THE NERVOUS SYSTEM made up of the brain, spinal cord, and peripheral nerves. senses the environment and creates a response. 1.Central Nervous System (CNS)

THE NERVOUS SYSTEM• made up of the brain, spinal cord, and peripheral

nerves.

• senses the environment and creates a response.

1. Central Nervous System (CNS)

• brain and the spinal cord

• protected from injury by bones and cerebrospinal fluid

2. Peripheral Nervous System (PNS)

• nerves that carry the signals between the CNS and body.

• relays instructions from brain to other parts of the body

• Reflexes - actions that do not require the brain: spinal cord

acts as a short cut for reflexes.

NERVES

• bundles of special cells called neurons, surrounded by

connective tissue

• send information around the body using electrical signals.

• approximately 100 billion neurons in the human brain.

• Sensory receptors - special cells that receive

input from the environment and send signals to CNS

• Information from different sensory receptors goes to

specific parts of the brain

• YouTube - Nerve impulse Animation

THE MUSCULOSKELETAL SYSTEM

• all of the bones and muscles

• supports the body and protects organs.

1. Skeleton:

• consists of bones, ligaments, and cartilage (three

types of

connective tissue).

2. Muscles• consists of bundles of long cells called muscle fibres

• contain specialized proteins that contract (controlled

by nerve cells).

• 3 kinds:

i. skeletal muscles - attached to the bone by tendons.

ii. smooth muscles - located in the intestines

iii. cardiac muscles - heart.

Osteoporosis:

• disease that involves the loss of bone tissue, makes

bones weak and brittle.

• common among older women.