CHP.4 - CENTRAL NERVOUS SYSTEM, PERIPHERAL NERVOUS SYSTEM & NEURONS: STRUCTURE & FUNCTION Flashcards
What is the CNS?
Central Nervous System
what comprises the CNS?
the brain and spinal cord
what is the PNS?
Peripheral Nervous System
the PNS is comprised of which two systems?
the Somatic nervous system and the Autonomic system
the Autonomic system has two branches known as what?
the Sympathetic and Parasympathetic nervous systems
how does the brain communicate with the body?
it sends messages from the CNS to the PNS, and vice versa
what are two functions of the PNS?
to communicate information from the body’s organs, glands and muscles to the CNS, from external and internal stimuli
to communicate information from the CNS to the body’s organs, glands and muscles via motor neurons
what is the Somatic nervous system responsible for?
the voluntary movement of skeletal muscles
what is the role of motor neurons?
to communicate messages from the CNS to move muscles
what are the role of sensory neurons?
transmitting sensory information from our environment to our brains
what is the Autonomic nervous system responsible for?
The Autonomic nervous system controls the function of all involuntary automatic internal organ function, the majority of which are needed for vital bodily functions
what is the Sympathetic nervous system responsible for?
it is responsible for the fight, flight or freeze survival response and activates in times of danger or stress
what is the Parasympathetic system responsible for?
it is responsible for maintaining the automatic day-to-day functions such as digestion, heart rate and breathing. this regular bodily functioning is also known as homeostasis
how do the sympathetic and parasympathetic nervous systems work together?
the achieve a balance of maintaining clam regular bodily functions but preparing those same organs for times of stress if needed
what are the role of neurons?
to receive information from other neurons, process this information and then pass it on to other neurons.
what are the three main elements comprising neurons?
dendrites, soma and axom
what is the function dendrites?
to receive information via synapses
what is the function of the soma?
the cell body, housing the nucleus
what is the function of the axon?
the ‘tail’, caries information via an electrical impulse called action potential down the axon to the terminal buttons at the end, where it passes on the message to other neurons with a chemical called neurotransmitter
what are glial cells?
a cell not part of the neuron that ‘glues’ or holds neurons together
what are the four functions of glial cells?
- to surround neurons and hold them in place
- to supply nourishment and oxygen to neurons
- to remove dead neurons
- to insulate one neuron from another and increase the transmission of nerve Impulses. to do this, glial cells produce myelin
what is myelin?
a fatty substance that covers the axon to insulate it and protect it. myelin is produced by glial cels
what are the nodes of ranvier?
gaps on the axon tail between myelin
what is a synapse?
the junction between two neurons, where the terminal buttons of one axon come into contact with the dendrites of another
the process of neurons communicating with other neurons is known as what?
synaptic transmission
what chemical is necessary for messages to pass from neuron to neuron within the synapse?
neurotransmitter
the pathways that nerve impulses take along neurons are known as what?
neural pathways
what is reaction time?
how fast we can process information and react
