Nervous system and endocrine system Flashcards
What is the nervous system?
Internal communication system based on electrical and chemical signals
Main functions of the nervous system:
Processes and responds to information in the environment.
Coordinate workings of different organs+cells in the body.
Role of the brain?
Centre of awareness
Divided into two hemispsheres
Role of the spinal cord?
Extension of the brain
Transports messages to and from brain to peripheral nervous system
Responsible for reflexes
What is the peripheral nervous system?
Transmits messages via neurons to and from CNS.
What is the somatic nervous system?
Receives info from the senses and transmits it to CNS —–> further transmits info to CNS to movement of muscles.
What is the autonomic nervous system?
Responsible for vital functions e.g.: heartrate, breathing, sexual arousal.
What is the endocrine system?
Instructs glands to release hormones into the body.
Work alongside Nervous System
Hormones only affect cells which contain the necessary receptors.
e.g: thyroid releases thyroxine which increases heart/metabolic rate.
Difference between two systems?
Chemical messengers vs electrical impulses
Longer-lasting vs short-lived
Longer vs quicker
Permanent and widespread vs temporary and localised.
Describe flight/fight response
The endocrine system and ANS work parallel with one another.
Acute response and automatic reaction in the body.
When stressor perceived—> pituitary gland activated by hypothalamus.
Triggers sympathetic nervous system.
ANS changes from usual resting state (parasympathetic nervous system).
How is adrenaline released
Adrenaline released from
the adrenal medulla into the bloodstream
Physical arousal for fight/flight
Theres a shutdown of non-essential functions like digestion.
Once threat has passed, the parasympatheic nervous system restored to natural resting state.
What happens in sympathetic state?
Increased heart rate
Increased breathing
Pupils dilate
No digestion/saliva production
What happens in parasympathetic response?
Decreased heart rate
Decreased breathing
Constricted pupils
Stimulation of digestion/saliva production
