Control of the Heart PDF

Topic 1-6 Control of the Heart Home is where the heart is  Control of the Heartbeat Internal control – Cardiac muscle (aka myogenic muscle) differs from other muscles in the body because it contracts without external stimulation – Contractions...

Topic 1-6 Control of the Heart Home is where the heart is  Control of the Heartbeat Internal control – Cardiac muscle (aka myogenic muscle) differs from other muscles in the body because it contracts without external stimulation – Contractions are due to electrical impulses from two nodes located in the heart atria ventricles  Internal Control - 2 nodes exist in heart Sinoatrial node (SA node) – Starts electrical signal – Bundle of nerves and muscles – Also known as the pacemaker - sets the tempo of the heart (approximately 70 beats per minute and 70-mL of blood at each beat) – Located in the right atrium – Starts contraction of the atria, pushing blood into ventricles – Nerve impulse travels from SA node to other muscle cells by modified muscle tissues Bill Nye- Valves and pump 1:55 – 3:44 Heart beat; sympathetic NS 4:30 – 5:17 SA node 5:29 – 6:33 http://www.youtube.com/watch?v=GbttJ- 5do9M&safety_mode=true&safe=active  Internal Control Atrioventricular node (AV node) – Picks up the impulse from the SA node – Causes contraction of the ventricles – Sends blood out to lungs and body – Passes nerve impulses along special fibers (Purkinje fibers) along septum and muscle tissue Electrical Activity  An artificial pacemaker is Artificial Pacemaker - Link used to emit electrical impulses when the SA node is not functioning properly Arrhythmia = irregular heartbeat Video: Pacemaker Video: http://www.youtube.com/w http://www.youtube.com/ atch?v=rpwryb5o8s4&feat watch?v=IR0nWe47eek&f ure=related&safety_mode eature=related&safety_m =true&persist_safety_mod ode=true&persist_safety_ e=1 mode=1  External Control Nervous Stimulation – Two regulatory nerves of the autonomic nervous system help to control heart rate Sympathetic nerves Parasympathetic nerves – Responds to the needs of the body by conducting impulses from the medulla oblongata (brain) to the pacemaker (SA node).  Nervous Stimulation Sympathetic stimulated in times of stress “Fight or flight” Increases heart rate Blood flow to tissue increases Parasympathetic – Relaxation – Slows heart rate  Adjustment Due to Exercise Increase in carbon dioxide in the blood due to exercise stimulates the medulla oblongata of the brain The medulla sends a nerve impulse to the SA node to increase the heart rate The increased heart rate circulates the blood to the lungsremoving the excess carbon dioxide  Other Factors high temperature increases heart rate release of hormones (such as adrenaline) also increases heart rate. Synthetic Estrogen Disorders of the Circulatory System  Atherosclerosis Buildup of fatty material inside arteries Arteries become hard Causes high blood pressure, or hypertension Arteries can rupture or blood clots can form  Angina Chest pain due to poor blood circulation to the heart Not enough oxygen to the heart What is a heart attack? (cardiac arrest) Caused by a blockage of the coronary arteries This reduces blood flow to the heart = NO oxygen = HEART DIES!! Heart attacks can be caused by high cholesterol and smoking! Bill Nye – clots; heart surgeon 4:30 – 7:58 http://www.youtube.com/watch?v=RiYOuI7iyp8&safety_mode =true&safe=active CPR – Stayin’ Alive. http://www.youtube.com/watch?v=n5hP4DIBCEE&safety_mode=true&safe=active  The result of a heart attack could be complete stoppage (cardiac arrest – lack of a pulse) or reduced function of the heart.  Symptoms: Stroke – Weakness on one side, Occurs when blood clot trouble speaking, lodges in a blood vessel in paralysis on one side. the brain or if a blood – Unequal pupils, facial vessel ruptures problems (facial muscle weakness, swallowing Tissue damage becomes problems, drooling) significant after about 4 minutes Can result in death or mental/physical problems News reporter has stroke on air? http://www.youtube.com/watch?v=AVKDm4 PhEwI&safety_mode=true No – actually, the news reporter had a migraine. Stroke  A blood clot that dislodges and later jams Embolus in another vessel  Aneurysms are due to a weak spot in an artery. Causes a Bulge in artery wall If left undiscovered, can be extremely dangerous – rupture may cause instant death  Flashcard Review On your flashcards write the following in BIG writing: 1. SA Node 2. AV Node 3. Arrhythmia 4. Atherosclerosis 5. Angina 6. Heart Attack 7. Stroke 8. Embolus 9. Aneurysm  Topic 1-8: Lymphatic System The lymphatic and circulatory system are closely related – intertwined and similar to the circulatory system The lymphatic system returns extracellular fluid (protein and bacteria) leaked from capillaries back to circulatory system – Lymph is fluid (protein) leaked from the capillaries  Some fluid seeps through capillary wall & is called lymph This fluid is returned to the blood via the lymphatic system  Lymphatic System In blood, the fluid is called plasma. When it leaves the capillaries, it is called lymph.  Lymphatic System Fluid moves through lymph vessels by skeletal muscle contractions – No backflow due to one way system of valves (similar to veins in this way)  Lymph Nodes Before lymph is returned to the blood it passes through lymph nodes Nodes contain white blood cells (which combat infections!) The WBCs filter lymph for invaders – Will destroy foreign particles by phagocytosis Lymph is returned to the circulatory system through ducts Bozeman interstitial fluid 4:54 http://www.youtube.com/watch?v=B 658Yn3INYc&safety_mode=true  What role does the lymphatic system serve in delivering digested fat to the tissues of the body? Digested fats that are absorbed by the small intestine through the lacteals (lymphatic system) ALSO enter the blood. Topic 1-9 Blood Structure & Function  Components of Blood What is blood made up of? 1. Plasma (water like) 55% 2. white blood cells (WBCs) 3. red blood cells (RBCs) (45%) 4. platelet cells (clotting factors) Plasma (55%) WBC + Platelets (1%) RBC (44%)  Blood Slide View Platelets Erythrocyte Leukocyte (RBC) (WBC) Leukocyte (WBC) Leukocyte (WBC) Plasma Leukocyte Leukocyte (WBC) (WBC)  Composition of Blood Plasma Plasma – 92% water, 8% dissolved molecules Proteins (fibrinogen) Glucose Vitamins Minerals Gasses Waste products nutrients  Blood Cells RBC Platelets WBC  Erythrocytes (RBC) Structure Biconcave disks No nucleus when mature- – Blood can carry more O2 Short lifespan – 120 days Contain hemoglobin – Pigment (makes blood red) – Contains iron which absorbs O2  Erythrocytes Function RBC’s carry O2 to tissue – Exchange for CO2 to be respired Anemia RBC deficiency Not enough iron = decreased O2 to cells Low energy levels RBCs are formed from stem cells in the bone marrow  Blood Cell Production All blood cells come from stem cells located in bone marrow!!  Leukocytes White blood cells (WBCs) Ratio of red to white = 700:1 Structure Have a nucleus, largest of blood cells Function Engulf invading cells through phagocytosis – Digests microbe – forms pus – Pus – used up WBC’s, dead tissue and bacteria make antibodies (various specialized cells – immune response) Also originate from stem cells (like RBCs)...  Platelets Structure: Small Fragile Contain specialized proteins (thromboplastin) Function: Start clotting – Join with calcium in plasma – First step in clotting Also originate from stem cells (like RBCs, WBCs)... 1. Platelets hit a rough edge of a injured blood vessel, rupture and release thromboplastin. 2. Thromboplastin (from platelets) and Ca2+ (from blood) convert fibrinogen into fibrin! 3. Fibrin is a stretchy net that traps RBCs and seals wound. Thromboplastin Fibrinogen Ca2+ Fibrin (From platelet) (Blood protein) (in blood) (Blood clot) fibrin  Circulatory System Lab The sphygmomanometer (blood pressure cuff) is made up of an inflatable cuff and an air pump bulb. 1. Place the cuff around the upper arm of your partner. Ensure that your partner is seated and they have their elbow resting on a desk. 2. With the stethoscope in your ears, place the head just under the cuff on inside of elbow. Inflate the cuff to at least 160 mmHg by squeezing the pump. Watch the display to ensure that you have sufficiently inflated the cuff. 3. Start releasing pressure by turning the valve on the pump to the left. When you start to hear the heartbeat, record the number as the systolic pressure. When you stop hearing the heartbeat, record the number as the diastolic pressure. Instructional Video for Taking Blood Pressure https://www.youtube.com/watch?v=Y5AEquO13eI  Your Blood Pressure Another Group Member’s Activity (systolic/diastolic) Blood Pressure (mmHg) (systolic/diastolic) (mmHg) Sitting  Background Information on Station 2- Blood Pressure Blood pressure (BP) is the arterial pressure exerted by ventricles when they contract and relax. Systolic blood pressure is the pressure when the heart beats while pumping blood. Diastolic blood pressure is the pressure when the heart is at rest between beats. If your numbers stay above normal most of the time, you're at risk. High blood pressure is called hypertension. All levels above normal blood pressure raise your risk, and the risk grows as blood pressure levels rise.  Low Blood Pressure When a person's blood pressure is lower than normal blood pressure, they are said to be suffering from lower blood pressure. Some of the common symptoms of low blood pressure are: dizziness, fatigue, fainting spells or light-headedness. When the blood pressure levels are too low, you have insufficient flow of blood to the brain, heart, and other important body organs.  High Blood Pressure High blood pressure – also known as hypertension – affects one in five Canadians. Yet 42% of Canadians with high blood pressure don't even know they have it because there are no symptoms. WHY? High blood pressure leads to increased risk of strokes, heart attacks, and heart and kidney failure. It is also related to dementia and sexual problems. These problems can be prevented if high blood pressure is controlled. Blood Pressure Chart  Risk Factors for High Blood Pressure As age increases, so does the risk of high blood pressure. – Why? arteries become hardened, less active; kidney function decreases; body does not process salt as well; hormonal changes such as menopause. Being overweight increases your risk of developing high blood pressure. In fact, blood pressure rises as body weight increases. Losing even 10 pounds can lower blood pressure — and it has the greatest effect for those who are overweight and already have hypertension. Smoking injures blood vessel walls and speeds up the process of hardening of the arteries, which raises blood pressure. Lack of exercise, poor eating habits, drinking alcohol in large amounts are also risk factors for high blood pressure.  Prevention of High blood pressure You can take steps to prevent high blood pressure by adopting a healthy lifestyle. What can we do? maintain a healthy weight be physically active follow a healthy eating plan, that emphasizes fruits, vegetables, and low-fat dairy foods choose and preparing foods with less salt drink LESS alcoholic beverages, or practice moderation. Station 2 - Stethoscope The stethoscope is an instrument used to listen to the sounds of the human body. ** Wipe the ear pieces with the alcohol swabs before use! Do not tap the bell piece of the stethoscope! ** 1. Place the earpieces in your ears to listen for heart beat sounds. With a timer, determine your normal heart rate (number of heart beats per minute). Record in the table below. 2. Do 20 jumping jacks or run up and down a flight of stairs 5 times, or run on the spot for 3 minutes. With a timer, determine your heart rate (number of heart beats per minute). Record in the table below. 3. Use the stethoscope to listen for breathing sounds. Activity Your Heart Rate (bpm) Another Group Member’s Heart Rate (bpm) Standing or Sitting at Rest After Exercising for 3 minutes. (jumping jacks, stairs or running)  Station 3- Components of the Blood Blood can be separated into its 55% component parts with