Cardiovascular System Full FL24 PDF

Cardiovascular KIN 476: Module 3 Why Care? #1 cause of mortality globally ~18,000,0 00 deaths annually VO2max is the #1 predictor of all cause mortality!  VO2max The maximum amount of O2 someone can intake, transport, and utilize ↑ 1 Met = ↓ 13% ↑ 1 Met = 3.5 m...

Cardiovascular KIN 476: Module 3 Why Care? #1 cause of mortality globally ~18,000,0 00 deaths annually VO2max is the #1 predictor of all cause mortality!  VO2max The maximum amount of O2 someone can intake, transport, and utilize ↑ 1 Met = ↓ 13% ↑ 1 Met = 3.5 ml O2/kg/min How do we increase CRF? 01 Cardiovascul ar System Basics  Components Heart & Blood Systemic Circulatio Pulmonar n y Circulatio n 12  Purposes Deliver O2 to Transport of 1 2 tissues & nutrients & transport CO2 to hormones to lungs tissues Maintain 3 4 Maintain blood thermoregulatio pressure n & blood pH  Blood Basics 5 liters of blood in system 55% plasma Used to measure Hydratio 45% hematocrit n Blood Basics  Blood Basics Plasm a Blood Basics WBC Blood Basics RBC  Blood Basics Hematocri t Sex Differences Males ~40-45% Females ~35-40% Polycythemi a Vera excess production of RBC’s hematocrit’s > 60%  Quiz!! — Name the two types of circulation involved in the cardiovascular system. — What are the two primary components of blood? — On average, how much blood is in the human body? 02 The 02 Heart 24 “Automaticity ”to depolarize Intrinsic ability itself  Intrinsic Conduction System  Extrinsic Conduction System What division of the nervous system is this? Z Disc A-Band I-Band H Zone Myocardium Very high amount of slow oxidative muscle fibers  Quiz!! — What is the term for the heart being able to depolarize itself? — The extrinsic conduction system of the heart uses what division of the nervous system? — Myocardium is made up of mostly what type of muscle fiber? 03 Vascular System  Vascular System Veins Arteries High compliance High elasticity vessel Properly Can hold provides increased blood constant blood volumes flow Contain valves to direct flow one-way Vascular System  Arterioles  primary function: blood flow regulation  contain smooth muscle  Sympathetic Nervous System (SNS) controlled  resistance vessels,  blood velocity  Capillaries  thin walled, one-layer of cells, porous  exchange of gases & nutrients  Venules  on venous side of capillaries  fluid and molecule exchange 41  Systemic Circuit Flow from high to low pressure Lowest velocity? Highest x-sectional area? Greatest drop in BP in one column?  Pulmonary Circuit Lower Pressures compared to systemic CSA is very high in pulmonary capillaries  Neural/Hormonal Control Sympathetic & systems compete Parasympathetic control for control at rest Catecholamines Epi & norepi in the blood?  Quiz!! — Which portion of the vascular system has the highest pressure? — What are the two catecholamines that are transported in the blood that assist the SNS? — What circuit has the lowest pressure?  Cardiac Function Terms  Cardiac Function Terms Cardiac Heart Rate Output (HR) (Q)of blood Volume Heart beats pumped per minute per minute Q = HR x SV (bpm) Avg = 5 L/min Stroke Volume (SV) Volume of blood ejected per beat (ml/beat) EDV: end-diastolic volume SV = EDV - ESV ESV: end-systolic volume Cardiac Function Terms Cardiac Function Terms  Cardiac Cycle! The Wiggers Diagram Phase 1. Ventricular filling: AV valves open Occurs during mid to late diastole Don’t forget “atrial kick”! Up to 30% more blood Phase 2: Isovolumetric contraction All valves closed Pressure is building in ventricles Phase 3: Ejection Once pressure in ventricles exceeds aortic/pulmonary pressure….. Phase 4: Isovolumetric relaxation Starts when All valves closed ventricular pressure falls below aortic/pulmonary AV valves open once ventricular pressure falls below atrial  Reminder Do both Both ventricles atrium pump at pump out the same time same amount of Both ventricles blood pump per beat? at same time Cardiac Cycle Summary Phase 1: Ventricular Filling: AV Valves Open ○ Occurs during mid to late diastole ○ Atrial contractions pushes the final 30% blood through Phase 2: Isovolumetric contraction ○ All valves are closed ○ Ventricular contraction to increase Cardiac Cycle Summary Phase 3: Ejection ○ Occurs during systole once ventricular pressure > arterial pressure ○ Semilunar valves open Phase 4: Isovolumetric relaxation ○ All valves are closed ○ Occurs early to mid diastole Cardiovascula r Responses to Exercise  Review of Systems Heart Stroke Rate Volume Cardiac Blood Output Pressure Resting Heart Rate < 60 Bradycardia 60- Normal 100 Sinus Rhythm >10 (NSR) Tachycardia 0 Sex Differences Males ~65-75 bpm Females ~75-85 bpm Exercise Heart Rate Anticipatory Reponse Anticipatory response Steady State Steady State Typically takes ~2-3 minutes to achieve HR Recovery Recovery Will recover faster in trained individuals  Incremental Exercise HRmax  ~1 beat/yr Impact of Training HRmax Decreases Heart Rate Variability (HRV) Heart rate variability is where the amount of time between your heartbeats fluctuates slightly. 71  Heart Rate Variability (HRV) 72 73  Heart Rate Variability High HRV Low HRV Low stress High “Well Stress Recovered “Less ” Recovered Easy ” Response Tough 74 Stroke Volume  SV Regulation Preload Ventricular Ventricular Afterload (EDV) chamber size contractility intrinsic x-sectional extrinsic Aortic/PA regulation area regulation pressure  Preload (EDV) “Frank-Starling Law of the Heart” (intrinsic) Stretch or load placed increase EDV on the myocardium increased “stretch” on myocardium change in fiber length  force of contraction Contractility  Afterload Resistance that must be overcome by ventricles Afterload What types of pressures can impact this?  SV Regulation Preload Ventricular Ventricular Afterload (EDV) chamber size contractility intrinsic x-sectional extrinsic Aortic/PA regulation area regulation pressure SV During Exercise SV During Exercise Untrained Trained SV Rest 70 ml/beat 80 ml/beat SV Max 120 ml/beat 200 ml/beat Plateau at ~40% SV During Exercise Untrained Trained SV Rest 70 ml/beat 80 ml/beat SV Max 120 ml/beat 200 ml/beat May not plateau  Q During Exercise Rest HR SV Q Untrained 72 bpm 70 ml 5.04 L/min Trained 50 bpm 100 ml 5.00 L/min Exercise HR SV Q Untrained 200 bpm 120 ml 24.0 L/min Trained 190 bpm 180 ml 34.2 L/min LV Adaptations Endurance training Eccentric Hypertrophy Resistance Training Concentric Hypertrophy Eccentric Hypertrophy Increased EDV  Concentric Hypertrophy Increased Contractility Pathologic Hypertrophy  Ventricular Hypertrophy Summary Eccentric Increased ventricular volume Concentri c Increased wall thickness Volume stays the Pathologic same Increased wall thickness Volume 90 decreases  Ventricular Hypertrophy Summary Ventricular Type of Ventricular Wall Stroke Cause Hypertrophy Volume Thickness Volume Eccentric + = + Endurance Training Concentric = + + Resistance Training Pathologic - + - Disease or Lifestyle Cardiac Output Blood Flow  Oxygen Delivery During Exercise Oxygen demand of Potential limitation of CV 2 muscles things the CV system can do during to overcome: system? 1. increase Q (5-6 x’s rest) finite amount of blood exercise: 2. redistribute many blood x’s greater than rest from non-active volumeto active - how sites much? Functional Sympatholysis  Functional Sympatholysis  SNS & local control  redirects BF to meet demand of exercise  preferentially more to skin, muscle, heart  away from kidneys, liver, GI tract At rest: ~ 15% of total BF to During max exercise: muscle 80-85% of total BF to muscle Constant Percent Constant Amount Blood Pressure BP Responses to Exercise SBP:  with exercise intensity  Q, SV Prolonged exercise: may see slight  in SBP due to vasodilation Vasodilation DBP: same or slight   Different than BP Responses to Exercise your book!  MacDougall et al., 1985 Largest increases after 80% of 1RM