1. The Nervous System and the Control of Movement

2. The Nervous System
The nervous system is the body's way of gathering information, storing it, and responding to it
Main role is to assemble information about conditions external and internal to the body
Analyze this information
Initiate responses that may be necessary to satisfy certain needs

3. Two Components of the Nervous System
Brain + spinal cord = central nervous system (CNS)‏
Peripheral nervous system (PNS) = responsible for other things
i.e. Heart
Digestive system
Muscular control
All voluntary and involuntary neuromuscular controls

4. The Brain Control centre or “computer” of the body
Incapable of performing physical tasks, therefore it sends commands to other parts of the body to perform them
6 main parts: cerebrum, cerebellum, brain stem, diencephalon, limbic system, reticular activating system

5. Cerebrum Largest part of the brain
Contains nerve centres that control sensory and motor activities
Can be divided into two halves or “hemispheres”
Each hemisphere is divided into 4 lobes (named after the bone that they lie over
Frontal lobe, temporal lobe, parietal lobe, occipital lobe

6. Cerebellum Second largest region Lies behind and below the cerebrum
Main function is to coordinate muscle movement and control balance

7. Brain Stem Below cerebrum and in front of cerebellum
Links the cerebrum with the spinal cord
Houses brain centres responsible for autonomic functions, postural control, muscle tone, and eye movement

8. Diencephalon Consists of thalamus and hypothalamus
Thalamus relays most sensory stimuli to the cerebral cortex
Controls awareness of pain, screening of incoming signals, focusing attention
Hypothalamus controls body temperature, appetite, emotions and various automatic functions

9. Limbic System
Composed of a collection of structures within the cerebral hemispheres that regulate basic drives i.e. Hunger, aggression, emotional drives
Screens information going to the cerebral cortex

10. Reticular Activating System
Network of neurons
Fans out through the cerebral cortex
Directs information to appropriate centres for interpretation
Crucial for maintaining consciousness

11. Vertebral Column and the Spinal Cord
Main pathway for information connecting the brain and peripheral nervous system
Spinal cord runs through the vertebrae
Starts from the the base of the brain stem and travels down to the second lumbar vertebra
Spinal nerves carry sensory information towards the CNS and motor commands away from the CNS

12. Peripheral Nervous System
Consists of the parts of the nervous system that lie outside the CNS (everything but the brain and spinal cord)‏
Carries information in and out of the CNS
Motor Nerves – aka efferent nerves carry information from the CNS to the body's organs
Sensory Nerves – aka afferent nerves carry information from sensory receptors to the CNS

13. Autonomic Nervous System
Subsystem of the PNS
Controls involuntary actions (i.e. Heart beat)‏
Comprised of two branches which act as opposing systems
Sympathetic system
Parasympathetic system

14. Sympathetic System
Causes localized bodily adjustments to occur (i.e. Sweating)‏
Prepares bodies for emergencies
This involves release of adrenaline, increased heart rate, widening of blood vessels, and “fight or flight” responses

16. Parasympathetic System
Helps to return the body to normal after it has been altered by the sympathetic system
i.e. Sympathetic system will increase heart rate, parasympathetic system will decrease heart rate to bring it back to its resting state.

17. Somatic Nervous System
Another subsystem of the PNS
Responsible for our awareness of the external environment
Contains both afferent and efferent nerve fibres
Through this system, the PNS receives and processes information from receptors in the skin, voluntary muscles, tendons, and joints
Gives us the sensations of touch, pain, heat, cold, balance, body position, and muscle action

18. Cont...
Handles the muscles in our extremities
Allows us to move