Nervous System

C(Central) and P(Peripheral)

• 1. Brain
• 2. Spinal Cord
• 3. Neuroglial Cells

CNS support cells

they cannot conduct action potential

• 1. Somatosensory Nervous System
• 2. Cranial Nerves
• 3. Autonomic Nervous System (visceral motor)
• 4. Enteric

Sensory and Motor (voluntary)

12 total nerves

• 1. Sympathetic
• 2. Parasympathetic

fight or flight responce

rest and digest responce

digestive tract

• AKA Nerve
• conducts an action potential

• 1. Receptors
• 2. Dendrites
• 3. Soma
• 4. Axon
• 5. Synaptic Knob

modified dendritic endings

primary site for recieving signals, resembles bare branches of a tree

The body of a nerve cell and the decision maker

• 1. Nucleus & Nucleolus
• 2. parikaryon with Nissl Bodies
• 3. Grey Matter

Make a decision

The cell body

bundles of ribosomes that make some proteins and neurotransmitters

is Hydrophillic, indicates nerve cell bodies due to having nissl bodies

• hillock
• terminals
• Myelin Sheath
• Schwann/neurolemmal cells
• Nodes of Ranvier
• *conducts action potential

is the beggining of the axon and starts the action potential

the branches at the end of an axon that have synaptic knobs at the end of them

a fatty insulater; type of nerve fiber

make myelin in layers to form the Myelin Sheath

is the last layer of myelin produced by a schwann cell and has the nucleus in it

unmyelinated gaps between neurolemmal cells

• 1. Saltatory Conduction
• 2. Continuous Propagation

Only occurs on Myelinated Nerves, is extremely fast, the action potential appears to jump from Node to Node of Ranvier

occurs only on nonmyelinated nerves, is slower, voltage gated channels along cell open and close in a series as the action potential moves along

some neurotransmitter are stored here and are released when action potential reaches it

• 1. Unipolar
• 2. Bipolar
• 3. Multipolar
• 4. Anaxonic

has only one distinctive axon; somatosensory neuron located in DRG(Dorsal Root Ganglion)

has two distinct axons; located in the retina of the eye

has many poles but only one distinct axon; alpha motor neurons located in anterior motor horn

has many poles and no axon; interneurons of CNS

• 1. Presynaptic Neuron
• 2. Synaptic Cleft
• 3. Postsynaptic Neuron

transmittes nerve impulse by releasing neurotransmitters into cleft

is the space between 2 neurons

recieves the nerve impulse as neurotransmitters

• 1. Polorized aka resting potential
• 2. Depolarized aka action potential
• 3. Repolarization

is when there is a negatively charged cell -70mV has a threshold of -60mV when the Gates open

is when there is a rush of positively charged sodium ions(Na+) inside cell bringing the internal charge to +30mV

• 1. Hyperpolarization
• 2. Sodium/Potassium Pump

is when there is a rush of positively charged potassium ions(K+) outside cell bringing the internal charge to -90mV

is the gradual exchange of sodium ions out of cell and potassium ions into cell until the cell is polarized with an internal charge of -70mV

• 1. Microglial Cells
• 2. Ependymal Cells
• 3. Astrocytes
• 4. Oligodendrocytes

support cells of CNS

are immune cells(phagocytes) that remove waste and toxins; eat

occur in clusters located in the choroid plexus and produce CSF(Cerebral Spinal Fluid)

make up the Blood Brain Barrier to prevent bacteria and viruses from entering the CNS

Make Myelin in the CNS

protective tissue around the CNS

• 1. Dura
• 2. Arachnoid
• 3. Pia

outermost layer of the meninges, strong

spider web like tissue that contains CSF(Cerebral Spinal Fluid) in the Subarachnoid Space; creates a cushion against movement

intimately attached to CNS, is form fitting

treat with antibiotics

palliative care/ wait it out

stimuli senstitive

ortho test/SOTO HALL- pain in back of neck, old test

• 1. secreted by choroid plexus in each lateral ventrical
• 2. into third ventrical
• 3. third ventrical choroid plexus adds fluid
• 4. into fourth ventrical
• 5. fourth ventrical choroid plexus adds more fluid
• 6. flows through 3 apertures
• 7. fills subarachnoid and spinal canal
• 8. at arachnoid granualations absorbed into blood

CSF(Cranial Spinal Fluid) build up/ swelling

nerves infected; ex. west nile

• 1. Ganglion
• 2. plexus
• 3. 31 pairs of spinal nerves
• 4. Cervical Enlargement
• 5. Intercostal Nerves
• 6. Lumbar Enlargement
• 7. Conus Medularis
• 8. Cauda Equina
• 9. Filum Terminale

a group of nerve cell bodies; appears as fat area in nerve

a group of nerve fibers/axon & dendrites

• 1. Cervical Plexus
• 2. Brachial Plexus

Phrenic Nerve which intervates the diaphragm

• 1. Radial Nerve
• 2. Median Nerve
• 3. Unlar Nerve

wrist extensors and thumb

wrist flexors

Pinky

located between ribs assist in breathing

DRG(Dorsal Root Ganglion) sensory of intercostal nerves

anterior motor horn or alpha motor neuron and causes paralysis

• 1. Lumbar Plexus
• 2. Sacral Plexus

• 1. Obturator Nerve
• 2. Femoral Nerve
• 3. Tibial Nerve

adductor group/medial thigh

knee extensors/quads; front of thigh/knee; L4

knee flexors/hamstrings

Sciatic Nerve aka sciatica

• Hamstrings
• peroneal/fibular nerve/calf muscles plantor flexors

where spinal cord ends; near L2

the spinal nerves that continue down spinal canal inferior to conus medularis

the terminal ligaments end of meninges which attaches to coccyx

L4

• 1. Spinal Nerve
• 2. Dorsal Root Ganglion
• 3. Grey H
• 4. Columns
• 5. Denticulate Ligament
• 6. Central Canal

a mixed nerve

a sensory nerve cell/somatosensory nerve cell

• 1. Anterior Motor Horn
• 2. Lateral Horn

Interneuron

Alpha Motor Neurons

sympathetic nerve cell bodies

association neurons that provide and gather information