The Nervous system coordinates actions and sensory information by transmitting signals to and from different parts of the body.
The soma of a neuron contains a nucleus and other organelles, including lysosomes, mitochondria, and a golgi complex. The axon is a cylindrical projection from the cell body that transmits nervous impulses to other neurons or effector sites (i.e.,muscles, organs, other neurons). The dendrites gather information from other structures and transmit it back into the neuron.
Neurons collectively innervate to form nerves, two divisions of the nerves include the central nervous system (which contain the brain and spinal cord) and peripheral nervous system (which contain nerves branching out of the central nervous system).
Sensory (Afferent) Neurons:
send signals to the CNS from the ends of the body, They are commonly termed as “Receptors”, Major Receptors are:
– Chemoreceptors detect the presence of chemical substances
– Thermoreceptors detect changes in temperature
– Mechanoreceptors detect changes in muscle length
– Photoreceptors detect light during vision
There are two major mechanoreceptors, Golgi Tendon Organs (GTO) and Muscle Spindles.
Motor (Efferent) Neurons: send signals from the CNS to the ends of the body
Motor Neurons are of Two types:
– Somatic: Responsible for voluntary movements
– Autonomic: Responsible for Involuntary Movements
Autonomic Neurons are of two types: