Week 7- Nervous system

central nervous system (CNS)

consists of brain and spinal cord

peripheral nervous system (PNS)

Consists of cranial and spinal nerves, autonomic nervous system, and ganglia

Neuron

Basic unit of the nervous system

neuron types

sensory, associative, motor

sensory neurons

called afferent (ascending, info coming up INTO brain)

associative neurons

connecting neurons

motor neurons

called efferent or descending (info coming DOWN out of brain to tell body what to do)

parts of the neuron

cell body (soma), dendrites, an axon

cell body (soma)

has nuclei inside CNS, ganglia outside CNS

Dendrites

carry impulses TOWARD the cell body

combining form for dendrites

dendr/o

axon

carry impulses AWAY from the cell body

combining form for axon

ax/o

Synapse

space between the two neurons or between a neuron or a receptor

combining form for synapse

synaps/o and synapt/o

neurotransmitters

chemical substance released into the space (synapse) to allow info to be relayed

neuroglia or glial cell

the supportive cells of the nervous system

combining form gli/o

means glue

contents of the glial cells

astrocytes, microglia, oligodendrocytes, schwann cells

Astrocytes

form BBB

Microglia

fight infection

oligodendrocytes

form myelin in CNS

Schwann cells

Form myelin in the PNS

Myelin

protective covering over some nerve cells and parts of the spinal cord. Serves as an electrical insulator. white in color

Nodes of Ranvier

gaps that interrupt myelin for ion exchange

Nerve

one or more bundles of impulse carrying fibers that connect the CNS to other parts of the body

combining form for nerve or nerve tissue

neur/i and neur/o

innervation

supply/stimulation of a body part through the action of nerves

receptors

receive external info, transmit to sensory neurons

nociceptive

pain that happens after and injury or tissue damage

proprioceptive

The sense that tells you where your body parts are and how they are positioned in relation to themselves and the environment

Reflex

automatic, involuntary

Stimulus or stimuli

creates an impulse

Combining form for brain

encephal/o

Combining form for the spinal cord

myel/o (Remember this is also combining form for bone marrow)

Meniges

Three layered membrane that surrounds the CNS

Mening/o and meningi/o

Combining form for meninges

Layers of the meningies

dura mater, arachnoid membrane, and pia mater

Cerebrospinal fluid (CSF)

Clear, colorless ultrafiltrate that nourishes, cools, and cushions the CNS. Made by the Choroid plexus

Choroid plexus

vascular folds of the pia mater that lines the ventricles of the brain

The brain

the enlarged and highly developed portion of the CNS that lies in the skull and is the main site of the nervous control

The cranium

Is the portion of the skull that encases the brain

combining form for skull

Crani/o

encephal/o

combining form for brain

Main parts of the brain

Cerebrum, cerebellum, brainstem

Cerebrum

The largest part of brain, and is responsible for receiving and processing info. Cerebrum is divided into two parts (cortex and medulla)

Medulla of cerebrum

White matter

Cerebral Cortex

gray matter, the gyri and sulci

Brainstem

connects the cerebral hemisphere with the spinal cord and supports basic life functions. consists of the pons and medulla oblongata

Spinal cord

the continuation of the medulla oblongata of the brainstem. passes through the opening in the occipital bone (the foramen magnum)

Intumescence

cervical and lumbosacral

Spinal cord discs

House the spinal cord to protect it from injury

intervertebral discs

layers of fibrocartilage located between the vertebrae that form pads separating and cushioning the vertebrae from each other. Consist of nucleus pulposus and annulus fibrosis

nucleus pulposus

nucleus of the intervertebral discs

annulus fibrosis

the bottom of the intervertebral disc

Cranial nerves

12 pairs of nerves that originate from the undersurface of the brain

Spinal nerves

arise from the spinal cord and supply sensory and motor fibers to the body

automatic nervous system

Part of the PNS that innervates smooth muscle, cardiac muscle, and glands- work together to maintain homeostasis. Has two divisions (sympathetic and parasympathetic)

Sympathetic ANS division

fight or flight

parasympathetic

maintains normal body function (rest and digest), decreases heart rate and slows breathing

BAR

bright alert and responsive

PLR

Pupillary light response

Paralysis

-plegia

sensation

-esthesia. mono: one limb paralyzed, hemi: one side of the body paralyzed, Para: One half paralyzed like both legs, tetra: all four limbs

Weakness

-paresis. hemi/para: weakness on one half of the body

laminectomy

remove part of the spial cord