like middle layer of the meninges

subarachnoid space

space between the arachnoid mater and the pia mater that contains the cerebrospinal fluid

pia mater

Thin, innermost layer of the meninges

conus medullaris

What marks the end of the spinal cord?

Cauda Equina of the spinal cord

collection of spinal nerves below the end of the spinal cord that go into the sacral canal

Filum Terminale

_____ of the spinal cord

anchors spinal cord to coccyx and protects cauda equina

Dentriculate Ligaments

extensions of pia mater that secure cord to the dura mater

thoracic

the lateral horn is only found in which vertebrae

vertebral foramen

spinal nerves pass through the ________ in the spinal cord

sensory

dorsal horns receive ___________ input

motor

ventral horns receive ____________ input

towards the brain/sensory inputs

white matter that runs ascending goes...

away from the brain/to lower cord levels (motor inputs)

white matter that runs descending goes...

side to side

white matter that runs transverse goes...

1

Somatic Spinal Nerve has ___ motor neuron(s)

2

Autonomic Spinal Nerve has ___ motor neuron(s)

epineurium

outermost layer of connective tissue that covers bundles of fascicles (entire nerve)

perineurium

connective tissue line that covers 1 fascicle (collections of axons)

endoneurium

innermost connective tissue layer that covers a single axon

only in thoracic and superior lumbar region of the spine

where are lateral horns located

motor

the anterior (ventral) nerve root contains __________ fibers from ventral horn motor neurons that innervate skeletal muscles

sensory (afferent)

the posterior (dorsal) nerve root contains _____ fibers from sensory neurons in dorsal root ganglia that conduct impulses from peripheral receptors

deep muscles

skin

the posterior ramus is the smaller of the two main branches in the rami and innervates the ______ of the back and the ______ of the back

trunk

upper and lower limbs

the anterior ramus is the larger of the two main branches in the rami and innervates _____ and the ______

meningal branch (with spinal nerves)

tiny branch that re-enters vertebral canal to innervate meninges and IV discs

rami communicates

contain autonomic nerve fibers that join ventral rami in thoracic region

dermatome

area of skin innervated by cutaneous branches of single spinal nerve (sensory)

myotome

Area of muscle innervated by motor fibers

dermatomes

Extent of spinal cord injuries ascertained by affected....

nerve plexuses

All ventral rami except T2-T12 form interlacing nerve networks called ...

T2-T12

All ventral rami except ______ form interlacing nerve networks called nerve plexuses

central canal

what part of the cross section of the spinal cord does cerebrospinal fluid run through

ventral dorsal and lateral columns

what parts of the cross section of the spinal cord include all white matter/myelinated

ventral dorsal and lateral horns

what parts of the cross section of the spinal cord contain gray matter

gray commissure

what part of the cross section of the spinal cord communicates from left to right

gray matter

where are nuclei located in the cross section of the spinal cord

white matter

where are tracts located in the cross section of the spinal cord

dorsal root ganglion

where are ganglia located in the cross section of the spinal cord

roots

where are nerves located in the cross section of the spinal cord

false

t or f: cell bodies are located in the white matter

endoneurim

what connective tissue lining surrounds 1 axon

perineurium

what connective tissue lining surrounds 1 fascicle of axons

epineurium

what connective tissue lining is a nerve (fascicles together)

dorsal roots

ventral roots

what roots have sensory fibers? motor fibers?