Note
Studied by 15 people
nervous and endocrine system
nervous system
The nervous system collects, processes and responds to info in the environment and coordinates cells/organs
Central — origin of complex commands/decisions
Includes brain and spinal cord
Peripheral — sends info to CNS, transmits its messages to muscles/glands
Somatic — transmits info from receptor cells in sense organs to CNS which directs muscles to act
Autonomic — transmits info to and from organs, involuntarily
Includes: sympathetic and parasympathetic
Fight or flight — response when stressed:
Stressor is perceived
Hypothalamus is alerted, it detects stress as acute and triggers ANS
ANS changes to sympathetic state, activating sympatho-medullary pathway
Adrenaline and noradrenaline released from adrenal medulla in adrenal gland
Physiological changes occur to prepare for fight or flight
Acute stress: short term, immediate (when threat is perceived)
Chronic stress: long term, persistent and perceived as out of control, it can weaken immune system
Parasympathetic — rest and digest
Contracts pupils
Stimulates saliva flow
Slows heart rate
Constricts bronchi
Stimulates stomach, pancreas and intestine function
Stimulates bile release
Contracts bladder
Sympathetic — fight or flight
Dilates pupils
Inhibits saliva flow
Accelerates heart rate
Dilates bronchi
Halts stomach, pancreas and intestine function
Converts glycogen to glucose
Secretes adrenaline
Inhibits bladder contractions
endocrine system
The endocrine system instructs glands (organs that synthesise substances) to release hormones
Hormones are substances that affect receptor cells with slow but powerful effects
Pituitary (master gland) — regulates endocrine system, communicates with glands to release hormones
Adrenal — facilitates the release of adrenaline for fight or flight response
Testes — facilitates the release of testosterone for reproduction
Ovaries — facilitates the release of oestrogen and progesterone to regulate menstrual cycle and for reproduction