nervous system and endocrine system Flashcards
(15 cards)
define the nervous system
a network of specialised cells in the human body, our primary internal communications system
what are the two functions of the ns
to collect, process and respond to info in the env.
to coordinate the working of different organs and cells in the body
name the two sub systems of the ns
the central ns and the peripheral ns
what does the cns consist of
the brain and spinal cord
describe the brain in the cns
centre of conscious awareness, outer layer called the cerebral cortex is highly developed and distinguishes our higher mental function from those of animals
describe the spinal cord in the cns
extension of the brain, responsible for reflex actions, passes messages between the brain and the pns
what is the function of the pns
transmit messages via neurons to and from the cns
name and describe the sub systems of the pns
autonomic ns - governs vital functions such as breathing, heart rate and digestion
somatic ns - controls muscle movement and receives info from sensory receptors
define the endocrine system
works alongside the ns to control vital functions in the body
how does the endocrine system work in comparison to the ns
acts much more slowly
how does the es use hormones
glands in the body produce hormones which are secreted into the bloodstream and affect any cell in the body that has a receptor for that hormone
how is the thyroid gland and thyroxine an example of the es
affects the cells in the heart and increases the heart rate, affects metabolic rate (chemical processes in cells) and growth
how is the pituitary gland an example of the es
located in the brain, ‘master gland’ that controls the release of hormones from all other endocrine glands in the body
name and describe the sub systems of the ans
the parasympathetic ns - controls homeostasis and the body at rest, ‘rest and digest’ functions
sympathetic ns - controls response to threat, ‘fight or flight’ response
describe the stages of the fight or flight response
perceived threat
pituitary gland releases acth (adrenocortiotrophic), which causes the adrenal glands to release adrenaline into the bloodstream
adrenaline triggers the sns, creating physical arousal (pupils dilate, inhibit salivation, relax airways)
threat passes and pns returns body to resting state (pupils constrict, stimulate saliva, constrict airways, digestion)
