Histology Flashcards
What is parenchyma?
Secretory epithelial cells
What is the stroma?
Connective tissue of glands that divides them into lobes and lobules
The shape of secretory epithelium may be ___?
Tubular or acinar/alevolar
Define exocrine glands
Secrete into ducts connected to a surface
Define endocrine glands
Secrete directly into blood vessels
Define merocrine secretion and give example
exocytose vessicles, serrous glands (exocrine pancreas, salivary, goblet cells)
Define apocrine secretion and give an example
Apical portion of gland is shed with lipid secretion (mammary gland, prostate)
Define holocrine secretion
Cell undergoes apoptosis, releasing secretory contents (sebaceous glands)
List six major functions of saliva
Buffering, breakdown (amylase lipase), bacteria control (lysozyme, IgA, lactoferrin), moisture, mineralization (Ca2+, K+), Protective film (protein)
What are the functions of striatedd ducts?
Production of bicarbonate, reabsorption of sodium chloride
What are the 3 types of secretion
Serous, mucous, mixed
Describe serous secretion. What gland has serous acini?
Proteinaceous, watery consistency, parotid gland
Describe mucous secretion. Which gland has mucous acini?
Glycoproteinaceous, complex polysaccharides, viscous. Sublingual gland.
What secretory gland of the upper GI system has mixed acini?
Submandibular gland, mixed acini result in serrous demilunes
Describe striated ducts
Pizza shaped epithelial cells with basal plasma membrane infoldings and mitochondria
Describe the difference between serous and mucous acini?
Serous acini- the cytoplasm is basophilic basally (RNA), eosinophlic apically (zymogen), small lumen, round nuclei, intercellular cannaliculi.
Mucous acini- flattened nuclei on basal side, lighter staining, bigger lumen.
What cells surround secretory acini? What can they be stained with?
Myoepithelial cells, F-actin stain
What are the 4 types of papillae found on the tongue?
Foliate, fungiform, filiform, circumvallate
Which papillae of the tongue do not have taste buds?
Filiform papillae
What are von Ebner’s glands?
Serrous secreting glands in the furrow of circumvalate papilla
What are the 3 layers of the tongue?
Stratified squamous epithelium, connective tissue, skeletal muscle (oblique and longitudinal)
Describe taste buds
Onion shape with sensory and supporting cell “petals,” taste pore at surface, basal stem cells, afferent nerve terminals on sensory cells
Describe the structure of the teeth
Enamel, dentin, odontoblasts, pulp chamber, root canal, periodontal ligament, alveolar bone
What cells produce enamel? What happens to them?
Ameloblasts produce enamel towards the odontoblasts. They die when the cell breaks the surface.
Name and describe the layers of the GI tract
Mucosa (epithelium, lamina propria, muscularis mucosa), submucosa (DICT), muscularis externa (smooth muscle bilayer), serosa (mesothelium) OR Adventitia (DICT)
Describe the muscularis externa in general
Inner circular smooth muscle, outer longitudinal smooth muscle
Where is Auerbach’s plexus?
The myenteric plexus- between the layers of the muscularis externa
Where is Meissner’s plexus?
Submucosa- allows the muscularis mucosa to contract independently of the muscularis externa.
Dscribe the muscularis externa in the esophagus
Upper 1/3 = skeletal muscle,
Middle 1/3 = skeletal and smooth muscle
Lower 1/3 = smooth muscle
What type of epithelium does the stomach have?
Simple columnar epithelium
What type of epithelium does the esophagus have?
Stratified squamous non-keratinized epithelium
Where are cardiac glands and what do they do?
In the stomach near the esophageal orifice, they secrete bicarbonate rich mucous
What is the difference between exocrine and endocrine glands?
Exocrine glands have ducts with a lumen which travel to the apical side of the cell to discharge secretions, endocrine glands secrete on the basal side of the cell directly into the bloodstream (hormones) and thus have no lumen.
Name and give an example of the four types of exocrine glands
1) Simple tubular- luminar surface, i.e. intestinal glands
2) Simple acinar (alveoli)- sebaceous glands
3) Compund tubulo-acinar- salivary
4) Compound acinar- pancreas
Name and describe the 6 types of ducts
1) Acinus: secrete mucins, proteins, and enzymes, transport Na+, Cl-, H2O, IgA.
2) Intercolated (transport)
3) Striated: Prominent epithelial basal membrane folding to increase surface area for pumps in plasma membrane, prominent mitochondria, secrete bicarbonate, reabsorb Na+, Cl-, much larger than intercolated ducts
4-6) Intralobular, Interlobular, Lobular
Describe the parotid gland
located anterior and posterior to the ear, have long intercollated ducts, contain serous acinus (basophilic, nuclei near center of pie wedge, secrete protein, watery consistency)