The nervous system Flashcards
Define the term nervous system.
It’s a specialised network of cells in the human body and is our primary internal communication system.
What are the two main functions of the nervous system?
To collect, process and respond to information in the environment.
To coordinate the working of different organs and cells in the body.
What are the two subsystems the nervous system is divided into?
Central nervous system (CNS).
Peripheral nervous system (PNS).
Define the term central nervous system.
It consists of the brain and spinal cord, which are involved with complex commands and decisions
Describe the function of the brain.
It’s the centre of conscious thoughts. The brain’s outer layer, the cerebral cortex, is highly developed in humans and is what distinguishes our higher mental functions from animals.
Describe the function of the spinal cord.
Is an extension of the brain. It’s responsible for reflex actions.
Define the term peripheral nervous system.
It’s responsible for transmitting messages to and from the CNS through neurons (nerve cells).
What are the two subsystems the peripheral nervous system is divided into?
Automatic nervous system (ANS)
Somatic nervous system (SNS)
Define the autonomic nervous system.
Governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress arousal.
Define the term somatic nervous system.
It controls muscle movement and receives information from the sensory receptors.
List biological changes associated with a sympathetic response.
Increases heart rate Increases breathing rate Dilates pupil Inhibits digestion Inhibits saliva production Contracts rectum
List biological changes associated with a parasympathetic response.
Decreases heart rate Decreases breathing rate Constricts pupil Stimulates digestion Stimulates saliva production Relaxes rectum
