GRADE 9 SCIENCE HANDOUTS FOR WEEK 1 AND 2.docx
- 1. MAAM ORBE HANDOUTS IN SCIENCE 9 FIRST QUARTER Unit 1: Living Things and Their Environment Module 1: Respiratory and Circulatory Systems Working with Other Organ System LEARNING OBJECTIVES At the end of the lesson the students should be able to: Identify the key parts of breathing system (Respiratory System) Give the function of each part of the breathing system Explain how the lungs work Describe the movement of the diaphragm helps the air to go in and out of the lungs Describe blood flow ang gas exchange within the heart, circulatory system and lungs systems to work together Explain the mechanism of how the respiratory and circulatory systems work together LESSON 1 HUMAN BREATHING SYSTEM INTRODUCTION: Respiratory systems allow animals to move oxygen (needed for cellular respiration) into body tissues and remove carbon dioxide (waste product of cellular respiration) from cells. DISCUSSION: Respiratory system is made up of the organs in the body that help us to breathe. Gas Exchange Between the Blood and Alveoli LESSON 2 HOW THE LUNGS WORK INTRODUCTION The respiratory system is made up of several parts that work together to bring air in and out of the body. Nose- the organ through which the air enters and is filtered. Nasal passageways- serve as channel for airflow through the nose in which the air is warmed, cleaned, and moistened. Pharynx- Funnel shaped passageway that connects nasal and oral cavities to larynx. Passageway of food into the esophagus and air into the larynx. Larynx- Located between pharynx and trachea , prevents food from entering the trachea and lungs during swallowing. Also known as the voice box. Tracheal tube or trachea- also called windpipe; a hollow tube that serves as passageway of air into the lungs. Bronchi - also called bronchial tubes; two branching tubes that connect the trachea to the lungs. Bronchioles - the finer subdivisions of the bronchi hairlike tubes that connect to the alveoli. Alveoli- also called airsacs, allow the gas exchange in lungs. Diaphragm- muscle that controls the breathing process. Breathing In Breathing Out The diaphragm is a muscle located at the bottom of the ribcage separating the chest and abdominal cavities. The diaphragm contracts and relaxes to regulate the flow of air in and out of the lungs. Inhaling causes the diaphragm to contract and move downwards, while exhaling causes the diaphragm to relax and move upwards. The diaphragm contracts and flattens, expanding the chest cavity and creating low pressure that draws air into the lungs. The diaphragm relaxes and moves upwards, decreasing the chest cavity volume and creating high pressure that pushes air out of the lungs. DISCUSSION When you breathe in, or inhale, the diaphragm muscle contracts. Inhaling moves the diaphragm down and expands the chest cavity. Simultaneously, the ribs move up and increase the size of the chest cavity. There is now more space and less air pressure inside the lungs. Air pushes in from the outside where there is a higher air pressure. It pushes into the lungs where there is a lower air pressure. When you breathe out, or exhale, the diaphragm muscle relaxes. The diaphragm and ribs return to their original place. The chest cavity returns to its original size. There is now less space and greater air pressure inside the lungs. It pushes the air outside where there is lower air pressure.
- 2. MAAM ORBE LESSON 3 CIRCULATORY SYSTEM BlOOD FLOW LEARNING OBJECTIVE At the end of the lesson the students should be able to: Identify and give the functions of the components of the circulatory system. Explain the different types of circulation. Illustrate blood circulation. INTRODUCTION The central organ of the cardiovascular system is the heart. This is a hollow, muscular organ that contracts at regular intervals, forcing blood through the circulatory system. The heart is cone-shaped, about the size of a fist, and is located in the center of the thorax, between the lungs, directly behind the sternum (breastbone). The heart is tilted so that the base is tilted to the left. The heart is made up of a cardiac muscle and has rich supply of blood, which ensures that it gets plenty of oxygen. Our hearts beat about once every second of every day of our lives, or over 2.5 million times in an average life span. The only time the heart gets a rest is between beats DISCUSSION Circulatory System also known as cardiovascular system, life structure that nourishes your cells with nutrients from the food you eat and oxygen from the air you breathe. Transport gases, nutrients and waste materials, hormones, enzymes and heat within the body. PARTS OF THE HEART HOW THE HEART WORKS All of the muscle tissues of the heart do not contract at the same time. Different parts of the heart contract at different times. When the top portion contracts, the bottom part relaxes. When the bottom contracts, the top relaxes. When a chamber contracts, it becomes smaller and the blood inside gets squeezed or pumped out. HEARTBEAT or CARDIAC CYCLE 1. Systole- contraction of the heart. 2. Diastole- relaxation of the heart. o The right side of the heart pumps ‘deoxygenated blood (actually, blood low in oxygen) from the body into the lungs, where gas exchange takes place. o The left side of the heart pumps oxygenated blood (blood with high level of oxygen) from the lungs to the rest of the body. Types of Circulation 1. Pulmonary Circulation- Movement of blood from the heart to the lungs and back to the heart. 2. Coronary Circulation- Movement of blood through the tissues of the heart. 3. Systemic Circulation- Movement of blood from the heart to the rest of the body excluding the lungs. BLOOD Blood is a fluid that moves through the vessels of the circulatory system. Composed of plasma and blood cells. Plasma- liquid portion of the blood. RBC (red blood cell) or Erythrocytes- carries oxygen WBC (white blood cell) or leukocytes - defense from bacteria and viruses Platelets- has major role in blood clotting. BLOOD VESSELS Carries the blood throughout the body. Arteries- carry oxygenated blood away from the heart to the cells, tissues and organs of the body. Thicker and stronger elastic walls. Veins- carry deoxygenated blood to the heart. Thinner elastic walls. Capillaries - the smallest blood vessels in the body, connecting the smallest arteries to the smallest veins - the actual site where gases and nutrients are exchanged. Smallest and most numerous. INFLATION OF THE BALLOONS The air pressure inside the bottle is lowered by increasing the space inside the bottle. The outside air then enters through the tube, which makes the two balloons inside the bottle 'chest' expand. DEFLATION OF THE BALLOONS The air pressure inside the bottle is increased by decreasing the space inside the bottle. The inside air then exits through the tube, which makes the two balloons inside the bottle return to their original size. Heart is a hollow muscle with four chambers: 1. Atria ( Atrium)- upper chambers -receiving chambers of the heart, accepting blood from the body ( right atrium)and from the lungs ( left atrium) 2. Ventricles- lower chambers - Pumping chambers , moving blood to the lungs (right ventricle) and into the body (left ventricle) VALVE- found between each atrium and ventricle to prevent the blood from flowing backwards. BLOOD CIRCULATION The Pathway of Blood to and from the Heart 1. Blood that has circulated through the body, which has lost its oxygen and collected carbon dioxide, enters through the superior vena cava and inferior vena cava into the right atrium of the heart. 2. The right atrium contracts and pumps the blood through the tricuspid valve and into the right ventricle. 3. The right ventricle then pumps blood through the pulmonary artery into the lungs. 4. In the lungs, tiny blood vessels called capillaries absorb carbon
- 3. MAAM ORBE The heart and lungs work together to make sure the body has the oxygen-rich blood it needs to function properly. The right side of the heart picks up the oxygen-poor blood from the body and moves it to the lungs for re- oxygenating. Once the blood is re-oxygenated, the left side of the heart moves the blood throughout the body, so that every part receives the oxygen it needs.