H UMAN N ERVOUS S YSTEM

F UNCTIONS : Controls, monitors and coordinates all body activities Receives information from our surroundings Interprets information and converts them into ideas or thoughts and memories

2 PARTS OF THE NERVOUS SYSTEM : I. Central Nervous System  2 Parts: 1. Brain -interprets information -major control centre of the body 2. Spinal Cord -protected by bones called vertebrae -connects the brain to the rest of the nervous system (31 pairs of nerves)

2 PARTS OF THE NERVOUS SYSTEM : II. Peripheral Nervous System  This is made up of the nerves in our body  Nerves are connected to sense and internal organs, muscles  2 Types of Nerves: 1. Somatic -controls voluntary movements (ex. Raising of arms, chewing) 2. Autonomic -controls non-voluntary movements (ex. Heart beating)

P ERIPHERAL N ERVOUS S YSTEM

N EURONS  Nerve Cells: -all information that moves to the body travel through these special cells -we are born with all the neurons we can ever have because these cells cannot duplicate

P ARTS OF A N EURON

CLASSIFIED N EURONS CAN BE CLASSIFIED BY THE DIRECTION THAT THEY SEND INFORMATION : Sensory neurons Sensory neurons: from sensory receptors (e.g., in skin, eyes, nose, tongue, ears) TOWARD the central nervous system Motor neurons: send information AWAY from the central nervous system to muscles or glands.Interneurons: send information BETWEEN sensory neurons and motor neurons