Cardiovascular System Duarte Ferreira, PhD Karolinska Institutet, Department of Physiology and Pharmacology 29th October 2019 [email protected] BLOOD Blood Tortora GJ, Principles of Anatomy and Physiology Plasma Plasma • Mainly water + - • Bicarbonate pH buffer (H HCO3 ) • Plasma proteins • Albumin • Immunoproteins • Antibodies • Glucose • Lipids Erythrocytes (Red blood cells) Tortora GJ, Principles of Anatomy and Physiology Tortora GJ, Principles of Anatomy and Physiology Leukocytes (white blood cells) Tortora GJ, Principles of Anatomy and Physiology Leukocytes Tortora GJ, Principles of Anatomy and Physiology Platelets or Thrombocyte Wilmore, et al. Physiology of Sport and Exercise. Different blood groups Tortora GJ, Principles of Anatomy and Physiology Different blood groups Tortora GJ, Principles of Anatomy and Physiology HEART Position of the heart Tortora GJ, Principles of Anatomy and Physiology Blood flow through the heart Tortora GJ, Principles of Anatomy and Physiology Cardiac muscle Tortora GJ, Principles of Anatomy and Physiology Cardiac muscle Tortora GJ, Principles of Anatomy and Physiology Action potential The electrical system of the heart Tortora GJ, Principles of Anatomy and Physiology Pacemaker cells Tortora GJ, Principles of Anatomy and Physiology Aktionspotential av myocyter Tortora GJ, Principles of Anatomy and Physiology Action potential of myocytes Tortora GJ, Principles of Anatomy and Physiology Electrocardiogram (ECG) Tortora GJ, Principles of Anatomy and Physiology Electrocardiogram (ECG) Tortora GJ, Principles of Anatomy and Physiology Electrocardiogram (ECG) Tortora GJ, Principles of Anatomy and Physiology Electrocardiogram (ECG) Tortora GJ, Principles of Anatomy and Physiology Heart sounds Tortora GJ, Principles of Anatomy and Physiology Cardiac output Cardiac output = Heart rate × Stroke volume Volume/min = Beat/min × Volume/beat Cardiac output (CO) à The flow of blood delivered by the heart, or the total mean flow in the circulation. Stroke volume (SV) à The output during a single heartbeat, from either the left or the right ventricle Heart rate (HR) à The speed of the heartbeat measured by the number of contractions of the heart per minute. (Chronotropy) Cardiac output Cardiac output = Heart rate × Stroke volume Martini & Nath. Fundamentals of Anatomy and Physiology. Pearson, 2009. Preload and Afterload Preload: ~ End Diastolic Volume ~ the volume of blood being returned to the right side (atrium) of the heart from the systemic circulation, before the beginning of a new contraction. Stretch/Contraction of the cardiac muscle. Afterload: ~ End Systolic Volume ~ the volume of blood in a ventricle at the end of contraction, or systole, and the beginning of filling, or diastole Squeeze/Resistance the left ventricle has to overcome to eject the blood. The Frank-Starling Law “The mechanical energy set free on passage from the resting to the contracted state depends on the area of ‘chemically active surfaces,’ i.e., on the length of the fibres.” Therefore, the initial length of myocardial fibers determines the work done during the cardiac cycle. Boron & Boulpaep. Medical Physiology. Elsevier, 2016. The Frank-Starling Law Boron & Boulpaep. Medical Physiology. Elsevier, 2016. Nervous system control of the heart Boron & Boulpaep. Medical Physiology. Elsevier, 2016. Nervous system control of the heart Boron & Boulpaep. Medical Physiology. Elsevier, 2016. PERIPHERAL CIRCULATION Blood circulation Tortora GJ, Principles of Anatomy and Physiology Blood vessels Tortora GJ, Principles of Anatomy and Physiology Blood vessels Tortora GJ, Principles of Anatomy and Physiology Blood vessels Tortora GJ, Principles of Anatomy and Physiology Pressure and flow in the peripheral circulation Mechanism promoting venous return Tortora GJ, Principles of Anatomy and Physiology Factors that affect Blood pressure Tortora GJ, Principles of Anatomy and Physiology Different measurement for blood pressure Tortora GJ, Principles of Anatomy and Physiology Increased mean arterial pressure Tortora GJ, Principles of Anatomy and Physiology Regulation of blood pressure Tortora GJ, Principles of Anatomy and Physiology Capillary fluid exchange Hydrostatic pressure gradient Colloidosmotic pressure gradient Capillary fluid exchange Pc pc Pi pi Hydrostatic pressure in the capillary, Pc Hydrostatic pressure in the interstitium, Pi Colloidosmotic pressure in the capillary, pc Colloidosmotic pressure in the interstitium, pi V = CFC * [(Pc – Pi) – (pc - pi)] Capillary solute exchange Continuous Fenestrated Discontinuous heart kidney bone marrow sk.muscle intestinal mucosa liver sinusoids connective tissue adipose tissue BLOOD PRESSURE REGULATION Local control of the blood flow Wilmore, Costill & Kenney. Physiology of Sport and Exercise, Human Kinetics. Endotelial regulation of blood flow Central blood pressure regulation Tortora GJ, Principles of Anatomy and Physiology Baroreceptors Boron & Boulpaep. Medical Physiology. Elsevier, 2016. Baroreceptors Boron & Boulpaep. Medical Physiology. Elsevier, 2016. Renin-angiotensin-aldosteron system (RAAS) Mandatory lab Tuesday 12/11!! Cardiovascular and Respiratory Systems Go to www.menti.com and use the room code 97 49 27 97 49 27 97 49 27.