The nervous system Flashcards
The nervous system has two main functions
- to collect process and respond to information in the enviroment.
- to co-ordinate the working of different organs and cells.
The central nervous system
Made up of the brain and spinal chord
Center of all conscious awareness
CNS passes messages to and from the brain and connects nerves to the peripheral nervous system.
The peripheral nervous system
Transmits messages via neurons, to and from the CNS. Subdivided into the somatic nervous system and the automatic nervous system.
The somatic nervous system
Conscious control
‘Body’
Carries out sensory and motor information to and from the spinal cord
Transmits information from the senses to the CNS and from the CNS to muscles.
The autonomic nervous system
Unconscious control
‘organs’
Governs vital functions in the body like breathing, HR and digestion.
Divided into the sympathetic nervous system (arousing) and the parasympathetic nervous system (calming. They work in opposition.
The sympathetic nervous system in fight or flight
Prepares the body for action by increasing arousal levels i.e increasing HR
The parasympathetic nervous system in fight or flight
Returns the body to normal resting state. decreases heart rate.
what is the purpose of the autonomic nervous system and homeostasis
Works in opposition to create a homeostasis.
The eye and the automatic nervous system
SNS pupil dilates
PNS pupil constricts
The heart and the automatic nervous system
SNS heart rate increases
PNS heart rate decreases
Salivary glands and the automatic nervous system
SNS increases saliva production
PNS decreased saliva production
What controls fight or flight
The autonomic nervous system
What does the SNS do in fight or flight
releases adrenaline from the adrenal medulla
What does the pineal gland do
Releases melatonin, important for biological rhythms like the sleep/wake cycle.
What does the hypothalamus do
Stimulates and controls the release of hormones from the pituitary gland.
