Chapter 13

Nervous tissue

what does the central nervous system (CNS) incliude?

associated with the brain and the spinal cord, integrating, processing, and coordinating, intelligence memory, learning, and emotion

what does the peripheral nervous system (PNS) include

associated with the tissue outside the CNS, neural tissue outside the CNS, provides sensory information to the CNS, carries motor commands to peripheral tissues

what are the subdivisions of the peripheral nervous system (PNS)

afferent, receptors, efferent, effectors

what are afferent?

brings sensory information toward the CNS

what are receptors

transforms different stimuli into action potential

what are efferent

carries motor commands away from the CNS

what are effectors

responds to the CNS commands

where does the sensory portion and visceral portion belong to

afferent

what monitors skeletal muscles and joints

sensory portion

what monitors smooth muscles, cardiac muscle, and other internal organs

visceral portion

where does the somatic and autonomic nerves belong to

efferent

what controls skeletal muscle contraction

somatic nerves

what controls internal organ acitivities

autonomic nerves

what receptors does the afferent division carry information from

somatic sensory receptors, visceral sensory receptors, special sense organs

where does the somatic sensory receptors carry information from

skeletal muscles, joints, and the skin

where does the visceral sensory receptors carry information from

smooth muscle, cardiac muscle, and glands

where does the special sense organs carry information from

eye, nose, tongue, and ear

where does the efferent division begin and end

begins inside the CNS and ends at an effector

what is the somatic nervous system responsible for

skeletal muscle contractions

is the somatic nervous system voluntary or involuntary

may be both voluntary or involuntary

what is the autonomic nervous system responsible for

visceral motor system

what does the autonomic nervous system include

smooth muscle, cardiac muscle, and glands; includes sympathetic and parasympathetic

is the autonomic nervous system voluntary or involuntary

involuntary

what two cell types does the neural tissue consist of

neurons and neuroglia

what are nerve cells responsible for

the transfer and processing of information in the nervous system

what do neurons consist of

soma, axon, and dendrites

what is the neuroglia responsible for

supporting cells and protecting the neuron

what are the functions of neuroglia

provides framework for the neural tissue, maintain the intracellular environment, act as phagocytes, roughly five times the number of neurons, and have the ability to reproduce

what are also called glial cells

neuorglia

what are the neuroglial cells of the CNS

astrocytes, oligodendrocytes, microglia, ependymal cells

what are the neuroglial cells of the PNS

satellite cells, schwann cells

what are astrocytes

most numerous glial cells, have a large number of cytoplasmic processes, controls the chemical content of the interstitial environment, maintains the blood-barrier, isolates the neurons from general circulation, creates a 3D framework for the CNS, performs repair in damaged neural tissue, guides neuron development

what are oligodendrocytes

cytoplasmic extensions contact the somas or axons, tie axons together in a sheath of myelin

what are microglia

phagocytic cells, protects the neuron by removing waste and debris

what are ependymal cells

lines the ventricles of the brain, lines the central canal of the spinal cord, monitors the CSF composition, and some ependymal cells secrete CSF

what are satellite cells

regulates the exchange of material between the cell body and the environment

what are schwann cells

form a myelin sheath

what are schwann cells also called

neurolemmocytes

what does the cell body consist of

nucleus, ER, ribosomes (nissl bodies), neurofilament

what are cell extensions

dendrite, axon

what makes up the axon

initial segment, axon terminal, axon collateral, axolemma, nodes

what is an initial segment

the very beginning of the axon

what are axon terminals

the very end of the axon

what are axon collateral

the side branches of axon

what is the axolemma

the outermost covering of an unmyelinated axon

what are nodes

area of myelinated axon that are ot covered by myelin

what are the sensory neurons

sends information from the PNS to the CNS

what are motor neurons

sends information from the CNS to the periphery

what are interneurons

analyzes sensory input and coordinate motor outputs

what do sensory neurons monitor

receptors

what are exteroceptors

external environment; touch temperature, and pressure sensations

what are the special senses of exteroceptors

sight, smell, and hearing

what are proprioceptors

internal environment; position and movement of skeletal muscles and joints

what are interoceptors

internal environment; digestive, respiratory, cardiovascular, urinary, and reproductive system

what are the sensations of the interoceptors

deep pressure and pain as well as taste