Arteries - Home - Oracabessa High School



Teacher: Mr. JamesGrade: 101&2 Human & Social BiologyTopic: The Human Transport SystemSubtopic: Structure and Function of the Circulatory system Date May 4, 2020Duration 1 weekObjectives:Students should be able to:1. describe the structure and function of the circulatory system in humans;2. explain the concept of blood pressure;3. relate the components of the blood to its function;4. relate the structures of the arteries, veins and capillaries to their functions.Video Links: , The Circulatory System:The heart and blood vessels carry out a transport function. They carry food molecules, water and oxygen to cells and remove waste products such as carbon dioxide. They form the circulatory system.A double circulation:Instead of just being a single loop the circulation has two interconnected loops, in a sort of figure of eight. Blood returns from the body to the right atrium. The blood has lost most of the oxygen it carries and is now deoxygenated.The right ventricle pumps the blood along the pulmonary artery to the lungs where it picks up fresh oxygen. It is now oxygenated.The oxygenated blood enters the left side of the heart and is pumped out through the aorta to the body.Once it reaches the capillaries around the body, oxygen diffuses out to the surrounding cells.The deoxygenated blood is carried back towards the heart in the veins. These join up to form the vena cava which is the largest vein.Types Of Circulation:There are two types:Blood passes through the heart twice on its way around the body once. Pulmonary Circulation:This is the passage of blood around from the heart to the lungs and back to the heart.Systemic Circulation: This is the passage of blood around the rest of the body, and its return to the heart.The cardiac Cycle:This is the complete sequence of events during one beat of the heart.Contractions of the heart chambers are called systole.When the chamber relax it is called diastole. Blood Pressure:?Normal Adult Blood Pressure (BP) = 120/80120mmHg Systole/ 80mmHg Diastole?Measurement Device- Sphygmomanometer (Blood Pressure Cuff)?Disorder- Hypertension (High Blood Pressure)Diagnosis- Blood Pressure number greater than 140mm Systole or 90mm DiastoleTreatment- exercise, weight loss and medicationThe Blood:Blood isn't just a red liquid. It is five litres of a careful mixture of plasma and blood cells. These cells come in three varieties: red, white and platelets.PlasmaThe plasma makes up most of the blood. It is mainly water but carries lots of other essential ingredients.The following substances are carried in the plasma:1. Dissolved carbon dioxide: This is the waste gas produced by respiration in cells2. Dissolved glucose and amino acids: Food molecules for respiration, building and repairing cells3. Urea: Waste product of digestion, this is lost from the kidney.4. Antibodies and antitoxins: Chemicals that protect us from disease and poisons5. Hormones: Chemicals that control some of our body functionsPlasma has a yellowish appearance. It sometimes oozes out of blisters. Nice! Red Blood CellsThe best known of the cells are the red blood cells, correctly called erythrocytes.Erythrocytes contain the oxygen carrying molecule haemoglobin; this is a special pigment that gives blood its red colour. Iron is needed in the production of haemoglobin; if your diet lacks this mineral you can develop the condition anaemia.Red blood cells are unlike other cells in that they do not contain a nucleus. They are really just a bag containing the haemoglobin. The cells have a doughnut-shape with a flattened centre instead of a hole. When blood picks up oxygen, we say that it has been oxygenated. This happens because haemoglobin molecules form weak bonds with oxygen to make a new complex molecule called oxyhaemoglobin. White Blood CellsWhen blood picks up oxygen, we say that it has been oxygenated. This happens because haemoglobin molecules form weak bonds with oxygen to make a new complex molecule called oxyhaemoglobin. PlateletsPlatelets are fragments of larger cells. Their job is to form part of a clot so that they plug a wound and stop too much blood being lost.Blood VesselsThe heart pumps the blood along a series of tubes that are collectively called blood vessels. But they are more than just simple pipes. ArteriesArteries carry blood away from the heart.Each time the heart beats it fires blood into the arteries at a high pressure, so they need to be tough so that they don’t burst. They are also quite thick with only a small space, known as the lumen, down the centre.Fortunately, arteries are provided with a tough outer layer and another layer inside this that can cope with the stretching the pulses of blood. This elastic layer is made up of elastic fibres and smooth muscle which contracts and helps to keep the blood moving along.The third layer that lines the lumen of the artery is called the endothelium. This is made up of special endothelial lining cells which give a smooth surface to the lumen.VeinsVeins carry blood back to the heart.The blood returning from the body is at a much lower pressure than that fired out by the beating heart. So veins do not need to be as strong as arteries. Veins have a cross-sectional structure that is very similar to arteries. One of the obvious differences is that they have a much wider lumen and thinner walls. The other main difference is that veins have valves inside them, while arteries do not.The valves occur occasionally along their length and ensure that blood can only travel in one direction. Having valves in arteries would not be much use as it would slow the blood down and stop it reaching those important bits of you, like your head. CapillariesCapillaries are tiny, thin-walled vessels. They carry blood close to all the body’s cells in its tissues and organs. They may not be the most glamorous of the vessels but they are perhaps the most important.Capillaries are made up of a single layer of endothelial cells around a very small lumen. Molecules can easily move into and out of the capillaries by diffusion. This allows food, gas and waste molecules to be taken to and from every cell in the body.Activity: Circulatory System Structure and Basic FunctionsName: ____________________________________ Date: May 4, 2020.Label the Heart Diagram using the word list provided. Each answer is worth 1/2 mark each.Word List:Superior vena cava Right pulmonary arteryRight pulmonary veinsRight atrium Rt. AV Valve (Tricuspid)Right ventricleInferior vena cava Left pulmonary arteryLeft pulmonary veinsLeft atrium Lt AV Valve (Bicuspid)Aorta 511175243522500Left ventricle Septum42291002616200__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ ______ / 700__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ ______ / 7Fill in the blanks using the words provided: / 8 AortaVeinsArteries Pressure Circulates Oxygen Nutrients Waste CO21. Blood pumping through our arteries causes ______________ __ on them._________________ are important because they carry blood from the body back to the heart.2. Our blood_____ through our body in our blood vessels.3. The _________is the biggest artery in the body and its attached to the Left Ventricle.4. The circulatory system carries and___ to our cells, and take __________________ and _________ ___away. Types of Blood Vessels: ______ / 9 With the features listed below, write the correct 3 in each of the spots provided for each blood vessel diagram.Features: Medium-sized blood vessels Tough, flexible and thick wallsCarries blood back to the heart The Smallest blood vesselsThin Walls due to less blood pressure Carries blood away from the heartWalls are only one-cell thick The largest blood vesselsExchanges oxygen and waste with the bloodArteriesCapillariesVeinsList the 3 features from aboveList the 3 features from aboveList the 3 features from above1.________________________________________________1.______________________________________________________1.__________________________________________________2._________________________________________________2.____________________________________________________2._________________________________________________3._________________________________________________3.____________________________________________________3._________________________________________________Multiple choice Questions: Each is worth one mark; CIRCLE THE MOST CORRECT ANSWERS.1. Why is oxygen important to blood and to the cells? ____ / 10 Oxygen helps the blood to clot.Oxygen brings food to the cells.Oxygen is necessary for cell growth and energy.Oxygen is not important -- carbon dioxide is the most important substance to the body.2. Which type of blood vessels carries blood away from the heart?Veins Arteries Capillaries Arteries, veins and capillaries3. When oxygen-rich blood leaves the lungs for the heart, it enters the heart through the pulmonary vein into the __________________left ventricleright atriumright ventricleleft atrium None of these4. How many times does the average adult heart beat per minute while at rest?1504012070355. A pulse is caused by ________________.the valves in an artery opening and closingoxygen entering the blood in the lungs red blood cells colliding with each other in the arterieschanges in blood pressure in an artery6. Which one of the following is NOT a blood vessel?CapillaryArteryColonVeinThe all are blood vessels-1790703238500Use the heart diagram on the right to answer the next 2 questions…376237597790007. How many blood vessels leave the heart?24138. Which part of the heart has the thickest walls?Right ventricleLeft atriumLeft ventricleRight atrium 9. The blood vessel that carries deoxygenated blood from the body to the right side of the heart is called the__________________.Pulmonary veinaortapulmonary arteryvena cava(s)10. Which one of the following describes a vein?It has thin walls and carries oxygenated blood away from the heart.It has thick walls with valves and carries blood under pressure.It has a very thin wall with valves and carries blood under pressure.It has thin walls with valves, and carries blood to the heart. / 35 ................
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