the nervous system and the endocrine system Flashcards
what is the nervous system?
a specialised network of cells in the body
what type of communication is the nervous system?
our primary internal communication system
what is the nervous system based on?
electrical and chemical signals
what is the endocrine system based on?
hormones
what are the nervous systems two main functions?
- collect, process and respond to info in the environment
- co-ordinate the working of different organs and cells in the body
what are the two sub-systems that the nervous system is divided into?
- central nervous system
- peripheral nervous system
what is the CNS made up of?
the brain and spinal chord
what is the brain the centre of?
all conscious awareness
what is the brains outer layer?
the cerebral cortex
how thick is the brains outer layer?
3mm thick
what does the outer layer of the brain cover? where is this found?
the brain this is only found in mammals
what does the brain distinguish?
our higher mental functions from those of other animals
what is the brain divided into?
two hemispheres
what is the spinal chord?
an extension of the brain
what does the spinal chord do?
passes messages to and from the brain and connects nerves to the PNS
what is the spinal chord responsible for?
reflex actions
How does the PNS transmit messages?
via millions of neurons to and from the central nervous system
what is the PNS further subdivided into?
- Autonomic nervous system
- somatic nervous system
what does the automimic nervous system do?
Controls smooth muscles and glands and is involuntary
what does the somatic nervous system do?
Controls skeletal muscles and is under conscious control
what does the endocrine system work alongside?
the nervous system
what does the endocrine system control?
vital functions in the body
compared to the nervous system how does the endocrine system work?
slower but has very widespread and powerful effects
where are hormones secreted?
into the bloodstream and affect any cell in the body that has a receptor for that particular hormone
how do most hormones effect cells?
in more than one body organ leading to many diverse and powerful responses
what are the main glands in the endocrine system?
hypothalamus - brain
pituitary - brain
thyroid
parathyroid
adrenals
pancreas
ovaries - female
testes - male
what is the key endocrine gland?
pituitary gland in the brain
why is the pituitary gland called the master gland?
it controls and releases hormones from all other endocrine glands in the body
how do the endocrine and ANS often work?
in parallel
what happens when a stressor is percieved?
the hypothalamus activates the pituitary gland which triggers activity in the sympathetic branch of the ANS
when a stressor is perceived what happens to the ANS?
it changes from its normal resting state (parasympathetic) to the physiologically aroused sympathetic state
where is adrenaline released from?
the adrenal medulla
what does adrenaline trigger?
physiological changes in the body which creates physiological arousal necessary for the fight or flight response
what type of response is the release of adrenaline?
acute response and an automatic reaction in the body
what happens once the threat has passed?
the parasympathetic nervous system returns the body to its resting state
What does the parasympathetic branch of the ANS work in opposition to?
the sympathetic nervous system - actions are antagonistic to the sympathetic nervous system
