obturator internus muscle

Information about obturator internus muscle

The obturator internus and nearby muscles
Coronal section of anterior part of pelvis, through the pubic arch. Seen from in front. (Obturator internus labeled at right.)
Latinmusculus obturatorius internus
subject #128 477
Origin:Ischiopubic ramus & obturator membrane
Insertion:medial aspect of the Greater trochanter
Artery:
Nerve:Nerve to obturator internus (L5, S2)
Action:Abducts & rotates laterally thigh, and stabiliser of the hip during walking
Dorlands/Elsevier m_22/12549929
The obturator internus muscle originates on the medial surface of the obturator membrane, the ischium near the membrane, and the rim of the pubis.

It exits the pelvic cavity through the lesser sciatic foramen.

The Obturator internus is situated partly within the lesser pelvis, and partly at the back of the hip-joint.

It arises from the inner surface of the antero-lateral wall of the pelvis, where it surrounds the greater part of the obturator foramen, being attached to the inferior rami of the pubis and ischium, and at the side to the inner surface of the hip bone below and behind the pelvic brim, reaching from the upper part of the greater sciatic foramen above and behind to the obturator foramen below and in front.

It also arises from the pelvic surface of the obturator membrane except in the posterior part, from the tendinous arch which completes the canal for the passage of the obturator vessels and nerve, and to a slight extent from the obturator fascia, which covers the muscle.

The fibers converge rapidly toward the lesser sciatic foramen, and end in four or five tendinous bands, which are found on the deep surface of the muscle; these bands are reflected at a right angle over the grooved surface of the ischium between its spine and tuberosity.

This bony surface is covered by smooth cartilage, which is separated from the tendon by a bursa, and presents one or more ridges corresponding with the furrows between the tendinous bands.

These bands leave the pelvis through the lesser sciatic foramen and unite into a single flattened tendon, which passes horizontally across the capsule of the hip-joint, and, after receiving the attachments of the gemelli, is inserted into the forepart of the medial surface of the greater trochanter above the trochanteric fossa.

A bursa, narrow and elongated in form, is usually found between the tendon and the capsule of the hip-joint; it occasionally communicates with the bursa between the tendon and the ischium.

Additional images


Right hip bone. External surface.

Right hip bone. Internal surface.

Right femur. Anterior surface.

Structures surrounding right hip-joint.

Muscles of the gluteal and posterior femoral regions.

Sacral plexus of the right side.


External links

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.
 •  • [ e]
Muscles of lower limbs
ILIAC REGION/ILIOPSOASpsoas major - psoas minor - iliacus
BUTTOCKSgluteals: (maximus, medius, minimus) - tensor fasciae latae
lateral rotator group: piriformis - obturator externus - obturator internus - inferior gemellus - superior gemellus - quadratus femoris
THIGHanterior compartment: sartorius - quadriceps (rectus femoris, vastus lateralis, vastus intermedius, vastus medialis) - articularis genu
medial compartment/adductor: gracilis - pectineus - adductor brevis - adductor longus - adductor magnus
posterior compartment/hamstring: biceps femoris - semitendinosus, semimembranosus
LEGanterior compartment: tibialis anterior - extensor hallucis longus - extensor digitorum longus - fibularis tertius
posterior compartment: superficial - calf/triceps surae (gastrocnemius, soleus) - plantaris deep - popliteus - tarsal tunnel (flexor hallucis longus - flexor digitorum longus - tibialis posterior)
lateral compartment: fibularis muscles (longus - brevis)
FOOTdorsal - extensor digitorum brevis - extensor hallucis brevis
plantar first layer - abductor hallucis - flexor digitorum brevis - abductor digiti minimi
plantar second layer - quadratus plantae - lumbrical muscle
plantar third layer - flexor hallucis brevis - adductor hallucis - flexor digiti minimi brevis
plantar fourth layer - dorsal interossei - plantar interossei
pelvis (pl. pelvises or pelves) is the bony structure located at the base of the spine (properly known as the caudal end). The pelvis incorporates the socket portion of the hip joint for each leg (in bipeds) or hind leg (in quadrupeds).
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Latin}}} 
Official status
Official language of: Vatican City
Used for official purposes, but not spoken in everyday speech
Regulated by: Opus Fundatum Latinitas
Roman Catholic Church
Language codes
ISO 639-1: la
ISO 639-2: lat
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bold refer to the diagram at right.)

In the skull (8):
  • 1-9. cranium
  • 7. mandible
''In the middle ears (6):
  • malleus
  • incus
  • stapes
In the throat (1):
  • hyoid
In the shoulder girdle (4):
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The ischiopubic ramus is a compound structure consisting of the following two structures:
  • from the pubis, the inferior pubic ramus
  • from the ischium, the inferior ramus of the ischium
It serves as part of the origin for the Obturator internus muscle.
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The obturator membrane is a thin fibrous sheet, which almost completely closes the obturator foramen.

Its fibers are arranged in interlacing bundles mainly transverse in direction; the uppermost bundle is attached to the obturator tubercles and completes the obturator canal
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bold refer to the diagram at right.)

In the skull (8):
  • 1-9. cranium
  • 7. mandible
''In the middle ears (6):
  • malleus
  • incus
  • stapes
In the throat (1):
  • hyoid
In the shoulder girdle (4):
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The greater trochanter (great trochanter) of the femur is a large, irregular, quadrilateral eminence, situated at the junction of the neck with the upper part of the body.

It is directed a little lateralward and backward, and, in the adult, is about 1 cm.
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Arteries are muscular blood vessels that carry blood away from the heart.[1] All arteries, with the exception of the pulmonary and umbilical arteries, carry oxygenated blood.

The circulatory system is extremely important for sustaining life.
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  • Accessory nerve
  • Accessory obturator nerve
  • Alderman's nerve
  • Anococcygeal nerve
  • Ansa cervicalis
  • Anterior interosseous nerve
  • Anterior superior alveolar nerve
  • Aortic plexus
  • Auerbach's plexus
  • Auriculotemporal nerve
  • Axillary nerve

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The nerve to obturator internus is a nerve that innervates the obturator internus and gemellus superior muscles.

Course

The nerve to obturator internus originates in the sacral plexus.
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Kinesiology is the scientific study of the anatomy, physiology, and mechanics of body movement, especially in humans. [1] The word kinesiology is derived the Greek "kinesis" (motion) + the suffix -ology or -logy from the greek "logos" or "logia"(meaning a field of study).
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Abduction, in functional anatomy, is a movement which draws a limb away from the median (Sagittal) plane of the body. It is thus opposed to adduction.

Muscles of abduction

Upper limb

the coming together of two bones attached by a joint laterally

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External rotation (or lateral rotation) is rotation away from the center of the body.

The muscles of external rotation include:
  • of arm/humerus at shoulder[1]

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In humans the thigh is the area between the pelvis and buttocks and the knee. Anatomically, it is part of the lower limb.

The single bone in the thigh is called the femur.
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hip is the bony projection of the femur which is known as the greater trochanter, and the overlying muscle and fat. The hip joint is the joint between the femur and acetabulum of the pelvis and its primary function is to support the weight of the body in both static
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Elsevier, the world's largest publisher of medical and scientific literature, forms part of the Reed Elsevier group. Based in Amsterdam, the company has substantial operations in the UK, USA and elsewhere.
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The obturator membrane is a thin fibrous sheet, which almost completely closes the obturator foramen.

Its fibers are arranged in interlacing bundles mainly transverse in direction; the uppermost bundle is attached to the obturator tubercles and completes the obturator canal
..... Click the link for more information.
The ischium forms the lower and back part of the hip bone. It is situated below the ilium. The word comes from the Greek ischion, meaning "hip." (Taber's, 1985)

It is divisible into three portions:
  • Body of ischium
  • Superior ramus of the ischium

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Pubis may refer to the following:
  • Pubis (bone)
  • Mons pubis, a padding of fat that protects the pubis bone

..... Click the link for more information.
pelvis (pl. pelvises or pelves) is the bony structure located at the base of the spine (properly known as the caudal end). The pelvis incorporates the socket portion of the hip joint for each leg (in bipeds) or hind leg (in quadrupeds).
..... Click the link for more information.
An opening between the pelvis and the posterior thigh, the foramen is formed by the sacrotuberous ligament which runs between the sacrum and the ischial tuberosity and the sacrospinous ligament which runs between the sacrum and the ischial spine.
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The obturator foramen is the hole created by the ischium and pubic bones of the pelvis through which nerves and muscles pass.
  • In the male it is large and of an oval form, its longest diameter slanting obliquely from before backward.

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Inferior ramus can refer to:
  • Inferior ramus of the ischium
  • Inferior pubic ramus

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Pubis may refer to the following:
  • Pubis (bone)
  • Mons pubis, a padding of fat that protects the pubis bone

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The ischium forms the lower and back part of the hip bone. It is situated below the ilium. The word comes from the Greek ischion, meaning "hip." (Taber's, 1985)

It is divisible into three portions:
  • Body of ischium
  • Superior ramus of the ischium

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The hip bone (or innominate bone) is a large, flattened, irregularly shaped bone, constricted in the center and expanded above and below. It is one of the few ball and socket synovial joints in the body.
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pelvic brim. The "linea terminalis" consists of the pectineal line, the pubic crest and the arcuate line

External links

  • SUNY Labs 44:os-0504
This article was originally based on an entry from a public domain edition of Gray's Anatomy.
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The greater sciatic foramen is a major foramen of the pelvis.

Boundaries

It is bounded as follows:
  • anterolaterally by the greater sciatic notch of the illium
  • posteromedially by the sacrotuberous ligament

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The obturator foramen is the hole created by the ischium and pubic bones of the pelvis through which nerves and muscles pass.
  • In the male it is large and of an oval form, its longest diameter slanting obliquely from before backward.

..... Click the link for more information.
The obturator membrane is a thin fibrous sheet, which almost completely closes the obturator foramen.

Its fibers are arranged in interlacing bundles mainly transverse in direction; the uppermost bundle is attached to the obturator tubercles and completes the obturator canal
..... Click the link for more information.

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