Rest of it

Page 1: Neural Control of Exercising Muscle

  • Lecture Title: Neural Control of Exercising Muscle: Part 2

Page 2: Reading Materials

  • Chapter 3: Physiology of Sport and Exercise, Ninth Edition

  • Authors: W. Larry Kenney, Jack H. Wilmore, David L. Costill

  • Pages: 87-95

  • Access: HKPropel

Page 3: Additional Resource

  • Title: The Whole Brain

  • Authors: Keith A. Johnson, M.D., J. Alex Becker, Ph.D.

  • URL: http://www.med.harvard.edu/AANLIB/home.html

Page 4: Lecture Objectives – Brain and CNS

  • Identify key structures of the brain & central nervous system (CNS):

    • Cerebrum

    • Diencephalon

    • Cerebellum

    • Brain Stem

    • Spinal Cord

  • Understand location and generation of motor commands.

  • Describe spinal cord's role in motor actions.

  • Explain autonomic vs. somatic nervous system;

    • Differences between sympathetic and parasympathetic systems.

Page 5: Central Nervous System: Key Brain Structures

  • Cerebrum: Outermost region; processing center.

  • Diencephalon: Relay/regulation center inside the cerebrum.

  • Cerebellum: Calibration center (small lobe at rear).

  • Brain Stem: Connects to spinal cord; handles essential life functions.

  • Images from Kenhub.com.

Page 6: Key Brain Structures

  • Frontal Lobe: Higher cognition, movement.

  • Central Fissure: Divides the brain into parts.

  • Parietal Lobe: Sensory integration.

  • Occipital Lobe: Visual processing.

  • Lateral (Sylvian) Fissure: Separates temporal lobe.

  • Temporal Lobe: Auditory functions.

  • Cerebellum: Not part of cerebrum, critical for coordination.

Page 7: Brain Activity

  • Primary Motor Cortex (M1):

    • Located in the frontal lobe, last stop before motor commands.

    • Contains pyramidal cells leading to the corticospinal tract.

    • Interconnected with sensory cortex (S1).

    • Most signals decussate at the brain stem.

Page 8: The Motor Cortex (M1)

  • Organized connectivity between M1 and bodily regions.

  • Functionally integrates sensory and motor information.

Page 9: Brain: Primary Sensory Cortex (S1)

  • Location: Parietal Lobe.

  • Function: Processes sensory info from body.

  • Relay via thalamus to M1.

Page 10: Brain Structure Connections

  • Visual representation of coordination between: M1, S1, Central Fissure, and various lobes.

Page 11: Brain Regions and Connectivity

  • CT (Corticothalamic fibers), PT (Pyramidal Tract), TC (Thalamocortical Afferent) shown in structures.

Page 12: Brain: Diencephalon Components

  • Thalamus: Major sensory relay, determines conscious awareness.

  • Hypothalamus: Regulates homeostasis, including appetite, sleep, and autonomic functions.

Page 13: Brain: Diencephalon Representation

  • Visual representation of connections and components in diencephalon.

Page 14: Cerebellum Functions

  • Controls rapid, complex movements.

  • Coordinates timing, sequences movements.

  • Receives input from M1 and periphery for correction.

Page 15: Cerebellum and Motor Control

  • Experimental study on cerebellum functionality with visual distortions (prism goggles).

  • Stroke affects correction abilities in movement.

Page 16: Brain Stem Overview

  • Connects brain and spinal cord, includes midbrain, pons, medulla oblongata.

  • Coordinates motor and sensory functions, vital autonomic controls.

Page 17: Brain Stem: Case Study

  • Example of "Mike, the headless chicken" exhibiting basic life functions sustained by intact brain stem.

Page 18: Brain Stem: Decussation

  • Most corticospinal tracts cross at medulla pyramids before descending to spinal targets.

Page 19: Spinal Cord Structure

  • Continuous with medulla, facilitates two-way nerve impulse conduction (efferent and afferent).

Page 20: Brain: Spinal Cord and Interneurons

  • Interneurons: Abundant, create reflex circuits.

  • Propriospinal fibers link various segments.

Page 21: Spinal Cord Neuron Types

  • Alpha Motor Neuron: Efferent motor neuron, controls movement.

  • Gamma Motor Neuron: Regulates spindle tension.

Page 22: Sensory Receptors of Muscle

  • Muscle Spindle: Detects muscle length and stretch rate.

  • Golgi Tendon Organ (GTO): Senses tendon tension and its changes.

Page 23: The Stretch-Contract Reflex

  • Sudden muscle stretch excites spindle, leading to muscle contraction via reflex action.

Page 24: Golgi Tendon Organ (GTO) Functions

  • Protects against muscle tears via autogenic inhibition, signaling force levels throughout muscle activity.

Page 25: Summary of Concepts

  • Sensory input = motor output

  • Breakdown of brain areas and their functional roles in movement, energy usage, and metabolism.

Page 26: Rate Coding in Motor Control

  • Mechanisms of motor unit recruitment and firing rates as they relate to muscle force production.

Page 27: Rate Coding Summary

  • Discusses the relationship between motor unit firing rates and effective force generation.

Page 28: Questions Section

  • Introduction to next lecture on fuel for exercise.

Page 29: Lecture 5 - Fuel for Exercise

  • Overview of upcoming content regarding energy sources in exercise physiology.

Page 30: Reading Materials for Lecture 5

  • Chapter 2: Physiology of Sport and Exercise, Ninth Edition, Pages 55-64.

Page 31: Key Lecture 5 Objectives

  • Overview of energy sources, control mechanisms, storage forms, and metabolic processes.

Page 32: Energy Requirements in the Body

  • Brain functionality, essential life functions, and other physiological processes requiring energy.

Page 33: Global Energy Sources

  • Plants’ process of photosynthesis as a primary energy source. Introduction to caloric measurement in metabolism (calories vs. kilocalories).

Page 34: Metabolism Explanation

  • Definition of metabolism as the sum of chemical reactions in the body that convert food to usable energy.

Page 35: Macronutrient Energy Contribution

  • Discussion on the roles of carbohydrates, fat, and protein as energy sources.

Page 36: Nutrient Energy Data

  • Caloric content of macronutrients outlined with calculation examples.

Page 37: Substrate Stores in the Body

  • Detailed energy storage estimates by location (liver, muscle, fat) and respective energy content.

Page 38: Control of Energy Production

  • Factors regulating food energy release, including substrate concentration and enzyme effects.

Page 39: Enzymatic Role in Metabolic Reactions

  • Enzymes facilitate controlled energy production; they do not initiate reactions but lower activation energy.

Page 40: Rate Limiting Enzymes

  • Identifies the concept of rate-limiting enzymes in metabolic pathways and their feedback mechanisms regulating energy production.

Page 41: ATP as Energy Currency

  • Description of ATP structure and its function in energy transfer within the body.

Page 42: Basic Energy Systems

  • Overview of the three main ATP synthesis pathways: ATP-PCr system, glycolytic system, and oxidative system.

Page 43: Interplay of Energy Systems

  • Chart displaying energy supply dynamics over various exercise durations and their predominant system contributions.

Page 44: High Energy Phosphates Overview

  • ATP’s role in muscle contraction and the enzymatic processes involved in its regeneration.

Page 45: ATP-PCr System Description

  • Process for quick ATP regeneration during high-intensity activities using phosphocreatine.

Page 46: Phosphocreatine in ATP Rebirth

  • Details how PCr serves as a buffer for ATP during intense exercises and its recycling mechanism.

Page 47: Key Enzyme in ATP-PCr System

  • Creatine Kinase (CK): Enzyme regulating PCr pathways and ATP production based on energy demand.

Page 48: Summary of ATP-PCr System

  • Anaerobic energy production details, mechanisms in the cytoplasm, and efficiency in intense exercises.

Page 49: Summary of Energy Systems Dynamics

  • Further insight into the interplay of aerobic and anaerobic energy systems based on specific activities.

Page 50: Basic Energy Systems Recap

  • Brief mention of three main ATP synthesis pathways: ATP-PCr, glycolytic, and oxidative systems.

Page 51: Energy Production Pathways Overview

  • Visual representation of the energy production through various substrates (fat, carbs, protein).

Page 52: Glycolytic System Mechanics

  • Detailed description of glycolysis and sub-pathways for glucose breakdown for energy.

Page 53: Glycolysis Process Breakdown

  • Fundamental steps of glycolysis leading to the net production of ATP.

Page 54: Glycolysis: Phases Explained

  • Breakdown of glycolysis into investment and payoff phases with associated ATP production.

Page 55: Gluconeogenesis Functionality

  • Importance of gluconeogenesis in glucose supply, especially under low glucose availability.

Page 56: Reverse Pathway of Glycolysis

  • Overview of gluconeogenesis and how it mirrors glycolysis pathways with certain adaptations.

Page 57: Enzymatic Pathway of Gluconeogenesis

  • Detailed enzyme processes involved in gluconeogenesis, emphasizing key limits.

Page 58: Substrates for Gluconeogenesis

  • Identifying liver-specific substrates for glucose synthesis via gluconeogenesis.

Page 59: Energy Systems Duration Overview

  • Description of ATP generation sources and their durations based on types of exercise performed.

Page 60: Lecture 6 - Overview

  • Introduction to next lecture focusing on fuel for exercise II.

Page 61: Reading Materials for Lecture 6

  • Chapter 2: Physiology of Sport and Exercise, Pages 65-78.

Page 62: Key Objectives for Lecture 6

  • Focus on oxidative metabolism, fat oxidation, and energy integration during exercise.

Page 63: Overview of Oxidative System

  • Description of the aerobic energy system and its ATP yield efficiency.

Page 64: Role of Mitochondria

  • Positioning of mitochondria for optimal oxygen use within muscle cells.

Page 65: Oxygen Demand in Muscle Energy Production

  • Explanation of how oxygen delivery limitations can affect energy production during exercise.

Page 66: Krebs Cycle Overview

  • Description of the Krebs cycle function, focusing on ATP and related metabolites output.

Page 67: Krebs Cycle Details

  • Summary of how energy substrates contribute to the Krebs cycle.

Page 68: Krebs Cycle Fuel Sources

  • Overview of primary substrates used from various macronutrients entering the Krebs cycle.

Page 69: Regulation of Krebs Cycle

  • Identify rate-limiting enzyme and its regulatory feedback mechanisms on Krebs cycle activity.

Page 70: Electron Transport Chain Function

  • Overview of the electron transport chain's role in ATP production from high-energy molecules.

Page 71: Mapping the Electron Transport Chain

  • Visual representation and detailed account of ATP generation in the mitochondrial environment.

Page 72: Summary of Oxidative Respiration

  • Concise summary of how substrates convert into ATP through various metabolic pathways in mitochondria.

Page 73: Comprehensive Breakdown of ATP Yield

  • Detailed calculations showing total ATP output from glucose oxidation in various metabolic phases.

Page 74: Cori Cycle Functional Importance

  • Discusses the role of lactate during exercise and its reconversion into glucose.

Page 75: Metabolism of Fat as Energy

  • Overview of fat oxidation processes and their implications for energy during endurance activities.

Page 76: Fat Breakdown Overview

  • Details on how triglycerides are converted to useable fatty acids for energy production.

Page 77: Fat Oxidation and Beta Oxidation

  • Description of beta oxidation mechanics and how FFAs are utilized in the Krebs cycle.

Page 78: ATP Yield from Fatty Acids

  • Details on how much ATP can be generated from palmitate via oxidation processes.

Page 79: Protein Metabolism Discussion

  • Examining the role of proteins as an energy source during metabolism but typically in lesser amounts.

Page 80: Interaction of Energy Systems Summary

  • Insight into how all energy systems work together depending on exercise intensity and duration.

Page 81: Crossover Concept Explanation

  • Identification of how carbohydrate and fat usage varies with exercise intensity.

Page 82: Metabolic Interchangeable Systems

  • Overview of metabolic pathways showing how various substrates interconvert and contribute to energy supply.

Page 83: Summary of Energy Systems

  • Brief summary of macronutrient roles in storage and breakdown concerning exercise.

Page 84: Introduction to Lecture 7

  • Upcoming lecture topic on hormonal control during exercise.

Page 85: Reading Materials for Lecture 7

  • Chapter 4: Physiology of Sport and Exercise, Pages 101-124.

Page 86: Key Objectives for Lecture 7

  • Overview of endocrine responses during exercise and metabolic influences from various hormones.

Page 87: Endocrine System Overview

  • Structure and functions, signaling pathways in the endocrine system with various types.

Page 88: Neuroendocrine System Function

  • Interplay between nervous system response and hormone regulation during metabolic activities.

Page 89: Hormone Secretion Patterns

  • Explanation of hormonal release mechanisms and feedback systems regulating concentrations.

Page 90: Insulin Feedback Model

  • Description of how insulin and glucagon function to regulate blood glucose have practical activity examples.

Page 91: Hormonal Binding Dynamics

  • Discussion on hormone-receptor interactions and the importance of receptor presence for hormonal actions.

Page 92: Hormonal Concentrations Overview

  • Visual transcription of relative hormone concentrations in the blood and their regulatory effects.

Page 93: Non-Steroid Hormones

  • Mechanisms of signaling through non-steroid hormones, type and classifications.

Page 94: Hormone Transport Mechanisms

  • Methods of hormone transport in blood based on hormone types (water-soluble vs. lipid-soluble).

Page 95: Hormonal Activation Overview

  • Explanation of free vs. bound hormones regarding biological activity level with practical examples.

Page 96: Nonsteroid Hormones Signaling

  • Mechanism detailing the function of non-steroid hormones in cellular processes through second messengers.

Page 97: Steroid Hormones Overview

  • Characteristics of steroid hormones, their origins, and effects at cellular levels.

Page 98: Steroid Hormone Action Mechanism

  • Stepwise illustration of how steroid hormones activate gene expression within cells.

Page 99: Hormonal Effects on Sensitivity

  • Examination of how exercise-conditioned changes can affect hormone levels and their receptor sensitivities.

Page 100: Key Hormonal Regulators

  • Hormonal influences on metabolism discussed through four main glands/tissues pivotal during exercise.

Page 101: Hormone Concentration Dynamics

  • Graphic representation of hormone fluctuations during exercise in response to physiological stress.

Page 102: Anterior Pituitary Hormones

  • Functions of pituitary hormones such as Growth Hormone (GH) and Thyroid Stimulating Hormone (TSH).

Page 103: Thyroid Gland Hormones

  • Roles of thyroid hormones in regulating metabolic rates and related physiological processes.

Page 104: Adrenal Medulla Functions

  • Description of catecholamine functions in metabolic response and their specific actions during exercise.

Page 105: Pancreas Hormonal Functions

  • Overview of glucagon and insulin roles and how they interact with blood glucose levels during exertion.

Page 106: Carbohydrate Metabolism During Exercise

  • Mechanisms ensuring glucose availability, including glycogen breakdown and liver glucose production.

Page 107: Changes in Glucose and Insulin Dynamics

  • Graphical representation of insulin and glucose folding during exercise time-course.

Page 108: Hormonal Regulation of Glucose

  • Summary of other hormones contributing to glucose mobilization during physical activity.

Page 109: Fat Metabolism During Exercise

  • Processes explaining how fats are mobilized for energetic demands during prolonged exercise.

Page 110: Protein Metabolism Insights

  • Overview of the lesser role proteins play in energy metabolism except in extreme conditions.

Page 111: Hormones and Fluid Balance

  • Discusses fluid shift impacts on performance, involving the endocrine's regulatory role during activity.

Page 112: Electrolytic Regulation During Exercise

  • Description of kidneys' involvement in maintaining electrolyte balance, focusing on hormonal influence.