chapter 16- nervous tissue Flashcards
central nervous system structure and function
brain and spinal cord, integration and command center
peripheral nervous system structure and function
paired spinal and cranial nerves, carry messages to and from CNS
3 functions of nervous system
sensory input, integration, motor output
what happens in motor output
effector organs (muscles and glands) are activated to produce a response
sensory afferent division
peripheral division that carries info TO the brain
sensory afferent fibers
carry impulse from skin, skeletal muscles, and joints to the brain
visceral afferent fibers
carry impulse from visceral organs to brain
motor efferent division
carry info FROM brain to effector organs
somatic nervous sustem
voluntary control of skeletal muscles
autonomic nervous system
involuntary control of smooth and cardiac muscles, glands. sympathetic or parasympathetic
nervous tissue is vascular or avascular
vascular
structural unit of nervous system
neurons
neuron characteristics
large, can’t replace, extreme longevity, high metabolic rate, need carbs, all have cell body and at least one process
neuron processes
dendrites and axons
dendrite
branches that receive messages and send them to neurons
axons
generate and transmit action potentials and secrete neurotransmitters form axon to chemical signals
neuroglia
small cells that support, nourish, and protect neurons, replace when damaged
neuroglia of CNS
astrocytes, microglial, ependymal, oligodendrocytes
myelin sheath
composed of myelin- white protein lipid substance that protects and electrically insulates axons, increases speed of neuron transmitters
myelinated fibers
sheath surrounding most large axons, faster
nonmyelinated fibers
no sheath, slower
