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)