Chapter 7 In the news… Alkaline Diet Alkaline Update Alkaline Diet update What is the Alkaline Diet? • Diet that helps balance the pH level of the fluids in your body, including your blood and urine • What to eat? • Fruits & Vegetables, raw foods, plant proteins (e.g., almonds, beans), Alkaline water, green drinks Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 MEAL FREQUENCY Is the "six small meals a day" plan beneficial? Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Class Question Is the "six small meals a day" plan beneficial? Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Conclusion People that eat more frequently: • • • • Eat smaller meals Tend to consume lower calories Make better food choices Not get as hungry and over eat Most important is daily calories consumed Personal preference Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Can someone be allergic to exercise? Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Exercise Induced Anaphylaxis (EIA) Symptoms include: pruritus, urticaria, flushing, profuse sweating, angioedema, abdominal pain, dysphagia, nausea, diarrhea, respiratory distress (laryngeal edema), vascular collapse, syncope Cholinergic Urticaria Sometimes triggered by temperature, medications, or food Food-triggered EIA: can be controlled by avoidance of food before exercise Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 EXERCISE PHYSIOLOGY Theory and Application to Fitness and Performance 10th Edition The Nervous System: Structure and Control of Movement Chapter 7 Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 General Nervous System Functions General Nervous System Functions Control of the internal environment – With the endocrine system Voluntary control of movement Programming spinal cord reflexes Assimilation of experiences necessary for memory and learning Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Organization of the Nervous System Chapter 7 Organization of the Nervous System Central nervous system (CNS) – Brain and spinal cord Peripheral nervous system (PNS) – Neurons outside the CNS – Sensory division Afferent fibers transmit impulses from receptors to CNS – Motor division Efferent fibers transmit impulses from CNS to effector organs to either produce movement or release hormones Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Organization of the Nervous System Relationship Between PNS and CNS Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Organization of the Nervous System Chapter 7 Structure of a Neuron Cell body – Contains the nucleus Dendrites – Conduct impulses toward the cell body Axon – Carries electrical impulse away from cell body – May be covered by Schwann cells Forms discontinuous myelin sheath along length of axon Synapse – Contact points between axon of one neuron and dendrite of another neuron Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Organization of the Nervous System Chapter 7 Synaptic Transmission Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Clinical Applications 7.1 Chapter 7 Multiple Sclerosis and Nervous System Function Neurological disease that destroys myelin sheaths of axons – Has genetic component – Due to immune attack on myelin Results in progressive loss of nervous system function – Fatigue, muscle weakness, poor motor control, loss of balance, mental depression Exercise can improve functional capacity – Leads to improved quality of life Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Organization of the Nervous System Chapter 7 Neurons are an “excitable tissue” Ability to respond to a stimulus and convert it to a neural impulse (irritability) Negative charge inside cells at rest – -5 to -100 mv – -40 to -75 mv in neurons (skeletal muscle neurons ~ 65mv) Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Organization of the Nervous System Chapter 7 Resting Membrane Potential Determined by: – Permeability of plasma membrane to ions – Difference in [ion] across membrane Na+, K+, Cl–, and Ca++ Maintained by sodiumpotassium pump – K+ tends to diffuse out of cell – Na+/K+ pump moves 2 K+ in and 3 Na+ out Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Organization of the Nervous System The Sodium-Potassium Pump Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Organization of the Nervous System Chapter 7 Action Potential Occurs when stimulus of sufficient strength depolarizes the cell – Opens Na+ channels, and Na+ diffuses into cell Inside becomes more positive Frog Legs Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Organization of the Nervous System Chapter 7 Repolarization Once a cell has been depolarized, it must return to a resting state Repolarization – Return to resting membrane potential K+ leaves the cell rapidly Na+ channels close All-or-none law – Once a nerve impulse is initiated, it will travel the length of the neuron Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Organization of the Nervous System Depolarization and Repolarization of a Nerve Fiber Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Organization of the Nervous System Chapter 7 Neurotransmitters and Synaptic Transmission Synapse – Small gap between presynaptic and postsynaptic neuron Neurotransmitter – Chemical messenger released from presynaptic membrane – Binds to receptor on postsynaptic membrane – Causes depolarization of postsynaptic membrane – Neurotransmitters can be excitatory or inhibitory Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Sensory Information and Reflexes Chapter 7 Sensory Information and Reflexes Proprioceptors – Receptors that provide CNS with information about body position – Located in joints and muscles Provide sensory feedback to nervous system – Muscle spindle – Golgi tendon organ Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Sensory Information and Reflexes Chapter 7 Muscle Spindles Responds to changes in muscle length – Wrapped around intrafusal muscle fibers in a spiral pattern Stretch reflex – Stretch on muscle causes reflex contraction Knee-jerk reflex Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Muscle Spindles Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Sensory Information and Reflexes Golgi Tendon Organ (GTO) Monitors tension developed in muscle – Prevents muscle damage during excessive force generation Stimulation results in reflex relaxation of agonist muscle – Also, results in contraction of antagonist muscle Ability to voluntarily oppose GTO inhibition may be related to gains in strength Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Sensory Information and Reflexes Chapter 7 The Golgi Tendon Organ Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Somatic Motor Function and Motor Neurons Chapter 7 Somatic Motor Function Somatic motor neurons of PNS – Carry neural messages from spinal cord to skeletal muscles Motor unit – Motor neuron and all the muscle fibers it innervates Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Somatic Motor Function and Motor Neurons Chapter 7 Somatic Motor Function Innervation ratio – # of muscle fibers per motor neuron – Low ratio in muscles that require fine motor control 2-3/1 in extraocular muscles – Higher ratio in other muscles 1,000/1 or greater in large muscles Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. A Closer Look 7.1 Chapter 7 Motor Unit Recruitment and the Size Principle Motor unit recruitment – Recruitment of more muscle fibers through motor unit activation Size principle – Smallest motor units recruited first Types of motor units – Type I fibers or Type S (slow) [smallest] – Type IIa fibers or Type FR (fast, fatigue resistant) [intermediate] – Type IIx fibers or Type FF (fast, fatigable) [largest] Recruitment pattern during incremental exercise – Type I type IIa type IIx Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Electromyography EMG can help visualize and quantify the activation levels of muscles. Not a direct measure of strength, force, or torque EMG will reflect amount of motor units firing – Neuromuscular activation Surface: – Electrodes applied to skin with conductive gel – Broad representation of entire muscle Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Snarr and Esco, 2014 Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Byrne et al., 2014: J Strength Cond Res Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Byrne et al., 2014 Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Spinal Automaticity Ability of neural circuitry of spinal cord to interpret complex sensory info – Spinal cord can make appropriate decisions to generate successful postural & locomotor tasks (independent of the brain) – Spinal cord has ability to learn motor tasks to reduce time needed from supraspinal centers and impose disadvantages in execution of task (critical for survival, but helps with elite athletics) – Thus, walking, jogging, running, swimming, etc. are actually spinal reflexes (anticipated responses) Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 Rat & Cat Experiments Rat Model Cat Model Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter 7 KAHOOT Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.
