Lab 10:The Skeletal System: Appendicular Skeleton

Question 1

What is the appendicular skeleton composed of?

Answer 1

126 bones that form the upper limbs, pectoral girdle, lower limbs, and pelvic girdle.

Question 2

What is the main function of the appendicular skeleton?

Answer 2

Provides important surfaces for muscle attachment, enabling complex body movements.

Question 3

What bones make up the appendicular skeleton?

Answer 3

Pectoral Girdle: Clavicle, Scapula

Upper Limb: Humerus, Ulna, Radius, Carpals, Metacarpals, Phalanges

Pelvic Girdle: Coxal bone

Lower Limb: Femur, Patella, Tibia, Fibula, Tarsals, Metatarsals, Phalanges

Question 4

What does each pectoral girdle consist of?

Answer 4

One scapula and one clavicle (right and left sides).

Question 5

What is the function of the pectoral girdles?

Answer 5

Provide attachment sites for muscles of the shoulder and brachium (upper arm).

Question 6

What is the scapula?

Answer 6

Also called the shoulder blade, it is a triangular bone with projections for muscle attachment.

Question 7

What are carpals?

Answer 7

Eight short bones that form the wrist (carpus).

Question 8

What is the function of the pelvic girdle?

Answer 8

Supports the upright weight of the body and provides attachment sites for muscles of the hip and thigh.

Question 9

What does the pelvic girdle consist of?

Answer 9

Two hip (coxal) bones, which connect the lower limb to the axial skeleton.

Question 10

What are the three bones that fuse to form a coxal bone during childhood?

Answer 10

Ilium, ischium, and pubis.

Question 11

What is the acetabulum?

Answer 11

A large socket that receives the head of the femur at the hip joint.

Question 12

What is the obturator foramen?

Answer 12

A large opening in the coxal bone that allows nerves and blood vessels to pass through.

Question 13

Where do the two coxal bones articulate?

Answer 13

Anteriorly: At the pubic symphysis (slightly flexible joint)

Posteriorly: With the sacrum at the sacroiliac joints

Question 14

What structure do the coxal bones and sacrum form together?

Answer 14

The pelvis.

Question 15

What are the differences between male and female pelvises?

Answer 15

Male pelvis: Thicker, rougher, more vertical, heart-shaped pelvic inlet, pubic arch ≤ 90°

Female pelvis: Larger, round pelvic inlet, pubic arch ≥ 100°, tilted posteriorly and flared — allows more space for childbirth