Matric Notes Biology Class 10th Ch 13 Support and Movement Short Questions

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Q1: Why are bones considered as dynamic structures?

Ans: Bones are dynamic structures:

Definition: Dynamic structure are those structure which could be changed or modified.

Reason: Bones are the dynamic structure due to the following reason.

1. In embryonic stage ( in fetus) the whole skeletal is made from cartilage which is changed into bony skeleton during birth.
2. At the time of birth the baby body possess 350 bones , which are fused together and reduced to 206 bones.
3. Reducing of fracture bones can occur which shows its dynamic nature. Mineralization of calcium salts always occur which make the bones strong.
4. De mineralization of calcium occurs due to which the bones become weak , fragile , bend which lead to osteoporosis.

Q2: What is the contribution of VESALIUS in understanding the human skeleton?

Ans: Contribution Of Vesalius(1514-1564): Andreas Vesalius was born in Brussels. He was professor of anatomy at Padua University in Italy.

His book: In 1543, he wrote the first major book on human anatomy. It was called “de Humani Corpris Fabrica” (The Fabric of the Human Body).

His work: Vesalius worked closely with the famous artist titian who produced 277 anatomical illustrations for his book.. He explained the different parts of the human skeleton, including the number of bones . he also described the source and position of each muscles and provided information on their respective function.

Q3: Describe the function of three major types of joints and give an example of each.

Ans: Joints: The meeting points (junction) of two or more bones are called joints. At the joints bones are held together by the ligaments. Function :

i. Joints keep our bones together by holding them with each other.
ii. They also allow the bones to move in different directions.
iii. They give mobility to our body.
iv. Without joints our skeleton would be stiff , rigid and one piece.

Types of joints:

Joints are classified into the following three sections.

1. Immovable joints.
2. Slightly movable joints
3. Freely movable joints

1. Immovable joints: In immovable joints the bones are fused together and do not allow any movement.

For example: The joints present among the bones of the skull are immovable.

2. Slightly movable joints: These are the joints which allow the little movement.

For example: Joints of the vertebral column , ribs etc.

3. Freely movable joints: These are the joints which allow free movement.

Types:

There are two major types of freely movable joints.

• Hinge joints
• Ball and socket joints.

Hinge joints: Hinge joints allow movements only in two directions.

Examples:

• Elbow joint
• Knee joints

Ball and socket joints Ball and socket joints allow movements in all directions i.e

• Up
• Down
• Forward
• Backward

Example:

✓ Hip joints
✓ Shoulder joints

Q4:How are the different types of arthritis caused?

ANS: Definition: Arthritis is the disorder of the joints when they get inflamed. This is a degenerative disease that damage the joints permanently.

Symptoms:

a. Pain of the joints
b. stiffness of the joints
c. swelling of the joints

In this disorder , membrane lining the joints thicken and fluid production is decreased , which result in increased friction causing severe pain and in later stages complete immobility. With the passage of the joints become permanently swollen and get de-shaped.

Types:

The different types of arthritis are

i. osteoarthritis
ii. arthritis
iii. rheumatoid gouty arthritis

Causes :

The causes of the arthritis depends upon the form of arthritis. It includes

• Injury leading to osteoarthritis
• Metabolic abnormalities
• A reduction in the normal amount of cartilage tissue cause some form arthritis.
• Alcohol and tobacco
• Salts and preservatives
• Fried and processed
• Sugar and refined carbs

Q5: Differentiate between the skeletal muscles origin and insertion?

Ans: Origin: One end of a skeletal muscle is always attached with some fixed bone while the other end is attached to a moving bone. The point where the muscle attaches to the fixed bone is called origin.

Insertion: The point where the muscles attaches to a movable bone is called insertion.

Q6: State the function of flexors and extensors.

1. Ans: Flexion:- When we try to bend ( or flex ) the lower arm, the biceps contracts, its insertion with ulna bone pulls the born upward, at the same time the triceps relaxes and the lower arm move upwards and the flexion takes place at elbow joint.

2. Extension:- When we try to straighten our hand the triceps first, its insertion with radius bone pulls the bone back. At the same time the biceps relaxes and allows the ulna bone to move down easily, hence extension of lower arm takes place at elbow joint.

Q7: What are the ligaments and tendons? What function do they perform?

Ans: Ligaments: Ligaments are tough bands of connective tissue.

Function: It holds the bones at the joints, in place.

Tendons: Tendons are tough connective tissues which attach muscles to bones.

Function : When the muscles contract, the tendons exert a pulling force on the attached bones. As a result the bone is pulled towards the muscle.

Q8: State the five function of bones?

Ans: Bones: Bones are the hardest and the most rigid form of connective tissue in the human body.

1.Aid in movements: The bones are helpful and supportive in movements, muscles pull over bones to enable movements.

2. Storage area for minerals: They act as a storage area for minerals, particularly calcium.

3. Shape and structure: Bones give shape and structure to the body.

4. Protection: It provides support and protection to the delicate internal organs.

5. Blood cells: The internal portion of the many bones produces many red blood cells, platelets and white blood cells.