nervous sytem Flashcards
what are the main functions of the nervous system
-To collect, process and respond to information within the environment
-To co-ordinate the workings of different organs and cells within the body
Outline the nervous system
Peripheral Nervous system:
-somatic nervous system
-autonomic nervous system :sympathetics nervous system and parasympathetic nervous system
Central nervous system:
-Brain
-Spinal cord
what does the preipheral nervous system do
transmits messages via neurons to and from the CNS
what does the autonomic nervous ssytem do
-Governs vital functions in the body eg. breathing and heart rate
-Involuntary system
-Only has motor pathways
-Controls smooth muscles, internal organs and glands
what does the somatic nervous system do
-Controls muscle movement by transmitting info form Brian via spinal cord
-Under conscious control
-Transmits info form sensory receptors to CNS
-Has sensory and motor pathways
-Controls skeletal muscles
what does the central nervous system do
-Brain has outer layer (cerebral cortex) and is divided into two hemispheres
-Spinal cord passes messaged to and from the brain and connects the nerves to the peripheral nervous system
-Spine is responsible for reflex action’s
what is the endocrine system
An informaiton system which instructs gland to release chemical signals (hormones) directyl into the bloodstream
what role do glands and hormones play in the endocrine system
-Glands produce hormones
-Hormones act as chemcial messengers which circulate in blood and affect target organ
what is the pituitary gland
-main gland in the endocrine system
-Located in the brain
-controls release of hormones from all other endocrine glands in the body
What role does the adrenal gland have
-Releases adrenaline and noradrenaline from the adrenal medulla
-Controls sympathetic division and is important for fight or flight response
what role does the thyroid gland have
-Releases thyroxine
-Responsible for regulating metabolism
-Increases heart rate and affects growth
what role do the overaies have
-Release oestrogen
-Controls regulation of reproductive system including menstrual cycle and pregnancy
what role does the pineal gland have
-Releases melatonin
-Responsible for important biological rhythms including regulating sleep-wake cycle
outline fight or flight system
-Stressor is perceived
-Hypothalamus activates the pituitary gland which triggers the autonomic nervous system
-ANS changes from normal resting state (parasympathetic) to a physiologically aroused state (sympathetic)
-Adrenaline is released, triggering physiological changes eg. increased heart rate and body become reading for fight or flight
-Once threat is past parasympathetic system returns body to resting state (rest and digest response)
what phsyiological changes occur in the sympathetic state
-Increased heart rate
-Increased breathing rate
-Dilates pupils
-Inhibits digestion
-Inhibits saliva production
-Contracts rectum
what physiological changes occur in the parasympathetic state
-Decreases heart rate
-Decreases breathing rate
-Constricts pupils
Stimulates digestions
-Stimulates salivia production
-Relaxes rectum
