week 3 Flashcards
3 basic functions of NS
sensory - integrative - motor
general sensory receptors
- sensory input
Located: skin, skeletal muscles, tendons, joints and visceral organs - thermoreceptors, nociceptors, mechanoreceptors (tactile, baro, proprioceptors)
special sensory receptors
- located eye, ears, mouth and nose
- photoreceptors - chemoreceptors - mechanoreceptors (hair cells)
peripheral NS
- sensory receptors and the cranial, spinal and peripheral nerves that link all parts of the body to the CNS
- cranial (head and neck) and spinal nerves (all body)
2 functional divisions: PNS
sensory division (affarent)
motor division (efferent)
somatic NS
conveys somatic motor output from the CNS to bodies skeletal muscles
- control voluntary skeletal movements and involuntary skeletal muscle movements = somatic reflexes
autonomic NS
conveys autonomic motor output from the CNS to bodies cardiac and smooth muscles
- involuntary activities; heart rate, respiration, pupil diameter, blood vessel diameter, digestion of food, urination, defecation and salivation
ANS: sympathetic division
- controls fight or flight activities
- activates body functions that support physical activities
- increases HR, respiratory airflow, blood flow to skeletal muscles and sweat glands, dilates pupils, digestive functions, inhibits urination and deification
ANS: parasympathetic NS
controls rest and digest activities - activates body functions that converse and restore body energy
- stimulates digestive functions, urination and deification, decreases heart rate and airflow
dendrites
main receptive (input) region of a neuron
- sensory receptors - detects stimuli - receives info from other neurons
cell body
receives information from other neurons and converts this into graded potential - integrates information and conveys info towards towards to the initial segment of the axon
axon
generates and conducts action potentials to convey the information from the initial segment to the axon terminals
myelin sheath
protects and insulates the axon terminal
- increases the speed of signal conduction
axon terminals
forms a synapse with another cell
- secretory region contains synaptic vesicles that store and release neurotransmitters
nuclei (nucleus)
clusters of neuron cell bodies in CNS
ganglia (ganglion)
clusters of neuron cell bodies in PNS
tracts
bundles of neuron axons in CNS
nerves
neuron axons bundled in PNS