Circulatory System Past Paper (EBRO-SCIENCE)

WELCOME TO SCIENCE CLASS HEARTBEAT COUNTING FEEL YOUR PULSE BY PLACING YOUR FINGERS ON YOUR WRIST OR NECK. COUNT YOUR PULSE SILENTLY FOR 1 MINUTE. HOW MANY BEATS YOU COUNTED? HEARTBEAT COUNTING DO A SHORT EXERCISE (JUMPING JACKS FOR 1 MINUTE). CHECK YOUR PULSE AGAI...

WELCOME TO SCIENCE CLASS HEARTBEAT COUNTING FEEL YOUR PULSE BY PLACING YOUR FINGERS ON YOUR WRIST OR NECK. COUNT YOUR PULSE SILENTLY FOR 1 MINUTE. HOW MANY BEATS YOU COUNTED? HEARTBEAT COUNTING DO A SHORT EXERCISE (JUMPING JACKS FOR 1 MINUTE). CHECK YOUR PULSE AGAIN AND COMPARE THE RESULTS. HEARTBEAT COUNTING WHAT DID YOU NOTICE ABOUT YOUR HEARTBEAT BEFORE AND AFTER THE EXERCISE? HEARTBEAT COUNTING WHY DO YOU THINK YOUR HEART BEATS FASTER WHEN YOU EXERCISE?  THE CIRCULATORY SYSTEM The role of the heart, blood and blood vessels  WHAT IS YOUR PULSE RATE? To check your pulse, place the tips of your index and middle finger on your wrist. Feel your pulse and count the beats for 15 seconds. Then, multiply that number by four to find out how many times your heart beats in one minute.  TODAY, YOU WILL... Name and describe the Describe the role of the main parts of the human heart, blood and blood circulatory system. vessels.  THE HUMAN CIRCULATORY SYSTEM Function Main Parts To transport blood, Has three main oxygen and nutrients parts: the heart, to the body blood vessels and blood  left atrium right atrium What is the function of the heart in the circulatory system? right ventricle left ventricle  THE HEART right atrium left atrium It works as a pump to move the blood around the body. It has four chambers—two right ventricle left ventricle atria (upper chambers) and two ventricles (lower chambers). LESSON CHECK: THE HEART How does blood circulate through the body?  THE HEART Let’s examine how blood flows through the heart. 1 The right atrium takes from upper body in blood carrying carbon dioxide. to left lung 2 Blood is squeezed down 1 into the right ventricle and taken to the lungs, where oxygen replaces carbon 2 dioxide.  THE HEART Let’s examine how blood flows through the heart. 3 Oxygen-carrying blood to body from the lungs enters the left atrium. 3 from left lung 4 Blood is pumped into the left ventricle and 4 starts its journey again throughout the body.  BLOOD It is a special fluid primarily contained within the blood vessels. It has four main components— red blood cells, white blood cells, platelets and plasma.  BLOOD Our blood has four main components: Platelets Red Blood Cells carry oxygen, gather at the site nutrients and of injury and help wastes the clotting process White Blood Cells Plasma fight diseases and straw-coloured liquid protect the body where the other from infection components float in BLOOD When someone has a blood test, a small amount plasma of blood is taken and kept white blood cells and platelets in a tube for testing. red blood cells To closely examine it, blood undergoes component separation. One common Blood is divided into its method involves spinning it components, with the at very high speeds in a heaviest parts at the centrifuge. bottom. BLOOD VESSELS These are tubes or channels that carry blood throughout our body. There are three types of blood vessels—veins, arteries and capillaries. Each one differs in size and structure.  BLOOD VESSELS Let’s take a closer look at the three types of blood vessels: It has the thickest wall of all three, allowing it Artery to withstand the high pressure created by the heart. It has the thinnest wall to allow substances Capillary such as oxygen and sugars to pass through its wall—into or out of the blood. It is less muscular and stretchy than an artery, so blood moves through it with low Vein pressure. It also has a special valve that helps blood go only one way.  BLOOD VESSELS Each type of blood vessel has a unique role in the circulatory system. Artery Capillary Vein Carries blood Assists in the Carries blood back away from the exchange of towards the heart substances between heart the blood and tissues TIP Remember ‘A’ for ‘artery’ and ‘away’ from the heart! LESSON CHECK: SICKLE CELL DISEASE Sickle cell disease (SCD) is an inherited blood disorder. People with SCD have red blood cells that become hard and sticky, forming a C-shaped blood cell instead of the healthy disc-shaped one. Considering what you’ve learnt about blood and blood vessels, how does this shape affect blood flow in the circulatory system? LESSON CHECK: SICKLE CELL DISEASE Considering what you’ve learnt about blood and blood vessels, how does this shape affect blood flow in the circulatory system? The irregular shape of the sickle-shaped blood cell makes it easy to clog and block the blood flow. This can cause pain and other serious infections.  A RECAP The circulatory system delivers oxygen and nutrients to the body, while also removing wastes. Heart Blood Blood Vessels Muscular organ Has four components: Has three types: that has four plasma, red blood cell, arteries, veins and chambers white blood cell and capillaries platelets Pumps blood Serve as channels Carries oxygen, around the body nutrients and wastes for the blood  Create a flowchart that shows the journey of blood through the circulatory system. TIP Remember ‘A’ for ‘artery’ and ‘away’ from the heart!