nervous tissues Flashcards
what are the three functions of nervous system?
sensory receptor (detects internal and external stimuli), integration( processing of sensory info), and activation of effectors(muscles and glands respond)
what are the two structural divisions of nervous system?
central nervous system and peripheral nervous system
what does the CNS consist of?
brain and spinal cord
what are the functions of CNS
command centre, interprets sensory info, coordinates response
what does the PNS consist of>
cranial nerves, spinal nerves, ganglia and receptor’s
functions of the PNS?
relays info from body to CNS (sensory division) and relays info from CNS to body “motor division”
what are the two types of neural tissue?
Neurons and nerugolia
what are the functions/characteristics of neurons?
conduct electrical impulses, long lived, do not divide, high metabolic rate of O2 and glucose are critical
what are the four structural classifications of neurons?
multipolar, bipolar, unipolar, anaxonic
what does a multipolar neruon look like?
many dendrites single axon, most numerous neuron in cns and pns
what does a bipolar neuron look like?
2 processes extend from cell body, special sensory is ear and eye
what does a unipolar neuron look like?
1 process extends from cell body(most sensory neurons)
what does anaxonic neuron look like?
no axon dendrites only, rare, in brain and some sense organ
what are the three functional classifications of neurons?
sensory, motor and internueron
what does sensory (afferent ) neurons do?
transmit impulses towards CNS
bipolar or unipolar
what does motor (effferent) neurons do?
transmit impulses away from CNS to effectors
multipolar
what does interneuron (association neurons do?)
connect sensory and motor neruons
majority of neurons in CNS
multipolar
what are the nueroglia in the CNS?
astrocytes, mircoglia, ependymal cells, oligodendrocytes
what are astrocytes?
star cells, most numerous, regulate chemicals in ECF, maintain blood brain barrier, structural framework in brain and spinal cord, guide neuron growth/repair
what are microglia?
phagocytes engulf bacteria and dead cells, increase in response to infection/injury
what are ependymal cells?
line cavities of spinal cord and brain, ciliated and circulate cerebrospinal fluid
what are oligodendrocytes?
form myelin sheath around axons in CNS, one cell forms sheath around several neurons
what are the types of neruoglia in PNS
satelite cells and schwann cells
what do satellite cells do?
surround cell bodies of neruons, regulate ions, nutrients, waste in ECF
