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THE ABDOMEN

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CLINICAL EXAMINATION OF THE ABDOMEN

Two kinds of pain:

Abdominal Medical History: (pqr)2st3

OBSERVE: Watch patient walk to table. Look for visible pain and discomfort. Note vital signs, stretch marks, scars, vascular pattern, etc.

LISTEN (AUSCULTATE):

PERCUSSION: Best way to examine liver is by percussion, to feel for borders. Can percuss for spleen to determine if it is enlarged.

PALPATE: Feel all major organs for inflammations, abnormalities, position, etc.


Four Quadrants:

Nine Regions:


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ANTERIOR ABDOMINAL WALL

Boundaries of the Abdomen:

PELVIC BRIM: Inferior border of the abdomen.

UMBILICUS: Found between L3 and L4 in physically fit persons.

Grandparents Like Pediatric Doctors Preventing Kids Sickness: One Transpyloric Plane -- The Transpyloric plane passes through L1 and contains the following structures:

Processus Vaginalis: The portion of peritoneum that remains with the testes when they descend into the scrotum.

7 Layers of the Abdominal Wall:

Linea Alba: The best place to make a surgical cut and not hit any nerves is straight down the linea alba.

NERVOUS SUPPLY of Anterior Wall: Ventral Rami of T7 - T12, and L1.

McBurney's Point: The point of surgical incision for an appendectomy.

ARTERIAL SUPPLY of Anterior Wall:

VENOUS SUPPLY of Anterior Wall: The same as the veins above.


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INGUINAL REGION

Inguinal Canal: Formed from the aponeuroses of the three flat muscles.

Inguinal Triangle (Hesselbach's Triangle): An area of weakness in the aponeurosis, where direct hernias can occur.

HERNIAS: The protrusion of intraperitoneal guts outside of the peritoneum (i.e. through the peritoneal wall).


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PERITONEUM

Spleen: It is actually mesodermal in origin, not endodermal like the rest of the abdominal organs.

Retroperitoneal Space: The area behind (posterior to) the peritoneum. Any organs not completely (or almost completely) covered by peritoneum are considered retroperitoneal organs.

Abdominal Cavity: Everything but the lateral, posterior, and anterior body walls of the abdomen, including both the peritoneal cavity and the retroperitoneal space.

Peritoneal Cavity: That part of the abdomen invaginated by peritoneum.

Subphrenic Recess: The recess where the peritoneum reflects off the liver (right side) on the inferior surface of the diaphragm.

OMENTA: Peritoneum surrounding the stomach

Superior Recess: Where the Lesser Omentum stops at the coronary ligament of the liver and reflects back onto the liver. Essentially, the space between the stomach and

Inferior Recess: Along the greater curvature of the stomach, where the greater omentum reflects onto the transverse mesocolon. Essentially, the space between the stomach and transverse colon, inferior to the stomach.

Intra-Peritoneal Organs: Organs completely or almost completely enclosed by peritoneum.

Retro-Peritoneal Organs: Organs that are located mostly or completely behind the posterior parietal peritoneum.

Mesentery: Two layers of peritoneum opposing each other. Vessels and nerves often lie in the mesentery, where they can easily reach the organ where the peritoneal layers separate and reflect off the organs.

The Anterior Surface of the Diaphragm:


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SUMMARY ACCORDING TO THE GUTS

FOREGUT:

MIDGUT:

HINDGUT:


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THE STOMACH

DEVELOPMENT:

LOCATION: The pylorus of the stomach at the level of L1, in the transpyloric plane.

EXTERNAL MORPHOLOGY:

INTERNAL MORPHOLOGY:

RELATIONSHIPS:

CLINICAL CONSIDERATIONS:

VASCULAR / LYMPH SUPPLY:

NERVE SUPPLY:


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THE SPLEEN

DEVELOPMENT: It is mesodermal -- not derived from gut (i.e. nongut)

LOCATION: Upper left quadrant, left hypochondriac region, articulated with ribs 9-11 (laterally).

EXTERNAL MORPHOLOGY: It has three grooves (surfaces)

INTERNAL MORPHOLOGY:

RELATIONSHIPS:

CLINICAL CONSIDERATIONS:

VASCULAR / LYMPH SUPPLY:

NERVE SUPPLY:


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THE DUODENUM

DEVELOPMENT: Duodenum is the dividing point between the foregut and midgut.

LOCATION: It is retroperitoneal. (The first portion is actually intraperitoneal, but we won't count that).

EXTERNAL MORPHOLOGY: It is a C-Shaped portion of the gut.

INTERNAL MORPHOLOGY:

RELATIONSHIPS:

CLINICAL CONSIDERATIONS:

VASCULAR / LYMPH SUPPLY:

NERVE SUPPLY:


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THE PANCREAS

DEVELOPMENT:

LOCATION: Retroperitoneal.

EXTERNAL MORPHOLOGY:

INTERNAL MORPHOLOGY:

RELATIONSHIPS: Also see external morphology

CLINICAL CONSIDERATIONS:

VASCULAR / LYMPH SUPPLY:

NERVE SUPPLY:


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THE LIVER

DEVELOPMENT: Foregut, closely associated with primitive cystic and pancreatic ducts.

LOCATION:

EXTERNAL MORPHOLOGY:

INTERNAL MORPHOLOGY:

RELATIONSHIPS:

CLINICAL CONSIDERATIONS:

VASCULAR / LYMPH SUPPLY:

NERVE SUPPLY:


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THE GALLBLADDER

DEVELOPMENT:

LOCATION: Located in the gallbladder fossa of the liver, on visceral (posterior side), medial-left lobe.

EXTERNAL MORPHOLOGY: A pear-shaped sac, containing concentrated gallbladder bile.

INTERNAL MORPHOLOGY:

RELATIONSHIPS:

CLINICAL CONSIDERATIONS:

VASCULAR / LYMPH SUPPLY:

NERVE SUPPLY:


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THE SMALL INTESTINE (JEJUNUM / ILIUM)

DEVELOPMENT: Small intestine develops as a herniation into the umbilical region.

LOCATION: It occupies most of the left upper quadrant and right lower quadrant of the abdomen.

EXTERNAL MORPHOLOGY:

INTERNAL MORPHOLOGY:

RELATIONSHIPS:

CLINICAL CONSIDERATIONS:

VASCULAR / LYMPH SUPPLY:

NERVE SUPPLY:


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THE LARGE INTESTINE (COLON)

DEVELOPMENT:

LOCATION: All four quadrants. In the nine-region system, it is located in the bottom six regions -- not the epigastric / hypochondriac regions.

EXTERNAL MORPHOLOGY:

INTERNAL MORPHOLOGY:

RELATIONSHIPS:

CLINICAL CONSIDERATIONS:

VASCULAR / LYMPH SUPPLY: Colic arteries have variations.

NERVE SUPPLY:


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THE ABDOMINAL VASCULATURE

Abdominal Aorta:

Celiac Trunk: Located just inferior to Aortic Hiatus.

Superior Mesenteric Artery:

Inferior Mesenteric Artery:

Pancreaticoduodenal Arcade: An alternative route for blood flow through the branches of the celiac, if there should be an occlusion in the celiac trunk.

Lumbar Arteries: Supply the posterior abdominal wall.

PORTAL VENOUS SYSTEM: Takes blood from the entire abdomen and dumps it into the liver for processing ------> out the Suprahepatic Inferior Vena Cava.


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THE NERVOUS SYSTEM

CNS: The brain and the spinal chord.

Peripheral Nervous System: All other nerves, consisting of the Autonomic Nervous System (ANS) and Somatic Nervous System (SNS).

Autonomic Nervous System: Involuntary innervation of visceral structures.

Somatic Nervous System: Voluntary innervation of somatic structures (skeletal muscles and skin).

Types of Nerves fibers: There are many types of nerve fibers in a single nerve bundle.

MIXED NERVE: Nerves such as vagus and phrenic carry both afferent and efferent fib3ers, and both somatic and autonomic. Therefore they are mixed nerves.

REFERRED PAIN: The interpretation of dermatomal layers in the brain is responsible for the concept of referred pain.

STRUCTURE OF PARAVERTEBRAL GANGLIA:

SYMPATHETIC PARASYMPATHETIC
Spinal Chord Origin Thoracolumbar: T5-T12, L1-L2 Craniosacral: C10 (Vagus Nerve), S2-S4.
Effects Widespread, low precision Specific, discrete, local, acute.
Location of cell bodies Along the spinal chord, at the sympathetic chain ganglia.

Plexuses are found along the midline of the body -- pre-aortic ganglia, mesenteric plexuses.

Adjacent to or in the target organ.
Pre-Ganglionic Fiber Short Long
Post-Ganglionic Fiber Long Short
Pre-Ganglion : Post-Ganglion fiber ratio Low ratio -- one pre-ganglion spreads to lots of post-ganglion, hence the effect is widespread and imprecise High Ratio -- 1:1 or near 1:1, hence the effect is more localized.
Neurotransmitter Acetylcholine at pre-synapse terminals

Norepinephrine at post-synapse terminals

Acetylcholine
General energy use and metabolism Fight or flight -- expenditure of energy. Intake and conservation of energy

The Vagus Nerve: Foregut and Midgut innervation

Pelvic Splanchnic Nerves: Hindgut innervation

Greater Thoracic Splanchnics: T6-T9. Sympathetic spinal nerves supplying the foregut and midgut.

Lesser Thoracic Splanchnic: T10-T11. Sympathetic spinal nerves supplying the hindgut, generally.

Least Thoracic Splanchnic: T12. It supplies the Renal Plexus.


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POSTERIOR ABDOMINAL WALL

Three Hiatuses of the Diaphragm:

Diaphragmatic Crura: Left and Right Crus of the diaphragm, on posterior wall.

LUMBOCOSTAL ARCHES (ARCUATE LIGAMENTS): The ligaments connecting the diaphragm to the posterior wall. They are condensations of transversalis fascia.

Muscles of the Posterior Abdominal Wall:

Thoracolumbar Fascia: Actually an extension of the aponeuroses of the transversus abdominis and external abdominal oblique muscles.

Nerves of the Posterior Wall:

Nerves of the lumbar plexus:

Lumbosacral Trunk: L4-L5


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KIDNEYS AND SUPRARENAL GLANDS

Suprarenal Glands:

KIDNEYS:


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LYMPHATIC SYSTEM

General stuff about the Lymphatic System:

Thoracic Duct: Carries most of the lymph from the abdomen. All things empty into the thoracic duct.

Lymphadenitis: Infections within the lymph node(s).

Lymphangitis: Infections within lymph vessels


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Copyright 1999, Scott Goodman, all rights reserved