Circulatory System - BIOL100 - Columbia College - PDF

Circulatory System BIOL100 – Concepts in Human Health and Biology Vinicius C. Azevedo - Columbia College Why do humans have a circulatory system? Transport O2 and CO2 Nutrients/Water Wastes Heat Hormones Defence cells and antibodies (System regulation and signalization) Why do humans have a circulat...

Circulatory System BIOL100 – Concepts in Human Health and Biology Vinicius C. Azevedo - Columbia College Why do humans have a circulatory system? Transport O2 and CO2 Nutrients/Water Wastes Heat Hormones Defence cells and antibodies (System regulation and signalization) Why do humans have a circulatory system? Food Respiratory System Internal Internal medium medium (Constant) (Constant) Respiratory system Dige stive Syst em Excretory System (Water, salts, urine) External medium (Variable) Circulatory system Circulatory System Digestive system (Nutrients, water) ies r a l l i p ca e h t in Blood Waste excretion Cell Skin (Water, salts) Neuroendocrine Regulation Interstitial fluid Excretory System Solid waste Nervous System (Stimulus) Liquid waste Endocrine System (Hormones) Humans cardiovascular system have THREE basic components A Circulatory Fluid ✓Medium where gases, nutrients and wastes dissolve and/or are carried Blood A Set of Tubes ✓Confined spaced where the blood moves Blood Vessels A Muscular Pump ✓Provides the driving force that makes the blood moves in the blood vessels Heart Human circulatory system is divided in THREE circuits Pulmonary Circuit ✓Heart -> P. Artery -> Lungs -> P. Vein -> Heart. ✓Oxygenate the blood. ✓Bring nutrients to the lungs. Systemic Circuit ✓Heart -> Aorta -> Body -> Vena Cava -> Heart. ✓Bring nutrients and oxygen to the entire body. Coronary Circuit ✓Heart -> Aorta -> Heart ✓Bring nutrients and oxygen to the heart. Coronary Circuit (O2 rich blood to the heart) Humans cardiovascular system have THREE basic components A Circulatory Fluid ✓Medium where gases, nutrients and wastes dissolve and/or are carried Blood A Set of Tubes ✓Confined spaced where the blood moves Blood Vessels A Muscular Pump ✓Provides the driving force that makes the blood moves in the blood vessels Heart What are the fours types of tissues ? Blood is a…. Composed of: ✓Plasma - 55% ✓Red blood cells (Erythrocytes) Cellular ✓White blood cells (leukocytes) elements ✓Platelets (Thrombocytes) (45%) Human Blood Under the Microscope PowerPoint® Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Plasma Blood plasma is about 90% water The remaining 10% makes up the following: ✓ Electrolytes - inorganic salts in form of dissolved ions + + 2+ (i.e., Na , K , Ca , Cl , HCO3 ). ✓ Plasma proteins – some function include lipid transport, immunity, and blood clotting (i.e., albumin, fibrinogen, antibodies). ✓ Nutrients (i.e., amino acids, sugars, lipids), gases (i.e., CO2, O2), hormones and cell waste. Human Erythrocyte (Red Blood Cells) O2 and CO2 transport Do not have nucleus (biconcave) ✓Allow the cell to contain more hemoglobin ✓Biconcave shape allows cells to bend to move in the capillaries Lifespan: 120 days Erythrocyte and Hemoglobin Human erythrocyte are constituted by globulin and hemoglobin Hemoglobin (Hb) ✓The respiratory pigment of several animals, including humans. ✓Possess FOUR molecules of iron (Fe). ✓ O2 binds to the iron molecule. ✓ Most CO2 transported by erythrocytes does not bind to hemoglobin Leukocytes (White Blood Cells) Part of the immune system Protect the organism against parasites and infections. Remove dead and defective cells. Thrombocytes (Platelets) Involved in blood clotting. Platelets are actually cell fragments that broke off from larger cells called megakaryocytes (in general, megakaryocytes are 10 to 15 times larger than a typical red blood cell). Humans cardiovascular system have THREE basic components A Circulatory Fluid ✓Medium where gases, nutrients and wastes dissolve and/or are carried Blood A Set of Tubes ✓Confined spaced where the blood moves Blood Vessels A Muscular Pump ✓Provides the driving force that makes the blood moves in the blood vessels Heart There are THREE Main Types of Blood Vessels Arteries: blood flows away from the heart (most arteries carry oxygenated blood … exception is pulmonary artery). Arteries split. Veins: blood flow towards the heart (most veins carry deoxygenated blood … exception is pulmonary vein). Veins join. Capillaries: exchange of O2, CO2, nutrients and waste between blood and body tissues. Arterioles and Venules Arterioles are smaller arteries. ✓Arteries split into smaller vessels called arterioles Capillary beds are network of capillaries ✓Site of chemical exchange between the blood and the interstitial fluid. Venules are smaller veins. ✓Venules join together to form bigger veins. All blood vessels have an epithelial layer called endothelium Arteries and Veins, in addition to the endothelium, also have smooth muscle and connective tissue Patterns of blood pressure and flow reflect on the structure of arteries and veins Arteries Veins ✓ Higher pressure and flow. ✓Lower pressure and flow. ✓Thicker walls than veins to ✓Thinner walls compared accommodate the high pressure of blood pumped from the heart. ✓ Arteries are more elastic than veins due to the thicker muscle layer. to arteries. ✓Have valves to prevent back-flow of blood. Returning the Blood to The Heart The blood return to the heart faces two problems: Low pressure and Gravity Solving low pressure ✓Smooth and skeletal muscle contraction assist veins in returning blood to the heart. Solving gravity (back flow) ✓Bicuspid valves present in the veins prevent blood’s back-flow due to gravity. Capillary Structure and Function The smallest blood vessels of the body ✓about 5 to 10 micrometres in diameter Endothelium with one cell layer thick (simple squamous layer) ✓makes it easier for exchange to occur between the blood and interstitial fluid which surrounds tissues Erythrocyte travel in a single file through the capillaries Blood Pressure The force of blood on the wall of the blood vessel ✓Blood pressure is higher in arteries compared to veins. ✓In humans, blood pressure is measured in the arteries. ‣ Higher pressure during systole (heart contraction) ‣ Lower pressure during diastole (heart relaxation) Variables that Affects Blood Pressure Blood Pressure (BP) = Cardiac output (CO) X Peripheral Resistance (PR) Cardiac output ✓Volume of blood pumped by the heart per unit of time ✓Usually measured in ml per minute (ml/min) or litres per min (l/min) Peripheral resistance ✓Resistance to blood flow resulting from friction of blood against the walls of the vessels ✓Usually measured in mmHg (unit of pressure) x min/ml Cardiac Output Cardiac Output (CO) = Heart Rate (HR) X Stroke Volume (SV) ml/min beats/min ml/beat Heart Rate ✓Number of beats per unit of time ✓Usually measured in beats per minute (bpm) Stroke Volume Stroke Volume (SV) = End-Diastolic Volume (EDV) – End-Systolic Volume (ESV) ✓Volume of blood ejected during the contraction of the left ventricle ✓EDV = volume of blood after left ventricle relaxation (initial blood volume). ✓ESV = volume of blood after left ventricle contraction (volume of blood not ejected during contraction) ✓Usually measured in milliliters (ml)/beat Peripheral Resistance Narrower the vessels, higher the resistance Wider the vessels, lower the resistance Vasoconstriction ✓Process of narrowing the blood vessels (usually arteries) ✓Contraction of blood vessel smooth muscles ✓Increase peripheral resistance Vasodilation ✓Process of widening the blood vessels (usually arteries) ✓Relaxation of blood vessels smooth muscles ✓Decrease peripheral resistance Blood Pressure Summary Blood Pressure (BP) = Cardiac output (CO) X Peripheral Resistance (PR) Cardiac output ✓Higher the heart rate, higher the blood pressure ✓Higher the stroke volume, higher the blood pressure Peripheral resistance ✓Vasoconstriction increases blood pressure ✓Vasodilation decreases blood pressure Humans cardiovascular system have THREE basic components A Circulatory Fluid ✓Medium where gases, nutrients and wastes dissolve and/or are carried Blood A Set of Tubes ✓Confined spaced where the blood moves Blood Vessels A Muscular Pump ✓Provides the driving force that makes the blood moves in the blood vessels Heart Heart Heart is a specialized muscular organ responsible for pumping blood through the blood vessels of circulatory system ✓Adult human heart is normally slightly larger than a clenched fist, and weighs approximately 300 grams In humans, the heart is located between lungs in thoracic cavity (but apex of heart is slightly towards the left) Heart Anatomy - Tissue Layers How many chambers does the human heart have? Heart Anatomy - Chambers Mammalian heart (including humans) has FOUR chambers Two atria (upper right and left) ✓Atrium wall is made up of thin myocardium. ✓Right atrium receive deoxygenated blood from vena cava. ✓Left atrium receive oxygenated blood from pulmonary vein. ✓Pump blood to ventricle. Two ventricles (lower right and left) ✓Blood received from the atria. ✓Ventricle wall is made up of thick myocardium. ✓Right ventricle pumps deoxygenated blood to the pulmonary circuit (pulmonary artery). ✓Left ventricle pumps oxygenated blood to systemic circuit (aorta). Heart Anatomy - Septum Mammalian heart (including humans) has FOUR chambers Septum ✓Extension of the myocardium. ✓Separates atria and ventricles into left and right chambers Heart Anatomy - Valves FOUR valves prevent back-flow of blood in the heart TWO atrioventricular (AV) valves ✓Separate each atrium and ventricle ✓Tricuspid valve is located between right atrium and ventricle ✓Bicuspid (or mitral) valve = between left atrium and ventricle TWO semilunar valves ✓Control blood flow to the pulmonary artery (right) and aorta (left). ✓Pulmonary valve = between right ventricle and pulmonary artery ✓Aortic valve = between the left ventricle and aorta Heart Anatomy - Valves FOUR valves prevent back-flow of blood in the heart Tricuspid, aortic and pulmonary valves ✓Composed of THREE closure flaps of tissue. Bicuspid valve (mitral) ✓Composed of TWO closure flaps of tissue. The heartbeat sound is caused by the closure of the atrioventricular valves and semilunar valves. Human circulatory system is divided in THREE circuits Pulmonary Circuit ✓Heart -> P. Artery -> Lungs -> P. Vein -> Heart. ✓Oxygenate the blood. ✓Bring nutrients to the lungs. Systemic Circuit ✓Heart -> Aorta -> Body -> Vena Cava -> Heart. ✓Bring nutrients and oxygen to the entire body. Coronary Circuit ✓Heart -> Aorta -> Heart ✓Bring nutrients and oxygen to the heart. Coronary Circuit (O2 rich blood to the heart) Heart Anatomy - Right Side X Left Side Right Side Left Side ✓Deoxygenated blood. ✓Oxygenated blood. ✓Deoxygenated blood from ✓Oxygenated blood from the superior and inferior vena pulmonary circuit cava enters the right atrium. (pulmonary vein) enters the ✓Blood moves into right ventricle. ✓Blood is pumped from the right ventricle into the left atrium. ✓Blood moves into the left ventricle. ✓Blood is pumped from the pulmonary circuit via left ventricle into the pulmonary vein systemic circuit via the aorta. Human circulatory system is divided in THREE circuits Pulmonary Circuit ✓Heart -> P. Artery -> Lungs -> P. Vein -> Heart. ✓Oxygenate the blood. ✓Bring nutrients to the lungs. Systemic Circuit ✓Heart -> Aorta -> Body -> Vena Cava -> Heart. ✓Bring nutrients and oxygen to the entire body. Coronary Circuit ✓Heart -> Aorta -> Heart ✓Bring nutrients and oxygen to the heart. Coronary Circuit (O2 rich blood to the heart) If the heart receives blood all the time, why the heart needs its own circuit? Heart Anatomy - Right Side X Left Side Right Side Left Side ✓Deoxygenated blood. ✓Oxygenated blood. ✓Deoxygenated blood from ✓Oxygenated blood from the superior and inferior vena pulmonary circuit cava enters the right atrium. (pulmonary vein) enters the ✓Blood moves into right ventricle. ✓Blood is pumped from the right ventricle into the left atrium. ✓Blood moves into the left ventricle. ✓Blood is pumped from the pulmonary circuit via left ventricle into the pulmonary vein systemic circuit via the aorta. If the heart receives blood all the time, why the heart needs its own circuit? The coronary circuit brings oxygenated blood to the right side of the heart that only carries deoxygenated blood Heart - Contraction Phases Heart contraction is separated in two phases Systole ✓Contraction or pumping Diastole ✓Relaxation or filling Left ventricle is most muscular to help force blood into systemic circuit after contraction. Systemic circuit is longer and has more resistance (capillary beds) Maintaining the heart’s rhythmic beat 1. The sinoatrial (SA) node, or pacemaker (located in the upper wall of the right atrium), sets the rate and timing at which cardiac muscle cells contract. 2. Impulses from the SA node spread through both atria to cause contraction. 3. Impulses from the SA node ultimately travel to the atrioventricular (AV) node (located between the right atrium and right ventricle). 4. At the AV node, the impulses are delayed and then travel to the bundle branches…afterwards, impulses move to the Purkinje fibres, which cause ventricles to contract. Electrocardiogram Impulses that travel during the cardiac cycle can be recorded as an electrocardiogram. Electrocardiogram The P wave represents systole of the atria (ventricles undergoing diastole) ✓ This means that the AV valves are open and the SL valves are closed The QRS complex represents systole of the ventricles … atria undergoing diastole but wave is masked by QRS complex ✓ This means the SL valves are open and the AV valves are closed The T wave represents ventricular diastole (atria still at diastole) ✓ This means the SL valves close and the AV valves remain closed Humans cardiovascular system have THREE basic components A Circulatory Fluid ✓Medium where gases, nutrients and wastes dissolve and/or are carried Blood A Set of Tubes ✓Confined spaced where the blood moves Blood Vessels A Muscular Pump ✓Provides the driving force that makes the blood moves in the blood vessels Heart Using the blood vessels, heart chambers, and organ/body parts listed below, draw a flow chart showing the pulmonary and the systemic circuits. Right atrium Pulmonary artery Left atrium Aorta Left ventricle Body Vena cava Right ventricle Lung Pulmonary vein Main Blood Vessels of the Pulmonary Circuit R.Atrium -> R.Ventricle -> Pulmonary Artery -> Lungs -> Pulmonary Vein -> L. atrium. Tricuspide valve Pulmonary valve Capillary beds Function ✓Bring blood for gas exchange. ✓Bring nutrients to the lungs. Right and left ✓Humans have a right and left lung, therefore the pulmonary artery and vein is also split in left and right. Pulmonary Circuit Main Blood Vessels Deoxygenated blood Oxygenated blood Right pulmonary artery Right Lung Right pulmonary vein Left pulmonary artery RA RV Arteries: take blood away from the heart Veins: take blood to the heart Organs and body parts are in purple LA Left pulmonary vein Left lung Main Blood Vessels of the Pulmonary Circuit L.Atrium -> L.Ventricle ->Aorta-> Body -> Vena cava (inf/sup) -> R. atrium. Bicuspide valve Aortic valve Capillary beds Function ✓Bring oxygenated blood to the body tissues. ✓ Excrete wastes (renal circulation). Main Blood Vessels of the Systemic Circuit L.Atrium -> L.Ventricle ->Aorta-> Body -> Vena cava (inf/sup) -> R. atrium. Upper body circuit ✓Supply blood to the head and superior limbs (arms) ✓Major vessels: - Aorta - start, blood vessel that leaves the heart - R & L Subclavian arteries and veins (shoulder) - R & L Brachial arteries and veins(arm) - R & L Carotid arteries (head) - R & L Jugal vein (head) - Super vena cava: common end, return to heart Lower body circuit Systemic Circuit Main Blood Vessels - Upper Body Deoxygenated blood Head/Brain Oxygenated blood Jugal vein Right Arm Right subclavian artery Right brachial artery Right brachial vein Right subclavian vein Left Right carotid carotid artery artery Superior vena cava Organs and body parts are in purple LA LV Arteries: take blood away from the heart Veins: take blood to the heart Left subclavian vein Aorta RA RV Left Subclavian artery Left Brachial artery Left Brachial vein Left Arm Main Blood Vessels of the Systemic Circuit L.Atrium -> L.Ventricle ->Aorta-> Body -> Vena cava (inf/sup) -> R. atrium. Upper body circuit ✓Supply blood to the head and to superior limbs (arms) ✓Major vessels: - Aorta - start, blood vessel that leaves the heart - R & L Subclavian arteries and veins (shoulder) - R & L Brachial arteries and veins(arm) - R & L Carotid arteries (head) - R & L Jugal vein (head) - Super vena cava: common end, return to heart Lower body circuit ✓Supply blood to the digestive system, excretory system, reproductive system and inferior limbs. ✓Major blood vessels: ‣Aorta - start, blood vessel that leaves the heart ‣Digestive System Circuit: - Celiac artery - Hepatic portal vein - Hepatic vein ‣Renal (kidney) Circuit: - R & L Renal artereis and veins. ‣Inferior limb (legs) circuit: - R & L Iliac arteries and veins (hip) - R & L Femoral arteries and veins (leg) ‣Inferior vena cava: common end, return to heart Systemic Circuit Main Blood Vessels - Lower Body Deoxygenated blood Aorta Oxygenated blood Arteries: take blood away from the heart RA Digestive system LA Hepatic portal vein (Nutrient rich blood) LV Veins: take blood to the heart Organs and body parts are in purple Celiac Artery Inferior vena cava RV Liver Hepatic vein L&R renal artery Kidney L & R renal vein L & R iliac vein L&R femoral vein Legs L&R femoral artery L & R iliac artery Head/Brain Deoxygenated blood Oxygenated blood Right arm Right brachial artery Right brachial vein Jugal vein Right subclavian artery Right subclavian vein Left carotid artery Right carotid artery Superior vena cava Left subclavian artery Digestive system Aorta RA LA Hepatic portal vein Celiac artery R&L renal artery (Nutrient rich blood) Liver Inferior vena cava LV Kidney RV Hepatic vein Arteries: take blood away from the heart R & L renal vein Veins: take blood to the heart Organs and body parts are in purple Left brachial Left arm artery Left brachial vein R & L iliac vein R&L iliac Artery R&L femoral vein Legs R&L femoral artery Common cardiovascular and blood diseases Stroke ✓ a medical emergency that occurs when there is a ruptured blood vessel in the brain, or when blood supply to the brain has been blocked (in either case, the result is cell death as brain tissue is deprived of oxygen and nutrients) - arteries and veins can be affected ❖ Ischemic stroke = due to lack of blood flow to the brain ❖ Hemorrhagic stroke = due to rupture of a blood vessel that leads to bleeding in the brain Hemorrhagic stroke Ischemic stroke Common cardiovascular and blood diseases Aneurysm ✓ Occurs when the connective tissue surrounding a blood vessel weakens and the smooth muscle bulges outwards ✓ It can affect any part of the body, including the brain and heart ✓ If this bulge bursts, it can be lethal; for example, an aneurysm in the brain can lead to a stroke ✓ Arteries are more likely to be affected than veins. Weakened connective tissue causes smooth muscle to bulge outwards Fish gill Common cardiovascular and blood diseases Myocardial ischemia ✓ occurs when blood flow to your heart muscle is decreased by a partial or complete blockage of your heart's arteries (coronary arteries) … this reduces oxygen supply to the heart ✓ However, if myocardial ischemia lasts too long, the oxygen-starved heart tissue dies, which leads to a myocardial infarction Myocardial infarction ✓ Commonly known as a “heart attack”… occurs when blood flow stops to part of the heart causing permanent damage to heart muscle. Common cardiovascular and blood diseases Iron deficiency anemia ✓ Develops when body stores of iron drop too low to support normal red blood cell production (especially when hemoglobin production is impaired). ✓ As a result, fewer red blood cells are made, and those that are made are thinner because they carry less hemoglobin. Normal Anemic Common cardiovascular and blood diseases Sickle Cell Disease ✓ Genetic disease in the hemoglobin molecule. ✓ An erythrocyte from an individual with sickle cell anemia is crescent-shaped (due to this irregular shape, they are broken down in the spleen, resulting in anemia). ✓ Due to its shape, it can easily block blood flow, which leads to pain and increases the chances of stroke. Common cardiovascular and blood diseases Spherocytosis ✓ Genetic disease causing red blood cells to have a weaker cell membrane than usual. ✓ Too much water is also able to enter the red blood cell, causing them to be spherical shaped, rather than biconcave. ✓ Such cells have lost their biconcave shape. ✓ Because of their increased fragility (due to weakened cell membrane), these cells tend to be broken down more easily in the spleen, resulting in anemia. Common cardiovascular and blood diseases Atrial and Ventricular Fibrillation ✓ Fibrillation is a form of arrhythmia, or irregular heartbeat. ✓ Atrial fibrillation: arrhythmia in the atria. ✓ Ventricular fibrillation: arrhythmia in the ventricles. ✓ The fibrillation is easily observed in the ECG. Common cardiovascular and blood diseases High blood pressure (hypertension) Blood Pressure (BP) = Cardiac output (CO) X Peripheral Resistance (PR) Ø Causes ✓ Obesity ✓ Consuming too much salt It increases blood volume, increasing stroke volume, and cardiac output. ✓ Consuming too much caffeine Caffeine causes vasoconstriction, leading to an increase in peripheral resistance ü Stress It can affect several things, including heart rate, peripheral resistance and cardiac output Ø Symptoms Common cardiovascular and blood diseases High blood pressure (hypertension) Blood Pressure (BP) = Cardiac output (CO) X Peripheral Resistance (PR) Ø Causes ✓ Obesity ✓ Consuming too much salt It increases blood volume, increasing stroke volume, and cardiac output. ✓ Consuming too much caffeine Caffeine causes vasoconstriction, leading to an increase in peripheral resistance ü Stress It can affect several things, including heart rate, peripheral resistance and cardiac output Ø Problems it can cause Common cardiovascular and blood diseases Low blood pressure (hypotension) Blood Pressure (BP) = Cardiac output (CO) X Peripheral Resistance (PR) Ø Causes Ø Symptoms ✓ Pregnancy ✓ Dehydration It decreases blood volume, decreasing stroke volume, and cardiac output. ✓ Some medications They can lead to vasodilatation, leading to a decrease in peripheral resistance ü Internal bleeding and blood loss from trauma They decrease blood volume, decreasing stroke volume, and cardiac output.