PDBIO 210 --Lesson 6 -- Appendicular Skeleton--Pelvic girdle, os coxae
What are the characteristics of the male pelvis?
- Tilted less forward - Cavity of true pelvis is narrow and deep - Bones heavier and thicker - Acetabula closer together - More triangular in shape
What are the articulations of the os coxa?
-- each os coxa articulates posteriorly w/an auricular surface of the sacrum at the sacroiliac joint --femur articulates w/ the acetabulum on the lateral surface of the os coxae
pubic crest
-- margin of bone between the pubic tubercles of adjacent pubis bones --roughened ridge on the anterosuperior surface of the superior ramus; ends at pubic tubercle
posterior inferior iliac spine
-- process inferior to the posterior superior iliac spine
What four bones make up the adult pelvis?
-- the sacrum --the coccyx --right os coxa --left os coxa
What are the characteristics of the female pelvis?
-- tilted forward --True pelvis is wide, broad and shallow with greater capacity - Bones lighter and thinner - Acetabula farther apart - More rectangular in shape - Adapted for childbearing
iliac fossa
--a depression on medial side of the fan shaped portion of the ilium
pubic tubercle
--anterior prominence superior to the pubic symphysis, -- lateral end of pubic crest --attachment site for the inguinal ligament
anterior superior iliac spine
--anterior termination of the iliac crest
appendicular skeleton
--consisting of bones of the: ** pectoral girdle, upper limbs, pelvic girdle, and lower limbs
What is the pelvic girdle?
--consists of left and right ossa coxae only
What are the differences between female and male pelvis?
--female is shallower and wider than male (accommodates infants head as passes through birth canal) --males have narrower hips than females --female ilium flares more laterally; --male ilium projects more superiorly --because female pelvis is wider, greater sciatic notch is wider also **males greater sciatic notch is narrower and U-shaped --females have a preauricular sulcus (depression/groove) between the greater sciatic notch and the sacroiliac articulation (males don't usually have this) --females have a shorter and wider sacrum --coccyx projects more vertically in men **female coccyx has a posterior tilt --body of pubis in females is much longer and almost rectangular compared to the shorter, triangular male pubis body --subpubic angle (pubic arch) much wider and more convex in females (usually 100 degrees ) ** male pubic arch is much narrower and usually doesn't extend past 90 degrees. ***the difference in the male/female pelvis help females in the birthing process. Makes it easier for their bodies to accommodate birth
inferior ramus (of the pubis)
--flattened medial border of the obturator foramen
ramus (of the ischium)
--flattened part of the ischium --extends from ischial tuberosity toward its anterior fusion w/the pubis
superior ramus (of the pubis)
--flattened superior border of the obturator foramen --orginates at anterior margin of acetabulum
os coxa (sometimes coxal bone, or innominate bone)
--hip bone **composed of three separate bones: (these bones fuse between 13-15 to form os coxae) --ilium -- ischium --pubis --these three bones all contribute to a portion of the acetabulum
ischial tuberosity
--inferior roughened surface of the ischium for ligament and muscle attachment --posterolateral border of the ischium
pubic symphysis (symphisis pubis)
--joint with fibrocartilage disc joining the two os coxa anteriorly
obturator foramen
--large opening between ischium and pubis -- space in os coxae encircled by both pubic and ischial rami
acetabulum
--lateral depression of the os coxa which articulates with the head of the femur --deep curved depression on lateral surface of ox coxa --lunate surface (smooth curved surface on acetabulum) is C-shaped and articulates w/ the femoral head
pubis
--most anterior portion of the os coxa --fuses w/ the ilium and ischium at the acetabulum
lesser sciatic notch
--notch (semicircle deprssion) immediately inferior to the ischial spine
ischium
--posterior and inferior portion of the os coxa --fuses w/ the ilium near the superior and posterior margins of the acetabulum --ischium accounts for posterior 2/5 of acetabular surface
greater sciatic notch
--posterior indentation in ilium
posterior superior iliac spine
--posterior termination of the iliac crest
anterior inferior iliac spine
--process inferior to the anterior superior iliac spine
ischial spine
--process located posterior to the acetabulum --projects medially --bulky bone superior to the spine is the ischial body
What is the function of the pelvis?
--protects and supports the viscera in the inferior part of the ventral cavity of the body
auricular surface (of the ilium)
--region on the ilium for articulation with the sacrum --located on the posteromedial side --ilium articulates w/ the sacrum at the sacroiliac joint
iliac crest
--ridge on the superior border of the ilium
ilium
--superior flattened portion of the os coxa, (top half of the os coxa) --also forms the largest portion of the acetabular surface --largest of 3 coxal bones
ala
--wide fan shaped portion of the ilium --ala terminates inferiorly at a ridge called the arcuate line on the medial surface of the ilium -- on medial side of ala is the iliac fossa
Which of the following is true about the male pelvis?
A. Bones are lighter and thinner B. More rectangular in shape C. Acetabula closer together D. The cavity of the true pelvis is broad and shallow ***Acetabula closer together (correc)