circulation the body’s transport system a closer look at blood vessels blood and lymph...

Circulation

The Body’s Transport System

A Closer Look at Blood Vessels

Blood and Lymph

Cardiovascular Health

Table of Contents

Circulation - The Body’s Transport System

The Cardiovascular SystemThe 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.

Circulation

The Cardiovascular System

Jobs of the Cardiovascular System

1.Deliver Needed Materials• Blood carries oxygen to

all the cells in your body

2.Remove Waste Products• When cells break down

glucose for energy, carbon dioxide is released as waste

3.Fight Disease• Blood transports disease-

fighting cells all around your body


The HeartThe 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.

Circulation

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

As blood flows out of the heart and toward the lungs, it passes through a valve like the one here.

Circulation

How the Heart WorksThere are two main phases of action:

1.Heart muscle relaxes while the heart fills with blood

2.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

Circulation

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

Circulation

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

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.

Circulation

Heart Activity

Click the Active Art button to open a browser window and access Active Art about the heart.

- The Body’s Transport System

Circulation

SequencingAs 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

Lungs

Left side of heart

Body

- The Body’s Transport System

Circulation

End of Section:The Body’s Transport

System

Circulation

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

Circulation

Blood Vessels of the BodyAfter 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

Circulation

ArteriesPurpose: 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

Circulation

The Arteries Regulate Blood FlowThe 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?

Circulation

CapillariesPurpose: 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

Circulation

VeinsPurpose: 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

Circulation

Blood PressureQ: 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

Circulation

Complete the Target Reading Chart on Comparing Blood Vessels!

Circulation - A Closer Look at Blood Vessels

Blood Vessels

The walls of arteries and veins have three layers. The walls of capillaries are only one cell thick.

Circulation

Calculating a Rate 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.

- A Closer Look at Blood Vessels

Circulation

Calculating a Rate

Practice Problem

Calculate your pulse rate if your heart beats 170 times in 2.5 minutes.

68 beats per minute


Circulation - A Closer Look at Blood Vessels

Artery and Vein

In this photo, you can compare the wall of an artery with the wall of a vein.

Circulation

Blood Vessel Function Structure of Wall

Comparing and ContrastingAs you read, compare and contrast the three kinds of blood vessels by completing a table like the one below.

Artery Carries blood away from the heart

Thick wall consisting of three cell layers with thick muscle in the middle layer

CapillaryExchange of materials between the blood and body cells

Thin walls consisting of one cell layer

VeinCarries blood back to the heart

Thick walls consisting of three cell layers with thin muscle in the middle layer


Circulation

End of Section:A Closer Look at

Blood Vessels

Circulation - Blood and Lymph

Blood

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


Blood Types

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

Circulation

Blood Type Distribution

The circle graph shows the percentage of each blood type found in the U.S. population.

- Blood and Lymph

Circulation


The percentage of each blood type found in the United States population

Reading Graphs:

What does each edge of the graph represent?

- Blood and Lymph

Circulation


AB (4%), B (11%), A (40%), O (45%)

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?

- Blood and Lymph

Circulation


84%; 16%

Calculating:

According to the graph, what percentage of the population is Rh positive? What percentage is Rh negative?

- Blood and Lymph

Circulation


O negative or B negative blood; 9%

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?

- Blood and Lymph

Circulation


The data should be arranged in three columns and eight rows.

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.

- Blood and Lymph


The Lymphatic System

The lymphatic system is a network of veinlike vessels that returns the fluid to the bloodstream.

Circulation

Identifying Main IdeasAs 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.

Blood is made up of four components.

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.

Main Idea

Platelets help form blood clots.

Detail Detail Detail Detail

- Blood and Lymph

Circulation

Blood

Click the Video button to watch a movie about blood.

- Blood and Lymph

Circulation

Links on Blood

Click the SciLinks button for links on blood.

- Blood and Lymph

Circulation

End of Section:Blood and

Lymph

Circulation

Asking QuestionsBefore 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.

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.

Question Answer

Cardiovascular Health

- Cardiovascular Health

Circulation

Links on Cardiovascular Problems

Click the SciLinks button for links on cardiovascular problems.

- Cardiovascular Health

Circulation

End of Section:Cardiovascular

Health

Circulation

Graphic Organizer

Loop

Right sideLoop One

Loop Two

Side of Heart Where Loop Starts

Where Blood Flows to

Where Blood Returns to

Left side

Lungs Left atrium

Body Right atrium

Circulation

End of Section:Graphic Organizer

circulation the body’s transport system a closer look at blood vessels blood and lymph...

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