PHYSIO-s10_12 - 3/7/2010 BIOL 260: Human Physiology Human...

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Unformatted text preview: 3/7/2010 BIOL 260: Human Physiology Human Spring 2010 Spring M, Mar. 8, 2010 Mar. 1. Pre-Lab Writeups: Be sure to prepare before each Monday or Lab W riteups Be before each Monday or Wednesday labs (for WHOLE week!)!! Wednesday – (What? Why? How? are we doing in the lab??) 2. THIS Week: Open lab!! Catch up on 6, 8, 9. Open • Open Lab NEXT Monday!! No class NEXT Wednesday. 3. Midterm #1 will be returned today, with M/C Answer KEY posted under Midterm will “Additional Materials”. 4. NEXT WEEK: Quiz #3. NEXT Quiz • Expt. 10: Cardiovascular ECGs; Aerobic exercise. Cardiovascular ECGs • Short sleeves or tank- tops best. tops 5. MUSCLES (Report #3): Library research exercise. (Due Mon./Wed., 3/15-17) 5. a) b) c) d) Citations APA style, etc.: Citations Canada Library website: Canada http:// Pubmed:; http:// MUST USE a Peer-reviewed journal! (current: muscle physiology) MUST Peer reviewed journal! • (PRIMARY literature – includes original research and original Data!) 1. Diagram and describe 6 main steps in the Sliding Filament Theory of muscle Diagram main Sliding of contraction, including all of the molecular players involved. contraction, • Actin, myosin, Ca++, tropomyosin, troponin, nebulin, titin myosin, tropomyosin troponin nebulin titin 2. Describe and diagram the process of Excitation-Contraction coupling. Include all Describe Excitation Include proteins and ions involved in both parts of the event. proteins 3. Compare the roles of phosphocreatine and lactic acid in muscle fatigue. Compare phosphocreatine REVIEW TODAY: Students should be able to…... 1. Define and illustrate the concepts of Tetanus, Summation, Define and Twitch. and 2. Define a motor unit, and explain how Recruitment affects the force of contraction? 3. Compare Isotonic and Isometric contractions. What are the muscle and associated tissues doing? What factors control the force and speed of contraction? 4. Compare the anatomy, regulation, and mechanics of contraction in Skeletal, Smooth, and Cardiac muscle. • Consider cellular connections/coordination, proteins involved, and responses to IC Ca++. 1 3/7/2010 Fiber Contraction Speed: Fiber B. Oxidative Fast & Slow B. 1. Oxidative Fast Twitch a) Intermediate speed b) Anaerobic & aerobic 2. Slow Twitch: Aerobic, less fatigue a) b) c) More mitochondria More capillaries Myoglobin – high affinity O2 binding in muscle • Take O2 from blood and hold until needed. – Endurance activities – Postural muscles – body control Postural 12.7) Coordinating the Fibers: 12.7) A. Force of Contraction A. • Excitation and Twitch • Length–Tension: more crossbridges (actinmore crossbridges myosin contact) more tension/force! myosin No where to go!! Too short Too long M any “oars” aren’t Many hitting the water hitting Figure 12-16: Length-tension relationships tension in contracting skeletal muscle in 2 3/7/2010 Coordinating the Fibers: Coordinating B. Summation to Tetanus Tetanus = muscle relaxes muscle completely btw stimuli completely = closer stimuli do not closer allow muscle to fully relax allow Fused Tetanus: Fused = stimuli far apart stimuli enough to allow slight relaxation between each relaxation = muscle reaches steady17: Summation of contractions Figure 12- tension 12.8) Motor Unit: Fibers 12.8) Innervated from 1 neuron Innervated • “All or none” – Somatic motor neuron fires Somatic all fibers in motor unit contract! – But in a whole muscle, may fire But only a few motor units at a time. only • Fine touch: Fine – 1:1 nerve to fiber – Finger tips, eyes • Big muscles: – 1 nerve: 2000 muscle fibers – Leg muscles,… Figure 12-18: Motor units 3 3/7/2010 B. Recruitment of Fibers: B. Recruitment of Produce Graduated Force Produce 1. Weak stimulus a) Lowest threshold fibers b) Slow twitch typically 2. Moderate: • Adds Fast Oxidative 3. High stimulus: all fibers • Asynchronous: – Units take turns – Prevents fatigue Figure 12-18: Motor units 12.9) Mechanics of Body 12.9) Movement: Joints Movement: A. Tendons: connect muscle to bone B. Ligaments: connect bone to bone C. Muscles: contraction force 1. Isotonic: movement, constant force a) Concentric Actions - shortening b) Eccentric Actions - lengthening 2. Isometric: no movement, constant length 4 3/7/2010 A. Mechanics of Body Movement: A. Isotonic, Isometric Contractions Isotonic, Figure 12-19: Isotonic and isometric contractions Physics of Joint Movement: • Muscle: origin near body, insertion distal – Insertion point balances power/force vs. speed/distance • Levers = bones, bones, Fulcrum = joints Fulcrum Figure 12-21a: The arm is a lever and 21a: fulcrum system fulcrum Figure 12-20: Series Elastic Elements in Muscle Series 5 3/7/2010 12.10) Smooth Muscles: 12.10) Contrasted to Skeletal Muscle Contrasted a) Control fluid b) Sphincters 1. Homeostatic role 2. Tonic contractions a) Support tubes b) Move products 3. Slow contractions a) Little fatigue b) Low O2 use Figure 12-24: Duration of muscle contraction in three types of muscle A. Smooth Muscles: Types A. Figure 12-25: Types of smooth muscle 6 3/7/2010 B. Smooth Muscles: B. Characteristics Characteristics 1. Stimulation a) Electrically coupled • Gap junctions b) Hormones c) Paracrines d) Various receptors e) Single Unit – gap jxns gap jxns f) Multiple unit - varicosities 2. Single tapered cells 3. Longer actin & myosin Longer actin a) Actin jjoined at Dense Bodies oined Dense b) Diagonal/oblique arrangement c) Continuous myosin heads on thick filaments 4. Can contract without depolarization!! & Latch State Can Latch Smooth Muscle Characteristics Figure 12-27: Anatomy of smooth muscle 7 3/7/2010 C. Smooth Muscle Contraction: C. Mechanism Mechanism Fig. 12-28: Smooth muscle contraction ++ enters Ca++ enters from SR and ECF. D. Smooth Muscle D. Relaxation: Mechanism Relaxation: Ca++- ATPase Ca++/Na+ Antiporter Ca++- ATPase, Ca++/Na+ Antiporter Ca Exception: Latch State Exception: Latch Figure 12-29: Relaxation in smooth muscle 8 3/7/2010 12.11) Cardiac Muscle: 12.11) Contrasted to Skeletal Contrasted Figure 14-7h 1. Short branched fibers 2. Single nucleus 3. Intercalated discs 4. Gap junctions - syncytia 5. Stimulation: a) Pacemaker (smooth too) Waves of depolarization Leaky ion/Ca++ channels b) Autonomic • Nervous & Hormonal Cardiac Muscle: Contrasted to Skeletal Cardiac Contrasted Fig. 14-7gh. ANATOMY SUMMARY: The Heart Sarcomeres 9 3/7/2010 ** Summary: Comparison of ** Three Muscle Types ** Three Muscles: Review 1. Skeletal: Calcium initiation at Motor End Plate 2. Actin/Myosin complexes: contraction begins with contraction ++, ATP, troponin (TN), tropomyosin. Ca ATP, troponin (TN), tropomyosin Ca • Sliding Filament Theory Sliding • (sarcomere, myofibril, muscle fiber, fascicle, muscle) myofibril 3. Force: Optimum length, motor unit recruitment 4. Smooth muscle: oblique filaments, slow & sustained, gap oblique jxns, endo/paracrine, CaM (no TN), Ca++ depoln, K+ repoln jxns endo/paracrine CaM 5. Cardiac Muscle: autonomic, striated, intercalated discs/gap jxns, pacemaker potentials (leaky channels) jxns pacemaker (leaky 6. Ca++ actions: NT vesicle release, SR release for contraction NT troponin or calmodulin. Depolarizes smooth muscle AP. or calmodulin Depolarizes 10 3/7/2010 Chapter 14 Cardiovascular Cardiovascular Physiology Physiology 1. Blood flow pumping & Blood distribution distribution 2. Anatomy and histology of Anatomy the heart the 3. Mechanism of cardiac Mechanism contraction contraction 4. Heart beat sequence–how how the pump works the 5. Regulators of heart beat and Regulators volume pumped volume Overview of the Overview Cardiosvascular System Cardiosvascular • Heart and Blood vessels • Products transported to sustain all cells Table 14-1: Transport in the Cardiovascular System 11 3/7/2010 14.1) Circulation Reviewed • Heart – "four chambered" Heart – Right atrium & ventricle – Pulmonary circuit – Left atrium & ventricle – Systemic circuit • Blood Vessels – "closed circulation" Blood – Arteries –from heart – Capillaries – cell exchange Capillaries – Veins – to heart Circulation Reviewed • Circulatory system: transports oxygen, transports nutrients, Heat, & wastes nutrients, 1. Right side of heart: delivers deoxygenated delivers blood from the body to the lungs. lungs. • Pulmonary arteries – Pulmonary arteries away from heart, deoxygenated blood 2. Left side of heart: delivers oxygenated blood from delivers the lungs to the body. the • Pulmonary veins – Pulmonary veins towards heart, oxygenated blood Figure 14-1: Overview of Cardiovascular system anatomy 12 3/7/2010 14.2) Blood Flow: 14.2) A. Pressure Changes A. 1. Flows down a pressure gradient 2. Highest at the heart (driving P), decreases Highest over distance over 3. Hydrostatic (really hydraulic) pressure in (really hydraulic pressure vessels vessels 4. Decreases 90% from aorta to vena cava • Resistance due to vessel walls and Resistance suspended cells suspended Blood Flow: Pressure Changes 93 mm Hg in arteries few in last veins 93 Figure 14-2 : Pressure gradient in the blood vessels 13 3/7/2010 B. Some Physics of Fluid B. Movement: Blood Flow Movement: • Flow rate = vol/time vol/time (L/min) (L/min) • Flow velocity = rate/C-S area of vessel rate/C • Resistance slows flow – ↑ Vessel diameter = ↓R Vessel – ↑ Blood viscosity = ↑R Blood – ↑ Tube length = ↑R Tube Figure 14-4 c: Pressure differences c: of static and flowing fluid of Figure 14-3 Pressure differences in static Pressure and flowing fluid and Resistance and flow 14 ...
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This document was uploaded on 03/18/2010.

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