U3 AOS1 How does the nervous system enable functioning?

- Consists of the brain and the spinal cord

- Responsible for transmitting neural messages to and from the peripheral nervous system

- Contains all neurons outside the CNS

- Responsible for carrying information to and from the CNS

• The PNS can be further subdivided into two different systems:
• - Autonomic nervous system (ANS)
• - Somatic nervous system (SNS)

Responsible for organising, interpreting and coordinating actions, thoughts and behaviours

- Connects the brain to the peripheral nervous system

- Carries motor information from the brain and sensory information from the body.

The branch of the PNS responsible for sending motor information from the CNS to the body’s skeletal muscles and bringing sensory information from the body to the CNS in order to formulate voluntary responses

• This occurs through the communication between two different types of neurons:
• - Motor neurons (efferent neurons) – Carry messages from the brain to the skeletal muscles in order to initiate a voluntary response
• - Sensory neurons (afferent neurons) – Carry messages from the body’s sensations such as touch, smell, sight etc. to the brain to coordinate a response

The branch of the PNS responsible for connecting the CNS and the body’s visceral (non-skeletal) organs, muscles and glands like the heart and liver

• The ANS is further divided into three divisions:
• - Sympathetic nervous system
• - Parasympathetic nervous system
• - Enteric nervous system

Branch of the ANS responsible for activating the body’s visceral organs, muscles and glands to trigger a fight-flight-freeze response

Branch of the ANS responsible for returning and maintaining the body’s visceral organs, muscles and glands at optimal and balanced functioning. This balanced level of functioning is also known as homeostasis.

It receives and sends messages to the sympathetic and parasympathetic nervous system and is responsible for controlling the many functions of the digestive system

• Functions include:
• - Controlling movement of food through the digestive system
• - Regulating secretion of digestive enzymes