HA-The-Nervous-System-LEC.pptx

UNIVERSITY OF THE VISAYAS - MAIN CAMPUS “HUMAN ANATOMY LECTURE” Prepared by: Ms. Ariane Jane S. Satore  Functions of Nervous System  Sensory Function Sensory receptors gather information Information is carried to the CNS  Integrative Funct...

UNIVERSITY OF THE VISAYAS - MAIN CAMPUS “HUMAN ANATOMY LECTURE” Prepared by: Ms. Ariane Jane S. Satore  Functions of Nervous System  Sensory Function Sensory receptors gather information Information is carried to the CNS  Integrative Function Sensory information used to create: - sensations - memory - thoughts - decisions  Motor Function Decisions are acted upon Impulses are carried to effectors  NEURONS (Nerve Cells) Neurons have three fundamental physiological properties: 1. Excitability 2. Conductivity 3. Secretion A typical neuron is divided into three parts;  Soma or cell body (perikaryon)  Dendrites  Axon Structure of a Neuron  Classification of Neurons  Neurons may be classified according to structure or function. FUNCTION: STRUCTURE: Sensory (afferent) Unipolar neurons neuron Bipolar neurons Interneuron Multipolar (association) neurons Motor neuron Anaxonic neurons  NEUROGLIA (Glia)  There are six types of supportive cells  Four occur in the CNS  Oligodendrocytes  Ependymal cells  Microglia  Astrocytes  Two occur in the PNS Schwann cells (Neurilemmocytes) Satellite cells Types of Neuroglia ANATOMY OF THE BRAIN  Function of basal ganglia 1. Control of voluntary motor activity 2. Control of reflex muscular activity 3. Control of muscle tone 4. Role in arousal mechanism  The medulla oblongata contains motor fibers from the brain to spinal cord and sensory fibers from the spinal cord to the brain. Most of these fibers cross, or decussate, at this level. Cranial nerves IX through XII connect to the brain in the medula.  Structures protecting the brain The meninges (fibrous connective tissues that cover the brain and spinal cord) provide protection, support, and nourishment to the brain and spinal cord.  When excess pressure occurs in the cranial cavity, brain tissue may be compressed against the tentorium or displaced downward, a process called herniation.  Cerebrospinal fluid Clear and colorless fluid with a specific gravity of 1.007  Continuing below the second lumbar space are the nerve roots that extend beyond the conus, which are called the cauda equina because they resemble a horse’s tail. Similar to the brain, the spinal cord consists of gray and white matter Vertebral Column SPINAL NERVES