Nervous system Flashcards
1
Q
What is the nervous system?
A
- Specialised network of nerve cells in the human body made up of the PNS & CNS
- primary internal communication between neurons which uses electrical & chemical signals
- allows the brain, spinal cord & rest of body to communicate
2
Q
What are the two main functions of the nervous system?
A
- to collect, process and respond to information in the environment
- to co-ordinate the working of different organs and cells in the body
3
Q
What are the two subsystems of the nervous system?
A
- Central nervous system (CNS)
- Peripheral nervous system (PNS)
4
Q
What is the CNS made up of?
A
The brain and spinal cord
5
Q
What is the brain?
A
- centre of all conscious awareness
- the cerebral cortex is highly developed in humans
- coordinates sensation, intellectual & nervous activity
- The brain is divided into two hemispheres
6
Q
What is the spinal cord & role?
A
- An extension of the brain
- It passes messages to and from the brain
- connects nerves to the PNS
- responsible for reflex actions
7
Q
What is the job of the PNS?
A
- Transmits messages via neurons to and from the central nervous system
8
Q
What is the PNS further subdivided into?
A
- Autonomic nervous system
- somatic nervous system
9
Q
What are the functions of the Autonomic nervous system?
A
- Associated with involuntary (vital) actions E.g. breathing, heart rate, digestion etc.
- consist of motor pathways > which allows brain to control movement
- controls internal organs and glands
- has 2 further components (SNS, PSNS)
10
Q
What are the functions of the somatic nervous system?
A
- Carries sensory information from sense/body receptors to the brain and provides muscle responses via the motor pathways (sensory & motor pathways)
- transmits information from the brain to effectors to produce voluntary actions e.g. eating, walking (conscious control)
- controls skeletal muscle and movement
11
Q
What is the autonomic nervous system further divided into?
A
- Sympathetic nervous system
- Parasympathetic nervous system
12
Q
What is the role of the sympathetic nervous system?
A
- prepares body for flight or fight by releasing adrenaline which changes body from resting state to state of physiologically arousal due to perceived threat
e.g. increased heart/ breathing rate, pupil dilation, decreased food digestion, decreased saliva production, increased muscle tension, increased sweat production
13
Q
What is the role of the parasympathetic nervous system?
A
- ‘rest and digest response’
- when threat has passed, PSN calms the body from physiological aroused state to resting state > restores bodies normal functioning
