Student%20Lecture%208%20%28Cardiovascular%20-Vascular%29

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Unformatted text preview: Lecture 8 Cardiovascular Cardiovascular Cardiac / Vascular Thursday 2­4­09 Outline Outline Extra credit – February 19th, 1:30, Armstrong B061, Anne Cox, Illinois State University, “Physical education motivation: Do different reasons really matter” Continue Cardiac Anatomy / Function Vascular Anatomy / Function Grant assignment #2 Cardiac Output The amount of blood pumped out of heart The amount of blood pumped out of heart per minute. Average resting cardiac output is _____________________________ Cardiac Output (Q) = ___________ x Stroke Volume (ml/min). Regulation of Heart Rate Regulation _________ regulated _________ regulated – Parasympathetic – ____________ – SA Node – AV Node Fig 9.14 Parasympathetic Parasympathetic Vagal Nerve Vagal or Parasympathetic Tone Releases ______ – ______________________ _______________ – Opens K+ channels – __________ Ca channel opening by decreasing cAMP ++ ________________ (i.e. moves further away from depolarization threshold Heart, Opie Sympathetic Sympathetic ______________ Nerve Release __________________ that binds to beta receptors – Gs protein activation cause adenylyl cyclase to convert ATP cAMP. – cAMP opens membrane _____________. Heart, Opie Regulation of Heart Rate _____________ _____________ – _________ and Carotid Arteries blood pressure receptors – Changes in BP trigger baroreceptors ↑BP=↓HR ____________ ↓ BP=↑HR ____________ – _____________________________ _ ↑Pressure = ↑HR ↑Temp = ↑HR ↓ Temp = ↓ HR Atrial Receptors _______________ Chemoreceptors _____________ Fig 9.14 Regulation of Stoke Volume Regulation Amount of blood pumped per heart beat Factors affecting stroke volume – _________ – _________ – _________ Preload Preload Volume of blood in left ventricle at the end of _________ – Frank­Starling _____________________ _____________________ ____________ Factors affecting preload – – – _____________ _____________ _____________ Fig 9.16 Afterload Afterload Blood __________ that the heart has to exceed to eject blood. Stroke volume __________ proportional to afterload – ___________ = ↓ Stroke Volume ↓ Afterload = _______________ Contractility Contractility Force generated by left ventricle – _____________________ _________________ – Epi and Norepi bind to β receptors – _____________________ _________________ Open Ca++ channels Increase Ca++ ATPase pumps Phosphorylate TroponinT Cardiovascular Physiology, Berne and Levy Fig 9.18 Vascular Network Vascular Transport blood. 60,000 miles (2.5x around world) Three distinct networks – ______ _____________________ _____________________ ____________ __________________ _____________________ _____________________ _____________________ _____________________ – _______ – _______ Vessel Anatomy _______ _______ – – – – – Arteries Capillaries Veins Arteries Veins ________ ________ – Arteries – Veins Human Anatomy, Marieb & Mallatt Intima Intima Single layer of endothelial cells Involved in the regulation of: – – – www.cmj.org/paper_journal/02/06/F020617_04.htm ____________ _____________ _____________ Brachial Pig #9053 Media Media _________________ _____________ Involved in the regulation of: – Vascular tone ACSM’s Advanced Exercise Physiology Brachial Pig #9053 Adventitia Adventitia Connective tissue, nerves & vasa vasorum Function – ______________ – __________________ __________________ __________________ __________ Veins vs. Arteries Veins Wall thickness is less in veins compared to arteries – ____________________ ________________ – Less ability to regulate vascular tone Human Anatomy, Marieb & Mallatt ___________________ _______________ – Facilitates blood flow back toheart Exercise Physiology, McArdle, Katch & Katch Distribution of Vascular Network Distribution Aorta – Arch (ascending and descending), Thoracic, Abdominal Conduit Arteries _____________ Arterioles _________ Venules _________ Vena Cava – Superior, Inferior Exercise Physiology, McArdle, Katch & Katch Aorta Aorta Largest artery in body. All blood ejected from left ventricle moves through aorta. _________________ Cardiovascular Physiology, Berne and Levy Conduit Arteries Conduit _________________ _________________ ___________. Site of atherosclerotic plaque formation. Pig Femoral Artery 9054 Feed Arteries Feed _________________ _________________ _________________ _________ Site of blood flow ____________. Media comprised of three layers of smooth muscle. Arterioles Arterioles Group of small arteries that lie within organ system (i.e. skeletal muscle) Site of blood flow _________________. Media comprised of __ smooth muscle cell layers in proximal arterioles an _ smooth muscle cell layer in distal arterioles. Labeling of arterioles is determined by branching order __________________ ACSM’s Advanced Exercise Physiology Capillaries Capillaries Site of oxygen exchange _________________ _____________ Oriented in parallel with muscle fibers. Vena Cava, Veins, Venules Vena Majority of blood stored in __________________ Overview of Vascular Network Overview Cardiovascular Physiology, Berne and Levy Smooth Muscle Cells Smooth Different from skeletal and cardiac myocytes Diameter 5μm, Length 100μm ___________(no T­tubules) ___________ (no z­lines) ___________ (actin and myosin filament not oriented in sarcomeres) Less actin and myosin filaments. Sarcoplasmic reticulum in close proximity to ___________. ______ regulated contractions Contractions are slow and sustained. Smooth muscle cells oriented circumferentially around vessels. __________________ Heart, Opie Smooth Muscle Cell Smooth Actin and myosin filaments are arranged in a _________. Human Anatomy, Marieb & Mallatt Contraction of Smooth Muscle Agonists bind to receptor Agonists bind to receptor (Norepinephrine, Angiotensin II, Endothelin) G protein mediated activation of _______________ Converts phosphatidyl inositol into ___________. DAG stimulates Ca++ channels to open on sarcolemma and IP3 opens Ca++ channels on SR. ________________________ ________________________ ________________________ _______ Phosphorylation of ______ allows cross bridge interaction and cycling. Heart, Opie Relaxation of Smooth Muscle Relaxation Agonists bind to receptor (Epinephrine, Adenosine, Prostacyclin) or diffusing across sarcolemma (nitric oxide) ________________________ ________________________ ________________________ cGMP and cAMP decrease ____________ and inhibit phosphorylation of myosin. Heart, Opie Endothelium Endothelium Length _________, width ______, thickness 1μm. Align with direction of blood flow. Release – Dilators Furchgott – Constrictors _____________________ _____________________ ____________. Endothelin­1 Ignarro Nobel Prize 1998 (medicine) Murad Endothelium Endothelium Laughlin and Korzick, Blood Pressure Blood Force exerted by blood against arterial walls. _______________ – force exerted during contraction phase of the cardiac cycle. _______________ – force exerted during relaxation phase of the cardiac cycle. Mean arterial pressure – average pressure across cardiac cycle. Unable to calculate during exercise because ratio of time spent in systole and diastole is no longer 1/3 to 2/3. – ___________________________ Measuring Blood Pressure Measuring Sphygmomanometer (Blood Pressure Cuff) Stethoscope Systolic pressure Diastolic pressure – __________________ _____ – __________________ _________ Exercise Physiology, McArdle, Katch & Katch Factors Influencing Blood Pressure Factors Figure 9.8 Resistance Resistance ________________ Resistance = – (Length x Viscosity/__________) Physiologically ___________ contributes greatest to resistance. < Pressure ∆ Across Systemic Circulation Circulation Figure 9.21 Relationship Between Blood Flow, Pressure and Resistance Pressure Blood Flow = __________________ Resistance = __________________ – Increased resistance equals ____________________ – Decreased resistance equals _________________________ ...
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