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• • • • • • • • Transport in insects. Closed and open circulatory system. Mammalian circulatory system. The mammalian heart. Blood vessels – (Vascular system.) Blood structure and function. Lymphatic system. Immune responses. Mammalian circulatory system. • Task: - Identify if it is closed or open? • - Is mammalial circulatory system double or single circulation? • Insect circulatory system. Insect circulatory system. Insect circulatory system. General diagram. • Task: Identify the heart and the cavities. Insect circulatory system • Illustration. • BIOLOGY Topical Video clips\Transport in animals and plants\Transport system in cockroach.mp4 • Has open circulatory system consisting of a dorsal tubular heart and open cavities (Haemocoel, pericardial cavity). • Heart contracts... Haemolymph(blood) flows out via aorta to the cavities/sinuses. • Blood flows over tissues in the sinuses where there is exchange of substances. • Heart relaxes... Blood flows back to heart through ostia(singular- ostium). • Valves in aorta and ostia prevent back flow of blood. THE MAMMALIAN CIRCULATORY SYSTEM. • Is closed circulatory system since blood flows in closed blood vessels. • Is double circulatory system since blood flows twice through the heart before flowing to the rest of the body. • Single circulatory system – Blood flows in heart only once then to the rest of the body eg in fish and insects. • Hepatic circulation – Blood flow from heart to lungs then back to heart. • Systemic circulation – Blood flow from heart to rest of body then back to heart. • Pulmonary and systemic circulation. • Humans BIOLOGY Topical Video clips\Transport in animals and plants\Circulatory system.mp4 Differences between closed and open circulatory system. CLOSED OPEN 1. Blood flows at high pressure 1. Blood flows at low pressure 2. 2. 3. 3. 4. 4. 5. 5. 6. 6. THE MAMMALIAN HEART. • External structure features. (pg 21 KLB or pg 30 Longhorn- Draw) Mammalian Heart. • External structure. Mammalian heart. • External structure. • Internal structure. (Draw KLB – pg 22 or Longhorn pg 31) MAMMALIAN HEART. • Internal structure. • EXTERNAL • 1.Pericardium membrane secretes a fluid that acts as lubricant when the heart is working. Pericardium is tough and so prevents over dilation of heart. • 2. Layer of fat around the heart which is spongy acts as shock absorber/ cushions and protects the heart. • 3. Pulmonary vein and vena cava blood vessels have wide lumen and valves to ensure flow of blood to the heart right auricle and left auricle respectively. • 4. The aorta and pulmonary artery have thick muscular and elastic wall that transport blood with high pressure from heart. • Internal adaptations. • 5. Cardiac muscles of heart is myogenic and contracts and relaxes without fatigue and on their own without control of nervous system. • 6. Cardiac muscles have numerous mitochondria that generate energy for muscle contractions. • 7. Right atrium has pace maker (SAN) in its muscular wall which initiates heart beat. • 8. The septum has atrio ventricular node and purkinje tissue which spreads the waves of contractions from SAN to the ventricles. • 9. Cardiac muscles has interconnections that makes them strong and also spreads waves of contractions throughout the heart. • 10. Heart has 2 auricles with cavity surrounded by cardiac muscles which receives blood and pumps it to the ventricles. • 11. Two ventricles with cavity surrounded with thick cardiac muscles that receive blood from atriums and pump it out of heart. • 12. Left ventricle cardiac muscles are thicker so as to pump blood with high pressure to the rest of the body. • 13. Bicuspid valves are flaps of tissue that prevent back flow of blood to left atrium when left ventricle contract. • 14. Tricuspid valves are flaps of tissue that prevent back flow of blood to right atrium when right ventricle contract. • 15. Valve tendons are inelastic and prevent the atrioventricular valves from turning inside out when ventricles contract. • 16. Semilunar valves are pocket like and prevent blood in aorta and pulmonary artery from flowing back to the heart when the ventricles contract. • 17. Coronary artery has thick muscular wall and transports blood with high pressure from aorta to the heart muscles. • 18. Coronary vein has wider lumen and valves and transports de-oxygenated blood from cardiac muscles to the vena cava. • 19. Septum has tough cardiac muscles that separate the oxygenated blood in right ventricle from the oxygenated blood in the left ventricle. Heart muscles. • Are called cardiac muscles. • A B • F G • H S • Illustration-1 BIOLOGY Topical Video clips\Transport in animals and plants\Blood circulation in Heart.mp4 • Illustration – 2BIOLOGY Topical Video clips\Transport in animals and plants\How the cardiac cycle is produced by electrical impulses in the heart.mp4 • Deoxygenated blood from the body enter the heart right auricle through vena cava. • - Then to right ventricle via tricuspid valve. • - Then to lungs via Semilunar valve and pulmonary artery for oxygenation. • - Oxygenated blood flows back to heart left auricle via pulmonary vein then across bicuspid valve to left ventricle where it is pumped to the rest of the body via aorta. PUMPING MECHANISM OF HEART. • Involves two cycles namely: Diastole and Systole. • DIASTOLE (Relaxation cycle). • -The two ventricles relax at ago. Their volume increase while pressure decrease. • -This together with slight contraction of the auricles cause the cuspid valves to open and blood to flow from auricles to the ventricles. • -Semilunar valves close to prevent back flow of blood to to ventricles from aorta and pulmonary artery. • The two ventricles contract at ago. Their volume decrease and pressure increase. • Blood is pumped to the body via aorta and to lungs via pulmonary artery. • Semilunar valves open. • Cuspid valves close to prevent back flow of blood to the auricles. • • • • • • • • • • • Qn.1. What is heart beat? Ans- Systole followed by diastole. Qn.2. Determine your own heart beat now per minute. Ans – 60-70 times per minute. Qn.3. What can cause increase or decrease in heart beat. Ans- Exercise, excitement, emotions, sickness... Qn.4. Akid and an adult who has lowest heart beat? Ans – Adult. Qn.5. What is the role of vagus and sympathetic nerve. Ans- Vagus nerve slows heart beat. -Sympathetic nerve accelerates heart beat. • PICTURES: • Pictures Fish circulatory system . Pictures • Qn – Name the circulatory system in fish. • Ans – Is Closed circulatory system- Reason: Blood moves in blood vessels. - Is Single circulatory system – Reason- The blood flows through heart only once then to the rest of the body. • Qn - State 3 differences between single circulatory system and double circulatory system. WELCOME TO TODAYS LESSON WE SHALL LEARN ABOUT BLOOD VESSELS BLOOD VESSELS. •3 TYPES: •1. Arteries •2. Veins •3. Capillaries ADAPTATION OF ARTERIES AND VEINS • - Single layer of endothelium lining the inside which provides smooth lining which offers least possible resistance to blood flow. • - Layer of elastic fibers and smooth muscles whose contractions and relaxations creates pulsating action that plays role of regulating pressure of blood. • - Tough elastic collagen fibers that allows for pulsations and protects blood vessels from overstretching and busting. • Made of thin single layer of endothelium to allow for ultra filtration and to reduce diffusion distance for easy movement of substances in and out of capillaries. • Are numerous to increase surface area for supply of substances in blood to tissue cells. • Are tiny to be able to penetrate in between tissue cells. ARTERIES VEINS 1. Thick muscular walls 1. Thin muscular walls 2. No valves except aorta 2. Have valves throughout. 3. Blood flows rapidly under high pressure 4. Lie deep in body 3. Blood flows slowly at low pressure 4. Lie near body surface 5. Transport oxygenated blood except pulmonary artery. 6. Narrow lumen 5. Transport deoxygenated blood except pulmonary vein. 6. Wider lumen Arteries and veins • Images. • A Blood flow in valves • B Arteries and veins • Artery Vein • • General • What enables blood to flow forward in the veins despite the low pressure? • Why is the blood pressure in the arteries high? • Why is the blood pressure in veins low? • URL • BIOLOGY Topical Video clips\Transport in animals and plants\Circulatory system.mp4 DISEASES AND DEFECTS OF CIRCULATORY SYSTEM. • 1. THROMBOSIS • • • • Blockage of artery due to: a) Cholesterol accumulation. b) Blood clot c) Arteries becoming fibrous Thrombosis illustration • Pictures Causes of thrombosis: • • • • • i) Heavy intake of fats in diet. ii) Heavy intake of alcohol. iii) smoking. iv) Stress. v) Smoking. Effects of Thrombosis: • a) Reduces or stops Oxygen and nutrient supply to tissues supplied by the blocked blood vessel. • b) Stroke ( if brain artery is blocked). • c) Heart attack ( If coronary artery is blocked). • d) High blood pressure. • e) Rupture of the artery. Control of thrombosis • a) Avoid alcohol. • b) Avoid smoking. • c) Reduce fat intake. • d) Exercises. VERICOSE VEINS • • • • -Damaged valves of superficial veins. - Blood fails to flow well in veins. - Veins swell due to accumulation of blood. - Tissue fluid accumulate leading to some swelling of tissues. • CONTROL • -Surgery replacement of faulty valves. • - Exercises. HYPERTENSION • Normal blood pressure is 90/60 to 140/90 • Task: In 140/90 what does 140 and 90 stand for? • CAUSES: • 1. Arteriosclerosis • 2. Thrombosis (ie since the heart is overworked in forcing blood to flow through the narrowed arteries.). Other causes of hypertension • - Heavy alcohol intake • - Heavy smoking. • -Stress. • - High salt intake. Control of hypertension. • - Regular exercises • - Reduce salt intake. • -Avoid excessive alcohol intake and smoking. • Good stress management. ARTERIOSCLEROSIS • Cause- Deposition of calcium and formation of fibrous connective tissue in arteries which makes them thick, hardened and inelastic. • This occurs due to lack of exercises, overweight, and emotional stress. • Effect- Causes hypertension. • Control- Exercises and proper stress management. Module 3 MAMMALIAN BLOOD. • COMPOSITION: • 1. Cellular components. • a) Erythrocytes • b) Leucocytes • c) Thrombocytes • Fluid medium – The plasma. • Images. Blood smear. • Group discussion- identify all the blood components in this photomicrograph. • Images.- Blood smeer Mammalian blood • Images Group work. • Discus the differences between various types of blood cells in relation to their: • i) Shape • ii) Size • iii) numbers • Use the photo below: • -Pale yellow fluid. • 90% of plasma is water. • Has the following in solution form- nutrients (ie glucose, amino acids, mineral salts, vitamins, fatty acids and glycerol etc), hormones, enzymes, some dissolved oxygen and CO2 … • Has blood cells and plasma proteins like fibrinogen, albumin etc in suspension. Functions of plasma: • • • • • a) Transports blood cells. b) Transport of nutrients in solution form. c) Transport of metabolic wastes. d) Transport of hormones. e) Transport of plasma proteins e.g antibodies, fibrinogen etc • f) Regulation of pH of body fluids. • g) Regulate temperature by distributing heat around the body. Blood components • Role of components of blood • IllustrationBlood videos and others\The Components of Blood and Their Importance YouTube.WEBM