4.7 The Nervous System

The Nervous System

The mammalian nervous system is divided into 2:

• CNS - coordinates and controls activity of the animal
• peripheral NS - (nerves and ganglia) forms connecting link between organs and CNS

body function and actions involve the reflex arc which involves both

Nervous System:

• receptors detect infromation from insdie and outside the body
• role of the CNS (brain adn spinal cord) to proces infromation and initiate a response
• effectors bring about responses
• sesnory receptros detect one from of energy and convert it inot chemical energy - act as transducers
• electrical impulses travel along the nerves
• some nerves bring informaion to the CNS, others take it away

Different types of receptors:

• thermoreceptors: detect changes in temperature
• chemoreceptors: detect changes in chemicals
• photoreceptors: detect changes in light

Spinal Cord:

• part of the CNS
• travels through and protected by the vertebral column where ther peripheral nerves originate from

consists of:

• grey matter which contains cell bodies therfore containing cell nuclei and no myelin
• white matter which contains axons and therefore contains myelin
• sensory fibres of the peripheral system enter the cord via the dorsal routes
• cell bodies of sensory fibres are found in the dorsal route ganglion which lies alongside the spinal cord
• motor fibres leave via the dorsal routes

function:

• relay impulses in or out at any particular point along the cord
• relay impulses up and down the body…