XI - Digestive Tract Flashcards
Tongue Papillae: thin, long, “V”-shaped cones, increased keratinization
filliform
Tongue Papillae: most abundant, no taste buds, no gustatory function, mechanical
filliform
Tongue Papillae: mushroom-shaped, lightly keratinized, interspersed among filliform papillae
fungiform
Tongue Papillae: mostly at the apex and sides of the tongue, innervated by the facial nerve
fungiform
Tongue Papillae: 8-12 in number, largest, near sulcus terminalis
circumvallate
Tongue Papillae: associated with salivary (Von Ebner’s) glands and taste buds, innervated by CN IX
circumvallate
Tongue Papillae: ridges and grooves towards the posterior part of the roof of the mouth on lateral margins
foliate
Tongue Papillae: innervated by facial nerve (anterior papillae) and glossopharyngeal nerve (posterior papillae), rudimentary in humans
foliate
Epithelial cells of the tongue
stratified squamous
Tongue Innervation: anterior 2/3 - somatic
CN V (Trigeminal)
Tongue Innervation: taste
CN VII (Facial)
Tongue Innervation: posterior 1/3 - somatic and taste
CN IX (Glossopharyngeal)
Tongue Innervation: motor
CN XII (Hypoglossal)
Only muscle of the tongue not innervated by the hypoglossal (XII) nerve
palatoglossus (CN X - Vagus)
Parotid Gland: Secretion
serous, α-amylase, proline-rich proteins
Parotid Gland: Type
branched acinar
Parotid Gland: Innervation
CN IX (Glossopharyngeal)
Submandibular Gland: Secretion
serous > mucous, produces 2/3 of saliva, α-amylase, proline-rich proteins, other enzymes
Submandibular Gland: Type
branched tubuloacinar with serous demilunes
Submandibular Gland: Innervation
CN VII (Facial)
Sublingual Gland: Secretion
mucous > serous, mucin, amylase, lysozyme
Sublingual Gland: Type
branched tubuloacinar
Sublingual Gland: Innervation
CN VII (Facial)
70% of saliva is produced by
submandibular gland
Salivary gland associated with circumvallate papillae of the tongue
Von Ebner’s
Layer missing in the esophagus
serosa
Cells characteristic of Barrett’s Esophagus
goblet cells
Partial tear of the esophagus
Mallory-Weiss Tear
Full thickness tear of the esophagus, surgical emergency
Boerhaave’s Syndrome
Treatment for GERD
Nissen’s Fundoplication
Stomach: Lumen
folds of rugae
Stomach: Mucosa Epithelium
simple columnar epithelium, gastric pits or fovea covered with surface mucous cells
Stomach Cardia: Gastric Pits
shallow
Stomach Cardia: Lamina Propria
cardial glands, secrete abundant mucus
Stomach Fundus-Body: Gastric Pits
shallow
Stomach Fundus-Body: Lamina Propria
isthmus - parietal cells, neck - mucous cells, base - chief cells and enteroendocrine cells
Stomach Pylorus-Antrum: Gastric Pits
very deep
Stomach Pylorus-Antrum: Lamina Propria
pyloric glands, secrete abundant mucus
Stomach: Muscularis Mucosa
band of smooth muscle
Stomach: Submucosa
dense irregular tissue, Meissner’s plexus
Stomach: Muscularis Externa
inner oblique, middle circular (most abundant in pylorus), outer longitudinal
Stomach: Serosa
continuous with the mesenteries (thin loose CT with mesothelium)
Gastric Glands: gastric pit
surface mucous cells
Gastric Glands: isthmus
parietal cells
Gastric Glands: neck
mucous neck cells, parietal cells
Gastric Glands: base
chief cells, enteroendocrine / enterochromaffin / argentaffin / APUD cells
Gastric Glands: mucus
mucous neck cells
Gastric Glands: HCl
parietal cells
Gastric Glands: pepsinogen
chief cells
Gastric Glands: intrinsic factor
parietal cells
Gastric Glands: serotonin (5-hydroxytryptamine)
enterochromaffin cells (EC)
Gastric Glands: substance P
enterochromaffin cells (EC)
Gastric Glands: somatostatin
enterochromaffin cells (D)
Gastric Glands: bicarbonate
surface mucous cells
Gastric Glands: gastrin
enterochromaffin cells (G)
Gastric Glands: histamine
enterochromaffin-like cells
Site where digestive processes are completed and where the products of digestion are absorbed
small intestines
Small Intestines: Mucosa
simple columnar epithelium with villi and goblet cells
Small Intestines: Lamina Propria
crypts of Lieberkuhn, Paneth cells
Small Intestines: Submucosa
Meissner’s plexus (submucosal)
Small Intestines: Muscularis Externa
inner circular layer, Auerbach’s plexus (myenteric), outer longitudinal layer
Duodenum: Mucosa
Brunner’s glands
Duodenum: Lamina Propria
absent plicae circulares in the first part, (-) Peyer’s patches
Duodenum: Submucosa
Brunner’s glands
Jejunum: Lamina Propria
poorly developed plicae circulares and villi, (-) Peyer’s patches
Jejunum: Submucosa
(-) Brunner’s glands
Ileum: Mucosa
M cells
Ileum: Lamina Propria
plicae circulares, (+) Peyer’s patches (MALT)
Ileum: Submucosa
(-) Brunner’s glands
Diagnostic of duodenum, in the mucosa and submucosa, mucus rich secretion (pH 8.1-9.3), neutralizes chyme entering the duodenum and the pylorus
Brunner’s Glands
Columnar column cells, apical end has striated brush border, numerous microvilli that greatly increase luminal surface area
Enterocytes
Enterocytes produce
lactate, sucrase, maltase, peptidase, enterokinase
Enterocytes absorb
carbohydrates, protein, lipids, vitamins, calcium, iron
Crypts of Lieberkuhn: high rate of mitosis, replace surface absorptive cells and goblet cells every 3-6 days
stem cells
Crypts of Lieberkuhn: secrete lysozyme, phospholipase A, defensins
Paneth cells
Enteroendocrine Cells: small intestines, secretin, promotes pancreatic & biliary bicarbonate & water secretion, inhibits gastric acid secretion & stomach emptying
S cells
S Cells: Location
small intestines
S Cells: Hormone
secretin
Secretin: Promotes
pancreatic & biliary bicarbonate & water secretion
Secretin: Inhibits
inhibits gastric acid secretion & stomach emptying
Enteroendocrine Cells: small intestines, CCK, promotes pancreatic enzyme secretion & gallbladder contraction, inhibits gastric acid secretion
C cells
C Cells: Location
small intestines
C Cells: Hormone
Cholecystokinin
Cholecystokinin: Promotes
pancreatic enzyme secretion & gallbladder contraction
Cholecystokinin: Inhibits
inhibits gastric acid secretion
Enteroendocrine Cells: ileum & colon, glucagon-like peptide-1 (GLP-1) - promotes insulin secretion, inhibits gastric acid secretion & sense of hunger, peptide YY - promotes water & electrolyte absorption in large intestine, inhibits gastric acid secretion
L cells
L Cells: Location
ileum & colon
L Cells: Hormones
glucagon-like peptide-1 (GLP-1), peptide YY
Glucagon-like Peptide-1 (GLP-1): Promotes
insulin secretion
Glucagon-like Peptide-1 (GLP-1): Inhibits
gastric acid secretion & sense of hunger
Peptide YY: Promotes
water & electrolyte absorption in large intestine
Peptide YY: Inhibits
gastric acid secretion
Enteroendocrine Cells: duodenum & jejunum, gastrin inhibitory peptide (GIP), inhibits gastric acid secretion
K cells
K Cells: Location
duodenum & jejunum
K Cells: Hormone
gastrin inhibitory peptide (GIP)
Gastrin Inhibitory Peptide (GIP): Inhibits
gastric acid secretion
Enteroendocrine Cells: pylorus, duodenum & pancreatic islets, somatostatin, inhibits secretion from other DNES cells nearby
D cells
D Cells: Location
pylorus, duodenum & pancreatic islets
D Cells: Hormone
somatostatin
Somatostatin: Inhibits
secretion from other DNES cells nearby
Enteroendocrine Cells: stomach, small intestines & large intestines, serotonin & substance P, promotes gut motility
EC cells
EC Cells: Location
stomach, small intestines & large intestines
EC Cells: Hormones
serotonin & substance P
Serotonin: Promotes
gut motility
Substance P: Promotes
gut motility
Enteroendocrine Cells: small intestines, motilin, promotes gut motility
M cells
M Cells: Location
small intestines
M Cells: Hormone
motilin
Motilin: Promotes
gut motility
Enteroendocrine Cells: ileum, neurotensin, inhibits gastric acid secretion
N cells
N Cells: Location
ileum
N Cells: Hormone
neurotensin
Neurotensin: Inhibits
gastric acid secretion
Intestines: large valvular flaps protruding into the lumen, circular folds on mucosa and submucosa
valves of Kerkring, plicae circulares, valvulae conniventes
Intestines: finger-like projections of the mucosa
villi
Intestines: microscopic cellular protrusion on the apex of cells
brush border (microvilli)
80% of bile is absorbed in
terminal ileum
Colon: smooth, no plicae circulares or intestinal villi except in the rectum, crypts of Lieberkuhn, numerous goblet cells, MALT
mucosa
Colon: fatty layer
submucosa
Colon: Muscularis Externa
inner circular, outer longitudinal in 3 separate longitudinal bands (taenia coli)
Colon: forms small pouches of fatty tissue (appendices epiploicae)
serosa
Thickened wall due to lymphoid follicles, few crypts, no villi, no taenia coli
appendix
Most common cause of appendicitis in adults
fecalith obstruction
Most common cause of appendicitis in chicken
lymphoid hyperplasia
Anal Canal: Length
3-4 cm
Rectoanal Junction Epithelium
simple columnar → stratified squamous
Anal Canal: Longitudinal folds of mucosa and submucosa
anal columns
Anal Canal: inner circular layer of muscle
internal anal sphincter
Anal Canal: voluntary sphincter
external anal sphincter
Mixed exocrine and endocrine gland producing both digestive enzymes and hormones, retroperitoneal
pancreas
Amount of alkaline pancreatic juice secreted into the duodenum per day
1.5 L/day
Neutralizes acidic chyme from the stomach
bicarbonate
Establishes pH for optimal activity of pancreatic enzymes: proteases, α-amylase, lipases, nucleases
bicarbonate
The exocrine pancreas is regulated mainly by
CCK, secretin
Largest percentage of liver that can be safely resected without causing liver failure
80%
The liver is divided into 8 anatomic segments based on
hepatic venous drainage
75% of blood flow to the liver is provided by
portal vein
Pain in hepatitis and other inflammatory liver disease is caused by
stretching of Glisson’s capsule
Surrounded by a thin capsule that extends into the parenchyma dividing it into lobules
liver
Secretion of bile, synthesis and endocrine secretion into blood of major plasma proteins (albumin), conversion of AA into glucose, detoxification and conjugation of toxins and drugs
liver
AA deamination producing urea, storage of glycogen, triglycerides, vitamin A and other fat soluble vitamins, removal of effete erythrocytes, storage of iron in complexes with ferritin
liver
Functional unit of the liver
liver lobule
Liver Lobule: Structure
hexagonal with central vein, surrounded by 3-6 portal triads (venule, arteriole, bile ductule)
Portal Triad
venule, arteriole, bile ductule
Filled with cords of hepatic parenchymal cells, hepatocytes which radiate from the central vein and are separated by vascular sinusoids
liver lobule
Liver: vascular spaces lined by fenestrated endothelial cells, sparse basal lamina and reticular fibers, Kuppfer cells
sinusoids
Liver: space between the endothelium and the cord filled with plasma, Ito cells
space of Disse / perisinusoidal space
Tiny passage formed between hepatocytes
bile canaliculi
Liver: principal parenchymal cells, large, polyhedral, large centrally located nucleus, extensive reticular fibers holding cells together
hepatocytes
Liver: sinusoids, liver macrophages
Kuppfer cells
Liver: perisinusoidal space of Disse, stores vitamin A
Ito cells / stellate cells / lipocytes
Liver Acinus 1: Location
periportal - around portal triad
Liver Acinus 1: Blood Flow
abundant oxygen and nutrients
Liver Acinus 1: Necrosis
liver pathology, eclampsia/pre-eclampsia
Liver Acinus 2: Location
mid-zone
Liver Acinus 2: Blood Flow
intermediate
Liver Acinus 2: Necrosis
yellow fever
Liver Acinus 3: Location
centrilobular - around central vein
Liver Acinus 3: Blood Flow
low oxygen and nutrients
Liver Acinus 3: Necrosis
ischemic injury, R-sided heart failure
Biliary epithelium
tall columnar cells with microvilli except terminal ducts (cuboidal)
The gallbladder does not have
muscularis mucosae
Pockets in the gallbladder mucosa into the muscularis layer
Rokitansky-Aschoff sinus
Most common type of gallbladder CA
adenocarcinoma
Seen in 95% of patients with gallbladder adenoCA
gallstones
Most common area where biliary-enteric fistula occurs
duodenum
Ascending bacterial infection that causes partial or complete obstruction of the bile duct
Ascending Cholangitis
