Chapter 7 Part I The Nervous System (pp. 202-214)
What effect does the Nervous System have on you? It is the MASTER controlling and communicating system of the body. Your every thought, action, and emotion is based on this system. It communicates with your body’s cells. Communicates via electrical impulses It causes your muscle and glands to become active.
What are the three overlapping & major functions of the Nervous System? Sensory Input-collects information from you physical surroundings (think of your 5 senses) Integration-processing the information and making a mental decision on what to do. Motor Output-the actual and physical response (action and movement).
How to understand our nervous system? The nervous system is ONE complex system But in order to simplify and understand it—it has been broken down into divided into it structure and function.
Structure of your Nervous System 1. Structural Classification It is broken down into two subdivisions The Central Nervous System (CNS) The Brain and Spinal Cord Integrate the sensory input, then processes and makes the decision. Peripheral Nervous System (PNS) The nerves that extend from the brain and the spinal cord. Two types of PNS nerves exist. Spinal nerves carry impulses to and from the Spine. Cranial Nerves carry impulses to and from the Brain These two systems link all parts of the body by carrying impulses from the sensory receptors to the CNS and from there to appropriate glands or muscles.
Structure of your Nervous System 2. Functional Classification-PNS only Also, broken down into two subdivisions Sensory (Afferent) division Nerve fibers that bring impulses to the CNS from sensory receptors located throughout the body such as impulses coming from your skin. Motor (Efferent) division-carries impulses from the CNS and there are 2 components to the Motor division Somatic (voluntary) nervous system-this is were our control of voluntary functions or conscious actions occur. Autonomic (involuntary) nervous system-this you do not control but it happens (heart beating/digestion)
Structure of your Nervous System 2 Structure of your Nervous System 2. Functional Classification-PNS only (cont.) Visional representation from previous slide Sensory (Afferent) division Motor (Efferent) division-
Nerve Tissue Tissue by definition is an area where there are many cells next to each other that are the same type. Nerve Tissue is made up to two types of cells Supporting cells Neurons (nerve cell)
Nerve Tissue 1. Supporting Cells There are many types of supporting cells for neurons. They are in put into one group called Neuroglia (nerve glue). These support cells function to protect, insulate, and protect the neurons. They DO NOT transmit nerve impulses-that is the job of the neurons (nerve cell).
Nerve Tissue 2. Neurons (nerve cell) Specialize in transmitting message from one part of the body to the another. There are differently structured neurons BUT no matter what they all have two things in common: A cell body with a nucleus One or more “branches” coming out of the cell body.
Nerve Tissue Reflexes Occur over neural pathways called Reflex Arcs. One of the forms of communication that neurons must do DAILY (create reflexes) Reflexes are rapid, predictable, and involuntary responses to stimuli. Travel only in one direction (one way only) once they start.
Nerve Tissue Reflexes (cont.) Reflexes are classification into two classes: Autonomic Reflexes Involuntary Regulate the activity of smooth muscles, heart, glands, secretion of saliva, changes sizes of eye pupils, digestion, elimination (pooping), regulates blood pressure, and sweating Somatic Reflexes Voluntary Includes all reflexes that stimulate the skeletal muscles. Pulling your hand away from a hot object you picked up is an example of Somatic Reflexes.
Nerve Tissue Reflex Arc All reflexes work off of the “Reflex Arc” concept All Reflex Arcs have a minimum of five elements. Receptor Sensory neuron Integration center Motor neurons Effector
Be prepared for Exam on Tuesday Study and understand the material.