Nervous System Notes

Functions of the nervous system:

Receives information from inside & outside the body.

Controls & directs body’s functions & responses.

Helps maintain homeostasis.

Stimulus (stimuli)- anything that the body can react to. may be internal (from inside the body) or external (from outside the body) Response- the body’s reaction to a stimulus.

Divided into two parts: Central Brain Spinal cord Peripheral Body nerves

Spinal Cord Bundle of nerves that runs down the spine to carry messages between the brain and the rest of the body.

Peripheral NS Somatic NS- carries messages between brain & body to control voluntary muscles Sensory nerves Motor nerves Autonomic NS- Controls organs & involuntary muscles

Nerve Cells= Neurons Basic functioning units of the nervous system that carry messages called impulses.

The Brain Coordinates body activities Made up of approximately 100 billion neurons

The Brain Divided into 3 major parts- cerebrum cerebellum brain stem

Cerebrum (Cerebral Cortex) Coordinates Thinking & learning Creativity Five senses Memory & emotion Problem-solving Decisions Language & communication Body movements

Cerebellum Coordinates: Senses with other areas of the brain Most voluntary muscle movements Helps maintain balance & muscle tone

Brain Stem Connects brain to spinal cord Coordinates: (involuntary actions) Heartbeat Breathing Digestion Swallowing Blinking

Huntington’s disease Inherited genetic disease that causes the nerve cells in the brain to waste away.

Parkinson’s disease Degenerative disease that affects the neurons that control muscle movement.

Alzheimer’s disease Degenerative disease that affects the areas of the brain that control thought, memory & language.

Epilepsy Occurs when a cluster of neurons send out the wrong signals and results in seizures.

Meningitis Inflammation of the tissue that surrounds the brain & spinal cord can be caused by a bacteria or virus.