Week 6: Abdominal Viscera Flashcards
structure: esophagus, a 24 cm tube that connects the pharynx with the stomach
Innervation: recurrent laryngeal and vagus n.
structure: Cardiac region of stomach
innervation: Hepatic and left gastric plexuses (sympathetic innervation).
Gastric branches of vagus nerve (parasympathetic innervation).
Anterior and posterior esophageal plexus (parasympathetic innervation).
primary action: The cardiac region is the region where the esophagus joins the stomach and houses the cardiac orifice.
structure: fundus (of stomach)
The fundus is the rounded, dome-shaped superior portion of the stomach.
It is delineated by the initial convexity of the greater curvature.
Innervation: Hepatic and left gastric plexuses (sympathetic innervation).
Gastric branches of vagus nerve (parasympathetic innervation).
Anterior and posterior esophageal plexus (parasympathetic innervation).
structure: stomach body
The body is the midportion of the stomach and is the largest part.
innervation: Hepatic and left gastric plexuses (sympathetic innervation).
Gastric branches of vagus nerve (parasympathetic innervation).
Anterior and posterior esophageal plexus (parasympathetic innervation).
It is bordered superiorly by the fundus and inferomedially by the pyloric antrum.
The lateral border is formed by the greater curvature.
The medial border is formed by the gastric canal.
The anterior surface of the body is convex.
structure: Pyloric antrum
The pyloric antrum lies inferior to the body of the stomach and extends from the angular incisure to the sulcus intermedius.
Innervation: Hepatic and left gastric plexuses (sympathetic innervation).
Gastric branches of vagus nerve (parasympathetic innervation).
Anterior and posterior esophageal plexus (parasympathetic innervation).
It is bounded laterally by the body and medially by the pyloric canal.
Its superior and inferior borders are formed by the lesser and greater curvatures, respectively.
structure: pyloric canal
innervation: Hepatic and left gastric plexuses (sympathetic innervation).
Gastric branches of vagus nerve (parasympathetic innervation).
Anterior and posterior esophageal plexus (parasympathetic innervation).
The pyloric canal is situated to right of the stomach.
It is 2 to 3 cm long, extends from the pyloric antrummedially to the pylorus laterally, and is notched inferiorly by the sulcus intermedius.
structure: Pyloric sphincter
Innervation: Nerves from the hepatic and left gastric plexuses, derived from the celiac plexus (sympathetic).
Gastric branches of vagus nerve (parasympathetic).
The pyloric sphincter is a thickened ring of gastric muscle around the junction between the pyloric canal and the duodenum.
Along with the circular muscle fibers there is also a small number of longitundinal fibers.
The pyloric sphincter is usually in tonic contraction, relaxing only to allow sufficiently processed food into the rest of the alimentary tract.
Its presence creates a marked constriction around the pyloric canal.
structure: Duodenum
Innervation: Superior mesenteric plexuses (sympathetic innervation).
Intestinal branches of the vagus nerve (parasympathetic innervation).
Primary action: The duodenum is the conduit for bile, pancreatic secretions, and gastric contents.
structure: jejunum
innervation: Greater+ lesser splanchnic nerves from the superior mesenteric plexus, derived from the celiac plexus (sympathetic innervation).
Fibers from the posterior vagal trunk formed from the right vagus nerve (parasympathetic innervation).
Primary action: Responsible for absorbing nutrients, part of the small intestine
This has a diameter of approximately 4 cm, with thick walls, and a rich blood supply.
It lies largely within the umbilical region of the abdomen, with the first coil occupying a recess between the left kidney and the left part of the transverse mesocolon.
It has large circular folds and villi.
Structure: Ileum
innervation: Greater+lesser splanchnic nerves from the superior mesenteric plexus, derived from the celiac plexus (sympathetic innervation).
Fibers from the posterior vagal trunk, formed from the right vagus nerve (parasympathetic innervation).
Primary action: further digestion of food, absorption of nutrients *connects to the large intestine via the cecum
Structure: Cecum
Innervation: superior mesenteric plexus
Primary action: The cecum is a blind-ended sac that forms the beginning of the large intestine; its walls contain a large amount of lymphocytes.
Inferiorly it gives off the vermiform appendix; superiorly it receives the ileum at the ileocolic junction, which also marks its continuation upwards as the ascending colon.
structure: vermiform appendix
innervation: sup. mesenteric plexus
primary action: . It is an embryological remnant of a larger cecum and contains lymph nodules that play an important role in the bodies immunity. Its blind-ended structure provides an ideal growing environment for enteric bacteria, and is thereby at risk of inflammation.
The vermiform appendix is a 9 cm long, worm-like tube that extends from the inferior surface of the cecum.
structure: ascending colon
innervation: Branches from the superior mesenteric plexuses
Narrower than the cecum, the ascending colon extends for approximately 15 cm.
It ascends to the inferior surface of the right lobe of the liver before turning anteriorly and towards the left, forming the right colic flexure.
The ascending colon is covered by peritoneum except where its posterior surface contacts the iliac fascia, iliolumbar ligament, quadratus lumborum, and the aponeurosis of transversus abdominis.
Its anterior surface contacts the ileum, greater omentum, and anterior abdominal wall.
structure: transverse colon
primary function: absorbs water and salts
structure: descending colon
It follows the inferior part of the lateral border of the left kidney before descending towards the iliac crest. Here it curves inferiorly and medially, anterior to psoas major, and meets the sigmoid colon at the pelvic inlet.
Its surfaces are covered by peritoneum, except for the posterior aspects in contact with the left kidney, aponeurosis of transversus abdominis, and quadratus lumborum.
Structure: Sigmoid Colon
Primary function: continuation of the descending colon
Structure: Rectum
Primary function: downward continuation of sigmoid colon, has three transverse fold that retain feces whilst passing flatus
Structure: Hepatic flexure
Primary action: forms the junction between the ascending and transverse colon, and is near the R lobe of the liver
structure: splenic flexure
primary function: forms the junction between the transverse colon and descending colon, located inferior to the spleen and is attached to the diaphragm by a fold of peritoneum
structure: spleen
Primary function: part filter, part lymphocyte factory.
Filters the blood dead cells, and creates lymphocytes to fight organisms that can cause infection.
structure: pancreas (body)
primary function: both digestive and endocrine functions:
produces pancreatic juice that breaks down proteins to amino acids, starch to maltrose, fats to fatty acid and glycerol. Produces glucagon and insulin to regulate blood sugar, etc.
Structure: Liver (R Lobe)
Primary function: stores sugars, vitamins and minerals, produces blood-clotting proteins, and bile. Breaks down poisons and toxins,
largest part of the liver, divides from the left lobe anteriorly.
Structure: Liver, Caudate Lobe
Primary function: stores sugars, vitamins and minerals, produces blood-clotting proteins, and bile. Breaks down poisons and toxins
The small, tail-like caudate lobe lies on the posterior surface of the liver in the mid line, above the quadrate lobe and functions as part of the left lobe.
It is bordered by the fissure for the ligamentum venosum to the left, the porta hepatis inferiorly, and the groove for the inferior vena cava to the right.
Structure: Liver (L Lobe)
Primary function: stores sugars, vitamins and minerals, produces blood-clotting proteins, and bile. Breaks down poisons and toxins,
largest part of the liver, divides from the left lobe anteriorly.
Structure: Liver, Quadrate lobe
Primary function: stores sugars, viatmins and minerals, produces blood-clotting proteins, bile, breaks down toxins and poisons, insulin, converts hemoglobin into bilirubin
The quadrate lobe lies on the posterior surface of the liver in the mid line, below the caudate lobe and functions as part of the left lobe.
It is bordered by the fissure for the ligamentum teres medially, the porta hepatis superiorly, and the fossa for the gallbladder laterally.
Structure: Gallbladder
Primary function: stores and concentrates bile, releasing it into the duodenum where it emulsifies fats, stimulates peristalsis and acts as a channel for the excretion of
found under the R lobe of the liver.
Structure: Kidneys
Primary function: filter the blood, excreting waste and excess water as urine, regulating blood pressure, volume, pH and salt balance
Right suprarenal gland
- The right suprarenal gland is an irregular, tetrahedral-shaped gland attached to the anterior aspect of the superior pole of the right kidney.
- It lies posterior to the inferior vena cava and right hepatic lobe where the lack of peritoneum enables the gland to come in contact with the bare area of the liver.
- The inferior part of the gland may be covered by peritoneum and the duodenum may overlie it anteriorly.
- The hilum is located on the anterior border near the apex of the gland.
The left gland is semilunar in shape and both slightly larger and located more superiorly than the right gland.
- It is attached to the medial side of the superior pole of the left kidney and its anterior surface is covered by peritoneum, which separates it from the cardiac end of the stomach.
- Inferiorly, it is not covered by peritoneum and lies in contact with the posterior aspect of the pancreas and the splenic vessels.
The kidneys have three distinguishable regions: the renal cortex, renal medulla, and renal pelvis.
At the medial aspect of the kidneys lies the renal pelvis, which collects urine from the pyramids by enclosing their apices in extensions of the renal pelvis known as calyces.
Pelvis
- The pelvis is a single, funnel-shaped structure in each kidney which is formed by the union of the major calyces.
- It proceeds inferomedially through the hilus of the kidney and is continuous with the ureter in the pelvi-ureteric region.
- This region is generally located external to the hilus of the kidney, although in some cases it may be located within it.
Structure: Ureters
Function: • Urine is passed down it by peristaltic waves of the smooth muscle walls.
- Each ureter descends medially, anterior to psoas major and the genitofemoral nerve, but posterior to the gonadal vessels before entering the lesser pelvis anterior to the branch point of the external iliac vessels.
- From here, it descends posterolaterally along the lateral wall of the lesser pelvis to the ischial spine.
- Here it turns anteromedially, proceeding through fibrous adipose tissue to the bladder.
Structure: The minor calyces are trumpet-shaped structures located in the medulla of the kidney.
Each calyx surrounds the papillae formed at the tip of a renal pyramid.
Function: The minor calyces collect and convey urine produced by the kidneys to the major calyces.
Structure: R Major calyces. There are two or three major calyces in each kidney, each formed by the fusion of the minor calyces.
Function: The major calyces collect urine from the minor calyces and drain it into the renal pelvis.
Structure: Renal pyramids
The renal pyramids are cone-shaped structures that terminate medially by protruding into the minor calyces. The pyramids appear striated because they are packed with bundles of nephron loops and collecting tubules, plus the associated capillaries.
