Cardiovascular System: Human Anatomy & Physiology

Cardiovascular System. Dr. PJ Ruchaya Senior Lecturer in Medical Physiology BS4106 - Fundamentals in Human Anatomy and Physiology Learning Objectives To explain the general components of the CV system To demonstrate an understanding of the Heart- Structure and Function Compare the vess...

Cardiovascular System. Dr. PJ Ruchaya Senior Lecturer in Medical Physiology BS4106 - Fundamentals in Human Anatomy and Physiology Learning Objectives To explain the general components of the CV system To demonstrate an understanding of the Heart- Structure and Function Compare the vessels that constitute the vascular system To summarise the regulation of blood flow and pressure To understand the mechanisms of blood pressure regulation Learning Objectives To explain the general components of the CV system To demonstrate an understanding of the Heart- Structure and Function Compare the vessels that constitute the vascular system To summarise the regulation of blood flow and pressure To understand the mechanisms of blood pressure regulation  Cardiovascular System Heart Cardiovascular System Blood Vessels Systemic Circuit Pulmonary Circuit  Learning Objectives To explain the general components of the CV system To demonstrate an understanding of the Heart- Structure and Function Compare the vessels that constitute the vascular system To summarise the regulation of blood flow and pressure To understand the mechanisms of blood pressure regulation Cardiovascular  The Human Heart Your heart is about the size of your It beats at an average rate between 60-90 clenched fist. per minute. The force of your heart beat is sufficient to shoot blood 30 feet into the air Location of the Heart The heart is enclosed in a double walled sac called Pericardium Protection Anchor Reduce friction Prevent Over-expanding Structural Anatomy of the Heart Cardiac Myocyte Look similar to skeletal muscle cells Oxidative in nature Mitochondria Capillaries Single nuclei Intercalated discs Learning Objectives To explain the general components of the CV system To demonstrate an understanding of the Heart- Structure and Function Compare the vessels that constitute the vascular system To summarise the regulation of blood flow and pressure To understand the mechanisms of blood pressure regulation  Cardiac Cycle 2. Atrial Systole: Atria contract to push small amount of blood 3. Isovolumic ventricular into the ventricles. contraction: 1st phase contraction: pushes A-V valve closed but not enough pressure 1. Ventricular Filling: to open semilunar valves Both sets of chambers are relaxed and ventricles fill passively. 4. Ventricular ejection: 5. Isovolumic relaxation 2nd phase contraction: ventricular (early diastole): pressures increase > arteries Ventricles relax and pressure goes down semilunar valves open and blood is blood push cups of semilunar valves that ejected. will close later.  Learning Objectives To explain the general components of the CV system To demonstrate an understanding of the Heart- Structure and Function Compare the vessels that constitute the vascular system To summarise the regulation of blood flow and pressure To understand the mechanisms of blood pressure regulation Cardiovascular  Learning Objectives To explain the general components of the CV system To demonstrate an understanding of the Heart- Structure and Function Compare the vessels that constitute the vascular system To summarise the regulation of blood flow and pressure To understand the mechanisms of blood pressure regulation  Arterial blood pressure Blood pressure (BP) is the pressure exerted by the blood against a vessel wall Depends on the volume of blood and the resistance within the vessel The volume of blood entering & leaving the arteries is not constant during heart contraction (systole) & relaxation (diastole) BP is separated into systolic (high) & diastolic (low) Systemic BP is greater than pulmonary BP Normal values Systemic Arterial: Systolic BP =110-120 mm Hg Diastolic BP =70-80 mmHg Pulmonary Arterial: Systolic BP =25 mm Hg Diastolic BP =8 mmHg Mean Arterial Pressure (MAP) Calculation of MAP: Diastolic + (0.33 * (pulse pressure)) Diastolic + (0.33 * (Systolic-Diastolic)) e.g. 80 + (0.33 *(120 – 80)) Normal MAP=93 mm Hg  Learning Objectives To explain the general components of the CV system To demonstrate an understanding of the Heart- Structure and Function Compare the vessels that constitute the vascular system To summarise the regulation of blood flow and pressure To understand the mechanisms of blood pressure regulation Control of blood pressure Control of blood pressure Control of blood pressure- Vasoconstriction and vasodilation Control of blood pressure  Control of blood pressure & flow: summary Blood flow through tissues depends on the pressure gradient and vascular resistance Blood flows from high to low pressure down a pressure gradient (Û gradient = Û flow) Changes in blood volume, cardiac output and diameter of arterioles effects blood flow & blood pressure Blood pressure increases when the blood volume and cardiac output increases and/or diameter of arterioles decreases and vice versa References Textbook Rhoades, Rodney A (2013). Medical Physiology: Principles for clinical medicine (4th eds), Lippincott Williams & Wilkins. Journals Becker DE. Fundamentals of electrocardiography interpretation. Anesth Prog. 2006;53(2):53–64. doi:10.2344/0003-3006(2006)53[53:FOEI]2.0.CO;2Scand J Med Sci Sports. 2015 Dec;25 Suppl 4:83-7. doi: Casabianca AB, Becker DE. Anesth Prog. 2009 Summer; 56(2):53-9; quiz 60. YouTube http://tiny.cc/zctadz https://tinyurl.com/qrcqrz6 https://tinyurl.com/s3e3cqo