Study Notes for Health Test October 26

Study notes for Health

The nervous system makes sure all the different systems in the body work together.  When the systems are working correctly, your body is in balance.  This balance is called homeostasis. 

Your nervous system is responsible for maintaining your consciousness, keeping you alert and aware, responding to things, coordinate what you sense or feel using your ears, eyes, nose, skin and tongue. 

The nervous system is divided into 2 parts.  The central nervous system (CNS) and the peripheral nervous system.  The CNS is made up of the brain and the spinal cord.

The brain is protected by the skull.  The spinal cord is protected by the vertebrae in your spine.

Peripheral mean “outside”.

The peripheral nervous system is all the other nerves in your body including 12 pairs of cranial nerves coming from your head and 31 pairs of spinal nerves coming from your backbone.

The autonomic nervous system are the nerves that are responsible for the involuntary muscles.

Neurons are special cells and are part of the nervous system.

Dendrite receive messages and carry them to the nucleus in the center of the cell.

Axon carry messages away from the center of the cell towards other cells.

Sensory neurons are cells that gathers information and sends it to your brain or to your spinal cord.  

The empty space between cells is called a synapse.

The main organ of the nervous system is the brain.  The brain is divided into 3 areas.  Cerebrum, cerebellum and the brain stem.

Cerebrum controls all conscious body movements and interprets the information gathered by senses. It is divided into to halves or hemispheres.

Left side of brain – controls ability to speak, us math and think logically.

Right side of brain – controls musical ability artistic skills and emotions.

Cerebellum controls the voluntary muscles and makes sure they are smooth and coordinated. It also controls balance and muscle tone.

Brain stem connects your brain with your spinal cord. It controls the automatic body processes such as heartbeat, breathing and blood pressure.

A quick reaction is called a reflex.

2 Diagrams on P. 109, 110