Human Anatomy

1. ANATOMY
• GROSS ANATOMY
• LOWER LIMB
• GLUTEAL REGION
• Dr. Chongo Shapi (BSc. HB, MBChB)
• Medical Doctor
17/11/22 Dr. Chongo Shapi, BSc. HB,MBChB. 1

2. INTRODUCTION
• The name is derived from L. Regio
Glutealis
• Transitional region between the trunk and
free lower limb
• The most important feature is the rounded,
prominent posterior region, the buttocks
• Laterally there is less prominent hip (L.
coxa) or hip region, which overlies the hip
joint and greater trochanter of the femur.
• The gluteal muscles constitute the bulk of
this region.

3. BOUNDARIES
The gluteal region is bounded:
• Superiorly by the iliac crest,
• Medially by the intergluteal (natal) cleft
and
• Inferiorly by the skin fold (groove)
underlying the buttock, the gluteal fold (L.
sulcus glutealis).
• Laterally continuous with the thigh

4. THE SKIN
• Of the buttock is thick
• The fold of the buttock is the transverse
crease of the hip joint.
• Skin is adherent to underlying fat

5. Cutaneous innervation for the
quadrants for buttock
• Upper medial quadrant- upper three lumbar and sacral
nerves i.e. L1- L3 and S1- S3.
• Upper lateral quadrant – iliohypogastric (L1) and T12
• Lower lateral quadrant- lateral cutaneous nerve of the
thigh
• Lower medial quadrant– posterior cutaneous nerve of
the thigh
• The skin over the coccyx in the floor of the cleft between
the buttocks is supplied by small branches of the lower
sacral and coccygeal nerves

7. Fasciae
Superficial:
• Characteristic shape of the buttock is largely due to the
pad of adipose tissue/ panniculus adiposus/ layer of fat.
• It is thick particularly in women.
• The quantity of fat decreases as the fascia continues
with the neighbouring regions of the back, lateral and
anterior aspect of abdomen and the thigh.
• Small nerves and blood vessels reach the skin through
the superficial fascia after piercing the deep fascia.

8. Deep fascia
• Lower limb is invested in a sheath of deep fascia.
• It forms a more or less continuous stocking known as
fascia lata over the thigh.
• Deep fascia extends into the hip and gluteal regions to
attach to bony prominence and ligaments associated
with the pelvis.
• On the lateral surface of the thigh, the fascia is thickened
to form a strong, wide band the iliotibial tract which is
attached to the tubercle of the iliac crest above and the
lateral condyle of the tibia below.

9. Ligaments of the gluteal region
The functions
• To stabilize the sacrum and prevent its
rotation at the sacroiliac joint by the weight
of the vertebral column.
• They also convert the sciatic notches into
foramina.

11. The sacrotuberous ligament
• Connects the back of the sacrum to the
ischial tuberosity
• Attachments:
– Posterior border of ilium,
– Posterior superior and inferior iliac spines
– Sacrum
– Upper part of the coccyx

12. The sacrospinous ligament
• Connects the back of the sacrum to the
ischial spine
• Attachments
– Sacrum
– Upper part of the coccyx
– Spine of ischium

13. Foramina of the gluteal region
(see diagram above)
• The greater sciatic foramen is formed by the greater
sciatic notch of the hip bone and the sacrotuberous and
inferiorly by the sacrospinous ligament and ischial spine.
• It provides exit from the pelvis into the gluteal region of
the following:
– piriformis,
– sciatic nerve,
– posterior cutaneous nerve of the thigh,
– superior and inferior gluteal nerves and vessels,
– internal pudendal vessels,
– pudendal nerve and
– nerves to obturator internus and quadratus femoris.

14. The lesser sciatic foramen
• Is formed by lesser sciatic notch and the sacrospinous
ligament and the sacrotuberous ligaments.
• It provides entrance into the perineum from the gluteal
region.
• The following structures pass thru the foramen:
– tendon of obturator internus,
– nerve to obturator internus,
– internal pudendal vessels and pudendal nerve.

15. Structures in the gluteal region
• Nerves:
– Are branches of the sacral plexus.
– Both the plexus and the internal iliac vessels are
located in the pelvic cavity.
– They leave and enter the pelvis with the piriformis
muscles.
– Those for which distribution is primarily confined to
the buttock are the superior and inferior gluteal
nerves and the two small nerves to the obturator
internus and quadratus femoris.
– Those that pass through the buttock to another
distribution are, pudendal nerve, posterior cutaneous
nerve of the thigh, and sciatic nerve.

16. Sciatic nerve
• Is the largest nerve in the body and is formed in
the pelvis on the anterior surface of the
piriformis,
• Roots: L4,5 and S1,2,3
• It emerges in the buttock below the piriformis.
• In the buttock it is located half way between the
ischial tuberosity and greater trochanter
• It does not supply any structures in the buttock,
but its upper branches to the hamstring muscles
may arise at or above the level of the ischial
tuberosity.

17. Blood vessels:
• The vessels of the region are branches of the
internal iliac artery or tributaries of the internal
iliac vein.
• The vessels leave and enter the pelvis with the
piriformis muscles.
• Those for which distribution is primarily confined
to the buttock are the superior and inferior
gluteal vessels.
• Those that pass through the buttock to another
distribution are internal pudendal vessels

18. Contd
• Superior gluteal artery enters the buttock
above the piriformis.
• Inferior gluteal artery enters the buttock below
the piriformis muscle.
• The artery gives off other muscular twigs and
un-named anastomotic branches that join the
cruciate anastomosis.
• The arteria comitans nervei ischiadichi is a
small branch of the inferior gluteal artery.
• As its name implies, it accompanies, the sciatic
nerve, and is the remnant of the axial artery of
the developing lower limb.

20. Contd
• Of the vessels that pass through the buttock without
supplying structures in it, internal pudendal vessels are
the most medial and have the shortest course in the
buttock.
• The internal pudendal artery is a branch of the internal
iliac. They serve the perineum.
• They leave the pelvis with the piriformis, appear in the
buttock at the lower margin of the muscle and descend,
crossing the posterior surface of the superior gemellus
and, deep to it, the spine of the ischium.
• To reach the perineum, they pass medially through the
lesser sciatic foramen.
• The internal pudental vein runs with the artery and
nerve.

21. Anastomoses
Trochanteric anastomosis,
Main source of blood supply to the head of the femur.
Lies near the trochanteric fossa i.e. near the head of the
Femur. Arteries contributing are:
• Superior gluteal,
• Inferior gluteal,
• Medial femoral circumflex and
• Lateral femoral circumflex.

22. Cruciate Anastomosis
Formed at the level of lesser trochanter.
It connects internal iliac and femoral
arteries.
It is formed by:
• Medial femoral circumflex,
• Lateral femoral circumflex,
• 1st perforating branch of profunda femoris
artery and
• Inferior gluteal.

23. Lymphatics
Drain to the lateral group of superficial
inguinal lymph nodes

24. Muscles
• Gluteal region contains the chief abductor and
extensor muscles of the hip joint. It also has a
group which contributes to rotation of the femur.
• Most superficial: Gluteus maximus posterioly
and tensor fascia latae anteriorly
• Intermediate layer: Gluteus medius and gluteus
minimis
• Deep layer; five short muscles: Piriformis,
obturator internus, two gemelli and quadratus
femoris

27. Gluteus maximus
• It is the largest single muscle in the body and the
most powerful extensor of the hip. Gluteus
maximus covers most of the muscles and all
nerves and vessels in the gluteal region.
• Origin: It has a wide area of origin; outer surface
of Ilium, sacrum, coccxy and sacrotuberous
ligament.
• Insertion: Only the deep fibers of the lower half
of this thick, quadrangular muscle insert into the
gluteal tuberosity of the femur; the remaining
and far greater number insert into the iliotibial
tract.

28. Contd
Action; gluteus maximus is called into action
only during rapid and powerful extension or
when resistance has to be overcome. In the
normal gait cycle, hip extension is achieved
primarily by the hamstring muscles that arise
from the ischial tuberosity. Where the muscle is
definitely required is for hip extension in such
action as climbing, going upstairs, or getting up
from a squatting position. The gluteus maximus
can extend the femur not only through its bony
attachment but also through the iliotibial tract.

29. contd
Gluteus Medius and Minimus
• These two fan-shaped muscles are the chief
abductors of the hip.
• Origin: outer surface of ilium
• Insertion: greater trochanter.
• Gluteus minimus inserts on anterior surface
while medius lateral

30. Action of Glutuei medius and
minimus
• During walking, the two abductors on one side alternate
with those of the other side. The contraction occurs on
the side of the stance leg, its purpose being to prevent
the pelvis from sagging on the opposite side.
• During clinical evaluation, the efficiency of the abductors
may be tested by observing the level of the two anterior
and posterior superior iliac spines while the subject is
standing on one leg.
• If the abductors are weak, the anterior and posterior
superior iliac spines will sag on the opposite side. This
maneuver is known as the Trendelenburg test (fig. The
test is positive when the pelvis tilts downward on the
unsupported side, signifying weakness of the abductors
of the opposite side.

32. Contd
Tensor fasciae lata
• Origin: iliac crest
Insertion: Iliotibial tract
• Action: It assists gluteus maximus muscle
in extending the knee joint.

33. Short Rotators
• Lateral rotators of thigh at hip joint.
• Insert on upper border of greater
trochanter of femur except Quadratus
femoris on quadrate tubercle.
• Innervation is by sacral plexus

34. Cont’
• Piriformis arises from the anterior surface of
the sacrum. The pyramid-shaped muscle exits
the pelvis through the greater sciatic foramen
and inserts on the greater trochanter.
• The sacral plexus is formed largely on the pelvic
surface of the piriformis, and the branches of the
plexus emerge in the gluteal region along the
superior and inferior margins of the muscle.

35. Cont’
• Obturator internus has an extensive
area of origin from obturator membrane
and part of the coxal bone that surrounds
it.
• The muscle tapers posteriorly to a narrow
belly and tendon, and makes a sharp turn
around the lesser sciatic notch to head
toward its insertion to greater trochanter.

36. Cont’
• Superior and inferior gemelli arise from
the ischial spine, and the inferior gemellus
from the ischial tuberosity. They insert
into greater trochanter.
• Quadratus femoris arises form the ischial
tuberosity and inserts on the quadrate
tubercle.

37. Summary of nerve supply
1. Inferior gluteal nerve Gluteus maximus (L5,
S1 and S2)
2. Superior gluteal nerve Tensor fascia latae
(L4 and L5), Gluteus medius and Gluteus
minimis (L5 and S1 for the others)
3. Sacral plexus Piriformis (L5, S1 and S2)
Obturator internus,Two gemelli and Quadratus
femoris (L5 and S1 for the others)

38. Clinical considerations
• The upper lateral quadrant of the buttock and
also the anterior part of the relatively avascular
and free of major nerves- used for intramuscular
injection.
• Trendelenberg’s sign
• Ischial bursa inflammation- ischial bursitis
• Pressure on the ischial tuberosities eg
paraplegic persons leading to pressure sores
• Trochanteric bursitis in the gluteal and lateral
thigh regions
• Sciatica- pain in the distribution of the sciatic
nerve, usually by the pressure on its roots
• Injury to sciatic nerve leads many effects in the
lower limb

39. The end
• SOMETIMES IT’S NOT THAT YOU’RE
NOT YOU DON’T HAVE WHAT IT
TAKES, THEY THROW DOUBT
TOWARDS YOU CAUSE THEY SEE
YOU ON A PATH THEY THOUGHT IS AN
IMPOSSIBLE ONE TO BE ON.