QUIZ II Flashcards
what comprises the pelvis?
2 pelvic bones
1 sacrum
1 coccyx
what is the function of the pelvis?
contains and protects the pelvic organs, aid in locomotion via force transfer
what is unique about the sacrum?
5 vertebrae fused
recognized by its shape
base is narrower and length longer, greater curvature in males whereas in females, based is wider and length shorter with lesser curvature
what does the base of the sacrum articulate with?
L-5 vertebra
what does the apex of the sacrum articulate with?
coccyx
what is the coccyx?
4 vertebrae fused into 2 or 3 segments, aka the tail bone
- formed by fusion of the vertebral bodies
- last area in the body to complete ossification
Transverse Ridges (Lines) (4)
- allow passage of the ventral rami S-1 through S-4
- holes at anterolateral sacral canal
Anterior Sacral Foramina (4 pair)
- concave side to side and superior to inferior
anterior surface of the sacrum
- anterior superior edge of S-1 vertebra
- projects in anteroinferior direction in body
Sacral Promontory
(ala means wing)
- expansions from the base, laterally
- the fused transverse processes of S-1 vertebrae
Sacral Alae
- unfused superior articular processes of S-1
- visible from anterior side, are part of the posterior aspect
- articular surface is posterior
Superior Articular Processes
-no true features from anterior
anterior surface of coccyx
-spinal canal of the sacrum for passage of cauda equina
Sacral Canal
- midline projection from sacrum
- the fused spinous processes of S-1 through S-4
Median Sacral Crest
- the inferior opening of the sacral canal
- formed by the lamina and spinous processes from S-5 that do not fuse
- for passage of meninges and spinal nerves. Area of attachment for filum
terminale
Sacral Hiatus
- small projections at the lateral margins of the sacral hiatus
- formed by ligamentous attachment
Sacral Cornu
- for passage of dorsal rami S-1 through S-4
Posterior Sacral Foramina (4 pair)
- projection at the medial edge of the dorsal sacral foramina, and lateral to
the median sacral crest
39 - formed by fusion of the superior and inferior articular processes
Intermediate Sacral Crest
- depressed area between median and intermediate sacral crests
- formed by fusion of the vertebral laminae S-1 through S-4
Sacral Groove
- projection lateral to the dorsal sacral foramina
- formed by fusion of the transverse processes
Lateral Sacral Crest
- superior articular processes of Co-1 vertebra
- articulate with sacral cornu via ligamentous attachment
Coccygeal Cornu
- anterior part of the lateral surface, articulates with the pelvic bone
- part of the sacroiliac joint, a synovial joint, planar, functional diarthrosis
Auricular Surface
- all present at birth
- one in each vertebral body, one in each of the lamina (vertebral arches forming the
sacral canal), one in each segment of the lateral masses (costal elements)
Primary Centers of Ossification
- appear between puberty and age 18 years (as late as age 20) - tips of he spinous processes, tips of transverse processes, epiphyseal rings (i.e. the
upper and lower surfaces of the bodies), and epiphyseal plates on the lateral surface. - all fused by age 25 years except transverse ridges which take until middle age
Secondary Centers of Ossification
- also called os coxa or innominate bone - articulates posteriorly with the lateral surface of the sacrum, anteriorly with the
symphyseal surface of the other pelvic bone and laterally with the femoral head - composed of three bones fused into one
- recognized by its distinctive shape
Pelvic Bone (2)
- the large superior portion of the pelvic bone
Ilium
- the central part (more inferior)
iliac body of the Ilium
- the wing (large flattened part)
iliac ala of the Ilium
- the posteroinferior portion of the pelvic bone
Ischium of the Ilium
- the posterosuperior part of the ischium; triangular in a cross-sectional view
name the surfaces?
ischial body
femoral, pelvica and dorsal
the anteroinferior projection of the ischium?
ischial ramus
the external surface found on the ischium; faces laterally
- rough from soft tissue attachment
anterior surface of the ischial ramus
the internal surface on the ischium; faces medially
- smooth area
posterior surface of the ischial ramus
- the anteroinferior portion of the pelvic bone
Pubis
- the large anteromedial part of the pubis
pubic body
- the flattened medial surface of the body
- articulates with the other symphyseal surface at the pubic symphysis
symphyseal surface
- the anterior/external surface
femoral surface
- the posterior/internal surface
pelvic surface
the superior posterolateral projection of the pubis?
superior pubic ramus
the anterior surface of the superior pubic ramus at the medial end which spirals to an inferior position at the lateral end and is the continuation of the femoral surface of the body
obturator surface
- the superior surface of the superior pubic ramus
- narrow medially, expands laterally
pectineal surface
- the internal surface of the superior pubic ramus
- wide medially, narrows laterally
pelvic surface
the inferoposterolateral projection of the pubis
- joins the ischial ramus
- together the inferior pubic ramus and the ischial ramus may be referred to as the conjoined ramus or ischiopubic ramus
- can not distinguish one bone from the other after fusion
inferior pubic ramus
Features of the Pelvic Bone
medial view
- the superior border of the ilium or of the iliac ala
- can be palpated along its entire length
- most patients call this the hip bone
Iliac Crest
Features of the Pelvic Bone
medial view
- the anterior rounded end of the iliac crest
- can be palpated
- often used as a reference point to measure limb length
- for attachment of ligaments and muscle
Anterior Superior Iliac Spine (ASIS)
Features of the Pelvic Bone
medial view
- the posterior rounded end of the iliac crest - can be palpated, but may be difficult
- lies beneath the skin dimple at the low back
- for attachment of ligaments and muscle
Posterior Superior Iliac Spine (PSIS)
Features of the Pelvic Bone
medial view
- the small projection on the anterior border of the ilium just inferior to the anterior superior iliac spine
- can often be palpated just medial and inferior to the anterior superior iliac spine depending upon weight
- for attachment of muscle and ligament
Anterior Inferior Iliac Spine (AIIS)
Features of the Pelvic Bone
medial view
- the small projection on the posterior border of the ilium just inferior to the posterior superior iliac spine
Posterior Inferior Iliac Spine (PIIS)
Features of the Pelvic Bone
medial view
- the flattened internal or pelvic surface of the ala (wing) of the ilium
- for attachment of a muscle
Iliac Fossa
Features of the Pelvic Bone
medial view
- roughened area on the posteromedial surface of the ilium, posterior
to the iliac fossa and anterior to the posterior superior iliac spine - for the attachment of ligaments
Iliac Tuberosity
Features of the Pelvic Bone
medial view
- the synovial joint surface on the posteromedial surface of the ilium, posterior to the iliac fossa and inferior to the level of the posterior superior iliac spine
- for articulation with the auricular surface of the sacrum at the sacroiliac joint
- used as an age indicator. Young: well defined edges and surfaces. Old: irregular
surfaces and edges with pitting and lipping
Auricular Surface
Features of the Pelvic Bone
medial view
- the small sharp projection on the posterior border of the ischium
- inferior to the posterior inferior iliac spine
- for attachment of ligament
Ischial Spine
Features of the Pelvic Bone
medial view
- the large concavity posteriorly
- intermediate to the posterior inferior iliac spine and the ischial spine
- closed by the sacrospinous ligament to form the greater sciatic foramen,
then allows passage of neurovascular structures and the piriformis m. - used to determine gender. Male: narrow, V-shaped, 40-60 degree angle.
Female: wide, L-shaped, 70-90 degree angle
Greater Sciatic Notch
Features of the Pelvic Bone
medial view
- the large blunt projection on the posterior inferior aspect of the ischium
- weight-bearing when seated; the area of problem when “saddle sore”
- can be palpated through the soft tissue at the inferomedial gluteal region
- for attachment of ligament and muscles
Ischial Tuberosity
Features of the Pelvic Bone
medial view
- the small concavity intermediate to the ischial spine and the ischial tuberosity
- closed by the sacrotuberous ligament to form the lesser sciatic foramen,
then allows passage of neurovascular structures and obturator internus m.
Lesser Sciatic Notch
Features of the Pelvic Bone
medial view
- the large hole in the pelvic bone formed by the ischial ramus, the ischial body,
the pubic body and the pubic rami - covered by the obturator membrane
Obturator Foramen
Features of the Pelvic Bone
medial view
- the small roughened ridge at the anterior surface of the pubis
- extends from the symphyseal surface to the pubic tubercle
- can be palpated at the anteroinferior aspect of the abdomen
- for attachment of ligament and muscle
Pubic Crest
Features of the Pelvic Bone
medial view
- the small prominence at the lateral edge of the pubic crest
- can be palpated about 1” from the median plane
- for attachment of ligaments
Pubic Tubercle
Features of the Pelvic Bone
medial view
- separates the iliac body and ala
Arcuate Line
Features of the Pelvic Bone
medial view
- the border between the pectineal and pelvic surfaces of the pubis
- continuous with the arcuate line of the ilium via the iliopectineal line
Pecten Pubis / Pectineal Line of the pubis
Features of the Pelvic Bone
medial view
- a rise located at the junction of the iliac body and the superior pubic ramus
- the iliopectineal line traverses its medial edge and connects the pectineal
line with the arcuate line - used to determine gender. Male: robust and wide when viewed from above.
Female: gracile and narrow when viewed from above.
Iliopectineal Eminence / Iliopubic Eminence
Features of the Pelvic Bone
medial view
- central at the inferior part of the superior ramus of the pubis
- at the superior edge of the obturator foramen
- closed to form the obturator canal by the obturator membrane, then allows
passage of neurovascular structures
Obturator Groove / Obturator Sulcus
Features of the Pelvic Bone
medial view
- the flat surface on the medial surface of the pubic body
- for articulation with the symphyseal surface of the opposite pelvic bone at the pubic symphysis, a secondary cartilaginous joint
Symphyseal Surface
lateral view of the pelvis?
- a prominence at the lateral lip of the iliac crest 1” to 2” posterior to the anterior superior iliac spine
- can often be palpated at the superior lateral margin of the iliac crest
- for attachment of ligaments and muscles
Iliac Tubercle
lateral view of the pelvis?
- shortest marking line on the external iliac ala - directed anteroinferiorly from near the posterior superior iliac spine to the level of the posterior inferior iliac spine
- separates muscle attachments
Posterior Gluteal Line
lateral view of the pelvis?
- longest and most distinct marking line on external iliac ala
- directed posteroinferiorly from the iliac tubercle to the superior margin of the greater sciatic notch
- sometimes continues anteriorly to the anterior superior iliac spine
- separates muscle attachments
Anterior Gluteal Line
- least defined marking line on external iliac ala
- directed posteriorly from intermediate to the anterior superior iliac spine
and the anterior inferior iliac spine to the greater sciatic notch - separates muscle attachments
Inferior Gluteal Line
- the large cup-like depression where the three bones meet
- articulates with the femur at the hip joint, a synovial spheroid joint
Acetabulum
-formed by the body of the ilium
superior 2/5 or 40% of Acetabulum
-formed by the body of the ischium
posterior inferior 2/5 or 40% of Acetabulum
-formed by the superior pubic ramus
anterior inferior 1/5 or 20% of Acetabulum
- the smooth, crescent-shaped, synovial articular surface of the acetabulum
- for articulation with the femoral head
Lunate Surface
- the roughened central depression within the acetabulum
- formed mostly by the ischial body
- for passage of ligament and neurovascular structures
Acetabular Fossa
- the depressed area between the ends of the lunate surface
- formed mostly by the ischial body
- closed to the acetabular foramen by the transverse acetabular ligament
- for the passage of neurovascular structures
Acetabular Notch
- the outer, raised edge of the acetabulum
- for attachment of ligaments and muscle
Acetabular Rim
- the sharp border between the pectineal and obturator surfaces of the pubis
- at the anterior edge of the obturator groove
Obturator Crest
- from 3 primary centers and 5 secondary centers
Ossification of the Pelvic Bone
Primary Centers of the pelvic bone?
- one in each component bone
a. ilium - appears near 9th fetal week - in the iliac ala
b. ischium - appears early 4th fetal month - in the ischial body
c. pubis - appears late 4th fetal month - in the superior pubic ramus
secondary centers of the pelvic bone?
- appear near puberty and fuse from ages 15 to 25 years
a. iliac crest
b. acetabulum
c. pubic symphysis
d. ischial tuberosity
e. anterior-inferior iliac spine
- continuous line of the internal lateral and anterior walls of the pelvis
- found on each innominate bone
- formed by four separate structures that align end to end, name these?
linea terminalis
i. Arcuate Line
ii. Iliopectineal Line
iii. Pectineal Line / Pecten Pubis
iv. Pubic Crest
what are the imaginary lines found at the pelvic brim?
- across the sacral promontory and sacral alae
- across the symphysis pubis
- the pelvic area superior to the pelvic brim
- located superior and anterior to the lesser pelvis
- formed primarily by the iliac alae
Greater Pelvis / False Pelvis
- the pelvic area inferior to the pelvic brim
- located posterior and inferior to the greater pelvis
- formed by the pubic bones, ischial bones, iliac bodies, sacrum and coccyx
Lesser Pelvis / True Pelvis
- the inferior opening (exit) of the true pelvis
- border between pelvis and perineum
- Males: heart shaped
- Females: oval shaped
- Subpubic arch.
Males: Narrow, inverted V-shape. Females: Wide, inverted U-shape
Pelvic Outlet
the bone of the thigh
recognized by the angled head and the trochanters
largest bone in the body
femur
