Interdependency of cells
The cells in multicellular organisms do not work independently of each other. In animals for example, muscle cells in the legs depend on red blood cells in the blood to supply them with oxygen and neurons in the brain to make them contract.
To ensure that all the cells in a multicellular organism function correctly for the survival of an organism, the cells need systems for communication with each other.
The nervous system
Nervous systems
The building blocks of the nervous system are Another term for a nerve cell that is specialised to transmit electrical impulses. (nerve cells). Neurons are specialised to allow rapid communication between cells in different parts of the body by transmitting electrical impulses.
There are three types of neurons:
- sensory neurons
- inter neurons
- motor neurons
Some neurons are specialised to allow them to detect changes in environmental factors such as light, sound and temperature. These neurons are found in The organs with receptor cells adapted to detect specific stimuli e.g. skin, eyes and ears.
The central nervous system (CNS) is composed of all the neurons that make up the The organ of the central nervous system of mammals where vital functions are coordinated and The part of central nervous system of a mammal which runs inside its backbone.
The function of the The part of the nervous system made up of the brain and spinal cord. (CNS) is:
- To process sensory information. The CNS receives electrical impulses from sensory neurons connected to the sense organs.
- To coordinate the body's response. The CNS transmits electrical impulses, along motor neurons, to glands and muscles.
Muscles produce rapid responses by contracting. Glands produce responses more slowly by releasing chemicals.