unit 3 lesson 4 how do our bodies move, breathe, and circulate blood? copyright © houghton mifflin...

Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?

Copyright © Houghton Mifflin Harcourt Publishing Company

Strong Bones



Strong Bones


• Bones, ligaments, and cartilage form the skeletal system.

• Bones are organs that support and protect the body, store minerals, and allow movement.

• Bones have a hard outer layer that contains calcium and a spongy inner layer called marrow where blood cells are made.


Strong Bones



Strong Bones


• Cartilage cushions the ends of bones and forms flexible parts such as your ears and nose.


Strong Bones


• Ligaments connect bones at joints.

• The place where two or more bones meet is called a joint.


Strong Bones


• Some joints, like those in the skull, don’t move. Other joints allow movement.

• Ball-and-Socket Joints allow circular movement, like the joint in your shoulder.

• Hinge Joints allow back-and-forth movement, like the hinge in your knee.

• Pivot Joints allow rotation from side to side, like the joint in your neck.


Strong Bones



Mighty Muscles


• Muscles are organs that contract to produce movement in the body.

• There are three types of muscles in the muscular system.

1. The heart is made of one type.

2. The walls of blood vessels and organs are made of another type of muscle.

3. A third type, the skeletal muscle, pulls bones to help us move.


Mighty Muscles



Mighty Muscles



• Tendons are strong bands of tissues that connect skeletal muscles to bones.

Mighty Muscles



• Muscle movement can be involuntary or voluntary. • Involuntary movements happen without thinking about

them, like your heart beating.• Voluntary movements can be controlled, such as running

and playing.

Mighty Muscles



• Muscles often work in pairs.

• When one muscle contracts, the other muscle in the pair relaxes.

• The contracting muscle moves the bone that it’s attached to.

Mighty Muscles



Breathe In, Breathe Out


• Organs in the respiratory system bring in oxygen and release carbon dioxide.

• Lungs, the main organs of the respiratory system, are spongy organs that expand to fill with air.

• Air enters the body through the nose or mouth and flows through a tube in the throat called the trachea.




• The trachea branches into two smaller tubes called bronchi.

• Bronchi branch into many bronchioles in the lungs.• Tiny sacs called alveoli are attached to bronchioles. Red

blood cells in the alveoli absorb oxygen.




• They inflate and deflate as you inhale and exhale.





Word BankAlveoliAlveoliBronchiBronchi

BronchiolesBronchioles

TracheaTrachea

Carbon dioxideOxygen

Asthma Attack


• Asthma is an illness that makes it hard for a person to breathe.

• During an asthma attack, bronchi become swollen, making airways smaller. This makes it much harder to get air in and out of the lungs.


Constricted Airways

Asthma Attack



Constricted Airways

Asthma Attack



Triggers• The exact causes of

asthma aren’t known.

• Some people are born with asthma, while for other people, smoke, air pollution, and allergies can trigger an asthma attack.

Asthma Attack



• People can try to avoid asthma triggers; however, people can’t always avoid pollen or air pollution.

• A doctor can prescribe an inhaler, a device that delivers medication to the lungs. The inhaler releases a mist that can help open up airways.

Management

Beat It


• The heart, vessels, and blood are all part of the circulatory system.

• The heart is a muscular organ that pumps blood throughout the body. It contracts in two phases.

• When the top part relaxes, it fills with blood. When it contracts, the top part squeezes blood to the lower part.

• When the lower part contracts, it squeezes blood from the heart into vessels and all parts of the body.


Beat It


• Blood is made up of a clear liquid called plasma and small structures called blood cells.

1. Red blood cells carry oxygen throughout the body.

2. White blood cells help fight disease.

3. Platelets stop bleeding by forming clots.

4. Plasma carries nutrients throughout the body.


Beat It


• Arteries carry blood away from the heart. Veins bring blood back to the heart from the lungs and the body.

• Oxygen, nutrients, and carbon dioxide pass through capillaries, or tiny vessels with very thin walls, to parts of the body and into the blood.


Beat It



unit 3 lesson 4 how do our bodies move, breathe, and circulate blood? copyright © houghton mifflin...

Documents

blood cells

walls of blood vessels

muscle movement

ends of bones

bones meet

hinge joints

socket joints

circular movement