PHYSIO-s10_13 - 3/14/2010 BIOL 260: Human Physiology Human...

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Unformatted text preview: 3/14/2010 BIOL 260: Human Physiology Human Spring 2010 Spring M, Mar. 15, 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. Midterm #1 was returned, with M/C Answer KEY Midterm posted under “Additional Materials”. posted 3. T HIS WEEK: Quiz #3 due Wed. night! THIS Quiz due • Expt. 10: Cardiovascular ECGs; Aerobic exercise. Cardiovascular ECGs • Short sleeves or tank- tops best. tops 4. MUSCLES (Report #3): Library research exercise. (Due Mon./Wed., 3/15-17) 4. 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. Define and illustrate the concepts of Tetanus, Summation, and Twitch. Define Tetanus, 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? REVIEW TODAY: Students should be able to…... 1. 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++. 2. Contrast the purpose of the right and left halves of the heart. Draw a Contrast right Draw simple diagram showing the path of blood flow tthrough the heart, lungs, hrough path and upper and lower body. and 3. Describe the several different factors controlling the rate and velocity of Describe blood flow tthrough vessels. (resistance: length, radius, viscosity; pressure, C-S area) hrough (resistance: blood 4. Describe and diagram how the heart and blood vessels assure one-way Describe one way blood flow tthrough the heart, lungs, and body. (ie: valves, pressure changes) hrough blood 5. Diagram the how AP generates contraction in a muscle cell. Compare/ Diagram how Compare/ contrast cardiac muscle cell contraction with skeletal and smooth muscle. contrast 1 3/14/2010 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 2 3/14/2010 12.11) Cardiac Muscle: 12.11) Contrasted to Skeletal Contrasted 1. 2. 3. 4. 5. 6. 7. Shorter, branched fibers Single nucleus/fiber Intercalated discs between – – Desmosomes allow force to be transferred Gap junctions provide electrical connection Figure 14-7h Gap junctions - syncytia T-tubules are larger and branch Sarcoplasmic reticulum is smaller Mitochondria occupy one-third of cell volume 8. 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 3 3/14/2010 ** 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 4 3/14/2010 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 5 3/14/2010 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 6 3/14/2010 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 7 3/14/2010 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 8 3/14/2010 Some Physics of Fluid Some Movement: Blood Flow Movement: • Mean arterial pressure cardiac output peripheral resistance Mean cardiac Figure 14-6: Flow rate versus velocity of flow • Velocity: narrower vessel faster velocity of flow. narrower • Rate: how much volume flows per min/sec. 14.3) Heart Structure 1. Pericardium 2. Chambers 3. Coronary Coronary vessels vessels 4. Valves(one-way-flow) 5. Myocardium Figure 14-7 g: ANATOMY SUMMARY: The Heart 9 3/14/2010 Cardiac Muscle Cells: 1. Autorhythmic 2. Myocardial Cells a) Intercalated discs 1) Desmosomes – Hold together The SPIRAL arrangement The of ventricular muscle allows ventricular contraction to squeeze the blood upward from the apex of the heart. the 2) Gap Junctions – Fast signals – Cell to cell Contain Contain desmosomes that desmosomes that transfer force from cell cell-to-cell, and gap cell, junctions that allow electrical signals to pass rapidly from cell cell-to-cell. b) Many mitochondria c) Large T tubes Figure 14-10: Cardiac muscle 14.4) Mechanism of Cardiac Muscle of Excitation, Contraction & Relaxation Excitation, Ca++-induced induced Ca++ release!! Ca Figure 14-11: Excitation-contraction coupling and relaxation in cardiac muscle 10 3/14/2010 A. Modulation of Contraction 1. Graded Contraction: proportional to proportional # crossbridges formed. crossbridges – More [Ca++]: ↑ crossbridges, ↑ force & speed force ++) (↑Troponin-Ca 2. ↑ Ca++ ATPase activity quicker, Ca++ ATPase activity quicker, more frequent contractions (faster relaxation). more 3. Autonomic & epinephrine modulation a) Epi/norepi speed & force ( 1-R’s) b) ACh slows, force (mACh-R’s) slows, Modulation of Contraction EPI/NE STRENGTH (SV) SPEED (HR) Figure 14-30: Modulation of cardiac contraction by catecholamines 30: catecholamines 11 3/14/2010 B. More Characteristics of B. Cardiac Muscle Contraction Cardiac 1. Stretch-Length relationship a) stretch, Ca++ entering stretch, Ca++ b) contraction force b) contraction IIncluding stretching ncluding 2. Long action potential 2. 3. Long refractory period a) No summation!! b) No tetanus!! of heart muscle by Diaphragm!!!! Diaphragm!!!! 1. Myocardial Length-Tension Tension Relationship Relationship Isometric Figure 14-12: Length-tension relationships in skeletal and cardiac muscle 12 3/14/2010 2. AP in Cardiac Contractile Cell 1. Phase 4 = resting Vm resting Vm (-90mV) = EK!! 2. 0 = Depol’n; iinflux thru nflux + channels VG Na VG (double-gated) 3. 1 = iinitial repol’n; Na+ Ch. nitial repol Ch. + leaves Close, K leaves Close, (slow opening) (slow 4. 2 = Plateau: llong refr. ong refr Plateau: a) some K+ Ch. Close; Ch. b) very slow Ca++ Ch. Open!!! b) 5. 3 = Rapid Repol’n; Ca++ Rapid Repol Ch. Close; K+ influx again Figure 14-13: 13: AP in cardiac muscle cell AP 3. Cardiac Muscle Contraction: 3. Refractory Periods long!!! Figure 14-14ac: Refractory periods and summation in skeletal and cardiac muscle 14ac: muscle 13 3/14/2010 C. Autorhythmic Cells: C. Autorhythmic Cells: Initiation of Signals Initiation 1. Pacemaker membrane potential 2. If channels (“funny current”): ): + influx depol’n / spontaneous Na influx spontaneous pacemaker pacemaker 3. Ca++ channels – influx, to AP – Cardiac action potentials!!! 4. Slow K+ open – repolarization Autorhythmic Cells: Cells: Initiation of Signals Initiation Potentials Ion Movements Ion Channel Activity Figure 14-15: Action potentials in cardiac autorhythmic cells 15: autorhythmic 14 ...
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This document was uploaded on 03/18/2010.

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