ملخص Structure and support في العلوم باللغة الإنجليزية للصف السادس (2)

Structure and support -SUMMARY

What supports a body and enables it to move? Muscle

• Muscles enable the body to move but cannot function without the support of bones.
• The skeletal system and the muscular system work together and move your body. Joints
• A joint is where two or more bones meet and work together. Joints provide flexibility and movement.
• Bones are connected to other bones by tissues called ligaments. • When the bones in the joint move, ligaments stretch and keep the bones

from shifting away from each other.

Three different types of joints enable movement.

1. Ball and socket 2. Hinge 3. Pivot

Immovable joints are parts of your skeleton made of bones that connect but do not move. Your skull contains several

immovable joints

Functions of skeletal system ➢ Support

Bones provide support that helps you sit up, stand, and move your body. ➢ Protection

Bones protect soft fragile tissue of the brain and internal organs like the spinal cord, heart, and lungs from damage.

➢ Production and storage • Bones produce and store materials needed by your body. • Red blood cells are produced inside your bones. • Bones store fat and calcium. • When your body needs calcium, it is released from bones into the blood.

Types of support and structure. 1. Hydrostatic Skeletons (Fluid Support)

• It is a fluid filled internal cavity surrounded by muscle tissue. • Muscles help the organisms move by pushing the fluid in different

directions

• Examples: Sea anemones, flatworms, and earthworms.

2. Exoskeletons (External Support)

• A thick, hard outer covering that protects and supports (shells) an animal’s body.
• Examples: crabs, snails, and scorpion

3.Skeletal skeleton (internal Support)

• provide support that helps you sit up, stand, and move your body.

What do different types of muscles do?

1- Skeletal muscle is the type of muscle that attaches to bones. • Skeletal muscles are also called voluntary muscles, which are muscles you can

consciously control. • The contractions of skeletal muscles can be quick and powerful. 2- Cardiac Muscle cardiac muscle, which is found only in the heart. • A cardiac muscle is a type of involuntary muscle, which is muscle you

cannot consciously control. • When cardiac muscles contract and relax, they pump blood through

your heart and through blood vessels throughout the body.

3-Smooth Muscle Smooth muscles are involuntary muscles, named for their smooth appearance, that line blood vessels and many organs. •Contraction of smooth muscles helps move material through the body, such as food in the stomach and blood through the vessels.

What systems do plants have that give them structure and support?

1- Roots enable the plant to grow upright and not be blown away by wind or carried away by water.

2- Roots also absorb water and minerals from the soil for cellular processing.

3- Some plants store food in their roots. There are many different types of roots:

➢ There are many different types of roots : 1- Prop roots are additional small roots above ground, that help support the plant. 2- Fibrous roots consist of many small branching roots. 3- Fibrous roots can spread out and can absorb large amounts of water.

2-Stem:

The tree has a woody stem because it is rigid and not green, the vine has herbaceous stem because it is green and flexible.