Nervous system Flashcards
what is the difference between signalling between vs wishin neurons
within = electrical
between = chemical
the nervous system is divided into two, what are they
- central nervous system
- peripheral nervous system
what does the CNS do?
coordinates activities of all parts of the body
what does the PNS do?
connects to the CNS to enable the animal to respond to stimuli
What is the CNS composed of?
brain, spinal cord
- contains relay neurons
what is the PNS composed of?
Cranial nerves, spinal nerves, peripheral nerves
- contains sensory + motor neurons
what are the two types of autonomic nervous systems
parasympathetic division
sympathetic division
Parasympathetic division
body functions during rest
Sympathetic division
during activity or stress
what are ganglia
clusters of nerve cell bodies found throughout the body
what are the three major sections of the brain
Hindbrain, Midbrain, Frontbrain
function of the spinal cord
contains nerve tracts signals to and from the brain
- acts as the site for simple reflexes
main functions of the PNS in vertebrates
- connects CNS to organs
- carries info to and from CNS
- allows brain and spinal cord to receive and send into to other areas of the body
- regulates involuntary body functions (breathings)
Sensory-somatic nervous sytem
regulates activities under voluntary control
e.g. muscle movement
Visceral/ Autonomic nervous system
monitors internal environment and controls organ function (involuntary)
what are the three types of ion channels in neurons
voltage activated Na+
voltage activated K+
voltage gated Ca2+
4 stages of changes in the membrane potential (mechanisms)
Threshold, Upstroke, Overshoot, Afterpotential/Hyperpolarizatio
what happens in the threshold stage
depolarisation of the membrane
- eg inflow of sodium = inside becomes more positive
what happens in the upstroke stage
more positive and reaches a peak
what happens in the overshoot stage
shoot over the zero line (from peak to zero)
what happens in the after potential or hyperpolarization stage
sodium channels blocked or potassium pushed out of cells or inflow of chloride
(inside of the cells become negative again)
what is myelin used for relating to the cell membrane
reduces the membrane area, resulting in less contact with external environments
- pumps will have to do less work
what are the two types of synapses
chemical
electrical
