Science Gallery

By: GPRATT

2021

The Nervous System

What are the nervous system anatomy and physiology?

The nervous system composed of CNS the command centre of the body, and PNS that collects information and carries-out responses.

The central nervous system consists of the brain and the spinal cord, where sensory input is integrated, and responses originate. The brain has three major divisions: the hindbrain, in lower part of brainstem that coordinates functions such as respiratory rhythm, motor activity, sleep, wakefulness; midbrain, the information processing and motor output; forebrain is composed of two cerebral hemispheres in which gray matter of the cerebral cortex overlays white matter and islands of gray matter called the basal nuclei. The spinal cord separates into sensory and motor neurons and relays message to and from the brain.

The PNS consists sensory neurons and motor neurons. The sensory neurons carry impulses to the central nervous system, while motor neurons carry impulses from the central nervous system to effectors (muscle). The axons of sensory neurons enter the dorsal surface of the spinal cord and form the dorsal root of the spinal nerve, while motor axons leave from the ventral surface of the spinal cord and form the ventral root of the spinal nerve.  Motor neurons composed of somatic and autonomic system. Somatic NS controls movements, and autonomic nervous system controls involuntary functions through two divisions the sympathetic nervous system ‘’flight or fight’’ and parasympathetic divisions ‘’rest and repose’’ plus the medulla oblongata of the hindbrain, which coordinates the system (Raven et  al 2020).