Human Skeletal System

What is the main function of the skeletal system?

• Produce hormones

• Protect internal organs and provide structure

• Regulate body temperature

• Transport nutrients

Answer explanation

The main function of the skeletal system is to protect internal organs and provide structure to the body. It serves as a framework that supports the body and safeguards vital organs from injury.

How many bones are in the adult human skeleton?

• 200

• 206

• 212

• 215

Answer explanation

The adult human skeleton typically contains 206 bones. This number can vary slightly due to anatomical variations, but 206 is the standard count recognized in human anatomy.

What is the longest bone in the human body?

• Tibia

• Femur

• Humerus

• Radius

Answer explanation

The femur, or thigh bone, is the longest bone in the human body, measuring about 18 inches on average. It supports the weight of the body and allows for movement, making it crucial for activities like walking and running.

Which of the following bones is part of the axial skeleton?

• Femur

• Humerus

• Sternum

• Pelvis

Answer explanation

The sternum is part of the axial skeleton, which includes the skull, vertebral column, and rib cage. The femur, humerus, and pelvis are part of the appendicular skeleton, which supports limb attachment.

What type of joint allows for movement in all directions, such as the shoulder joint?

• Hinge joint

• Ball-and-socket joint

• Pivot joint

• Saddle joint

Answer explanation

The ball-and-socket joint, like the shoulder joint, allows for movement in all directions, including rotation. This is in contrast to hinge joints, pivot joints, and saddle joints, which have more limited movement.

Which bone protects the brain?

• Sternum

• Cranium

• Scapula

• Vertebrae

Answer explanation

The cranium is the part of the skull that encases and protects the brain. Other options like the sternum, scapula, and vertebrae do not serve this protective function.

The vertebral column is divided into how many regions?

• 2

• 3

• 4

• 5

Answer explanation

The vertebral column is divided into 5 regions: cervical, thoracic, lumbar, sacral, and coccygeal. Therefore, the correct answer is 5.

What is the primary mineral stored in bones that makes them strong?

• Potassium

• Sodium

• Calcium

Answer explanation

Calcium is the primary mineral stored in bones, providing strength and structure. It plays a crucial role in bone density and overall skeletal health, making it essential for strong bones.

Which part of the skeleton includes the limbs and girdles?

• Axial skeleton

• Appendicular skeleton

• Ribcage

• Vertebral column

Answer explanation

The appendicular skeleton includes the limbs (arms and legs) and the girdles (shoulder and pelvic girdles), while the axial skeleton consists of the skull, ribcage, and vertebral column.

What role does the periosteum play in the skeletal system?

• It produces red blood cells.

• It stores calcium and phosphorus.

• It is a tough membrane covering the bone that nourishes and protects it.

• It connects bones to muscles.

Answer explanation

The periosteum is a tough membrane that covers bones, providing nourishment and protection. It does not produce blood cells, store minerals, or connect muscles to bones, making the correct choice about its protective and nourishing role.