Histology Flashcards
One of the early vascular changes in inflammation is adhesion of ________________ to the endothelium. What is this called?
Neutrophils
Pavementing
Neutrophils are attracted to a site of tissue damage by ______________________. Two chemical mediators are: ______ & _____.
Chemotaxis
C5a & LTB4
The 3 major steps in acute inflammation.
- Vascular dilation
- Endothelial activation
- Neutrophil activation
Define opsonization
Coding bacteria with chemical markers (IG’s); this promotes phagocytosis
Name 1 serum test for generalized acute inflammation.
CRP
Define pus
Thick, semi-fluid containing neutrophils, fluid & necrotic tissue
Define abscess
Circumscribed collection of pus
What are the 3 major morphological variants of acute inflammation?
- Supperative/purulent
- Fibrinous
- Serous
Common examples of this type of inflammation include: lobar pneumonia, bronchopneumonia, acute appendicititis
Purulent inflammation
How would you classify these types of baceria? Sterpt, E. Coli, Pneumonia, N. meningitidis, N. gonorrhea
Pyogenic bacteria (promote purulent inflammation)
Describe what happens in pneumonia
Pulmonary alveolar capillaries in the walls between the alveoli are engorged with blood
Describe what happens in lobar pneumonia
Inflammatory response is localized to alveoli immediately adjacent to the fissure
Tracheobroncitis & bronchiolitis spread down the respiratory tract with this morphologic variant of acute inflmmation
Purulent inflammation
When a patient tells you he’s been coughing, what should be the first question you ask?
Is your cough productive, i.e. are you coughing anything up? What does it look like?
Where are you more likely to find fibrinous inflammation?
Serous-lined cavities (i.e. pleural, pericardial, periotoneal)
What is acute fibrinous pericarditis?
Fibrinous inflammation – a mat of fibrin coats the visceral layer of serous pericardium
This type of inflammation is characterized by an acute process by which the main tissue response is accumulation of fluid with a low plasma protein & cell content.
Serous inflammation
Differentiate between exudate & transudate
Exudate: low protein content
Transudate: high protein content
Give 2 examples of acute serous inflammation.
- Burns
2. Pleural effusion
What are the 5 cardinal signs of inflammation (Celus)
- Redness
- Swelling
- Pain
- Heat
(5. ) Loss of fx
What is salpingitis?
Inflammation of Fallopian tube?
What is pleurisy?
Pleuritis / inflammation of the pleura
What is acute cellulitis?
Infection causing inflammation of sub-cutaneous tissues
What is acute cholecystitis?
Inflammation of the gallbladder
What are the 3 determinants of outcome of acute inflammation?
- Severity of tissue damage
- Regeneration / stem cells
- Type of agent causing damage
In total resolution of acute inflammation, fibrin is broken down by ______________.
Fibrinolysins
Give 2 examples of scar formation.
- Bone fx
2. Astrocyte formation in brain
What are the 3 possible resolutions of acute inflammation?
- Total resoulution
- Healing by fibrosis
- Chronic inflammation
What are the different variations of chronic inflammation?
- Specific (Immune/non-immune) +/- granuloma
2. Non-specific - non-resolution acute inflammation
Why is fibrosis so serious in a virus like HBV?
The negative effect is a result of the fibrous tissue, and not necessarily the virus itself.
What are granulomas?
Clusters of:
- Epitheliod macrophages
- Multinucleated giant cells (20-30 cells)
What is a classic example of a chronic granuloma bacterial disease?
TB
What is diverticulosis?
Outpatching of the colon due to a low fiber diet
What is an example of an autoimmune condition leading to systemic fibrosis?
SLE
What are the primary components of infliltrate in chronic inflammation?
Plasma cells, lymphocytes, macrophages, eosinophils, fibroblasts (replace normal muscle and tissue!)
What are the 6 types of anemia?
- Fe-deficient
- Pernicious (Intrinsic factor/B12)
- Hemolytic (destn of cells)
- Aplastic (destn of marrow)
- Hemorrhagic
- Thalassemia
What is the difference between the dorsal and ventral tongue?
Dorsal - what you see when you stick your tongue out; Ventral- underneath
Differentiate between extrinsic and intrinsic muscles of the tongue.
Extrinsic- entire tongue moves; intrinsic- flexibility, speech swallowing
What divides the tongue into anterior and posterior parts?
Sulcus terminalis
What is the embryologic remnant found in the tongue?
The foramen cecum (at the apex of the sulcus terminalis)
Embryologic remnant of thyroid gland
The 3 major buds of the tongue. State which have taste buds.
- Filliform papullae (most numerous, flame shape; mechanical fcn)
- Fungiform papillae (Taste buds; not as highly keratinized as Filliform pap.)
- Circumuallate (Can be seen grossly; with taste buds; lines the sulcus terminalis)
What are the 3 cell types in taste buds?
- Basal/stem cells
- Supporting cells
- Neuroepithelial cells (sensory - CN 7, 9, 10)
Which are the 3/5 taste buds that require a G-protein coupled receptor (IP3–> Ca)
- Sweet
- Bitter
- Umami
Which 2 taste buds do not require a G protein?
Salty & sour [Have H+ & Cl- channels]
What are the 4 layers of the GI’s tissues?
- Mucosa (Epithelium, lamina propria (lymph glands), muscularis internale)
- Submucosa
- Muscularis externa
- Serosa/adventita
What is the function of mucosa?
Protection, absorption, secretion
What is submucosa made of?
Dense irregular C/T (usually no glands), Mesiner’s Plexus (enteric parasympathetics)
Where does submucosa have glands in the digestive system?
- Esophagus
2. Duodenum
Where do parasympathetics live in the GI tract?
Meisner’s Plexus (submucosal plexus)
What are the components of the muscularis externa?
- Inner circular - mixing of food
- Auerbach’s Plexus (Myenteric Plexus) - Outer longitudinal - propulsion of food
What is the function of muscularis externa?
Peristalsis
What is the function of serosa & adventitia?
- Serosa: C/T, mesothelium; friction free movement / continuous with mesentary
- Adventia: Connects to body walls
What are the primary digestive organs?
Esophagus, stomach (cardiac, fundus, pyloric), small intestine (duodenum, jejunum, ileum), colon (cecum (appendix), ascending, transverse, descending, sigmoid, rectum, anus)
What is the esophagus?
A tube from the oral cavity to the stomach
Fx: movement of food (which can be partially digested and abrasive)
Discuss the 4 layers of esophageal tissue.
- Mucosa (strat. sq. non keritinized); LP w/ glands, 1 longitundinal muscular layer
- Submucosa: dense irregular C/T; esophageal glands
- Musc:
Upper 1/3- striated
Mid 1/3- mixed striatead & smooth
Distal 1/3- only smooth - Serosa below diaphragm; adventitia above diaphragm
What are the 3 regions of the stomach?
- Cardiac
- Fundus
- Pyloric
What are the 5 types of cells found in the fundus?
- Surface mucous - gastric pits (secrete mucous with bicarbonate)
- Mucous neck cells - neck (secrete mucous for movement)
- Parietal cells - neck (secrete HCl, intrinsic factor for B12 absorption)
- Chief cells - base (secrete pepsinogen)
- Enteroendocrine cells - base (Secrete hormones into lamina propria; open/closed)
Who stimulates parietal cells?
Gastrin
What is the function of the small intestine and what are its components?
Digestion & absorption of nutrients
- Duodenum
- Jejunum
- Ileum
What are the specializations of the small intestine?
- Plicae circularis: permanent folds in jejunum
- Villi - evaginations (S/A)
- Microvilli - S/A
Discuss the 4 layers of stomach tissue.
- Mucosa - simple columnar [musc: inner circular, inner oblique w/ rugae folds, outer longitudinal]
- Submucosa - lymph and vessels
- Muscularis externale - inner oblique, inner circular, outer longitudinal
- Serosa
How do we differentiate stomach tissue?
By the presence of glands
- Cardiac - short pits, short glands
- Fundus - short pits, long glands
- Pyloric - long pits, short glands
Does the esophagus have glands in the submucosa?
Yes - Bruner’s glands
What covers microvilli?
Glycocalyx
How do we differentiate between the different areas of the small intestine?
- Duodenum - submucosal glands (Burner’s)
- Jejunum - no glands - pliae circularis
- Ileum - Peyer’s patches - lymphatics - M cells
What are the 5 cell types of the small intestine?
- Enterocyte - has microvilli / absorption & secretion
- Goblet - mucus –> lumen
- Paneth - antimicrobial
- Enteroendocrine - hormones
- M cell – modified enterocytes (appendix) – antigen transport molecules, near Peyer’s patches
Where are broken down proteins and carbohydrates absorbed?
Into the blood
Where are broken down fats absorbed?
Lacteals, the lymphatic system
What are the 4 hormones secreted by enteroendocrine cells?
- CCK - contrxn gallbladder, panc. secretion
- GIP - dec. gastric mobility
- Secretin - panc bicarb
- Motilin - inc. peristalsis
What are the regions of the colon?
Cecum, ascending colon, transverse colon, descending colon, sigmoid colon, sigmoid colon, rectum, anus
What is the function of the colon?
Reabsorption & movement of chyme –> anus
What are the 3 ways to identify the large intestine?
- Taenia coli - 3 long bands
- Haustra - sacculations
- Omental appendices - fat projections on wall
What are the characteristics of the mucosa in the colon?
- Goblet cells
- Enterocytes
- Invaginations
Does colonic mucosa have Paneth cells?
No – they would kill the normal gut flora
Why are gut flora important?
Aid in Vitamin K and Vitamin B digestion
What is the main characteristic of the muscular externale layer of the colon?
Tinea coli (3 longitudinal muscular bands)
How do you differentiate the appendix from the cecum histologically and grossly?
No tinea coli
Does the rectum have tenia coli?
No
What are the 3 zones of the anal canal?
- Colorectal, anal transition, squamous zone – keratinized
What prevents automatic defecation?
External anal sphincter w/ skeletal muscle
What is the function of the liver?
- Produce and secrete bile (exocrine)
- Manufacture blood proteins
- Detoxification
- Storage & breakdown of glycogen
What are the parenchymal cells in the liver?
Hepatocytes
What are 3 interpretations of the liver lobules?
- Classic hexagonal
- Portal lobule (bile centric; triad in the center)
- Liver acinus (zones, 1, 2, 3 – zone 1 in immediate zone of the toxic blood supply)
In the liver acinus model, cells in which zone are protected from ischemia? Which cells are most prone to toxins?
Zone 3- farthest from triad/closest to the central vein, protected from toxic, most impacted by ischemia.
What are the components of the portal triad?
- Hepatic artery
- Hepatic bile duct
- Portal vein
How many nuclei do hepatocytes have?
1-2
What are the functions of hepatocytes?
- Storage of glycogen & lipids
- Detoxification
- IgA release
- Gluconeogenesis
- Phagocytosis (Kupfer cells)
Trace the path backwards from the hepatic vein.
- IVC
- Hepatic vein
- Sublobular veins
- Central vein
- Sinusoids
What brings bile to the bile duct?
Bile canaliculi (Canal of Herring)
What are the phagocytic cells associated with hepatocytes?
Kuppfer cells
What type of capillaries are found in a liver plate?
Discontinuous; no basal connections
What is the name of the subendothelial space between hepatocytes and sinusoids?
Space of Disse
What do we find within the Space of Disse?
- Fat storing cells (Ino) / Vitamin A
- Reticular fibers
- Non-myelinated nerves
- Short microvilli of hepatocytes
What are the principal components of bile?
- Bilirubin
- Bile salts
- Cholesterol
- Phospholipids
- Ions
- Water
What are the endocrine products of the liver?
- Glucose
2. Plasma proteins (fibrinogen, albumin, Factor VIII)
How do we know we are looking at a gallbladder on a histological slide?
- False-lumens that result from folding
What is the function of the gallbladder?
Store & [bile]
Contraction of the gallbladder is stimulated by this hormone
CCK
What type of epithelium do we see in the gallbladder?
Simple columnar
What are the names of the deep invaginations we see in the gallbladder tissue?
Sinuses of Rokitansky
What are ducts of Luschka?
Non-functional cystic ducts
What type of muscle do we see in the gallbladder? a) circular b) longitudinal C) oblique d) all
c) oblique
What is responsible for removing H2O in the gallbladder?
Microvilli
What is the pancreas?
Retroperitoneal endocrine (Islets of Langerhan: alpha-glucagon; beta-insulin; delta: somatostatin; PP: polypeptide; gastrin: HCl/parietal cells) & exocrine (lipase, amylase, trypsin)
What stimulates acinar cells in the pancreas?
CCK (release enzymes)
What stimulates the centroacinar cells in the pancreas?
Secretin (release bile); the centroacinar cells lead to the intercalated duct, which eventually leads to the pancreatic duct
Why can pancreatitis be so severe and painful?
Pancreatic lipase & amylase literally digest the pancreas
Trace pancreatic juices from the pancreatic duct backwards.
Intercalated –> Intralobular –> Interlobular –> Pancreatic duct; the acinar units encapsulate the ducts
Differentiate between the pancreas and the parotid gland.
Pancreas: exocrine/endocrine, NO myoepithelial cells, no striated ducts
Parotid: exocrine, myoepithelials, striated duct
What is a myoepithelial cell?
contractile muscle cell found on the surface of some acini of the salivary glands, which is believed to facilitate the secretion of fluids from the gland
Sublingual gland
Mostly mucous with serous demilunes
Submandibular gland
Mostly serous
Parotid
Exclusively serous