NURS 620 Midterm 2024-2025
Fetal head positions - ANSWER
Identify the following bone structures/dimensions on a diagram or model and know their
significance within the context of pregnancy and birth: - ANSWER - Sacrum
o Sacral promontory
- Coccyx
- Pelvis (body, pubis, ischium)
o True vs false pelvis
o Pelvic Inlet vs pelvic outlet
o Obstetric conjugate
o Diagonal conjugate
o Symphysis pubis
o Subpubic arch
o Ischial spine
o Interspinous diameter
o Sacrospinous ligament
o Sacrospinous arch
o Ischial tuberosity
o Biischial diameter (also called bituberous or intertuberous diameter)
Sacrum - ANSWER 5 fused vertebrae
,Sacral promontory at S1 anterior protrusion
-used for measuring
- Coccyx - ANSWER 4 fused vertebrae, tailbone
pelvis - ANSWER
true pelvis - ANSWER surrounded by bone and lies inferior to flaring parts of the ilia;
passage for infant at birth in women
Ture pelvis: lies below the pelvic brim or linea terminalis
-Bony canal through which fetus must pass
-Consists of three parts:
Inlet (bound)
Pelvic cavity (curved canal)
narrowest portion -ishial spines (midplane, 0 station)
Pelvic outlet (diamond shaped, bound)
false pelvis - ANSWER above the pelvic brim
Located above the true pelvis,
Above the line terminals
obstetric function is to provide a reservoir for the expanded uterus during pregnancy
Pelvic Inlet and Pelvic Outlet - ANSWER Pelvic Inlet: Space between pelvic and
abdominal cavities, ie, between true and false pelves.
,Pelvic Brim: Margin of the pelvic inlet.
Pelvic inlet aka superior straight
Part of the ture pelvis
Inlet Diameters: no Know Obstetic conjugate and diagonal conjugate
Pelvic outlet
Has two Triangular planes - ant triangle and post triangle
Pelvic Outlet: Inferior opening defined by ischial tuberosities, etc. this is the bony
feature you sit on. The size of this outlet is important for a successful birth.
Obstetric conjugate ANSWER 11cm
Mid sacral promontory to posterior superior margin of pubic symphysis
Imp AP Diameter b/c fetus mast pass though this one
Diagonal conjugate - ANSWER 12. 5cm
Subpubic angle to middle of sacral promontory
Can be measured
**Imp clinically sig b/c subtracting 1.5 cm approximates length of Obstetric conjugate
symphysis pubis - ANSWER a cartilaginous joint that is the point of fusion for two pubic
bones
Cartilaginous joint, no capsule no synovial fluid, between your left pelvic bone and your
right pelvic bone
Stretched by relaxin at birth increase by 2cm
Subpubic arch - ANSWER (Or pubic angle) is the angle in the human body as the apex of
the pubic arch, formed by the convergence of the inferior rami of the ischium and pubis
on either side
, -very narrow in Android pelvis
-Very wide in platapoid pelvis type
-normal in gynecoid and and Anthropoid around 90 degree angle
Ischial Spine - ANSWER extends from the posterior border of the superior aspect of the
ischium at the level of the lower border of the acetabulum. It gives attachment to the
sacrospinous ligament.
Helps support pelvic floor
Interspinous diameter - ANSWER Distance between ischial spines
9.5-11.5 cm
In mid pelvis
Biischial diameter - ANSWER (also called bituberous or intertuberous diameter)
distances between two ishial tuberosites
should be at least or > 8 cm
Sacrospinous ligament - ANSWER Help to stabilize the pelvis
attached to the ischial spine, a bone prominence in the lower pelvis and to the lateral, or
side, areas of the sacrum, at the bottom of the spine and the coccyx, or tailbone.
Sacrospinous ligament- diff view - ANSWER
Sacrospinous arch - ANSWER ?
Fetal head positions - ANSWER
Identify the following bone structures/dimensions on a diagram or model and know their
significance within the context of pregnancy and birth: - ANSWER - Sacrum
o Sacral promontory
- Coccyx
- Pelvis (body, pubis, ischium)
o True vs false pelvis
o Pelvic Inlet vs pelvic outlet
o Obstetric conjugate
o Diagonal conjugate
o Symphysis pubis
o Subpubic arch
o Ischial spine
o Interspinous diameter
o Sacrospinous ligament
o Sacrospinous arch
o Ischial tuberosity
o Biischial diameter (also called bituberous or intertuberous diameter)
Sacrum - ANSWER 5 fused vertebrae
,Sacral promontory at S1 anterior protrusion
-used for measuring
- Coccyx - ANSWER 4 fused vertebrae, tailbone
pelvis - ANSWER
true pelvis - ANSWER surrounded by bone and lies inferior to flaring parts of the ilia;
passage for infant at birth in women
Ture pelvis: lies below the pelvic brim or linea terminalis
-Bony canal through which fetus must pass
-Consists of three parts:
Inlet (bound)
Pelvic cavity (curved canal)
narrowest portion -ishial spines (midplane, 0 station)
Pelvic outlet (diamond shaped, bound)
false pelvis - ANSWER above the pelvic brim
Located above the true pelvis,
Above the line terminals
obstetric function is to provide a reservoir for the expanded uterus during pregnancy
Pelvic Inlet and Pelvic Outlet - ANSWER Pelvic Inlet: Space between pelvic and
abdominal cavities, ie, between true and false pelves.
,Pelvic Brim: Margin of the pelvic inlet.
Pelvic inlet aka superior straight
Part of the ture pelvis
Inlet Diameters: no Know Obstetic conjugate and diagonal conjugate
Pelvic outlet
Has two Triangular planes - ant triangle and post triangle
Pelvic Outlet: Inferior opening defined by ischial tuberosities, etc. this is the bony
feature you sit on. The size of this outlet is important for a successful birth.
Obstetric conjugate ANSWER 11cm
Mid sacral promontory to posterior superior margin of pubic symphysis
Imp AP Diameter b/c fetus mast pass though this one
Diagonal conjugate - ANSWER 12. 5cm
Subpubic angle to middle of sacral promontory
Can be measured
**Imp clinically sig b/c subtracting 1.5 cm approximates length of Obstetric conjugate
symphysis pubis - ANSWER a cartilaginous joint that is the point of fusion for two pubic
bones
Cartilaginous joint, no capsule no synovial fluid, between your left pelvic bone and your
right pelvic bone
Stretched by relaxin at birth increase by 2cm
Subpubic arch - ANSWER (Or pubic angle) is the angle in the human body as the apex of
the pubic arch, formed by the convergence of the inferior rami of the ischium and pubis
on either side
, -very narrow in Android pelvis
-Very wide in platapoid pelvis type
-normal in gynecoid and and Anthropoid around 90 degree angle
Ischial Spine - ANSWER extends from the posterior border of the superior aspect of the
ischium at the level of the lower border of the acetabulum. It gives attachment to the
sacrospinous ligament.
Helps support pelvic floor
Interspinous diameter - ANSWER Distance between ischial spines
9.5-11.5 cm
In mid pelvis
Biischial diameter - ANSWER (also called bituberous or intertuberous diameter)
distances between two ishial tuberosites
should be at least or > 8 cm
Sacrospinous ligament - ANSWER Help to stabilize the pelvis
attached to the ischial spine, a bone prominence in the lower pelvis and to the lateral, or
side, areas of the sacrum, at the bottom of the spine and the coccyx, or tailbone.
Sacrospinous ligament- diff view - ANSWER
Sacrospinous arch - ANSWER ?
