Chapter 13: The nervous system: neural tissue

neural system and endocrine system

control and adjust the activities of other systems

nervous system

relatively swift but brief responses

endocrine system

slower but they often last much longer

CNS

brain and spinal cord

controls coordinating, processing, memmory, learning and intelligence

PNS

neural tissue outside the CNS

provides sensory information to the CNS

Autonomic nervous system

PNS and CNS

The PNS

subdivided into afferent and efferent divisions

afferent division

brings sensory information to the CNS

efferent divisions

brings sensory information away

also carries motor commands to muscles and glands

efferent subdivided divisions

SNS and ANS

visceral sensory receptors

smooth muscles, cardiac muscles, and glands

somatic sensory receptors

skeletal muscles, joints and skin

special sense organs

eye, nose, tongue and ear

SNS

skeletal muscle contractions

may be voluntary or involuntary

ANS

visceral motor system

involuntary

neurons

responsible for the transfer and processing of information to the nervous system

neuroglia functions

provide framework for the neural tissue

maintain the intercellular environment

act as phagocytes

100 billion neuroglia or glial cells

PNS

satellite cells and Schwann cells( help with injury)

CNS

oligodendrocytes, astrocytes, microglia, ependymal cells

astrocytes

blood brain barrier

will form scares

neurons have three functional groups

sensory neurons, motor neurons, interneurons

sensory neurons

most sensory neurons are pseduounipolar neurons

motor neurons

most motor neurons are multipolar neurons

interneurons

most interneurons are multipolar neurons

exteroceptors

external environment

examples: touch, temperature, pressure, smell hearing

proprioceptors

internal environment

examples: position and movement of skeletal muscles and joints

intereoreceptors

internal environment

digestive, respiratory, cardiovascular, urinary, and reproductive system

sensations of deep pressure and pain as well as taste

excitability

is the ability of a plasmalemma to conduct electrical impulses

nerve impulse

an action potential traveling along the axion