Small Group Session III

Answer the following question upon completion of your dissection of the inguinal region.

A. Inguinal and Femoral hernias.

a. Inguinal hernias are classified as direct or indirect. What is the anatomic basis for a direct
inguinal hernia? _____________________________________________________________________________
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b. What is the anatomic basis for an indirect inguinal hernia? ___________________________
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c. What is the anatomical criterion for a femoral hernia? _______________________________
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d. Describe the course of the "anomalous" obturator artery? ___________________________
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What artery is it replacing? ______________________________________________________
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What is the arterial distribution of the obturator artery? ________________________________
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What are the consequences of improper ligation of this artery during surgery to repair a
femoral hernia?________________________________________________________________
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B. Spermatic cord

a. What are the three major arteries enclosed within the spermatic cord?

1. _____________________________________________
2. _____________________________________________
3. _____________________________________________

b. A common surgical procedure is to perform a vasectomy to render a male sterile. Describe the basic features of this surgical procedure. ___________________________________________
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c. What might be some adverse consequences of a poor surgical procedure (bad outcome)?
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C. Remnant of the Round Ligament

a. What two arteries (or their origin) supply this structure?

1. ___________________________________________________________
2. ___________________________________________________________

b. Describe the lymphatic drainage of this structure? _________________________________
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c. Why is the lymphatic drainage of this structure clinically important? ___________________
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Bony Pelvis

Obtain a bony pelvis from the Gross Anatomy Office and record the number.
Bony Pelvis # ______________.

A. Describe the general features of this pelvis (size, weight, muscular impressions) ________
_____________________________________________________________________________
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B. Observe the various features of the ilium, pubic and ischial bones. Note that some parts of the
pelvis are thin, while other parts are thick. Explain these differences in terms of the function of
the pelvis and the orientation of these features with the pelvis in the normal anatomical position.
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C. The bony pelvis serves two major functions: 1) body support and transmittal of mass forces
to the two lower extremities, 2) and in the female, the transmittal of a fetal head through the
pelvic canal. These structural differences are reflected in the dimensions of specific features of
the bony pelvis. Measurement of these features are useful in OB/Gyn examinations; and provides
a good determination of sexual origin in forensic studies.

1. Sex estimation based on pelvic inlet data:

A. Antero-posterior ________________mm.
B. Transverse ____________________mm.
C. Oblique _______________________mm.
Calculate Area as Area =pi * A/2 * B/2; if Area > 10656 mm2 then Female.

2. Sex estimation based on pelvic outlet data:

A. Anterio-posterior _____________ mm.
B. Transverse __________________ mm.
C. Oblique ____________________ mm.
D. Interspinous ________________ mm.
Calculate Area = pi * (A + B)/4 *(C+D)/4; If Area > 6540 mm2 then Female.

3. Sex estimation based on the pelvic pubic angle. Place the pelvic on a flat surface with the
ischial tuberosities touching the surface. Measure the distance between the tuberosities (A)
and the distance from the symphysis to the flat surface (B).

Distance A _________________ mm
Distance B _________________ mm.

Pubic Angle = ArcTan (A/2/B) * 180/PI * 2
If Pubic angle > 70o = female

4. Sex estimation based on size of acetabulum.
Measure the greatest distance (A) from the anterior rim of the lunate articular surface to the
posterior rim. _____________mm.
Measure the greatest vertical dimension (B) from rim to rim. ______________mm.
If A => 45 and B=> 46 then it is probably a male pelvis.

5. Sex estimation based on Pelvic Ischiopubic Index. The superior pubic ramus is longer in the
female than in the male. Measure the two values from the point of convergence of the three pelvic
bones on the floor of the acetabulum. Measure A from the acetabulum to the pubic symphysis,
and B from the acetabulum to the ischial tuberosity.

Dimension A ______________mm.
Dimension B. ______________mm.
Ischiopubic Index = A/B. If Index > 1.25 then probably a female pelvis.

6. Sex estimation based on Pelvic Sacral Index. The width of the sacrum between the most
anterior points of the two articular surfaces (A); and the length (B) along the midline from the
anterior margin of the promontory to the apex (sacral-coccygeal joint).

Dimension A. _____________mm.
Dimension B. _____________mm.
Pelvic-Sacral Index = A/B. If Index > 0.9 then probably a male pelvis.

Sum up the number of diagnostic features for each sex to determine the probable sex. Remember
some pelvic bones will not unambiguously be male or female, but rather reflect a predominant
type. Based on the above morphometric data, what is the sex of this pelvis? _________________