nervous system - neurons Flashcards
what are neurons?
specialised cells to send and receive nerve impulses
what are neuroglia?
cells that have a support function
provide insulation and nutrients
may send and receive impulses
how are all the organs in the human body formed?
four types of tissue combine
what does nervous tissue do?
allow you to sense and respond to things
what do nervous tissue cells do?
they are specialised for receiving and sending information
where is the central nervous system?
made up of the brain and spinal cord
where is the peripheral nervous system
cranial nerves, spinal nerves, ganglia, peripheral nerves, and neuromuscular junctions
what is the function of the cns?
awareness, movement, speech, receiving, processing, responding to sensory information
what is the function of the pns?
sending information from different areas of the body back to the brain, and carrying out commands from the brain to various parts of the body.
how is the peripheral nervous system further subdivided?
into an afferent sensory division and efferent motor division
what are the peripheral organs
nerves and ganglia
how does the sensory division of the pns transmit impulses?
from the peripheral organs to the cns
how does the motor division of the pns transmit impulses?
from the cns to the peripheral organs
how is the motor division further subdivided
into a somatic motor division and an autonomic motor division
what does the somatic motor division do?
serves skeletal muscle
what does the autonomic motor division do?
serves smooth muscle, cardiac muscle and glands
what does the nervous system do?
contains sensory receptors which detect changes in the internal and external environment of the body
how does the nervous system send information?
via impulses
what are impulses?
a network of cells that use electrical signals
what happens when impulses are used?
responses are initiated to changes in the body, allowing the nervous system to maintain homeostasis
what does motor function do?
carries out effect
what does the integrative function?
decides response
what does the sensory function do?
detects stimulus / informs cns
what are the effectors of the somatic nervous system?
skeletal muscles
what are the effectors of the autonomic nervous system?
cardiac muscles, smooth muscle, glands
types of neuroglia
astrocytes
ependymal cells
microglia
oligodendrocytes
what is the function of astrocytes
found between neurouns and blood vessels (blood brain barrier)
regulate ion concentration in nervous tissue
multifunctional
what is the function of ependymal cells
cover the choroid plexus
line spaces in the brain (ventricles)
produce csf
what is the function of microglia
function as phagocytes
supportive function
what is the function of oligodendrocytes
form myelin in central nervous system
what is csf
cerebrospinal fluid: flows in and around the hollow spaces of the brain and spinal cord, and between two of the meninges
what is the node of ranvier?
exposed area of axon between myelin
gaps between neighbourign segments of the myselin sheath