Question

Illium is the part of
A. Small intestine
B. Pectoral girdle
C. Pulmonary tract
D. Pelvic girdle

Answer 1

Hint: Two irregularly shaped bones forming part of the pelvic girdle are the left and right hip bones (innominate bones, pelvic bones)-the bone structure that links the axial skeleton to the lower limbs.

Complete Answer:
- The hip bone consists of three parts: ilium, pubis and ischium. Prior to puberty, the triradiate cartilage divides these parts – and the fusion starts only at the age of 15-17.
- Together, ilium, pubis and ischium form a cup-shaped socket known as acetabuli (literal sense in Latin is 'vinegar cup').
- The ilium is the widest and highest of the three sections of the hip bone and is situated in a superior location. The body of the ilium is the upper portion of the acetabulum (acetabular roof). Immediately above the acetabular, the ilium extends to form a wing (or ala).

There are two surfaces on the wing of the ilium:
1. Inner surface – has a concave form that creates an iliac fossa (the origin site of the iliac muscle).
2. The external surface or the gluteal surface has a convex shape and the gluteal muscles are attached.
- The upper margin of the wing is thickened, creating an iliac crest. It ranges from the anterior upper iliac spine (ASIS) to the posterior upper iliac spine (PSIS).
- The widest measurement of the pelvis, taken across the upper iliac bones, is referred to as the biiliac width. This calculation is critically important in obstetrics, since it can be predicted whether or not a pregnant woman would require a caesarean section, based on the size of the head of the infant.
- As such, ilium has a weight-bearing purpose and is part of the system that ensures that the spine is stabilised while the body is upright. It is therefore important as part of the locomotive-enabled apparatus.

The correct Answer is option (D) Pelvic girdle.

Note: Problems in the pelvis — most frequently seen in women — may affect this bone, such as endometriosis (in which uterine lining is found outside the uterus, leading to bleeding and other symptoms), pelvic inflammatory disease (formation of scar tissue that interferes with fertility), uterine fibroids (benign uterine tumours), and others.