Gross Anatomy Exam 1

What are the functions of the nervous system

Retains homeostasis, converts energy into signals for CNS, transfer signals over long distances, store and process info, and release neurotransmitters

Neurons are…

functional units that are electrically excitable that transmit and process information. they make up the core components of brain, spinal cord, and peripheral nerves

Neuroglia

support and nourish neurons, act as scaffolding

myelin sheaths

form by glial cells to increase nerve conduction by insulating and help speed up

Oligodendrocytes

located in the central nervous system and act as myelinating cells

Schwann cells

acts as myelinating cells in the PNS

What are the dendrites

cellular extensions that receive impulses and conduct them to the neurons cell body

what is the cell body, what’s its other name

central part of the neuron that contains the nucleus, soma

what is the axon, what covers it

nerve fibers that conduct impulses away from the cell body to the synapse, the myelin sheath

what are axon terminals

contain synapses where neurotransmitters are released to communicate with another cell

What are the three types of neurons

bipolar, pseudounipolar, and multipolar

bipolar neurons

vision and smell, not that really important yet

pseudo unipolar sensory neurons

peripheral process (dendrite), a cell body, and a central process (axon). Carry information to the CNS by afferent nerves

Multipolar motor neurons

contain multiple dendrites, a cell body, and an axon. carry information away from the CNS by efferent nerves.

SAME

Sensory is affarent (towards CNS), motor is efferent (out of CNS)

What do somatic motor neurons control

conscious control, skeletal muscles and the skin over it

what do motor neurons control

involuntary movements, smooth muscle, cardiac muscle, and glands

the CNS contains the

brain and spinal cord

white matter

where axons form bundles within the CNS

Gray matter

where cell bodies (nuclei) congregate together in the CNS

Posterior Horn

section on top of posterior gray matter butterfly in spinal cord. Sensory info enters through here

Anterior horn

bottom of gray matter horn, less stretched out part. Motor neurons come out in a one way road to the mixed spinal nerve

spinal ganglion

Cell body location in spinal nerve

Posterior ramus of spinal nerve

controls facid joints, true back muscles, and skin over. lazy ramus

Anterior ramus of spinal nerve

Does everything the posterior doesn’t, aka limbs and rest of back

nerves

spinal and cranial

ganglia

sensory and autonomic

A nerve is

axons (bundles of neurons), myelinated by endoneurium, wrapped by perineurium, and wrapped up even more by epineurium. Blood vessels supply the nerves with nutrients and remove wasteoms

visceral nerves

nerves in organsraC

Cranial nerves exit from

foramen in the skull, 12 pairs

spinal nerves exit from

vertebral column via intervertebral foramina, 31 pairs

Accessory Nerve (CN XI)

does not arise in the brain, arises in the spine but ascends into the skull through the foramen magnum so its considered a cranial nerve. Can be seen in the traps

Spinal nerve identifications

8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal. om

motor nerves

multipolar neurons exiting the CNS via anterior roots of the spinal nerve

sensory nerves

pseudo unipolar neurons entering the CNS via posterior roots of the spinal cordp

process of sensory nervous system

in the peripheral process pseudo unipolar neurons where dendrite brings impulse to the cell body after the ganglia, then in the central process the axon sends impulses into the CNS via posterior root and synapses in posterior gray horns of CNS

Process of Motor nervous system

one or two neurons leaving the CNS, uses multipolar neurons to pass signal through the anterior root and ramiS

Somatic motor

one neuron from CNS to skeletal muscle

Visceral motor nerves

innervates smooth muscle, cardiac muscle, and glands

General sensory nerves

transmit sensations from the body to CNS

Visceral sensory nerves

transmit visceral sensations, both conscious and unconscious sensations

visceral motor neurons

two neurons between the CNS and effector organ. synapse occurs outside CNS in ganglion, and then is able to of to rami

somatic motor system

only one neuron between CNS and effector organ, voluntary muscle

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