Anatomy Ch. 2

central nervous system

central nervous system

brain and spinal cord

brain

The mass of nerve tissue that is the main control center of the nervous system- controls entire body bundle of nerves

spinal cord

Nerves that run up and down the length of the back and transmit most messages between the body and brain-goes brain to back connects pns and cns

sensory receptors

sensory nerve endings that respond to stimuli-afferent neurons and sensory neurons send stimuli from the outside to cns

associative (inter) neurons

neurons that are only found in the CNS-only brain and spinal cord

motor neurons

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands-in the muscles skeletal and smooth do the actions both voluntary and involuntary

afferent neurons

Nerve cells that carry impulses towards the central nervous system-sensory neurons

efferent neurons

Nerve cells that conduct impulses away from the central nervous system-motor neurons

peripheral nervous system

the sensory and motor neurons that connect the central nervous system to the rest of the body-all neurons that aren't in the brain and spinal cord

somatic portion

monitors skeletal muscles and joints-part you control conscious control

autonomic portion

-Automatically controls smooth and cardiac muscle, and glands.

-It has two components, a sympathetic division and a parasympathetic division.- no conscious control

sympathetic

fight or flight-excites nervous system

parasympathetic

rest and digest-relaxes nervous system

gray matter

Brain and spinal cord tissue that appears gray with the naked eye; consists mainly of neuronal cell bodies (nuclei) and lacks myelinated axons.- all cell bodies

white matter

myelinated axons

gilal cells

cells in the nervous system that support, nourish, and protect neurons-glial means glue-protects neurons and connect

oligodendorcytes

produce myelin in CNS-oligo means nutrients-provide nutrients to neurons- grow around them

microglia

Act as phagocytes, eating damaged cells and bacteria, act as the brains immune system-immune cells- first line of defense for immune system

astrocytes

Provide structural and metabolic support for neurons.-star cells- protect against microbial infenction

ependymal

a type of CNS supporting cell; lines the central cavities of the brain and spinal cord-line brain canvial and make csf (brain fluid)

schwann cell

Supporting cells of the peripheral nervous system responsible for the formation of myelin.-lipid cells that make the myelin sheath

soma/cell body

contains the cell nucleus and much of the chemical machinery common to most cells-perikaryon- cell part of your neuron that contains nucleus etc.

axons

Carry impulses away from the cell body-long part of the neuron carries info away from the neuron

axon terminals

branches at the end of the axon-have all the vesciles with neurotransmitters

dendrites

Branchlike parts of a neuron that are specialized to receive information.-receive messages and send them to the cell body

axon hillock

Cone shaped region of an axon where it joins the cell body.-axon meets the cell body

myelin sheath

A layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next.-insulator protects the axon makes the impulse go faster down the axon

nodes of ranvier

gaps in the myelin sheath- gapes between the shwann cells

perikaryon

cell body of a neuron-

nissl substance

specialized rough endoplasmic reticulum-and ribosomes in the cell body

synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron-space between the axon tips of one neuron and the dendrite of another axon- neurotransmitters go thru it until it becomes blocked neurons will continue be stimulated until it is blocked

synaptic cleft

The narrow gap that separates the presynaptic neuron from the postsynaptic cell.-

pre-synapse

Oxytocin releasing neurons - this is the end of the neurons axon which is known as the axon terminal

post-synapse

Oxytocin sensing neuron - these neurons express a receptor in the plasma membrane that oxytocin binds to and activates

multipolar neuron

A neuron with a single axon and multiple dendrites; the most common type of neuron in the nervous system.-many dendrites one axon-generic neuron pic

bipolar neuron

a neuron with one axon and one dendrite attached to its soma- one axon one dendrite

unipolar neuron

a neuron with one process extending from its cell body-

electrical impulse conduction

dendrites- cell body- to out

resting potential

The difference in electric charge between the inside and outside of a neuron's cell membrane

action potential

a neural impulse; a brief electrical charge that travels down an axon- resting potential is when the neurons aren't stimulated -70 volts- action is when neuron is stimulated

depolarization

The process during the action potential when sodium is rushing into the cell causing the interior to become more positive.- change in charge going from -70 to +30- causes electricity to go- creates the impulse

repolarization

Return of the cell to resting state, caused by reentry of potassium into the cell while sodium exits the cell.- goes back to resting

refractory period

a period of inactivity after a neuron has fired- part when the neuron takes a breather before it becomes stimulated again

threshold

the level of stimulation required to trigger a neural impulse- minimum voltage needed to repolarize

synpatic transmission

The relaying of information across the synapse by means of chemical neurotransmitters.

neurtransmitters

chemical messengers that cross the synaptic gaps between neurons; travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse- they are chemical take the impulse across the synapse

vesicles

small membrane sacs that specialize in moving products into, out of, and within a cell- sacs in the axon terminal that pull the neurotransmitter

reflex

a simple, automatic response to a sensory stimulus, such as the knee-jerk response- unconscious control they go through several neurons you never learned it you just knew

reflex arc

A relatively direct connection between a sensory neuron and a motor neuron that allows an extremely rapid response to a stimulus, often without conscious brain involvement.- stimulus from outside environment goes to sensory neurons to inter neurons to motor neurons

frontal lobe

pia mater arachnoid dura mater

temporal lobe

-auditory processing (hearing)

-language comprehension (Wermicke's area)

-memory/ information retrieval

brainstem

involuntary responses

cerebellum

balance and coordination

occipital lobe

-sight (visual cortex)

-visual reception and visual interpretation

parietal lobe

-touch preception (somatosensory cortex)

-body orientation and sensory discrimination

meninges

three protective membranes that surround the brain and spinal cord

pia mater

thin, delicate inner membrane of the meninges-blood vessles are located here and thin

arachnoid

middle layer of the meninges- look like spider web

dura mater

thick, outermost layer of the meninges surrounding and protecting the brain and spinal core- thick