Support and movement chapter 2 short question class 12 biology Sindh board New book

Question 1: How is cartilage useful for our skeletal system?

Cartilage plays several important roles in our skeletal system:

Joint cushioning: Cartilage covers the ends of bones in joints, acting as a shock absorber to reduce friction and prevent bones from rubbing against each other. This helps in smooth and pain-free movement.

Support and shape: Cartilage provides structure and support to various parts of the body, such as the nose, ears, and the trachea. It helps maintain the shape of these structures.

Flexibility: Unlike bone, cartilage is flexible and elastic, allowing for some degree of movement and deformation without breaking. This flexibility is crucial for the functioning of certain body parts, like the ribcage and the walls of the airways.

question 2: Give a compression of major types of joints

ans: here's a compression of major types of joints in the human body:

Ball-and-Socket Joints: These joints allow for the widest range of motion. The rounded end of one bone fits into a socket or cup-like structure of another, such as the hip and shoulder joints.

Hinge Joints: These joints enable movement in one direction, like a door hinge. Examples include the elbow and knee joints.

Pivot Joints: These joints allow rotational movement around a central axis. The joint between the first and second vertebrae in the neck is a pivot joint.

Gliding Joints: These joints permit sliding or gliding motions between bone surfaces. Examples include the joints between the wrist bones (carpals) and the ankle bones (tarsals).

Saddle Joints: These joints resemble a rider sitting in a saddle and allow for movement in two planes. The joint at the base of the thumb is a saddle joint.

Condyloid (Ellipsoidal) Joints: These joints have an oval-shaped end of one bone fitting into an elliptical cavity of another. The wrist joint is an example of a condyloid joint.

Question 3 : How is healing of fractured bone initiated pain developing

ans: The healing of a fractured bone involves a complex process, and pain can develop as a result of several factors:

Initial Injury: When a bone fractures, the initial trauma causes immediate pain. This pain can be severe and is often the result of nerve endings in the bone and surrounding tissues being damaged.

Swelling and Pressure: Swelling and the accumulation of fluids (inflammation) at the fracture site can put pressure on nerves, leading to pain. Swelling can also restrict blood flow, which can lead to discomfort.

Bone Healing Process: As the bone begins to heal, there may be pain associated with the formation of callus tissue and the remodeling of bone. This can cause discomfort until the fracture is fully healed.

question 4: How to conduct first aid treatment for joint injuries and fractures

here's the first aid that is required for the treatment for joint injuries and fractures

For joint injuries, immobilize the affected area, apply ice, elevate the affected part and seek medical help.

For fractures, immobilize the limb, apply a splint, and seek immediate medical attention

question 5: give a compression of types muscles.

Question 6 : Why is calcium essential for cross bridge formation

ans : Calcium is essential for cross-bridge formation in muscle contraction because it binds to the protein troponin, which is part of the thin filaments in muscle fibers. When calcium binds to troponin, it causes a conformational change that exposes the binding sites on the actin filaments. These binding sites are necessary for myosin, a thick filament, to attach to actin, forming cross-bridges. The formation of cross-bridges allows for the sliding of actin and myosin filaments, leading to muscle contraction. Therefore, without sufficient calcium, cross-bridge formation and muscle contraction cannot occur effectively.

question 7: How the nervous coordination regulate muscle contraction mechanism

answer: The nervous system regulates muscle contraction through the release of neurotransmitters at neuromuscular junctions, which triggers action potentials in muscle fibers, leading to the contraction of muscles.

question 8: how is tetany different from tetanus

ans : the tetany is different from tetanus in the following way

question 9 : explain the different types of cartilage

ans: There are three types of cartilage associated with skeleton which are different in their structure and function.

1) Hyaline cartilage is present in between ribs and sternum, nose and at the bone surface in many joints. It has a smooth surface that allows tissues to slide easily.

2) Fibrocartilage is the hardest among other cartilages. It is present as intervertebral disc, in knee joint and in pectoral girdle.

3) Elastic cartilage is the most flexible and strong cartilage. It is located in the pinna of the ear, external and internal auditory tubes, epiglottis, and larynx.