In this anatomy lesson, i’m going to cover the pelvic girdle, which consists of the 2 hip bones. The hip skeleton are described by various names, such as os coxae or coxal bones, innominate bones, or the pelvic bones.

You are watching: Deep socket in the hip bone that receives the head of the thigh bone

The pelvic girdle is part of the appendicular skeleton, and it not only protects the organs in your pelvic region, however it likewise attaches the lower limbs of the appendicular skeleton to the sacrum of the axial skeleton.

Are the Hipbones Classified as Irregular or level Bones?

Most anatomists this day classify the i know good bones as irregular bones, though some sources have actually classified lock as level bones in the past, therefore be conscious of that.

Hip Bone Anatomy (Pelvic Girdle)

Each hip bone is split into three main regions: The ilium, ischium, and pubis. These 3 regions begin as different bones in youth, yet they later fuse with each other to kind one solid hip bone. The image below is colored to aid you visualize the different areas, which helps in identifying landmarks.


These three hip regions accomplish in and also around the acetabulum, which is the deep socket the the i know good bone. The acetabulum is easily recognized in a rap exam, and it obtain the head the the femur to kind the acetabulofemoral joint, a ball-and-socket synovial joint.

The word acetabulum sound a lot choose “acid tablets,” and the indigenous literally means vinegar cup. So ns remember the this is the small cup of vinegar that I need to swallow my acid tablets.

Now let’s talk about each major region of the hip bone, beginning with the ilium.

Ilium Anatomy Landmarks and Features

The ilium renders up the remarkable (or upper) an ar of the hip bone, and also it is called after a Latin indigenous that means “flank” or “entrails,” because that’s what the supports.

The ilium can be subdivided right into two portions:

an inferior an ar (near the acetabulum) called the “body”a superior, fans out portion called the “wing,” or alaAnterior premium iliac spine – ~ above the anterior (or front) next of the ilium, the ilium has two point out (spines). The premium (or top) spine is referred to as the anterior superior iliac spine, and it permits for the attachments of the inguinal ligament, as well as the sartorius muscle.Anterior worse iliac spine – The anterior inferior iliac spine allows for the attachment of the the rectus femoris muscle, as well as the iliofemoral ligament that the i know well joint.Posterior remarkable iliac spine – ~ above the posterior (or back) next of the ilium, we additionally have 2 spines. The posterior exceptional (top) iliac spine permits for the attachment of component of the posterior sacroiliac ligaments, and the multifidus.Posterior inferior iliac spine – The posterior worse (lower) iliac spine is just below the superior iliac spine.Greater sciatic notch – just under the posterior worse iliac spine, you’ll notification a huge notched area, which is dubbed the better sciatic notch. This notch permits for the i of the sciatic nerve, and it will aid you determine the posterior region of the i know good bone.Gluteal surface – from the lateral (side) see of the ilium, you can see three distinct lines on the ala (wing) the are called after their loved one directional state (posterior, anterior, and also inferior gluteal lines). These lines carry out attachment for gluteal muscles.Iliac fossa – once you upper and lower reversal the hip bone around and also look in ~ the medial (inner) view, you’ll notification the huge depression at the anterior region, called the iliac fossa. This is wherein the iliacus muscle attaches.Auricular surface – The auricular surface is on the posterior region of the ilium, and also this articulates v the sacrum the the vertebral pillar to form the sacroiliac joint.Arcuate line – Finally, we have a significant line ~ above the medial side the extends from the auricular surface ar down come the pubis, dubbed the arcuate line. This line serves together a landmark that separates the human body of the ilium from the ala (wing).

Ischium Anatomy Landmarks and also Features

Now let’s talk about the ischium that the i know good bone (coxal bone), i m sorry is the lower rear section (or posterior worse region) the the hip bone.

Like the ilium, the ischium deserve to be split into two key regions:

The ischial body, which makes up the superior an ar of the ischium and forms around two-fifths the the acetabulumThe ischial ramus, i m sorry is a branch-like framework that provides up the inferior part of the ischium and connects come the inferior ramus that the pubisIschial spine – on the posterior region, you’ll an alert a projection dubbed the ischial spine. This permits for the attachment of assorted muscles and also ligaments: gemellus superior, coccygeus, levator ani, pelvic fascia, and also sacrospinous ligament.Lesser sciatic notch – below the ischial spine is the lesser sciatic notch, which permits the passage of nerves and vessels.Ischial tuberosity – on the lateral side of the ischium is the ischial tuberosity, a roughened bump that permits for the attachments of the sacrotuberous ligament, and also several muscles: adductor magnus, the biceps femoris, and also the semitendinosus.

Pubis Anatomy Landmarks and Features

Finally, we have actually the last significant section of the i know good bone, the pubis. Words pubis method “sexually mature,” and by thinking of her pubic region and private parts, you have the right to remember that this is the area of the i know good bone the is the anterior (front) portion. You can usually feel your pubic bone if friend palpate in the region.


Like the ischium and ilium, the pubis likewise has a body, however it has two rami coming off the body, which enable for the attachment of miscellaneous muscles and also ligaments.

Superior ramus – The premium ramus is the upper section of the pubis that branches out. Over there is a ridge on premium border the this ramus called the pectineal line, which allows for the attachment of miscellaneous ligaments and also muscles, and it forms part of the pelvic brim. Some of the structures that attach to this encompass the lacunar ligament, conjoint tendon, pectineal ligament, pectineus muscle, and psoas boy muscle.Inferior ramus – The inferior ramus is the lower section of the pubis the branches out.Obturator foramen – These 2 rami of the pubis sign up with the ischium, developing a large hole in the i know well bone dubbed the obturator foramen. Words foramen refers to a feet in a bone, and also this is the biggest “bone hole” in the human being body. This huge hole permits for the i of the obturator artery, vein, and also nerve. The obturator muscles also attach near this region. I had actually an anatomy professor in college that told united state that come remember the obturator muscle, we can imagine a man running his hand up a girl’s leg, reasoning that he’s some sort of smooth obturator (like the song).Pubic crest – top top the anterior (front) next of the pubis body, you’ll discover a pickled in salt of bone called the pubic crest, which enables for the attachments of the inguinal falx, and also the ab external oblique and also pyramidalis muscles.Pubic tubercle – over there is a tiny bump wherein the pubic stakes (laterally) joins with the premium pubic ramus (medially), dubbed the pubic tubercle, to which the inguinal ligament attaches.Pubic symphysis (or symphysis pubis) – The two pubic bones room joined with each other by a cartilaginous joint referred to as the pubic symphysis, i m sorry is a nonsynovial amphiarthrodial joint.

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Free Quiz and more Anatomy Videos

Take a complimentary hip skeletal anatomy quiz to test her knowledge. In addition, you might want to clock our anatomy and also physiology lectures top top YouTube, or inspect our anatomy and physiology notes.