Table of Contents The Body’s Transport System A Closer Look at Blood Vessels Blood and Lymph Cardiovascular Health

The Cardiovascular System - The Body’s Transport System The Cardiovascular System The cardiovascular system carries needed substances to cells and carries waste products away from cells. The circulatory system consists of the heart, blood vessels and blood In addition, blood contains cells that fight disease.

The Cardiovascular System Jobs of the Cardiovascular System Deliver Needed Materials Blood carries oxygen to all the cells in your body Remove Waste Products When cells break down glucose for energy, carbon dioxide is released as waste Fight Disease Blood transports disease-fighting cells all around your body

The Heart - The Body’s Transport System The heart is a hollow, muscular organ that pumps blood throughout the body. The right side of the heart is completely separated from the left side by a wall of tissue called the septum. Each side has an upper chamber, or atrium, and a lower chamber, or ventricle.

Heart Structure The Ventricles: pumps blood out of the heart Separated from the atria by valves Valves are flaps of tissue that prevent blood from flowing backward Valves are also present between the ventricles and the large blood vessels that carry blood away from the heart

The Heart - The Body’s Transport System As blood flows out of the heart and toward the lungs, it passes through a valve like the one here.

How the Heart Works There are two main phases of action: Heart muscle relaxes while the heart fills with blood Heart muscle contracts and pumps blood forward The heart beat sound (lub-dup) is the sound of blood being pushed forward and the valves closing shut http://www.youtube.com/watch?v=H04d3rJCLCE

The Force of the Ventricles The contraction of the left ventricle exerts more force than the contraction of the right ventricle The right ventricle pumps blood only to the lungs whereas the left ventricle pumps blood throughout the entire body

Regulation of Heart Beat The Pacemaker: A group of heart cells that send out signals that make the heart muscle contract, located in the right atrium of the heart Receives signals about the body’s oxygen needs and adjusts the heart rate to match Some people have damaged pacemakers that can result in slow or irregular heart beats

Two Loops - The Body’s Transport System Blood circulates through the body in two loops, with the heart at the center. In the first loop, blood travels from the heart to the lungs and then back to the heart. In the second loop, blood is pumped from the heart throughout the body and then returns to the heart.

Heart Activity - The Body’s Transport System Click the Active Art button to open a browser window and access Active Art about the heart.

Sequencing - The Body’s Transport System As you read, make a cycle diagram like the one below that shows the path that blood follows as it circulates throughout the body. Write each step of the pathway in a separate circle. Pathway of Blood Right side of heart Body Lungs Left side of heart

End of Section: The Body’s Transport System

Section 2 Learning Objectives: A Closer Look at Blood Vessels Describe the structures and functions of the arteries Describe the structures and functions of the capillaries and veins Explain what causes blood pressure

Blood Vessels of the Body After leaving your heart, blood travels in blood vessels through the body. You have 3 types of blood vessels 1. Arteries  carry blood away from the heart 2. Capillaries  narrow vessels where substances can be exchanged between the blood and the body cells 3. Veins  carry blood back to the heart

Arteries Purpose: The left ventricle pumps blood into the arteries that carry blood away from the heart and into the body Artery Structure Walls are very thick and have 3 cell layers giving strength and flexibility Innermost: epithelial cells, smooth Middle: Muscle tissue Outermost: flexible connective tissue Pulse Caused by expansion and relaxation of artery wall Ventricles contract pushing blood into circulation and causing the artery walls to expand

The Arteries Regulate Blood Flow The muscle in arteries act as a control gate. They can adjust the amount of blood being sent to different organs. When the muscle around the artery contracts, the artery becomes smaller When the muscle relaxes, the artery opening becomes larger Ex: After eating meal what do you think happens? What about when you are running? When you go outside on a cold day? Where do you think the arteries direct blood flow to?

Capillaries Purpose: To provide a place where nutrients can be delivered to cells and waste can be removed from cells. Q: What types of materials need to be delivered to cells? Removed? Diffusion: Molecules move from an area of high concentration to an area of low concentration (ex: blood glucose) Capillary Structure Walls are only one cell thick

Veins Purpose: After blood moves through the capillaries, it enters larger blood vessels called veins, which carry blood back to the heart. Structure: Similar to arteries, veins have 3 layers contained in their walls Walls of veins are much thinner than the walls of arteries Q: How does blood move through the veins? 1. Contraction of skeletal muscles helps move blood back 2. Larger veins contain valves which prevent backflow of blood 3. Breathing movements in your chest create a squeezing pressure against veins and force blood toward the heart

Blood Pressure Q: What causes blood pressure? Pressure is a force exerted over an area Blood Pressure is the force with which the ventricles contract As blood moves away from the heart, blood pressure decreases Blood flowing near the heart exerts the highest pressure, while blood pressure in the arteries further away from the heart is much lower Ex: Think of a garden hose or a faucet

Complete the Target Reading Chart on Comparing Blood Vessels!

Blood Vessels - A Closer Look at Blood Vessels The walls of arteries and veins have three layers. The walls of capillaries are only one cell thick.

Calculating a Rate - A Closer Look at Blood Vessels A rate is the speed at which something happens. When you calculate a rate, you compare the number of events with the time period in which they occur. Here’s how to calculate the pulse rate of a person whose heart beats 142 times in two minutes. 1. Write the comparison as a fraction: 2. Divide the numerator and the denominator by 2: The person’s pulse rate is 71 heartbeats per minute.

Calculating a Rate - A Closer Look at Blood Vessels Practice Problem Calculate your pulse rate if your heart beats 170 times in 2.5 minutes. 68 beats per minute

Artery and Vein - A Closer Look at Blood Vessels In this photo, you can compare the wall of an artery with the wall of a vein.

Comparing and Contrasting - A Closer Look at Blood Vessels Comparing and Contrasting As you read, compare and contrast the three kinds of blood vessels by completing a table like the one below. Blood Vessel Function Structure of Wall Thick wall consisting of three cell layers with thick muscle in the middle layer Artery Carries blood away from the heart Exchange of materials between the blood and body cells Capillary Thin walls consisting of one cell layer Thick walls consisting of three cell layers with thin muscle in the middle layer Carries blood back to the heart Vein

End of Section: A Closer Look at Blood Vessels

- Blood and Lymph Blood Blood consists of liquid plasma and three kinds of cells—red blood cells, white blood cells, and platelets.

Blood Types - Blood and Lymph The marker molecules on your red blood cells determine your blood type and the type of blood that you can safely receive in transfusions.

Blood Type Distribution - Blood and Lymph Blood Type Distribution The circle graph shows the percentage of each blood type found in the U.S. population.

Blood Type Distribution - Blood and Lymph Blood Type Distribution Reading Graphs: What does each edge of the graph represent? The percentage of each blood type found in the United States population

Blood Type Distribution - Blood and Lymph Blood Type Distribution Interpreting Data: Rank the four major blood types—A, B, AB, and O—from least common to most common. What is the percentage of each type? AB (4%), B (11%), A (40%), O (45%)

Blood Type Distribution - Blood and Lymph Blood Type Distribution Calculating: According to the graph, what percentage of the population is Rh positive? What percentage is Rh negative? 84%; 16%

Blood Type Distribution - Blood and Lymph Blood Type Distribution Predicting: What type of blood can someone who is B negative (blood type B and Rh negative) receive? What percentage of the population does that represent? O negative or B negative blood; 9%

Blood Type Distribution - Blood and Lymph Blood Type Distribution Creating Data Tables: Use the data to make a table of the eight possible blood types. Include columns for the A, B, AB, and O blood types; Rh factor (positive or negative); and percentage of the population. The data should be arranged in three columns and eight rows.

The Lymphatic System - Blood and Lymph The lymphatic system is a network of veinlike vessels that returns the fluid to the bloodstream.

Identifying Main Ideas - Blood and Lymph Identifying Main Ideas As you read the section titled “Blood,” write the main idea in a graphic organizer like the one below. Then write four supporting details that give examples of the main idea. Main Idea Blood is made up of four components. Detail Detail Detail Detail Plasma is the liquid part of blood. Red blood cells take up oxygen and deliver it to cells in the body. White blood cells fight disease. Platelets help form blood clots.

Click the Video button to watch a movie about blood. - Blood and Lymph Blood Click the Video button to watch a movie about blood.

Click the SciLinks button for links on blood. - Blood and Lymph Links on Blood Click the SciLinks button for links on blood.

End of Section: Blood and Lymph

Cardiovascular Health Asking Questions Before you read, preview the red headings. In a graphic organizer like the one below, ask a what or how question for each heading. As you read, write answers to your questions. Cardiovascular Health Question Answer What are some cardiovascular diseases? Cardiovascular diseases include atherosclerosis and hypertension. How can a person keep healthy? Exercise regularly, eat a healthy diet, and avoid smoking.

Links on Cardiovascular Problems - Cardiovascular Health Links on Cardiovascular Problems Click the SciLinks button for links on cardiovascular problems.

End of Section: Cardiovascular Health

Graphic Organizer Side of Heart Where Loop Starts Where Blood Flows to Where Blood Returns to Loop Loop One Right side Lungs Left atrium Loop Two Left side Body Right atrium

End of Section: Graphic Organizer