Dissection - Pelvis, General for Both Sexes Flashcards
What is the false pelvis?
What is the true pelvis?
False pelvis - everything contained within the bony pelvis that lies above the peritoneum, lined with peritoneum but located within the boundaries of the iliac bones
True pelvis - anything that lies deep to the peritoneum, the area inferior to the peritoneum.
Describe the floor of the true pelvis.
What is the perineum?
- The floor of the true pelvis is a muscular sling called the pelvic floor.
- The perineum is the area anterior to the pelvic floor that anchors the external genitalia.
Describe the tilting of the pelvis.
In anatomical position, the anterior superior iliac spines and the pubic tubercles are in the same coronal plane. The tilted orientation means that the pelvic inlet, or the entrance to the true pelvis, is oriented more anteriorly than strictly superiorly
Describe the location and angle of the urogenital and anal triangles.
The urogenital and anal triangles of the perineum are oriented at an obtuse angle to one another, due to the tilt of the pelvic girdle. The urogenital triangle is essentially parallel to the floor, but the anal triangle is oriented more vertically.
- The inguinal canal is a tubular passage through the […] through which the […] passes in people born with testes, and a […] runs in people born with ovaries.
- The medial end of the inguinal canal is called the superficial inguinal ring, which is an opening in the […].
- Anterior abdominal wall; Spermatic cord; Very small ligament
- aponeurosis of the external oblique
The deep inguinal ring is lateral to the […] and is an extension of the […].
- femoral vessels
- transversalis fascia
Discuss the developent of the urogenital system in a fetus with undifferentiated gonads.
During very early development, every fetus has undifferentiated gonads, which develop relatively high in the abdominal cavity. They are attached to the skin near the urogenital membrane by a structure called the gubernaculum. The fetal kidneys develop low in the abdomen near the bladder. During development, the gonads descend through the abdominal cavity as the gubernaculum shortens. The kidneys rise in the abdomen, and the two structures pass each other, with the kidneys dragging the ureters up, while the gonads drag their blood supply down. Once the fetus’s chromosomal makeup signals whether the gonads will become ovaries or testicles, the developmental trajectories differ. In fetuses with XX chromosomes, the ovaries stop their descent while still in the pelvic cavity. The gubernaculum becomes a functionless remnant in the adult known as the round ligament of the uterus. In fetuses with an X and a Y chromosome, the testicles continue their descent.
Describe what is seen in this image.
the testicle, pulled by the gubernaculum, pushes its way through the anterior abdominal wall musculature to create the scrotum
The scrotum is an extension of the […].
The […] becomes the external spermatic fascia.
The […] becomes the cremaster muscle
The […] becomes the internal spermatic fascia.
abdominal wall
aponeurosis of the external oblique
internal oblique
transversalis fascia
What are the contents of the spermatic cord?
Testicular vasculature and vas deferens
What is the reason why the superficial and deep inguinal canals are not perfectly lined up?
If the superficial and deep inguinal rings were perfectly lined up, intestines would fall out of the abdominal cavity all the time. As it is, they still manage to find their way into the inguinal canal pretty frequently.
What runs through the inguinal canal in persons born with ovaries?
The round ligament of the uterus, the remnant of the gubernaculum.
What is the physiologic difference between idirect and direct hernias?
Also - these are more common in persons born with ovaries than inguinal hernias.
- The levator ani muscle attaches from the […], and forms a sling on which the pelvic contents sit.
- Levator ani is comprised of three smaller muscles:
- […] runs from the ilium to the coccyx
- The […] runs from the pubis to the coccyx
- The […] arises on the pubis, and then runs posteriorly and wraps around the rectum and anus.
- The levator ani is breeched by what holes?
Middle of the obturator internus muscle
Iliococcygeus
pubococygeus
puborectalis; three holes for the anus, vagina, and urethra; or two for the anus and urethra.
Blood supply to the pelvis comes from the […]
Internal iliac artery
The bifurcation of the abdominal aorta happens at the level of the […] and branches into […], which then branch into […] and […].
umbilicus
common iliac arteries
External iliac and internal iliac
The external iliac artery gives off a single branch, the […] which then is renamed the […] when it passes under the […].
Inferior epigastric artery
Femoral artery
Inguinal ligament
True/False: The spermatic cord contains the vas deferens, the testicular artery, the pampiniform plexus, nerves, and the cremaster muscle.
False - the cremaster muscle wraps around the spermatic cord and is not located inside it
Which of these types of hernias is the most likely to strangulate and cause necrosis of herniated bowel contents?
a) Femoral
b) Umbilical
c) Direct inguinal
d) Indirect inguinal
A
While both the sacral and pelvic splanchnic nerves pass through the hypogastric plexus, which is the only one to synapse on it? Why is this the case?
Sacral splanchnic; pelvic splanchnic is parasympathetic and the PNS outside the head has its ganglions located near target organs, unlike the SNS which has its ganglions located in between the spinal cord and target organs in a named ganglion
Which of these is a major reason why people with vaginas are more prone to urinary tract infections than people with penises?
- longer urethra
- shorter urethra
- higher urine pH
- lower urine pH
B
A 60 year old woman, with a history of multiple vaginal childbirths, comes into the doctor after noticing leaking of urine whenever she coughs or sneezes. Weakening of which of these muscles could explain her condition?
a) Rectus abdominis
b) Levator ani
c) Quadratus lumborum
d) Detrusor
B
What comprises the lateral border of Hesselbach’s triangle?
Inferior epigastric vessels
True/False: There is one testicular artery and one testicular vein in the spermatic cord.
False - there are many veins but one artery
List the muscles that comprise the pelvic floor.
Levator ani; coccygeus
What tissues run through the inguinal canal in people born with testicles vs. people born with ovaries?
Testicles: spermatic cord; ovaries: Round ligament of the uterus
- True/False: An indirect hernia is when loops of bowel bypasses the deep inguinal ring and exits through the superficial inguinal ring.
- True/False: In an indirect inguinal hernia, the loops of bowel are found outside of the spermatjc cord.
- True
- False
What are two constrictions along the ureter where kidney stones can get stuck?
Ureteropelvic junction and ureterovesical junction
