nervous system Flashcards
What is the PNS
made up of the nerves outside of brain and spinal cord that connect CNS with receptors. nerves carry instructions from your brain to your limbs
what is the CNS
Includes your brain and spinal cord, receives info from the skin, joints and muscles of your body
uses the info to help you think, react, remember, plan and then sends out the appropriate instructions to your body.
PNS - automatic
regulates the function of internal involuntary organs such as heart, sweat glands, lungs
PNS- somatic
allows us to consciously or voluntarily control our skeletal muscles.
Somatic nervous system(PNS) contains?
sensory and motor neurons
sensory neuron-
transmit nerve impulses from receptors to CNS.
motor neuron-
carries impulses away from CNS to effectors (muscles, glands) controls voluntary movements by activating the skeletal muscles.
automatic- contains?
Sympathetic and parasympathetic
Sympathetic? what are some physiological effects of it?
Prepares body for physical or mental activity. produces autonomic fight or flight response to external stimuli - increases heart rate, dilates pupils, increase breathing rate, increases blood glucose levels. (expends energy)
parasympathetic
returns the body to a general slowdown and digest state, slows the body functions to conserve energy. - decreases heart rate, return breathing rate to normal
what does the spinal cord do?
connects the brain to the peripheral nervous system. transmits sensory info from receptors to brain and transmits motor messages from brain to receptors.
what is the PNS divided into to?
autonomic and somatic
What are nerves?
collections of neurons that connect to the CNS.
what are nerve fibres?
they are made of neurons
what is a interneuron?
connect sensory to motor neurons
what do motor neurons do in the somatic nervous system?
relay motor commands from the CNS to stimulate voluntary movements by activating the skeletal muscles for conscious responses from external enviroment.
what do the sensory neurons do in the somatic nervous system?
relay sensation from the body to thecentral nervous system
what do motor neurons do in the autonomic nervous system?
relay motor commands from the CNS to stimulate involuntary muscle contractions. to help maintain a constant internal environment for optimal body functioning.
what is the autonomic subdivided into
sympathetic and parasympathetic nervous system
