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Endocrine system
Pharyngeal arches, pouches, and clefts
Endocrine system anatomy and physiology
Anatomy of the thyroid and parathyroid glands
Anatomy of the abdominal viscera: Pancreas and spleen
Pituitary gland histology
Thyroid and parathyroid gland histology
Pancreas histology
Adrenal gland histology
Synthesis of adrenocortical hormones
Adrenocorticotropic hormone
Growth hormone and somatostatin
Hunger and satiety
Antidiuretic hormone
Thyroid hormones
Insulin
Insulins
Glucagon
Somatostatin
Cortisol
Testosterone
Estrogen and progesterone
Oxytocin and prolactin
Parathyroid hormone
Calcitonin
Vitamin D
Phosphate, calcium and magnesium homeostasis
Congenital adrenal hyperplasia
Adrenal insufficiency: Pathology review
Primary adrenal insufficiency
Waterhouse-Friderichsen syndrome
Hyperaldosteronism
Cushing syndrome and Cushing disease: Pathology review
Cushing syndrome
Conn syndrome
Pheochromocytoma
Adrenal masses: Pathology review
Adrenal masses and tumors: Clinical (To be retired)
Adrenal cortical carcinoma
Thyroglossal duct cyst
Hyperthyroidism
Hyperthyroidism: Pathology review
Graves disease
Thyroid eye disease (NORD)
Toxic multinodular goiter
Euthyroid sick syndrome
Hypothyroidism
Hypothyroidism: Pathology review
Hashimoto thyroiditis
Hypothyroidism and thyroiditis: Clinical (To be retired)
Subacute granulomatous thyroiditis
Riedel thyroiditis
Thyroid storm
Thyroid nodules and thyroid cancer: Pathology review
Thyroid cancer
Thyroid nodules and thyroid cancer: Clinical (To be retired)
Parathyroid disorders and calcium imbalance: Pathology review
Parathyroid conditions and calcium imbalance: Clinical (To be retired)
Hyperparathyroidism
Hypoparathyroidism
Hypercalcemia
Hypocalcemia
Diabetes mellitus
Diabetes mellitus: Pathology review
Diabetes mellitus: Clinical (To be retired)
Diabetic nephropathy
Diabetic retinopathy
Pancreatic neuroendocrine neoplasms
Diabetes insipidus and SIADH: Pathology review
Diabetes insipidus
Syndrome of inappropriate antidiuretic hormone secretion (SIADH)
Hypopituitarism: Pathology review
Hypopituitarism
Hyperpituitarism
Pituitary adenoma
Pituitary apoplexy
Pituitary tumors: Pathology review
Sheehan syndrome
Hyperprolactinemia
Prolactinoma
Hypoprolactinemia
Gigantism
Acromegaly
Constitutional growth delay
Puberty and Tanner staging
Precocious puberty
Delayed puberty
Kallmann syndrome
Disorders of sex chromosomes: Pathology review
5-alpha-reductase deficiency
Menstrual cycle
Polycystic ovary syndrome
Premature ovarian failure
Menopause
Androgen insensitivity syndrome
Autoimmune polyglandular syndrome type 1 (NORD)
Multiple endocrine neoplasia: Pathology review
Multiple endocrine neoplasia
Carcinoid syndrome
Neuroblastoma
Opsoclonus myoclonus syndrome (NORD)
Hyperthyroidism medications
Hypothyroidism medications
Hypoglycemics: Insulin secretagogues
Miscellaneous hypoglycemics
Mineralocorticoids and mineralocorticoid antagonists
Adrenal hormone synthesis inhibitors
Anatomy of the gastrointestinal organs of the pelvis and perineum
Anatomy of the oral cavity (dentistry)
Anatomy of the pharynx and esophagus
Anatomy of the anterolateral abdominal wall
Anatomy of the abdominal viscera: Blood supply of the foregut, midgut and hindgut
Anatomy of the abdominal viscera: Esophagus and stomach
Anatomy of the abdominal viscera: Small intestine
Anatomy of the abdominal viscera: Large intestine
Anatomy of the abdominal viscera: Pancreas and spleen
Anatomy clinical correlates: Anterior and posterior abdominal wall
Abdominal quadrants, regions and planes
Development of the digestive system and body cavities
Development of the gastrointestinal system
Development of the teeth
Development of the tongue
Gallbladder histology
Esophagus histology
Stomach histology
Small intestine histology
Colon histology
Liver histology
Pancreas histology
Gastrointestinal system anatomy and physiology
Anatomy and physiology of the teeth
Liver anatomy and physiology
Escherichia coli
Salmonella (non-typhoidal)
Yersinia enterocolitica
Clostridium difficile (Pseudomembranous colitis)
Enterobacter
Salmonella typhi (typhoid fever)
Clostridium perfringens
Vibrio cholerae (Cholera)
Shigella
Norovirus
Bacillus cereus (Food poisoning)
Campylobacter jejuni
Bacteroides fragilis
Rotavirus
Enteric nervous system
Esophageal motility
Gastric motility
Gastrointestinal hormones
Chewing and swallowing
Carbohydrates and sugars
Fats and lipids
Proteins
Vitamins and minerals
Intestinal fluid balance
Pancreatic secretion
Bile secretion and enterohepatic circulation
Prebiotics and probiotics
Cleft lip and palate
Sialadenitis
Parotitis
Oral candidiasis
Aphthous ulcers
Ludwig angina
Warthin tumor
Oral cancer
Dental caries disease
Dental abscess
Gingivitis and periodontitis
Temporomandibular joint dysfunction
Nasal, oral and pharyngeal diseases: Pathology review
Esophageal disorders: Pathology review
Esophageal web
Esophagitis: Clinical (To be retired)
Barrett esophagus
Achalasia
Zenker diverticulum
Diffuse esophageal spasm
Esophageal cancer
Esophageal disorders: Clinical (To be retired)
Boerhaave syndrome
Plummer-Vinson syndrome
Tracheoesophageal fistula
Mallory-Weiss syndrome
GERD, peptic ulcers, gastritis, and stomach cancer: Pathology review
Gastroesophageal reflux disease (GERD)
Peptic ulcer
Helicobacter pylori
Gastritis
Peptic ulcers and stomach cancer: Clinical (To be retired)
Pyloric stenosis
Zollinger-Ellison syndrome
Gastric dumping syndrome
Gastroparesis
Gastric cancer
Gastroenteritis
Small bowel bacterial overgrowth syndrome
Irritable bowel syndrome
Celiac disease
Small bowel ischemia and infarction
Tropical sprue
Short bowel syndrome (NORD)
Malabsorption syndromes: Pathology review
Malabsorption: Clinical (To be retired)
Zinc deficiency and protein-energy malnutrition: Pathology review
Whipple's disease
Appendicitis: Pathology review
Appendicitis
Appendicitis: Clinical (To be retired)
Lactose intolerance
Protein losing enteropathy
Microscopic colitis
Inflammatory bowel disease: Pathology review
Crohn disease
Ulcerative colitis
Inflammatory bowel disease: Clinical (To be retired)
Bowel obstruction
Bowel obstruction: Clinical (To be retired)
Volvulus
Familial adenomatous polyposis
Juvenile polyposis syndrome
Gardner syndrome
Colorectal polyps and cancer: Pathology review
Colorectal polyps
Colorectal cancer
Colorectal cancer: Clinical (To be retired)
Peutz-Jeghers syndrome
Diverticulosis and diverticulitis
Diverticular disease: Pathology review
Diverticular disease: Clinical (To be retired)
Intestinal adhesions
Ischemic colitis
Peritonitis
Pneumoperitoneum
Cyclic vomiting syndrome
Abdominal hernias
Femoral hernia
Inguinal hernia
Hernias: Clinical (To be retired)
Congenital gastrointestinal disorders: Pathology review
Congenital diaphragmatic hernia
Imperforate anus
Gastroschisis
Omphalocele
Meckel diverticulum
Intestinal atresia
Hirschsprung disease
Intestinal malrotation
Necrotizing enterocolitis
Intussusception
Anal conditions: Clinical (To be retired)
Anal fissure
Anal fistula
Hemorrhoid
Rectal prolapse
Carcinoid syndrome
Crigler-Najjar syndrome
Biliary atresia
Gilbert's syndrome
Dubin-Johnson syndrome
Rotor syndrome
Jaundice: Pathology review
Jaundice
Cirrhosis
Cirrhosis: Pathology review
Cirrhosis: Clinical (To be retired)
Portal hypertension
Hepatic encephalopathy
Hemochromatosis
Wilson disease
Budd-Chiari syndrome
Non-alcoholic fatty liver disease
Cholestatic liver disease
Hepatocellular adenoma
Alcohol-induced liver disease
Alpha 1-antitrypsin deficiency
Primary biliary cirrhosis
Hepatitis
Hepatitis A and Hepatitis E virus
Hepatitis B and Hepatitis D virus
Viral hepatitis: Pathology review
Viral hepatitis: Clinical (To be retired)
Autoimmune hepatitis
Primary sclerosing cholangitis
Neonatal hepatitis
Reye syndrome
Benign liver tumors
Hepatocellular carcinoma
Gallbladder disorders: Pathology review
Gallstones
Gallstone ileus
Biliary colic
Acute cholecystitis
Ascending cholangitis
Chronic cholecystitis
Gallbladder cancer
Gallbladder disorders: Clinical (To be retired)
Cholangiocarcinoma
Pancreatic pseudocyst
Acute pancreatitis
Chronic pancreatitis
Pancreatitis: Clinical (To be retired)
Pancreatic cancer
Pancreatic neuroendocrine neoplasms
Pancreatitis: Pathology review
Abdominal trauma: Clinical (To be retired)
Gastrointestinal bleeding: Pathology review
Gastrointestinal bleeding: Clinical (To be retired)
Pediatric gastrointestinal bleeding: Clinical (To be retired)
Abdominal pain: Clinical (To be retired)
Disorders of carbohydrate metabolism: Pathology review
Glycogen storage disorders: Pathology review
Glycogen storage disease type I
Glycogen storage disease type II (NORD)
Environmental and chemical toxicities: Pathology review
Medication overdoses and toxicities: Pathology review
Laxatives and cathartics
Antidiarrheals
Acid reducing medications
Amenorrhea
Shigella
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Kaylee Neff
Tanner Marshall, MS
Kaia Chessen, MScBMC
Shigella is a Gram-negative bacterium that belongs to the Enterobacteriaceae family.
There are 4 species of Shigella:
S. dysenteriae, S. flexneri; S. boydii; and S. sonnei, and each has its own serotypes.
In humans these species can all cause Shigellosis, which is a contagious infection of the intestines, particularly the colon.
And shigellosis can progress to dysentery, which is when the infection causes inflammation of the colon, resulting in severe abdominal pain and diarrhea.
Now, Shigella is a gram-negative, rod shaped bacterium, meaning it looks like a little red or pink stick on a gram stain.
And it’s a facultative anaerobe, so it can survive with or without oxygen in the environment.
It has no flagellum, making it nonmotile; and it doesn’t form spores.
It’s also a non-lactose fermenter, so it doesn’t ferment lactose; and it’s urease and oxidase-negative, meaning it doesn’t produce these enzymes.
Finally, it doesn’t produce hydrogen sulfide gas either, and this can be used to selectively identify Shigella on special culture mediums like MacConkey agar.
On this medium, Shigella mostly forms white, non-lactose fermenting, non-hydrogen sulfide-producing colonies
Now, once Shigella is ingested, it multiplies in the small intestine, and then passes into the colon.
There, it targets the epithelial layer of the mucosal lining where it infects colonic enterocytes and microfold cells, or M-cells.
And these M-cells phagocytose, which means they eat the bacteria from the intestinal lumen, and then spit it out into the underlying mucosa-associated lymphoid tissues, or MALTs.
MALTs are a type of mucosal immune tissue that extends into the submucosa, and contains plenty of immune cells like macrophages.
The macrophages gobble up Shigella to neutralize the pathogen, but the bacterium induces apoptosis, or programmed cell death, in the macrophage.
Shigella is a genus of bacteria known to cause a contagious form of gastroenteritis known as shigellosis. Shigellosis is characterized by an inflammation of the gastrointestinal tract, which causes destruction and inflammation of the epithelium, leading to dysentery with symptoms like severe abdominal and rectal cramping and pain, a fever, and watery diarrhea with mucous with or without blood or pus. Shigella is transmitted through the fecal-to-oral route, mainly through fingers, food, and flies. It's diagnosed with a fecal sample and treatment centers around fluid and electrolyte replenishment and antibiotics.
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