GI - Anatomy Clinical Correlations Flashcards
How accurately is pain localized in the parietal peritoneum? Is it more similar to visceral or dermatome pain?
Parietal peritoneum is supplied by vessels, lymphatics and nerves common to the external body wall and therefore the same modalities (pain, pressure, heat, cold) found in skin are easily localized to the body wall internally due to its precise spinal innervation.
What is rebound tenderness? What does it indicate?
Palpation of the abdominal wall that stretches the peritoneum, then abruptly letting go
-will cause severe pain in area of acute inflammation and infection, due to precise innervation of peritoneum
How accurately is pain localized to the visceral peritoneum?
Inaccurate - visceral pain
What is peritonitis? What can cause it? What are the symptoms?
Peritonitis, inflammation of the peritoneum, due to air, blood, bacteria, or fecal matter accumulating within the peritoneal cavity
Causes: abdominal lacerations, diverticulitis, ruptured appendix, or GI ulcers
Symptoms: extreme pain as the visceral and parietal layers appose one another during normal movements (walking, respiration, peristalsis).
What is ascites?
Accumulation of excess serous fluid within the peritoneal cavity is referred to as ascites.
How is ascitic fluid removed?
Removal of ascitic fluid is accomplished by paracentesis. A syringe or trocar inserted at the linea alba superior to the urinary bladder is used to “draw off” the excess fluid. Depending on the cause of the ascites, liters of fluid can accumulate that need to be removed.
Why are intraperitoneal injections useful? What is administered?
Due to the large surface area presented by the peritoneum and its absorptive nature, anesthesia and antibiotics can be administered by injecting them into the peritoneal cavity.
What is peritoneal lavage?
Washing the peritoneum with sterile water and antibiotics following abdominal surgeries, is used to reduce the occurrence of peritonitis
What is peritoneal dialysis?
In patients with renal failure, hypertonic solutions can be injected into the peritoneal cavity and then withdrawn after soluble metabolites have traversed blood vessels into the peritoneal cavity.
What are peritoneal adhesions? What are the symptoms?
Peritoneal inflammation, due to infection or endometriosis, can lead to adhesions forming between opposing layers of peritoneum, be it between adjacent layers of visceral peritoneum or between visceral and parietal peritoneum
Symptoms:
pain
impede the normal movement between organs or between the organs and the body wal
What is an adhesiotomy?
Surgical incision of peritoneal adhesions to allow for easier or pain-free movement of organs
Explain the pathology of endometriosis. Why does it occur? How is it treated?
Monthly sloughing of the endometrium, lining of the uterus, does not occur in a one way direction. The uterine tubes are open to the peritoneal cavity. Since the peritoneum provides a nutritive environment, endometrial cells which seed the peritoneal cavity develop into “islands” of endometrial tissue which respond to monthly hormonal changes, thereby effectively “spot welding” coils of intestine to one another as well as to the colon and body wall
resulting in peritoneal adhesions which are painful and may eventually impede the movement of intestinal contents.
Can be treated with adhesiotomy, or Fallopian tube ligation
How is the greater omentum protective?
The greater omentum is highly mobile and can effectively “wall off” areas which are inflamed so as to protect the other abdominal organs from the spread of infection. It also protects the abdominal organs from trauma and insulates the trunk preventing loss of heat.
What is an internal hernia?
All of the paraduodendal fossae can become confluent
Herniates at the duodenojejunal flexure during development
Mostly asymptomatic, discovered incidentally after death - autopsy, dissection
If intestines strangulate, repair is needed ASAP
When surgical repair of an internal hernia is attempted, what structures should you watch out for?
spare the inferior mesenteric vv and ascending branch of the left colic aa
What happens when patients with significant purulent ascites lie recumbent?
Fluid in the abdominopelvic peritoneal cavity can drain to the supracolic compartment by passing along the right paracolic gutter to the hepatorenal recess where an hepatorenal/subphrenic abscess can form.
An abscess here can dissect through the vertebrocostal trigone to involve the thoracic cavity.
What happens when patients with ascites turn over in sleep?
With repeated turning of the body during sleep, ascitic fluid can enter the omental bursa via the epiploic foramen and disseminate infection to the area behind the stomach (stomach bed)
What can accumulate in the omental bursa?
Fluid from other sources, i.e. accumulations of gastric fluid as a result of a perforated gastric ulcer
What is a pancreatic pseudocyst?
Fluid from an inflamed pancreas can “leaks” into the omental bursa
How is fluid in the scrotum managed via the abdominal scrotal opening?
The abdominal scrotal opening represents a potential path for extravasated fluid in the scrotum to ascend into the abdominal wall.
However, due to the previously mentioned attachments of the membranous layer of superficial fascia fluid remains in the flanks but does not progress into the lower limbs.
When doing abdominal surgery, how should you cut abdominal muscles? Why? Where is a ‘safe’ spot for abdominal incisions?
The fiber direction of the anterolateral and anterior abdominal wall musculature is arranged so that successive layers assume a non-congruent orientation, viz., vertical, horizontal, and oblique directions.
During surgery this arrangement is preserved by splitting muscles parallel to their fiber direction on a per layer basis.
Muscular fibers are never cut perpendicular to their fiber direction because they will scar, not only across the muscle fibers, but successive layers will adhere to one another impairing normal movements making them painful.
Whenever possible, abdominal incisions are placed on the mid-line (linea alba) where only fascial/tendinous tissue will be incised
What is the site of direct inguinal hernias?
Medial inguinal fossa
What is the site of indirect inguinal hernias?
Lateral inguinal fossa
Why does the lymphatic drainage of the testes play an important role in testicular cancer?
Testes drain lymph internally, to nodes located near Batson’s plexus
- allows for disseminated proliferation of malignant cancer cells
(Scrotum tends to drain more superficially, to inguinal LNs)
scrotal cancer first metastasizes to superficial inguinal nodes, while cancer of the testes metastasizes to lumbar nodes (nodes paralleling the lumbar aorta) via the lymphatics contained in the spermatic cord making it harder to diagnose its progression
What birth defect can lead to weakness of the anterior abdominal wall in the inguinal region? Why is this important?
Processus vaginalis is open in ~50% of infants until one month after birth
leads to weakness of anterior abdominal wall in the inguinal region
Contributes to indirect inguinal hernia
What is cryptorchidism?
undescended or incompletely descended testes
How is a hydrocele formed?
Fluid accumulation in the tunica vaginalis testis
- due to incomplete closure of processus vaginalis
Fluid can be from secretion of abnormal amounts of serous fluid by the serous membrane of tunica vaginalis
How is a hematocele formed?
Accumulation of blood in the scrotum in the tunica vaginalis testis
- due to trauma (blood)
- also due to incomplete closure of the processus vaginalis
What is a spermatocele?
Collection of fluid in the epididymis
- usually near its head
What is a varicocele?
Dilated veins of the pampiniform plexus.
Occurs more often on the left and can be a result of incompetent valves within the plexus or due to the angle at which the testicular v. enters the renal vein
What is testicular torsion?
Twisting of the spermatic cord due to an unattached gubernaculum
- is a medical emergency.
Twisting of the cord can lead to necrosis of the testes due to impeding vascular supply and drainage
Generally speaking, what is an abdominal wall hernia?
Hernias of the abdomen are protrusions of any portion of the abdominal contents beyond the confines of the abdominal cavity
What are the 5 types of hernias?
Epigastric Umbilical Spigelian Incisional Inguinal (direct and indirect)
Where does an epigastric hernia occur? What causes it?
Occur along the linea alba between the xipoid process and umbilicus
Can be due to gaps of CT fibers between the linea alba and rectus sheath, stresses of obesity and aging, consequence of surgical intervention
Where does an umbilical hernia occur? What is it due to?
Occur through umbilical ring
Due to weakness at site from incomplete closure of umbilical cord ligation and increased intra-abdominal pressure
Most common in neonates - associated with low birth weight
Where does a Spigelian hernia occur? What is it associated with?
Occur along the semilunar lines
Associated with obesity and in ages over 40 yrs
