Question

Os Innominatum consists of
a. Pubis
b. Ischium
c. Ilium
d. All of the above

Answer 1

Hint: The hip bone is also known as pelvic bone/coxal bone/innominate bone. The hip bone has numerous names such as Os coxae, innominate bone, pelvic bone, coxal bone. Pubic symphysis joins the left and right hip bones. Before puberty the components of hip bone are found separated by the cartilage but during puberty they get ossified.

Complete answer:

Structure: Hip bone consists of three bones - the ilium, ischium, and pubis. Pre puberty, these bones are separated by cartilage but during puberty the three parts fuse and ossify. The ilium or iliac bone is a paired bone that forms the uppermost part of the hip bone. The bone consists of a body and wing.
The ischium is a paired bone that forms the lower and posterior part of the hip bone. It has two parts: Body and Ramus.
The pubis or pubic bone is a paired bone that forms the anterior part of the hip bone and the anterior and inferior boundary of the obturator foramen. It is composed of three main parts: Body and Rami (Two in number) - superior ramus and inferior ramus. The three parts of the hip bone create anatomical structures between them such as the acetabulum and obturator foramen.
Acetabulum
The acetabulum is a cup-shaped deep cavity in the hip bone. It is the structure where the head of femur bone fits and forms the hip joint. Acetabulum is created by the joint association of all three bones of the hip bone.
The acetabulum has the following regions:
> lunate surface
> acetabular fossa
> acetabular notch
> iliopubic eminence
> Obturator foramen
The obturator foramen is a large opening on either side of the pelvic bone. It is formed by the ischium and pubis of the hip bone. It is the passage through which the obturator artery, vein, and nerve pass out of the pelvis.
Obturator foramen is marked by a deep groove called the obturator groove which runs from the pelvis obliquely in a medial and inferior direction. The obturator groove later changes into the obturator canal with the help of a ligamentous band. a specialized part of the obturator membrane. This ligamentous band attaches to two tubercles:
> posterior obturator tubercle
> anterior obturator tubercle

So, the correct answer is option (D) All of the above.

Note: The hip bone has numerous names such as Os coxae, innominate bone, pelvic bone, coxal bone. It has irregular structure. It is a large bone. Constriction is found in the center and is expanded from above and below. Before puberty the ilium, ischium, and the pubis of hip bone are found separated by the cartilage. During puberty they get ossified. Hip bone consists of three parts: the ilium, ischium, and the pubis.