Ch 12 Neural Tissue

basic cell of nervous system; excitable and convert stimulus into action potential

Support nerve cells by destroying pathogens, creating and supporting interstitial fluid matrix

largest organ of the nervous system

enclosed in the vertebral foramen; contains 100 million nerve cells

Bundle of nerve FIBERS (cells) located outside brain and spinal cord

masses of nerve TISSUE located outside brain and spinal cord

network (tangles) of nerves located outside brain and spinal cord

monitor change in the internal and external environment

brain and spinal cord

cranial and spinal nerves

towArd the CNS

from the CNS

receives impulses from head, body wall and senses. we respond voluntarily with Skeletal muscles

impulses received from visceral organs. Motor impulses sent to glands, smooth muscle and cardiac tissue...Involuntary

fight or flight

rest and relaxation

surrounds intestines can function independently of ANS and SNS aka "Brain of the gut"

Detect internal and external changes-Afferent-Dorsal

determine appropriate response, store info for future responses, use cells called interneurons

Axons travel a short distance and account for the majority of nerves in the body

responds to sensory receptors using muscles or glands Motor-Efferent -Ventral

Quick response using action potentials localized effects

central part of the neuron

short highly branched extensions conducts impulses away from the cell body

single long extension of cell body; conducts impulses toward the cell body

initial segment of axon where action potentials begin

highly branched fine processes located at the end of axon

flared swelling at end of axon terminal

tiny sacs in synaptic bulbs filled with neurontransmitters

Star shaped cells Surround and support neurons in CNS to support and isolate them from harm. create blood brain barrier

form multilayered lipid and myelin sheath around axons in the CNS

protect cells by engulfing and destroying microbes;act as phagocytes

produce cerebrospinal fluid

produce myelin sheath in PNS

surround and support neuron cell bodies in PNS ganglia

non insulated spots on myelin sheath. only areas for substances to eater and exit a myelinated axon

occur on unmyelated axons,signal spread slowly down the nerve

Occur on Myelinated axon through voltage channels on Nodes of Ranvier, high speed

Myelination, large diameter axon and warm temps.

point of communication between and axon and another structure such as another axon, neuron or gland

action potentials transmitted through cell junctions allowing for speed and synchronization with multiple cells

action potentials transmitted through the release of neurotransmitters

depolarize the post synaptic membrane making it less negative and closer to threshold; easier to excite

hyperpolarize the post-synaptic membrane making it more negative and further from threshold; difficult to excite.

several presynaptic neurons receiving stimulus at the same time like being hit all over

single synaptic neuron stimulus applied in rapid succession. like being poking repetitively in one spot

variety of molecules within axon terminals that are released in the synaptic cleft in response to a nerve impulse.

released at synapse and blocks pain signals from reaching the brain, morphine, opiates

caffiene, nicotine

Heavy metals like lead, mercury and arsenic, they demyelinate axons

GABA-neurotransmitter

Dopamine over stimulation disease

acetylcholine, glutamate and aspartate