The diencephalon is also known as the fore brain stem. This is located behind and below the cerebrum. The hemispheres are further divided into four lobes: Each hemisphere controls the activities of the side of the body opposite that hemisphere. The cerebrum is divided into two hemispheres. The cerebrum forms the bulk of the brain and is supported on the brain stem. It is located between the pons and the spinal cord and is only about one inch long. The brain stem is also known as the Medulla oblongata. White matter in the brain carries impulses to and from grey matter. Grey matter receives and stores impulses.Ĭell bodies of neurons and neuroglia are in the grey matter. There are two types of matter in the brain: grey matter and white matter. It has nerve cells called the neurons and supporting cells called the glia. The brain weighs approximately 1.3 to 1.4 kg. The brain consists of four principal parts: The brain lies within the skull and is shaped like a mushroom. The central nervous system is divided into two major parts: the brain and the spinal cord. The brain is the seat of consciousness and determines who we are as individuals. The CNS is also responsible for the higher functions of the nervous system such as language, creativity, expression, emotions, and personality. Using this sensory information, it makes decisions about both conscious and subconscious actions to take to maintain the body’s homeostasis and ensure its survival. The CNS takes in all of the conscious and subconscious sensory information from the body’s sensory receptors to stay aware of the body’s internal and external conditions. The CNS acts as the control center of the body by providing its processing, memory, and regulation systems. The brain and spinal cord together form the central nervous system, or CNS. The size of the nervous system ranges from a few hundred cells in the simplest worms, to around 300 billion cells in African elephants. The nervous systems of the radially symmetric organisms ctenophores (comb jellies) and cnidarians (which include anemones, hydras, corals and jellyfish) consist of a diffuse nerve net.Īll other animal species, with the exception of a few types of worm, have a nervous system containing a brain, a central cord (or two cords running in parallel), and nerves radiating from the brain and central cord. The only multicellular animals that have no nervous system at all are sponges, placozoans, and mesozoans, which have very simple body plans. Nervous systems are found in most multicellular animals, but vary greatly in complexity. Efferent nerves in the PNS carry signals from the control center to the muscles, glands, and organs to regulate their functions. The sensory nerves and sense organs of the peripheral nervous system (PNS) monitor conditions inside and outside of the body and send this information to the CNS. The brain and spinal cord form the control center known as the central nervous system (CNS), where information is evaluated and decisions made. Together, these organs are responsible for the control of the body and communication among its parts. The nervous system consists of the brain, spinal cord, sensory organs, and all of the nerves that connect these organs with the rest of the body. Subscribe now to remove this ad, read unlimited articles, bookmark your favorite post and soo much more