The skin performs all of the following except Production of chemical messengers Elimination of waste products Control of body temperature protection
Students will know… Explain what an action potential is? K+ ions are entering the neuron Negatively charged proteins are leaving the neuron Na+ ions are entering the neuron The myelin coat has broken down and ions are crossing freely
Students will know… Which is the correct path a nerve impulse will follow in a reflex arc? Put these three terms in order Motor neuron, sensory neuron and interneuron
Nervous System Chapter 33.1
Structure of the Nervous System Neurons conduct electrical impulses allow cells, tissues, and organs detect and respond to stimuli
Neurons Specialized cells Help you gather information
Neuron
Neuron Dendrites – receive signals and send them to the cell body
Neuron Dendrites – receive signals and send them to the cell body Cell body – nucleus of the neuron and other organelles
Neuron Dendrites – receive signals and send them to the cell body Cell body – nucleus of the neuron and other organelles Axon – caries the nerve impulse from cell body to other neurons and muscles
Reflex Arc Nerve pathway Basic structure of the nervous system Sensory neuron to an interneuron, and a motor neuron
An Action Potential Nerve impulse A stimulus reaches threshold Channels in the plasma membrane open Potassium ions leave the cell Change in charge moves
Action Potential
Dendrites and synapses Which of the following pairs lists the fiber-like extensions that are components of neurons? Axons and myelin Synapses and myelin Dendrites and synapses Dendrites and axons
Organization of Nervous System Chapter 33.2
Organization of the Nervous System Central nervous system Peripheral nervous system
The Central Nervous System CNS Spinal Cord Brain Relays messages Processes information Analyzes responses
The Brain Made up of 100 billion neurons Maintains homeostasis Control center
The Brain Made up of 100 billion neurons Maintains homeostasis Control center Homeostasis – maintains a constant condition
The Brain
The Brain
Cerebrum Largest part Divided into two hemispheres Thought process of memory, language, speech, voluntary body movements and sensory perception
Cerebellum Controls balance, posture and coordination Back of brain
Brain Stem Connects the brain to the spinal cord Made up of Medulla oblongata (signals between brain and spinal cord) Pons (signals between cerebrum and cerebellum)
Spinal Cord Nerve column from your brain to the lower back Protected by vertebrae
Spinal Cord
The Peripheral Nervous System Somatic Nervous System Autonomic Nervous System
Somatic Nervous System Relays information to and from skin and skeletal muscles Voluntary
Autonomic Nervous System Relays information to internal organs Involuntary
Autonomic Nervous System Sympathetic Parasympathetic Pupil dilation Heart rate increased Bronchial muscle relaxed Small intestine muscle contractions reduced Pupil constriction Heart rate decrease Bronchial muscles contracted Digestion increased
Unit 9 Chapter 33.3
Quiz 1. Draw and label a neuron Describe a Reflex Arc Pathway Describe an Action Potential
The Senses Chapter 33.3
The Senses Sensory receptors allow you to detect the world around you
Taste and Smell Stimulated by chemicals Work together
Smell Sensory receptors high in the nose Respond to chemicals Signal the brain
Taste Taste buds Detect sweet, sour, salty and bitter
Nature August 2006 Wrong!
Sight Light enters the eye Through the cornea Behind the iris is the lens To the retina (rods and cones) Signals sent to brain Brain interprets
Sight
Hearing and Balance Function of the ear Volume Highness and lowness
To Hear Sound waves Ear canal Eardrum to vibrate Through the malleus, incus, stapes Inner ear cochlea Sends signals to the brain
Ear
To Balance Cochlea Semicircular Canals At 900 Fluid filled, lined hairs Head moves the fluid moves and sends signals to brain
Ear
Touch Sensory receptors Respond to temperature pressure and pain Epidermis and dermis Tips of fingers have lots Not everywhere