Flashcards in Quiz 4 - Inguinal Region Deck (46):
inferior margin of the aponeurosis of the external oblique muscle extends from the ASIS to the ______
-is folded under upon itself and thickened to create the inguinal ligament
-created in the anterior abdominal wall in the fetal descent of the testis from the posterior abdominal wall into the scrotum
-in males, the spermatic cord lies in this canal
-in females, the ligamentum teres lies in this canal
what forms the inguinal canal?
-inferior portion: inguinal ligament
-superior portion: arching fibers of internal and transversus abdominis muscles
-anterior wall: external oblique aponeurosis
-posterior wall: transversalis fascia and the conjoint tendon (from int. oblique and trans. abdominis)
deep inguinal ring
-the internal (deep) opening of the inguinal canal
-thru the transversalis fascia
superficial (external) inguinal ring
-external opening of the inguinal canal; lies superior to the inguinal ligament
-thru the aponeurosis of the external oblique muscle
-results from the descent of the testis into the scrotum dragging with it its blood supply, nerves, lymphatics, and vas deferens
-3 layers of the abdominal wall are "pushed out" in front of the descending testis and thereby form the fascial coverings of the spermatic cord
fascial coverings of spermatic cord
-external oblique --> external spermatic fascia
-internal oblique --> cremasteric muscle and fascia
-transversalis fascia --> internal spermatic fascia
inguinal region (groin)
-junction of the lower abdomen and the upper, medial thigh
-abdominal wall is weaker here compared to other areas
-common site for herniation of peritoneum and abdominal contents
-formed by the thickened inferior margin of the external oblique aponeurosis
-extends from the anterior superior iliac spine (ASIS) to the pubic tubercle (both palpable structures)
major structures within the spermatic cord
1. vas (ductus) deferens
2. testicular artery
3. artery of the vas
4. pampiniform plexus of veins
5. processus vaginalis (obliterated peritoneum) at its center
-also, nerves and lymphatics
-surrounds the testicular artery
-serves as an important counter-current thermo-regulatory function
-protrusions of structures thru tissues that normally contain them
-in the abdominal wall, the most common hernias are in the umbilical region (around the bellybutton) thru poorly healed surgical incisions and in the inguinal region
-there must be a protrusion of the parietal peritoneum forming a sac which may or may not contain some intra-abdominal viscera
-either "direct" or "indirect," depending on whether they originate medial or lateral to the inferior epigastric vessels
-protrude thru the inguinal (Hesselbach's) triangle (medial to the inferior epigastric vessels) and is located alongside (not within) the spermatic cord.
-pass thru the internal (deep) inguinal rings and therefore must reside within the spermatic cord coverings
as the testis descends into the scrotum...
...it becomes enveloped in the various tissues that it encounters as it pushes thru the abdominal wall
first layer of the abdominal wall that the testis meets as it descends into the scrotum
-the transversalis fascia, which is pushes out in front of itself thereby forming the innermost layer of the testis and the spermatic cord, called the internal spermatic fascia
second layer of the abdominal wall that the testis meets as it descends into the scrotum
-internal oblique muscle
-some of its muscle fibers will be carried along to become the cremaster muscle fibers and its fascia
third layer of the abdominal wall that the testis meets as it descends into the scrotum
-external oblique aponeurosis, which will become the most superficial fascial layer of the spermatic cord, the external spermatic fascia
does the transversus abdominis contribute to the fascial coverings of the spermatic cord?
-no because it originates in part from the lateral 1/3 of the inguinal ligaments, so the testis (which descend at the midpoint of the inguinal ligament) "miss" it entirely.
bordered by the lateral edge of the rectus abdominis (semilunar line), inferior epigastric vessels, and the inguinal ligament
-one of two common sites for herniation; the other is the deep ring
how do the inferior epigastric vessels reach and ascend along the posterior surface of the rectus abdominis muscle?
-they must penetrate the transversalis fascia of the posterior rectal sheath inferior to the arcuate line
testes and ovaries begin their development where?
-near the posterior abdominal wall
-the testis descends from this position into the scrotum, passing thru the abdominal wall as it does so.
-the ovary descends from the posterior abdominal wall into the pelvis
-arise directly from the aorta in the superior portion of the posterior abdominal cavity (site of the embryonic origin of the testes)
-are "dragged" into the scrotum as the testes descend
descent of the testes
-occurs posterior to the peritoneal cavity of which the processus vaginalis is an outpouching
-testes do NOT enter the processus vaginalis, but travel posterior to it
proximal portion of the processus vaginalis normally obliterates, leaving ___
-the distal portion to become the tunica vaginalis
-the testis partially invaginates into the tunica vaginalis from posterior (fist in balloon)
the posterior layer of the tunica partially covers the testis as the ____ tunica vaginalis
the anterolateral layer of the tunica vaginalis becomes the ____ tunica vaginalis
there (is/is not) usually some fluid between the visceral and parietal layers of the tunica vaginalis
what do you need for healthy production of spermatozoa?
-the ambient temp of the testis must be lower than core body temp
-some of the core body heat carried in the testicular artery is transferred to the surrounding pampniform plexus of veins, and ascends, never reaching the testis
what else plays a role in the thermo-regulation of the testis?
-cremasteric skeletal muscle in the spermatic cord and smooth muscle fibers in the dartos fascia of the scrotum
-by contracting or relaxing they control the distance of the testes from the inguinal region and thereby help regulate the temperature
the testes reside in the scrotum and are covered by what?
-a thick fibrous layer called the tunica albuginea
testes are surrounded by which two layers of residual processus vaginalis (except on its posterior aspect)?
-the parietal and visceral layers of the tunica vaginalis
seminiferous tubules of the testes drain thru the ___
-straight tubules to the rete testis
-then the efferent ductules into the convoluted epididymis, which is situated on the posterior surface of the testis and which transports the spermatozoa to the vas deferens
testes originate in the embryo from ___
intermediate mesoderm in the posterior abdominal wall near the kidneys
-so, their arterial supply descends with them from the aorta into the scrotum, and the venous return is back to that same area
lymphatic drainage of testis differs how from that of the scrotal skin?
-lymphatics of testes drain into lateral (lumbar) and pre-aortic lymph nodes near the origin of the testicular vessels
-scrotal lymphatics drain into superficial inguinal lymph nodes
-abnormal accumulation of fluid between the parietal and visceral layers of the tunica vaginalis
-thought to develop when there is an imbalance between the secretion and reabsorption of fluid from the tunica vaginalis
-typically are asymptomatic, but pain/pressure will increase with size
-if left untreated, can get up to several L in size.
-at birth or infancy are associated with a patent processus vaginalis
visceral layer of tunica vaginalis is applied directly to ___
the fibrous capsule of the testis (tunica albuginea)
contents of the spermatic cord
-pampniform plexus of veins
-branches of the genitofemoral nerve, to supply the cremaster muscule
-first thing you notice when you open the abdominal cavity
-fatty fold of peritoneum which drapes inferiorly from the greater curvature of the stomach
-lies anterior to the transverse colon and much of the small intestine
what is visible when the greater omentum is elevated
-the transverse colon on the posterior surface of the omentum
small intestine attached to the posterior wall of the abdominal cavity by a _____
-mesentery (double layer of visceral peritoneum).
-allows the small intestine to be quite mobile
transversalis fascia --> ___ (in spermatic cord)
internal spermatic fascia
transversus abdominis --> ___ (in spermatic cord)
internal oblique --> ___ (in spermatic cord)