Anatomy Week 7 part 1-6: Walls/boundaries to esophagus

The abdomen lies between which two structures?

The diaphragm (roof) and the pelvis; no floor — continuous with the pelvic cavity

Superior border of the anterior abdominal wall

Xiphoid process + costal cartilages 7–10

Inferior border of the anterior abdominal wall

Iliac crest, ASIS, inguinal ligament, pubic tubercle, pubic crest, pubic symphysis

Inguinal ligament — what is it and where does it run?

Inferior edge of the external oblique aponeurosis; pubic tubercle → ASIS

Lacunar ligament

Medial extension of the inguinal ligament passing back to the superior pubic ramus

Transumbilical plane corresponds to which level?

Intervertebral disc between L3 and L4

RUQ contents

Right lobe of liver, gallbladder, head of pancreas

LUQ contents

Left lobe of liver, stomach, spleen

RLQ contents

Cecum, appendix, ascending colon

LLQ contents

Sigmoid colon, descending colon

Nine regions — name them (grid)

Top: R hypochondriac / epigastric / L hypochondriac. Mid: R lumbar / umbilical / L lumbar. Bottom: R inguinal / hypogastric / L inguinal

Subcostal plane

Passes through the inferior border of the 10th costal cartilage

Transtubercular plane

Through the iliac tubercles and the L5 vertebral body

Deep (internal) inguinal ring — opening in what layer?

Transversalis fascia (lateral)

Superficial (external) ring — opening in what layer?

External oblique aponeurosis (medial); bounded by medial + lateral crura, held by intercrural fibers

Spermatic cord contents (male)

Ductus deferens, testicular artery, pampiniform venous plexus, genital branch of genitofemoral nerve

Female structure passing through the canal

Round ligament of the uterus

Ilioinguinal nerve — course & supply

Rides on the surface of the cord, exits the superficial ring; sensory to anterior scrotum/labia + medial thigh

Genital branch of genitofemoral — course & supply

Enters the deep ring, runs inside the cord; motor to cremaster (+ scrotal skin)

Visceral vs parietal peritoneum

Visceral covers the organs; parietal lines the cavity walls

Intraperitoneal vs retroperitoneal

Intraperitoneal = suspended by mesentery inside the cavity; retroperitoneal = behind the parietal peritoneum on the posterior wall

Retroperitoneal organs (SAD PUCKER)

Suprarenals, Aorta/IVC, Duodenum (2–4), Pancreas (not tail), Ureters, Colon (asc/desc), Kidneys, Esophagus (distal), Rectum

Mesentery (proper) — attaches what?

Jejunum and ileum to the posterior wall; carries the neurovasculature

Mesocolon types

Transverse mesocolon and sigmoid mesocolon

Greater omentum — from → to

Greater curvature of stomach → drapes over gut → back up to transverse colon ('apron')

Lesser omentum — connects & parts

Liver → stomach; hepatogastric ligament (medial) + hepatoduodenal ligament (lateral)

Which ligament carries the hepatic triad?

Hepatoduodenal ligament (also anterior border of the omental foramen into the lesser sac)

Wall layers from lumen outward

Mucosa → submucosa → muscularis externa → serosa (visceral peritoneum)

Mucosa — three components

Mucous epithelium, lamina propria (loose CT), muscularis mucosae

Circular folds (plicae circulares)

Permanent folds of mucosa + submucosa, mainly small intestine, increase surface area

Submucosa + its plexus

Dense CT with vessels/lymphatics; submucosal (Meissner's) plexus controls secretion + local blood flow

Muscularis externa layers

Inner circular (constricts lumen) + outer longitudinal (shortens tract)

Myenteric (Auerbach's) plexus — location & job

Between the circular and longitudinal layers; regulates motility and muscle tone

Epithelium by region

Simple columnar in stomach/intestines; stratified squamous in esophagus and anal canal

Anterior 2/3 tongue — sensation vs taste

Sensation = CN V3 (lingual); taste = CN VII (facial, chorda tympani)

Posterior 1/3 tongue — sensation & taste

Both CN IX (glossopharyngeal)

Tongue root / epiglottis

CN X (vagus)

Other CNs contributing to 'flavor'

CN I (smell); CN II is a distractor (vision ≠ flavor)

Pharyngeal (adenoid) tonsil location

Nasopharynx (roof/posterior wall)

Palatine tonsil location

Oropharynx, between anterior & posterior pillars

Lingual tonsil location

Root of the tongue

Esophagus pierces the diaphragm at?

T10 (esophageal hiatus)

Esophagus meets the cardia at?

T11, left of midline

Inferior esophageal sphincter type

Physiological (diaphragmatic musculature), not a true anatomical sphincter

Muscle composition

Upper 1/3 voluntary (striated), lower 2/3 smooth; circular + longitudinal layers

Epithelium

Non-keratinized stratified squamous

Innervation by thirds

Upper = recurrent laryngeal; middle = mixed; lower = vagus (X) for smooth muscle + greater splanchnic

Barrett's esophagus

Squamous → columnar metaplasia from chronic reflux; predisposes to adenocarcinoma (distal)

Proximal esophageal cancer type

Squamous cell carcinoma

Recurrent laryngeal nerve injury sign

Hoarse voice → vocal cord paralysis