The nervous system begins pre-natally … It eventually develops into the spinal chord with a specialized extension , the brainstem The posterior portion of brain stem develops the more specialized cerebellum , and the anterior Develops the c erebral hemispheres
THE CENTRAL NERVOUS SYTEM Comprises two parts: the brain and spinal chord Encased in bone for protection. In addition , Cerebrospinal fluid circulates inside and around the brain for additional protection
Brain – the organ that directly controls our thoughts , emotions and motivations. Spinal cord – a series of interconnected neurons Extending from the brain to the center of the back . It carries information to and from the brain
the two directional communication in the nervous system involves two different kinds of nerves and neurons….. Receptors – are structures designed to receive sensory information from the outlying nerves of the body and transmit that information back to the brain thru the spinal chord Effectors – transmit motor information about how the nody should act in response to the information it receives. Usually, this information comes from the brain.
The Peripheral Nervous System Comprises all of the nerve cells except those of the brain and the spinal cord . The primary job of the PNS is to relay information between the CNS and the receptors And effectors lying outside the CNS. The PNS connects with the receptors in both our external sensory organs and our Internal body parts. it connects with the effectors that produce movement, speech and so on.
The PNS comprises of two main parts: Autonomic nervous system – controls movement of our non skeletal muscles (heart and smooth muscles). The smooth muscles include those of the blood vessels and the internal body organs the Autonomic system is divided into two parts…..
Sympathetic nervous system - is concerned primarily with ‘catabolism,’ the process by which your body captures stores and uses energy and materials from food and eliminate wastes Parasympathetic nervous system – concerned with ‘anabolism,’ the process that stores energy in the body . These two systems tend to work in tandem….
Somatic nervous system – controls quick and conscious movement of skeletal muscles. these muscles are attached directly to the bone and allow us to move. We have voluntary control over the muscles served by the somatic system
Forebrain <ul><li>Located toward the top and front of the brain </li></ul><ul><li>comprised of two parts: the telencephalon and diencephalon </li></ul>
Telencephalon: - three parts 1 ~ the cerebral cortex (outer layer of cerebral hemisphere) plays vital role in our thinking 2 ~ the basal ganglia - a collection of nerves crucial to motor functions 3 ~ the limbic system - imp. to emotion, motivation and learning. Comprises of 3 interconnected cerebral structures
Diencephalon - between the telencephalon and midbrain - comprises the thalamus and hypothalamus Thalamus - relays incoming sensory information thru projection fiber to the appropriate region in the cortex
Hypothalamus- involved in water balance in tissues and bloodstreams. It controls much of the autonomic nervous system and endocrine system - involved in temperature regulation. interacts with and is sometimes viewed as part of the limbic system. Therefore in involved in behavior related to survival : fighting, feeding, fleeing, mating. hypothalamus
the main source of control for visual and auditory information. The reticular activating system of the Midbrain regulates state of consciousness, including sleep, wakefulness Arousal, and attention, as well as breathing and heartbeat Midbrain
Hindbrain Most rearward portion of the brain <ul><li>Medulla oblongata- </li></ul><ul><li>part of the reticular </li></ul><ul><li>activating system </li></ul><ul><li>helps control </li></ul><ul><li>heartbeat, breathing, swallowing, digestion </li></ul>
2. pons- serve as a kind of relay station for signals passing from one part of the brain to another . 3. cerebellum- involved in bodily coordination, balance, and muscle tone.