Anatomy Flashcards
Retroperitoneal structures include GI structures that lack mesentery and non-GI structures.
Suprarenal (adrenal) glands
Aorta + IVC
Duodenum (2nd through 4th parts)
Pancreas (except tail)
Ureters
Colon (descending and ascending)
Kidneys
Esophagus (thoracic portion)
Rectum (partially)
Important gastrointestinal ligaments (6)
- Falciform
- Hepatoduodenal
- Gastrohepatic
- Gastrocolic
- Gastrosplenic
- Splenorenal
Falciform ligament
- Connects: liver to anterior abdominal wall
- Structures contained:
- Ligamentum teres hepatis (derivative of fetal umbilical vein)
- Notes:
- Derivative of ventral mesentery
Hepatoduodenal ligament
- Connects: liver to duodenum
- Structures contained:
- Portal triad - proper hepatic a., portal vein, common bile duct
- Notes:
- Pringle maneuver - ligament may be compressed between thumb and index finger (placed in omental foramen to control bleeding)
- Borders omental foramen (foramen of Winslow), which connects greater and lesser sacs
Gastrohepatic ligament
- Connects liver to lesser curvature of stomach
- Structures contained:
- Gastric arteries
- Notes:
- Separates greater and lesser sacs on the right
- May be cut during surgery to access lesser sac
Gastrocolic ligament
- Connects greater curvature and transverse colon
- Structures contained:
- Gastroepiploic arteries
- Notes:
- Part of greater omentum
Gastrosplenic ligament
- Connects: Greater curvature and spleen
- Contains:
- Short gastrics, left gastroepiploic vessels
- Notes:
- Separates greater and lesser sacs on the left
- Part of greater omentum
Splenorenal ligament
- Connects: Spleen to posterior abdominal wall
- Structures contained:
- Splenic artery and vein, tail of pancreas
Digestive Tract Anatomy
Layers of the gut (inside to outside - MSMS)
- Mucosa - epithelium, lamina propria, muscularis mucosa
- Submucosa - submucosal nerve plexus (Meissner), secretes fluid
- Muscularis externa - myenteric nerve plexus (Auerbach), motility
- Serosa (when intraperitoneal), adventitia (when retroperitoneal)
- Vasculature
- Lymphatics
Ulcers can extend into submucosa, inner or outer muscular layer.
Erosions = mucosa only
Frequencies of basal electric rhythm (slow waves)
- Stomach - 3 waves/min
- Duodenum - 12 waves/min
- Ileum - 8-9 waves/min
Digestive Tract Histology
Esophagus
Stomach
Duodenum
Jejunum
Ileum
Colon
- Esophagus:
- nonkeratinized stratified squamous epithelium
- Stomach:
- gastric glands
- Duodenum:
- villi and microvilli increase absorptive surface
- brunner glands (HCO3- secreting cells of submucosa)
- crypts of Lieberkuhn
- Jejunum
- Plicae circulares
- crypts of lieberkuhn
- Ileum
- Peyer patches (lymphoid aggregates in lamina propria, submucosa)
- Plicae circulares (proximal ileum)
- crypts of lieberkuhn
- Largest number of goblet cells in small intestine
- Colon
- crypts of lieberkuhn but NO VILLI
- Abundant goblet cells
Abdominal aorta and branches
Arteries supplying GI structures branch anteriorly.
Arteries supplying non-GI structures branch laterally and posteriorly.
“BiFOURcation” at L4
SMA (Wilkie’s) Syndrome
Intermittent intestinal obstruction symptoms (primarily postprandial pain) when transverse (third) portion of duodenum is compressed between SMA and aorta
Typically occurs in conditions associated with diminished mesenteric fat (e.g., low body weight/malnutrition)
GI Blood Supply and Innervation: Foregut
Artery: Celiac trunk (L gastric, common hepatic, splenic)
PSNS: Vagus
SNS: T5-T11
Vertebral level: T12-L1
Structures supplied:
- Pharynx (vagus nerve only), lower esophagus (celiac artery only) to proximal duodenum
- Liver, gallbladder, pancreas, spleen (mesoderm)
GI Blood Supply and Innervation: Midgut
Artery: SMA
PSNS: Vagus
SNS: T11-T12
Vertebral level: L1
Structures supplied:
- Distal duodenum to proximal 2/3 transverse colon