Quiz 4 - Inguinal Region

Question 1

inferior margin of the aponeurosis of the external oblique muscle extends from the ASIS to the ______

Answer 1

• pubic tubercle

- is folded under upon itself and thickened to create the inguinal ligament

Question 2

inguinal canal

Answer 2

• 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

Question 3

what forms the inguinal canal?

Answer 3

• 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)

Question 4

deep inguinal ring

Answer 4

• the internal (deep) opening of the inguinal canal

- thru the transversalis fascia

Question 5

superficial (external) inguinal ring

Answer 5

• external opening of the inguinal canal; lies superior to the inguinal ligament
• thru the aponeurosis of the external oblique muscle

Question 6

spermatic cord

Answer 6

• 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

Question 7

fascial coverings of spermatic cord

Answer 7

• external oblique –> external spermatic fascia
• internal oblique –> cremasteric muscle and fascia
• transversalis fascia –> internal spermatic fascia

Question 8

inguinal region (groin)

Answer 8

• 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

Question 9

inguinal ligament

Answer 9

• 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)

Question 10

major structures within the spermatic cord

Answer 10

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

Question 11

pampniform plexus

Answer 11

• surrounds the testicular artery

- serves as an important counter-current thermo-regulatory function

Question 12

hernias

Answer 12

• 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

Question 13

inguinal hernias

Answer 13

-either “direct” or “indirect,” depending on whether they originate medial or lateral to the inferior epigastric vessels

Question 14

direct hernias

Answer 14

-protrude thru the inguinal (Hesselbach’s) triangle (medial to the inferior epigastric vessels) and is located alongside (not within) the spermatic cord.

Question 15

indirect hernias

Answer 15

-pass thru the internal (deep) inguinal rings and therefore must reside within the spermatic cord coverings

Question 16

as the testis descends into the scrotum…

Answer 16

…it becomes enveloped in the various tissues that it encounters as it pushes thru the abdominal wall

Question 17

first layer of the abdominal wall that the testis meets as it descends into the scrotum

Answer 17

-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

Question 18

second layer of the abdominal wall that the testis meets as it descends into the scrotum

Answer 18

• internal oblique muscle

- some of its muscle fibers will be carried along to become the cremaster muscle fibers and its fascia

Question 19

third layer of the abdominal wall that the testis meets as it descends into the scrotum

Answer 19

-external oblique aponeurosis, which will become the most superficial fascial layer of the spermatic cord, the external spermatic fascia

Question 20

does the transversus abdominis contribute to the fascial coverings of the spermatic cord?

Answer 20

-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.

Question 21

inguinal triangle

Answer 21

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

Question 22

how do the inferior epigastric vessels reach and ascend along the posterior surface of the rectus abdominis muscle?

Answer 22

-they must penetrate the transversalis fascia of the posterior rectal sheath inferior to the arcuate line

Question 23

testes and ovaries begin their development where?

Answer 23

• 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

Question 24

testicular arteries

Answer 24

• 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

Question 25

descent of the testes

Answer 25

- 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

Question 26

proximal portion of the processus vaginalis normally obliterates, leaving ___

Answer 26

- the distal portion to become the tunica vaginalis | - the testis partially invaginates into the tunica vaginalis from posterior (fist in balloon)

Question 27

the posterior layer of the tunica partially covers the testis as the ____ tunica vaginalis

Answer 27

visceral

Question 28

the anterolateral layer of the tunica vaginalis becomes the ____ tunica vaginalis

Answer 28

parietal

Question 29

there (is/is not) usually some fluid between the visceral and parietal layers of the tunica vaginalis

Answer 29

IS

Question 30

what do you need for healthy production of spermatozoa?

Answer 30

- 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

Question 31

what else plays a role in the thermo-regulation of the testis?

Answer 31

- 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

Question 32

the testes reside in the scrotum and are covered by what?

Answer 32

-a thick fibrous layer called the tunica albuginea

Question 33

testes are surrounded by which two layers of residual processus vaginalis (except on its posterior aspect)?

Answer 33

-the parietal and visceral layers of the tunica vaginalis

Question 34

seminiferous tubules of the testes drain thru the ___

Answer 34

- 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

Question 35

testes originate in the embryo from ___

Answer 35

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

Question 36

lymphatic drainage of testis differs how from that of the scrotal skin?

Answer 36

- 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

Question 37

hydrocele

Answer 37

- 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

Question 38

visceral layer of tunica vaginalis is applied directly to ___

Answer 38

the fibrous capsule of the testis (tunica albuginea)

Question 39

contents of the spermatic cord

Answer 39

- testicular artery - pampniform plexus of veins - ductus deference - branches of the genitofemoral nerve, to supply the cremaster muscule

Question 40

greater omentum

Answer 40

- 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

Question 41

what is visible when the greater omentum is elevated

Answer 41

-the transverse colon on the posterior surface of the omentum

Question 42

small intestine attached to the posterior wall of the abdominal cavity by a _____

Answer 42

- mesentery (double layer of visceral peritoneum). | - allows the small intestine to be quite mobile

Question 43

transversalis fascia --> ___ (in spermatic cord)

Answer 43

internal spermatic fascia

Question 44

transversus abdominis --> ___ (in spermatic cord)

Answer 44

missed (bypassed)

Question 45

internal oblique --> ___ (in spermatic cord)

Answer 45

cremaster muscle

Question 46

external oblique --> ___ (in spermatic cord)

Answer 46

external spermatic fascia