Abdomen I: Anterior Abdominal Wall and Inguinal Canal

What are 6 bony landmarks of the surface anatomy?

1. xiphoid process (inferior sternum)

2. costal margin (inferior ribs)

3. anterior superior iliac spine

4. public crest

5. pubic tubercle

6. public symphysis

how is the abdomen divided?

using the median plane and umbilicus

external oblique: location

from ribs 5-12 to the iliac crest and pubic tubercle. aponeurosis forms the anterior inferior part

what are 3 main defining components of the external oblique?

superficial inguinal ring (triangular gap), inguinal ligament, linea alba

internal oblique: location

runs perpendicular to the external oblique fibers from the iliac crest to the linea alba

transversus abdominis: location + defining feature

costal margin and iliac crest to the linea alba, forms the deepest muscle layer. conjoint tendon— reinforces a weak area of the abdominal wall.

rectus abdominis: location

from symphysis pubis and pubic crest, and inserts into the 5th, 6th, and 7th costal cartilages

tranversalis fascia: location

fascia on the inner surface of the transversus abdominis— inguinal ring is an opening is the transversalis fascia. Deep to tranversalis fascia is the peritoneum

what functions would a person be unable to do if the muscles of the abdominal wall were damaged?

inability to laterally flex and rotate trunk, rectus abdominis unable to flex the trunk, inability to position the trunk to support limb movements. weakening of forced expiration.

how does the muscles of the abdominal wall play a role in respiration?

the muscles increase intra-abdominal pressure and elevate the diaphragm during forced expiration

the muscles of the abdominal wall increase intra abdominal pressure. other than respiration, what other functions does this help with?

urination, defecation, vomitting, and parturition (childbirth)

muscles of the abdominal wall help with what structurally?

help protect the viscera and maintain posture

the anterior abdominal walls are innervated by what nerve(s)?

By spinal nerves T7-L1: intercostal nerves, subcostal nerve, and ilio (-hypogastric & -guinal) nerves

what artery/arteries supply blood to the abdominal walls? Anastomoses provides collateral circulation btwn what arteries?

epigastric arteries: superior artery from the internal thoracic artery, inferior artery from the external iliac artery. Anastomoses provides collateral circulation between the subclavian external iliac arteries.

inguinal canal: male vs female

male: occupied by spermatic cord; female: occupied by round ligament of the uterus

superficial inguinal ring (characteristics)

a triangular shaped defect; exit of the inguinal canal

deep inguinal ring (characteristics)

oval opening— the internal entrance into the inguinal canal

this structure develops in the lumbar region deep to the transversalis fascia

testes

what structure secures the testicle to the bottom of the scrotum?

scrotal ligament— adult remnant of the gubernaculum

spermatic cord: where does it begin, where does it end?

spermatic cord begins at the deep inguinal ring and ends at the posterior border of the testis

spermatic cord: main structures and tissues (5)

1. ductus (vans) deferens

2. testicular artery

3. pampiniform plexus of veins (forms testicular vein)

4. autonomic nerves

5. cremasteric fascia and muscle (derived from internal oblique muscle)

we stroke the inner thigh but nothing occurs. what reflex is damaged?

cremasteric reflex

scrotum: describe + divisions + derivation

scrotum is a pouch of skin situated below the pubic symphysis. it is divided into skin and smooth muscle. Derived from the layers of the anterior abdominal wall

this peritoneal sac surround the testes.

tunica vaginalis

there is an abnormal accumulation of fluid in the cavity of the tunica vaginalis. what do we call this?

hydrocele

what nerve innervates the scrotum?

genital branch of the genitofemoral nerve, ilioinguinal nerve, pudenal nerve, and posterior femoral cutaneous nerve

testes: describe + function + surrounded by what?

testes are paired oval organs that produce spermatoza after puberty and secrete hormones. They are surrounded by the tunica albuginea.

where doo hernia occur most commonly?

inguinal, femoral, and umbilical regions.

what is one way hernias can occur?

weakened anterior abdominal wall— repeated increased intra-abdominal pressure may induce herniation.

testes: artery + vein

testes get their blood supply from the testicular artery, a branch of the abdominal aorta. The pampiniform plexus drains the testis. These converge to form the testicular vein

there is an enlargement of the veins of the spermatic cord. What is this condition? What does it often result from?

varicocele; often results from defective valves in the testicular vein

what structure connects the tubules in the testis to the ductus deferens?

epididymis

what is this condition: congenital weakness in the abdominal wall at the site of passage of the testis. result of persistent processus vaginalis. intestinal loop enters the deep inguinal ring. can or cannot pass the entire length of inguinal canal.

indirect inguinal hernia

what is this condition: protrusion is medial to the inferior epigastric artery and move forward to the superficial ring in the inguinal triangle. Hernia does not pass through the deep inguinal ring, but emerges through or around the conjoint tendon to reach the superficial inguinal ring.

direct inguinal hernia

what type of inguinal hernia is rare in women?

direct inguinal hernia