1. WELCOME BACK!! CONGRATULATIONS ON PASSING THE EXAM! BUT NOW KEEP UP THE GOOD WORKITS GOING TO BE A BUSY TERM! NEW LEARNER GUIDE READ AND MAKE USE OF IT! MAKE NOTE OF IMPORTANT DATES! PRAC 1 NEXT TUESDAY, 24TH! CLASS TEST 1 NEXT WEDNESDAY, 25TH!
2. NATIONAL SCIENCE WEEK Organised by the Department of Science & Technology Launch hosted by UJ, Soweto Campus, 28th July Aims to excite youth with science at a young age! You are invited free of charge! Launch day: 07:00 15:00 Register after class with ID number The rest of the week 14:30 15:30
3. POSTER PROJECT GROUPS OF 5 names on back of poster A3 POSTER ANY BIOLOGICAL TOPIC INTERESTING, INFORMATIVE, PICTURES, DIAGRAMS, COLOURFUL, FUN TARGET: High School Students DUE DATE: Next Tuesday, 24th July in class!!
4. TRANSPORT SYSTEMS IN ANIMALS (Campbell and Reece (2010), Chapter 42: P.898-915)
5. CIRCULATORY SYSTEMS IN ANIMALS Many invertebrates do not have a circulatory system at all. Their cells are close enough to their environment for oxygen, other gases, nutrients, and waste products to simply diffuse out of and into their cells. E.g. Hydra
6. CIRCULATORY SYSTEMS IN ANIMALS In animals with multiple layers of cells, their cells are too far from the external environment for simple osmosis and diffusion. In higher animals, there are two primary types of circulatory systems -open and closed.
7. CIRCULATORY SYSTEMS IN ANIMALS OPEN- CLOSED-
8. CIRCULATORY SYSTEMS IN ANIMALS OPEN The circulatory fluid Hemolymph (is the same as interstitial tissue fluid) The heart pumps hemolymph through vessels into sinuses (open fluid-filled spaces) Certain substances are exchanged between the hemolymph and the cells. Hemolymph returns to the heart through pores. The heart is a tubular structure.
9. CIRCULATORY SYSTEMS IN ANIMALS CLOSED Circulate blood entirely within vessels. So the blood is distinct from the interstitial fluid. Chemical exchange occurs between the blood and interstitial fluid as well as between interstitial fluid and body cells.
10. DOUBLE CIRCULATION The circulatory systems with two distinct circuits. The pumps of the two circuits serve different tissues but are combined into a single organ, the heart. The two circuits are called: 1. Pulmonary circuit 2. Systemic circuit
11. DOUBLE CIRCULATION 1. Pulmonary circuit The heart pumps deoxygenated blood to the lungs and oxygenated blood back to the heart. 2. Systemic circuit The heart pumps oxygenated blood to the body cells and the deoxygenated blood back to the heart.
12. DOUBLE CIRCULATION
13. DIFFERENT BLOOD VESSELS: ARTERIES, VEINS AND CAPILLARIES
14. FUNCTIONS OF CAPILLARIES Capillaries: Connect arteries and veins are structurally suited to facilitate the exchange of substances between the blood in the capillaries and the interstitial tissue fluid
15. FUNCTIONS OF ARTERIES Arteries: transport oxygenated blood except for the pulmonary artery. Main artery is called the Aorta pumping oxygenated blood from heart to rest of body. Other arteries: Renal artery (kidney) Hepatic artery (liver)
16. FUNCTIONS OF VEINS Veins : transports deoxygenated blood except for the pulmonary vein. Main vein is called the vena cava pumping deoxygenated blood towards the heart from the rest of the body. Other veins: Renal vein (kidney) Hepatic vein (liver)
17. THE HUMAN CIRCULATORY SYSTEM: HEART AND ASSOCIATED VESSELS
18. THE HUMAN CIRCULATORY SYSTEM: HEART AND ASSOCIATED VESSELS Mammals have a four-chambered heart with two atria and two ventricles The left side of the heart pumps and receives only oxygen-rich blood, while the right side receives and pumps only oxygen-poor blood The mammalian cardiovascular system meets the bodys continuous demand for O2. Blood begins its flow when deoxygenated blood flow from the body into the right atrium.
19. Blood then flows from the right atrium into the right ventricle through the tricuspid valve The blood is then pumped into lungs, through the semilunar valve via the pulmonary artery. In the lungs, the blood loads O2 and unloads CO2. Oxygen-rich blood from the lungs enters the heart via the pulmonary vein at the left atrium Blood then flows into the left ventricle through the bicuspid valve. This blood is then pumped through semilunar valve into the aorta with takes blood to the entire body.
20. Deoxygenated blood returns to the heart through the superior vena cava (blood from head, neck, and forelimbs) and inferior vena cava (blood from trunk and hind limbs) The superior vena cava and inferior vena cava flow into the right atrium. The atrioventricular (AV) valves (tricuspid and bicuspid valves) separate each atrium and ventricle The semilunar valves control blood flow to the aorta and the pulmonary artery.
21. THE EXTERNAL STRUCTURE:HUMAN HEART
22. THE INTERNAL STRUCTURE:HUMAN HEART
23. BLOOD FLOW THROUGH THE HEART RED: OXYGENATED BLOOD BLUE: DEOXYGENATED BLOOD
24. CARDIAC CYCLE The heart contracts and relaxes in a rhythmic cycle called the cardiac cycle The contraction, or pumping, phase is called systole The relaxation, or filling, phase is called diastole The heart rate, also called the pulse, is the number of beats per minute
27. MAINTAINING THE HEARTS RHYTHMIC BEAT Some cardiac muscle cells are self-excitable, meaning they contract without any signal from the nervous system The sinoatrial (SA) node, or pacemaker, sets the rate and timing at which cardiac muscle cells contract Impulses from the SA node travel to the atrioventricular (AV) node At the AV node, the impulses are delayed and then travel to the Purkinje fibers that make the ventricles contract
28. MAINTAINING THE HEARTS RHYTHMIC BEAT Fig. 42-9-5 1 Pacemaker generates wave of signals to contract. SA node (pacemaker) ECG 2 Signals are delayed at AV node. AV node 3 Signals pass to heart apex. Bundle branches Heart apex 4 Signals spread throughout ventricles. Purkinje fibers
29. WHAT WILL INFLUENCE THE HEARTS RHYTHMIC BEAT?
30. LYMPHATIC SYSTEM The lymphatic system returns fluid that leaks out in the capillary beds This system aids in body defence Fluid, called lymph, re-enters the circulation directly at the venous end of the capillary bed and indirectly through the lymphatic system The lymphatic system drains into veins in the neck. Lymph nodes are organs that filter lymph and play an important role in the bodys defence Edema is swelling caused by disruptions in the flow of lymph.
31. LYMPHATIC SYSTEM
32. LYMPHATIC SYSTEM VS. CIRCULATORY -
33. DISEASES OF THE HEART AND CIRCULATORY SYSTEM Cardiovascular diseases are disorders of the heart and the blood vessels They account for more than half the deaths in the South Africa One type of cardiovascular disease, atherosclerosis, is caused by the build-up of plaque (fat) deposits within arteries.
34. A heart attack is the death of cardiac muscle tissue resulting from blockage of one or more coronary arteries A stroke is the death of nervous tissue in the brain, usually resulting from rupture or blockage of arteries in the head. Hypertension, or high blood pressure, promotes atherosclerosis and increases the risk of heart attack and stroke. Hypertension can be reduced by dietary changes, exercise, and/or medication