Divisions of the Nervous System Flashcards
(18 cards)
What is the Nervous System
the nervous system is a complex network of nerve cells that carry messages to and from the brain and spinal cord to different part of the body and so helps all the parts of the body communicate with each other
collects information about the world, processes this information and takes action by directing organs and muscles via the transmission of electro chemical messages
provides the biological basis of psychological behaviour
divided into the central nervous system and peripheral nervous system
two sub-systems of the nervous system
Central Nervous System
Peripheral Nervous System
central nervous system
the central nervous system is a division of the nervous system
it is concerned with complex processing, including all life functions and psychological processes
it consists of the brain and spinal cord
divisions of the central nervous system
brain
spinal cord
brain
(+ brain stem)
the brain is a division of the central nervous system
the brain is the centre of all conscious awareness, and most unconscious processing
maintains life, involved in higher functions and psychological processes
consists of many regions, which are responsible for different functions.
the brain’s outer layer, the cerebral cortex, is highly developed in humans and is what distinguishes our higher mental functions from those of animals
the brain is divided into two hemispheres
The brain stem connects the brain and spinal cord and controls involuntary processes, including our heartbeat, breathing and consciousness.
spinal cord
the spinal cord is a division of the central nervous system
the spinal cord is an extension of the brain
it is responsible for simple reflex actions that do not involve the brain (eg pulling your hand away from something hot)
it is responsible for relaying info between the brain and the rest of the body
peripheral nervous system
the peripheral NS is a division of the central nervous system
bodywide network of the nerves outside the brain and spinal cord (messenger neurons)
the PNS transmits information via millions of neurons from the central nervous system(brain/body) to the rest of the body and back to the CNS.
sensory (afferent) neurons carry info to CNS, motor (efferent) neurons away from CNS
it involves the somatic nervous system and autonomic nervous system
divisions of the peripheral nervous system
somatic nervous system
autonomic nervous system
somatic nervous system
the somatic NS is a division of the peripheral nervous system
somatic NS controls voluntary actions (skeletal muscle movement)
made up of sensory receptors that carry information to the spinal cord and brain, and motor pathways that allow the brain to control movement.
achieved by receiving information from the senses and carrying sensory (afferent) and motor (efferent) information to and from the central nervous system
“maintains communication between the CNS and the outside world”
autonomic nervous system
the autonomic NS is a division of the peripheral nervous system
controls involuntary actions via internal organs and glands in the body
transmits information to and from internal organs to sustain life processes (homeostasis - regulation of internal environment/processes)
ANS governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal, and stress responses
ANS consists of motor pathways only (efferent), and carries only motor info to and from CNS
ANS involves the sympathetic nervous system and parasympathetic nervous system
divisions of the autonomic nervous system
sympathetic nervous system
parasympathetic nervous system
sympathetic nervous system
the sympathetic NS is a division of the autonomic nervous system
primarily involved in responses that help us deal with emergencies, eg preparing the body for fight or flight
Impulses travel from the sympathetic nervous system to organs and glands in the body to help us prepare for rapid action.
eg. SNS causes body to release stored energy, increase heart/breathing rate, pupils to dilate, hair to stand on end
generally increases bodily activities, and inhibits less important bodily processes such as digestion and urination
release noradrenaline
parasympathetic nervous system
the PNS is a division of the autonomic nervous system
generally maintains or decreases bodily activities
primarily involved in returning the body to a rest state once the emergency has passed (rest and digest)
eg. whereas the sympathetic branch increases heart rate, the peripheral branch slows heart rate/ breathing rate, constricts pupils
bodily processes that are inhibited by the sympathetic branch (eg digestion) are returned to normal
releases acetylcholine
differences between central nervous system and peripheral nervous system
CNS main function is to control behaviour and regulate body’s physiological processes, WHEREAS, PNS function is to relay nerve impulses from CNS to the body and from the body back to the CNS
CNS made up of brain and spinal cord, WHEREAS PNS made up of all the nerves outside of the brain/spinal cord
differences between somatic nervous system and autonomic nervous system
SNS carries sensory and motor information to and from CNS, whereas ANS carries only motor information to and from the CNS
SNS controls voluntarily actions in the body WHEREAS ANS controls involuntary actions in the body
differences between sympathetic branch and parasympathetic branch
SB involved in responses that help us deal with emergencies (eg fight or flight) WHEREAS PB involved in returning the body to a rest state (rest/digest)
SB prepares body for action and increases bodily activities (eg releases stored energy, increases heart rate) WHEREAS PB returns body to normal once a stressor has passed and decreases bodily activities (eg increased digestion, slows heart)
SB inhibits non emergency functions (eg digestion/urination), PB stimulates them
what is meant by homeostasis
regulation of the internal environment
in normal conditions there is a balance between sympathetic and parasympathetic systems (maintaining homeostasis)
maintains balance in processes like body temperature, heart rate, blood pressure
controlled by the autonomic system which communicates with glands and organs in the body
draw/label the divisions of the nervous system
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