Musculoskletal System

Question 1

What are the four main functions of the skeleton?

Answer 1

1. Support: Provides structure and shape to the body.
2. Protection: Protects vital organs (e.g., skull protects the brain, ribs protect the heart and lungs, vertebrae protect the spinal cord).
3. Movement: Acts as a framework for muscles to pull on, enabling movement.
4. Production of Blood Cells: Produces red blood cells, white blood cells, and platelets in the bone marrow.

Question 2

What are the two main divisions of the skeleton? Name the bones included in each.

Answer 2

1. Axial Skeleton: Skull, ribs (12 pairs), sternum, and vertebrae.
2. Appendicular Skeleton: Pectoral girdle, pelvic girdle, and attached limbs (arms and legs).

Question 3

How are the 12 pairs of ribs classified?

Answer 3

1. 7 pairs of true ribs: Attached to the vertebrae and sternum.
2. 3 pairs of false ribs: Attached to the vertebrae and the rib above them.
3. 2 pairs of floating ribs: Attached only to the vertebrae.

Question 4

What is the role of intervertebral discs of cartilage?

Answer 4

They absorb shock and protect the vertebrae.
They also allow slight movement between vertebrae.

Question 5

What is a joint, and what are the three main types?

Answer 5

A joint is where two bones meet. The three main types are:
1. Immovable joints: Allow no movement (e.g., skull).
2. Partially movable joints: Allow slight movement (e.g., between vertebrae).
3. Movable joints (synovial joints): Allow significant movement (e.g., shoulder, hip, knee).

Question 6

What are the two main types of synovial joints? Provide examples.

Answer 6

1. Ball and Socket Joints: Allow movement in all directions (e.g., shoulder and hip).
2. Hinge Joints: Allow movement in one direction (e.g., knee and elbow).

Question 7

What are the components of a synovial joint, and what are their functions?

Answer 7

1. Synovial fluid: Lubricates the joint and absorbs shock.
2. Cartilage: Reduces friction and acts as a shock absorber.
3. Ligaments: Attach bone to bone.
4. Tendons: Attach muscle to bone.
5. Synovial membrane: Produces synovial fluid.

Question 8

What are the functions of compact and spongy bone?

Answer 8

• Compact Bone: Provides strength and protection; found at the outer edges of bones and in the diaphysis.
• Spongy Bone: Makes bones lighter and contains red bone marrow for blood cell production; found in the epiphyses.

Question 9

Differentiate between red and yellow bone marrow.

Answer 9

1. Red Bone Marrow:
   • Produces blood cells.
   • Found in spongy bone (epiphyses).
2. Yellow Bone Marrow:
   • Stores fat and can convert to red marrow if needed.
   • Found in the medullary cavity.

Question 10

What is ossification, and where does bone growth occur?

Answer 10

• Ossification is the process where cartilage is replaced by bone.
• Bone growth occurs at the growth plate, a cartilage layer between the epiphysis and diaphysis.

Question 11

What are osteoblasts and osteoclasts? What roles do they play in bone development?

Answer 11

1. Osteoblasts: Bone-producing cells that deposit collagen and calcium salts to form bone.
2. Osteoclasts: Bone-digesting cells that break down bone, releasing calcium into the blood.
   Together, they ensure bones grow in size and strength without becoming too heavy.

Question 12

What factors affect bone renewal?

Answer 12

1. Activity: Physical activity strengthens bones by stimulating osteoblasts.
2. Diet: Calcium is essential for maintaining bone strength.
3. Hormones: Parathormone regulates calcium levels by removing it from bones when needed.

Question 13

Draw the structure of a long bone

Answer 13

Question 14

Draw a synovial joint

Answer 14

Question 15

How do muscles provide movement?

Answer 15

Muscles provide movement by pulling on bones when they contract. They are always arranged in pairs known as antagonistic pairs, which operate in opposite directions.

Question 16

What are antagonistic pairs of muscles, and give an example?

Answer 16

Antagonistic pairs are pairs of muscles that work in opposite directions.

Example: Biceps and triceps control arm movement. When the biceps contract, the arm is pulled up, and the triceps relax. When the triceps contract, the arm is pulled down, and the biceps relax.

Question 17

What is osteoporosis?

Answer 17

Osteoporosis is a condition where large spaces form in the bones, weakening them and making them more prone to fractures.

Question 18

What causes osteoporosis?

Answer 18

1. Changes in hormone levels (e.g., menopause in women). 2. Low levels of physical activity, particularly weight-bearing exercises. 3. Aging.

Question 19

How is osteoporosis treated?

Answer 19

Hormone Replacement Therapy (HRT): Helps restore hormonal balance. Calcium and Vitamin D supplements: Strengthen bones. Treatment varies depending on age, diet, and sex of the patient.

Question 20

How can osteoporosis be prevented?

Answer 20

1. Physical activity: Engage in weight-bearing exercises (e.g., walking, running) to stimulate bone growth. 2. Diet: Maintain a diet rich in calcium (e.g., dairy products, leafy greens) and vitamin D (e.g., sunlight, fish oils).