the endocrine system Flashcards
describe the endocrine system and its functions
the endocrine system works alongside the nervous system and controls vital functions in the body. It works slower than the NS but has widespread, powerful effects. It contains various glands that in turn contain hormones and these hormones are secreted into the bloodstream and affect any cell that has a receptor
what do the glands in the endocrine system contain?
hormones
what is the pituitary gland called and why?
the master gland because it controls the release of hormones from all other endocrine glands in the body
what does adrenaline trigger?
triggers physiological changes in the body like increased heart rate which can then trigger fight or flight
what is the role of thyroxine?
increases metabolic rate and affects growth rate
explain the fight or flight response
1: a stressor is perceived by the hypothalamus
2: pituitary gland is activated
3: sympathetic NS is activated
4: adrenaline is released into bloodstream by the adrenal medulla
5: HR increases, pupils dilate, digestion inhibited, saliva decreases
6: fight or flight
7: once stressor has passed, the parasympathetic NS kicks in and returns to homeostatis
explain the reflex arc
1: the sensory neurons and sensory receptors in skin detect the stimulus
2: this makes relay neurons in the CNS send this message to the CNS
3: The motor neurons send a message to the effector (eg muscle) which makes it react and for example, move away from the stimulus
what is the resting potential of a neuron?
when a neuron is in a resting state, the inside of the cell is negatively charged
describe parasympathetic action
once a stressor has passed, the parasympathetic NS returns the body to its resting state. it reduces the activities of the body that were increased by the actions of the sympathetic NS. Returns body to homeostasis
