Presentation on theme: "The circulatory system"— Presentation transcript:
1 The circulatory system Your body’s “internal transport system”!
2 What the Circulatory system does: The heart moves blood through blood vessels.Vessels move blood through the body to carry:OxygenCarbon dioxideNutrients
3 What is blood made of? 55% = plasma a clear liquid made up of 92% water8 % is salts, nutrients, proteins and other chemicalsThe rest of the blood = 3 kinds of blood cellsRed = carry oxygen to the bodyWhite = protect the body from diseasePlatelets = cell fragments that cause blood to clot
4 Hemoglobin = oxygen-carrying pigment in red blood cells What color is blood???Hemoglobin = oxygen-carrying pigment in red blood cellsIs bright red when attached to oxygenIs dark red when doesn’t have oxygenVeins appear blue b/c different colors of light reach different depths in the skin = the blue light is reflected back by the veins
5 How does the heart work? Beats constantly (no rest!) It pushes blood through the vesselsBlood carrying carbon dioxide returns from the body and enters the right atrium of heartAtrium = a chamber of the heart that RECEIVES bloodBlood is pushed to the ventricle = pushes blood OUT of the heart toward the lungs and other parts of the body
6 What makes the heart beat? Contraction of the heart!1. Signals at the top of the heart cause the heartbeat…2. A group of cells called the “cardiac pacemaker” or S-A node start a signal…3. The signal causes the atria to contract…4. The signal is passed to cells in the a-v node and along to ventricles…5. Ventricles contract…Yeah= you have a heartbeat!
7 TYPES OF BLOOD VESSELS: Arteries= Blood vessels that carry blood AWAY from the heartCapillaries=Tiny blood vessels that connect arteries to veinsVeins= Blood vessels that carry blood FROM all parts of body BACK to the heart