Circulatory System - PDF

THE CIRCULATORY SYSTEM (AKA cardiovascular system) Made up of three things: 1) Heart 2) Blood 3) Blood Vessels 5 Main Functions: 1) To transport of oxygen and nutrients to cells. 2) To remove C02 and Transport waste from cells. 3) To maintain of...

THE CIRCULATORY SYSTEM (AKA cardiovascular system) Made up of three things: 1) Heart 2) Blood 3) Blood Vessels 5 Main Functions: 1) To transport of oxygen and nutrients to cells. 2) To remove C02 and Transport waste from cells. 3) To maintain of body temperature. 4) To circulate hormones. 5) Carry white blood cells for body defense. Open Vs Closed System Closed System: Blood remains to the blood vessels. Nutrients diffuse out of blood vessels into cells and waste diffuses out. Ex. Worms Open System: Blood does not stay in one tube. Blood is not red, blood moves into heart by diffusion. Involves a heart/series of hearts that pump blood out of a vessel. Ex. Grasshopper Basically 2 systems Pulmonary Circuit Low pressure - Right side of heart; pumps to lungs. Systematic Circuit High Pressure Left side of heart; pumps to body. TYPES OF HEART Two Chambered Heart Slow circulation. Oxygen rich and oxygen poor blood mix. Not sufficient for large mammals. Ex. fish Three Chambered Heart 2 atria and 1 ventricle. Oxygenated and deoxygenated blood mix. Ex. Frog Four Chambered Heart Two separate high-speed pumps. Oxygen rich and oxygen poor blood NEVER mix. Ex. Humans TYPES OF CIRCULATION 1) Coronary (Cardiac) The hearts own supply. Blood leaves the heart chambers oxygen rich and returns oxygen poor. Heart attacks (AKA coronary/cardiac arrest) is a result of these arteries being blocked. 2) Pulmonary To the lungs. Blood leaves the heart oxygen poor and goes to lungs where it picks up oxygen and returns oxygen rich.  3) Systemic To the body. Blood leaves the heart oxygen rich and goes to the body cells and returns oxygen poor back to the heart. Heart Made up of all types of tissue (muscle, epithelial, nervous and connective). Cardiac Muscle is specific to the heart. Cardiac muscle contracts at the same tie and pushes blood through the heart. Your heart pumps with a regular beat. It is made up of four chambers. It pumps blood to the body and to the lungs. Blood Vessels 3 types! Arteries Are designed to carry blood away from the heart. Most of this blood is oxygen rich (except for the pulmonary artery). The pumping action of the heart cause this blood to be under high pressure and so the arteries have elastic walls called the endothelium to help handle the pressure. Arterioles is a word for small thin arteries. In addition, there are 3 layers of muscle that surround the artery to help deal with the pressure. These are: A) Tunica Intima – Muscle layer closes to the blood - is also elastic. B) Tunica Media – Middle layer of muscle – is very thick to withstand the pressure of the surging blood. C) Tunica Adventitia – Outermost layer of muscle. Veins: Valves Are designed to carry blood back towards the heart. Most of this blood is oxygen poor (except for the pulmonary veins) Has the same composition and layers as arteries, but are lower of a thickness (especially the tunica media). Venules is a word for small thin veins. In order to keep blood flowing, there are two adaptations in veins:  A) One-way Valves – only let blood flow one way towards the heart and close when blood tries to flow backwards. B) Muscle Motion – of muscles which surround the veins – as these muscles contract, they help to force blood back to the heart by squeezing the veins. (That’s why you get tired when you stand still for a long period of time – blood gathers in your legs – less available for your brain). Capillaries Are tiny blood vessels composed of a single layer of endothelial cells. Are the location of O2/CO2 and nutrient/waste exchange. Diffusion of these substances occurs through the cracks between the endothelial cells. No cell is more than 2 cells away from a capillary and capillaries are so tiny that blood cells can only squeeze through 1 at a time. (A bundle of 50 capillaries is still thinner than a human hair). Ex. Oxygen will leave blood and diffuse into cell while CO@ diffuses into blood to be carried always. Blood Pressure 120/80 (normal) Blood pressure is the force that blood exerts on the walls of the arteries. This pressure is created by the pumping of the heart. The heart creates its maximum pressure when it contracts. The contracted state of the heart is called Systole. The heart creates its minimum pressure (or resting pressure) when it relaxes. The relaxed state of the heart is called Diastole. Blood Pressure Cuff (Sphygmomanometer) works along the following lines: When the cuff is placed around your arm and inflated, it cuts off the blood flow through the subclavian or brachial artery. At the same time, the pressure in the cuff causes the needle to move in the gauge. Now as the pressure is released slowly, the needle slowly drops. At some point, the pressure exerted by the blood will be strong enough to force blood through the narrowed artery. A gurgling noise may be heard through the stethoscope followed by a pulse. The needle on the gauge will begin to bounce up and down slightly with the pulse. The pressure indicated on the gauge when this occurs is Systolic pressure. As the pressure continues to fall, the sound of the pulse will disappear from the stethoscope, and the needle on the will stop bouncing. This pressure indicated on the gauge when this occurs is the Diastolic pressure. Blood pressure is expressed as a ration: Systolic/Diastolic ---- 120/80. This pressure is considered normal but a lot of variance is seen.  The higher the diastolic pressure is – the greater the health risks due to greater strain on the heart and arteries. A blood pressure of 150/98 would be considered high enough for a doctor to prescribe medication to treat the problem. Factors Affecting Blood Pressure 1) Stress: The greater the stress levels, the higher the pressure. This is usually due to a narrowing of the blood vessels which makes it harder for blood to circulate. As a result, the heart has to work harder. 2) Salt: Salt makes your kidneys retain water. As a result, there is more fluid in your blood. 3) Cholesterol: Cholesterol tends to make arteries narrower. As a result, blood pressure must rise to force the blood through these vessels. 4) External Sources: Caffeine, nicotine, and other drugs create a stress like response in the body. Why is high blood pressure dangerous? High blood pressure increases the risk of stroke, aneurism, and heart attacks. Names of Important Veins and Arteries 1) Jugular vein (from head) 2) Right Common Corotid Artery (to brain) 3) Common carotid Artery (to brain) 4) Right Subclavian Artery (To right arm) 5) Left Subclavian Artery (To left arm) 6) Right subclavian vein (from right arm) 7) Left subclavian vein (from left arm) 8) Inominate Artery (first branch from the aortic arch that carries blood away from the heart, brings blood to neck, head and your right arm) 9) Aorta (Biggest artery) 10) Superior vena cava (deoxygenated blood entrance from upper body) 11) Inferior vena cava (deoxygenated blood entrance from lower body. 12) Coronary vein (from heart muscle) 13) Coronary Artery (to heart muscle) 14) Hepatic vein (from liver) 15) Hepatic (to liver) 16) Superior mesenteric artery (to colon/large intestines) 17) Inferior mesenteric artery (to small intestines) 18) Superior mesenteric vein (from colon/large intestines) 19) Inferior mesenteric vein (from small intestines) 20) Radial Artery (to forearm 21) Radial vein (from forearm) 22) Iliac vein (from legs)  23) Iliac artery (to legs) 24) Ulnar artery (to forearm) 25) Ulnar vein (form forearm) 26) Coeliac artery (to stomach and spleen) 27) Coeliac vein (from stomach and spleen) 28) Renal artery (to kidney) 29) Renal vein (from kidney) 30) Brachial artery (to arm) 31) Brachial vein (from arm) Cardiac Output and Fitness Cardiac Output The amount of blood pumped by your heart. Cardiac output = Stroke volume x heart rate. Stroke volume: amount of blood forced out of a ventricle. Heart rate: Pulse. Ex: Stroke volume (S.V.) = 70mL Heart Rate (H.R.) = 70 bpm Cardiac Output (C.O.) = S.V. x H.R. 70mL x 70 bpm 4900Ml/Min 4.9L/min People in Excellent physical conditions tend to: Have a low heart rate. High stroke volume. Stroke Volume is determined by: The amount of blood returning to the heart. The size of the ventricles and strength with which they contract. Control of Heart Rate (By the Brain) Note: Your heart can be independent of your body. Your body can only influence how fast it goes. Nervous Control (Medulla Oblangata) Vagus Nerve: Increased signals make heart slow down. Cardio-accelarator nerve: Increased signals make heart speed up. Chemical Control Stimulants: Caffeine, nicotine, other illegal substances. Increased heart rate. Depressants: Sleeping pills, alcohol and sedative. Decreased heart rate. Hormones – “Chemical messengers” o Adrenaline (Epinephrine) o Noradrenaline (Norepinephrine) Additional Parts of the Heart Node: a cluster of nerve cells. Sinoatrial Node (SA node) A cluster of nerve cells which control the rate of your heart by sending out signals. The pacemaker. Creates impulses which causes the atria to contract. Atrial Ventricle Node (Av node) Located in the septum below the atria to contract.  Increases the integrity of the SA node signal and transmits it to the ventricles. The amplifier. Delays the spread of the impulse by 0.1 seconds so the atria can contract first, then amplifies the signal to the larger ventricles to make them contract. Purkinje Fibers Nerve fibers that ensure that the AV node signals reaches the bottom of the ventricles first. Causes the heart to contract from the bottom-up. To push blood out of arteries. Bundle of HIS = AV node and Purkinje fibers. Electrocardiogram (ECG or EKG) Used to measure electrical impulses created by the SA node and AV node Normal Heart rate P, Q, R, S, T. P-Waves: The signal from the SA node (pacemaker), atria contract (depolarization). QRS-Waves: The Av node amplifies the P-wave, delaying it by 0.1 seconds and sends a signal to the ventricles (polarization). T-Wave: Recovery of the heart before the next beat (repolarization). The time from PT is fixed at 0.3 seconds. The time from T to next P is not fixed. Therefore, if this time is decreased, heart rate can be increased to a max of 200 beats/minute (above that heart failure will occur). Cardiac Cycles: Heart as a Pump Step A: Ventricular Filling Blood is moving from the pulmonary veins into the atria. This moving blood pours into the ventricles. Step B: Atrial Contraction A “P” wave has been generated causing the atria to contract. This forces more blood into the ventricles which are rapidly enlarging. Step C: Ventricular Contraction The AV node begins to spread the SA node signal. The valve snaps shut “lub”. Blood cannot leave the ventricle yet since there is not enough force to open the semi-lunar valve. Step D: Ventricular Ejection The AV node signal passes to rest of ventricle causing it to contract. Enough pressure is generated to force open the semi-lunar valve and about 50-60% of the blood leaves the ventricle. Step E: Ventricular Relaxation Ventricles stop contracting. Not enough pressure to keep the valve open, so it snaps shut “dub”. The heart will continue to relax until step A begins again. Note: The same thing happens at the same time on the right side of the heart. The entire process takes about one second. Normal Rhythm (PQRST)  “Sinus” rhythm. This refers to as the pacemaker. VPB Ventricular pre-beat. Most common type of irregularity. What looks like a QRS-wave is present, but missing P and T. AV node sent out a signal without receiving a signal from the pacemaker. Heart Block P-wave present but lacking QRS-wave. Either the SA node signal was not received or the AV node failed to respond to it. Medication may be needed to increase beating strength or a pacemaker may be required. Bradycardia Abnormally slow-rate pacemaker leaving too much time between signals. New “pacemaker” may be necessary to prevent heart rate from failing less than 30 bpm. Tachycardia Abnormally fast rate (120-180bpm) Causes person to feel tires/exhausted. Pacemaker is sending out signals too fast. Atrial Fibrillation To fibrillate-to vibrate or be in spasms. Too many SA node signals and the signals are not normal atria are in spasms. Atria cannot pump much blood into the ventricles. Ventricular Tachycardia Multiple rapid ventricles beats for every “P” wave, Ventricles do not have time to fill with blood. Circulation begins to collapse. Ventricular Fibrillation No coordinated heartbeat. Entire heart in spasms. No blood circulation occurs. Needs a defibrillator. Asystole Absence of electrical signal. Analysis of the Heart Continuation Pulse In the surging of blood through an artery. Can be used to monitor: o Heart Rate o Regularity and strength of heart. o Quality of circulation to a limb. Normal range: 54-90 beats per minute. Ex. Athletes may have pulse rate as low 30bpm which implies less stress on the heart in order to circulate blood. Max is 210bpm. Blood Pressure Refers to pressure blood exerts on the walls of the arteries as it flows. Two pressures are measured. Systolic: Max pressure of the heart and occurs when the heart contracts.  Diastolic: Lowest pressure and occurs when the heart relaxes. Expressed as a ratio: systolic/diastolic, 120/80. Stethoscope Instrument used to amplify sounds. “lub” – sound made from AV valves closing. “Dub” – Sound made from semi-lunar valves closing. Used to monitor: - Murmurs - Intestinal noises/peristalsis - Quality of breathing - Swallowing (epiglottis snapping shut) - Fetal heartbeat. Pulse Locations Radial – wrists Carotid – neck Brachial – elbow Popliteal – Behind knee Echocardiogram An ultrasound of your heart. Uses soundwaves to produce an image (both inside and out). These are used to detect… Valve murmurs or valved disorders. Holes in the septum. Proper blood flow in the chambers. Size of heart. “Bluebaby”: Colour results due to mixing oxygenated and deoxygenated blood due to holes in the septum. Stress Test A test designed to see how your heart responds to stress. Involving monitoring the heart while running on a treadmill that is continually elevated for a specific time span. Angiogram A test used to evaluate the quality of circulation or the extent of blockage in the coronary arteries. During an angiogram, a special dye is released into the coronary arteries from a catheter (special tube) inserted in a blood vessel. This dye makes the blood vessels stable when x-ray is taken. Angioplasty Is a term which means using a balloon to stretch open a narrowed or blocked artery. Ballon vs stent By-pass Surgery Using a vein from the leg to bypass the blockage. Human Blood And Blood Clotting Blood has two main parts which are: 1) Cellular which makes up 45% of the blood. 2) Plasma which makes up 55% of the blood. Details of #1 Has three main components A) Red blood cells also called erythrocytes. Description: Biconcave disks, 8um in diameter. Produced: Bone marrow (red), hips, femur, sternum. Life span: 90 to 120 days.  Number: 1 drop of blood contains 5 million red blood cells. Special Notes: o No nucleus o Carry oxygen to the cells. o Shape allows for flexibility through capillaries. Factors Influencing Oxygen pick up/drop off Partial Pressure ppO2 In lungs ppO2 is high in the alveoli and low in the capillaries and red blood cells. This causes oxygen to diffuse into red blood cells. In tissues ppO2 is low in the cells and high in the red blood cells so oxygen diffuses out into cells. pH In the lungs the pH of blood is slighter basic. This encourages the formation of bonds between oxygen and hemoglobin. In muscle cells, blood drops in pH (acidic) which causes the bond between oxygen and hemoglobin to weaken. B) White Blood Cells Two types: Leukocytes and Lymphocytes Leukocytes Description: clean, 25um (largest) Produced: Red bone marrow. Life span: a few hours to a few days. Number: 6000 millimeters cubed. Special notes: - Capable of moving in/out of blood vessels. - AKA macrophages. - Macrophages means phagocytotic. Lymphocytes Description: clear, 10um Produced: Thymus and red bone marrow. Life span: week to years. Number: 2000 millimeters cubed. Special notes: - Part of your acquired immune system. - B-cells and T-cells. - Helps develop immunity to pathogens. Immune Response - Injury or infection - Leukocytes arrive to area: - lives off histamines. - This causes blood vessels to enlarge so extra fluid moves into area making it swollen. Step by Step Macrophages detect foreign pathogens (due to antigens). These will digest some of the pathogens. Macrophages bring antigens from the pathogen to the helper T-cell. The helper T-cel activates killer T-cells which destroy any of the cells infected by the virus. B-cells bind to some of the pathogens that reach the lymph nodes. Some of the helper T- cells bind to the B-cells. This causes B-cells to split into two. B-cell Plasma: makes antibodies to fight off infections (2000/sec) Memory cells: enables a quicker response time in the future. Allergies Occurs when your immune system overreacts to a stimulus. Results in a runny nose, watery eyes, sneezing (ex. pollen). Antihistamines reduces the information caused by leukocytes.  Worst version “anaphylactic shock” can be fatal due to respiratory distress. Rheumatoid Arthritis Immune system attacks the joints. Auto-immune disorders Immune system attacks the lining of your nerves causing them to break apart. Ex. MS and MD c) Platelets (Thrombocytes) Description: small cellular fragments (2um) Produced: bone marrow Lifespan: 7-8 days, 1 week. Number: 250000 per millimeter cubed. Special Notes: o Contains chemical called thromboplastin that initiate clotting process. o Absence results in hemophilia. Details of #2 (Plasma) Colour: Straw Yellow Main Component: 92% water (remainder in protein and inorganic salts. Also contains: o Prothrombin and Fibrinogen which are important in clotting. o Serum globullins which help to make antibodies. Helps to maintain blood cells in an isotonic solution. Platelets  Release thromboplastin  mixes with prothrombin (in plasma  Thrombin (only in the presence of calcium and vitamin K)  Fibrinogen (in plasma)  Fibrin: forms a net to catch blood cells, as it dries it forms a scab. Blood Types Rh Factor (Rhesus factor) A protein marker on our red blood cells. If you have the antigen = Rh positive If you don’t have it, you have the antibody = Rh negative. If mom is Rh negative and baby is Rh positive then the blood may cross the placenta, causing the baby’s blood to clump leading to anemia, brain damage or death. Mom is given Rhogam injections to decrease immune response. Antigen Surface cell marker that identifies that cell it causes formations of antibodies. Antibodies Protein that inactivates a foreign substance by binding to it. Blood Typing Chart Type Antigen present Antibody present Give To Receive From A A Anti-B A, AB A, O B B Anti-A B, AB B, O AB A, B None AB All O None Anti-A All O Anti-B The universal donor is type O. The universal receiver is type AB.