Histology Flashcards
definition of mucous membrane (tunica mucosa)
epithelium and the underlying loose connective tissue which may contain a tunica muscularis mucosae, covers the cavities connected to the outside of the body
definition of a tonsil
lymphatic aggregation in the mucous membrane
definition of a serous membrane (tunica serosa)
mesothelium and the underlying loose connective tissue, covers the closed body cavities and therefore the external surface of most of the GI tract
composition of the mucous membrane
surface epithelium, lamina propria mucosae (loose CT), and muscularis mucosae (inner circular and outer longitudinal smooth muscle)
CT comprising submucosa
dense irregular CT, contains glands, vessels and nerve plexuses
composition of the serous membrane
lamina propria serosae (loose CT) and mesothelium (simple squamous)
functions of the alimentary mucosa
1) barrier - prevent entry of bacteria and substances
2) secretion - enzymes, HCl, mucous
3) absorptive - breakdown products of the digestion
4) immunologic - lymphatic tissue serves as a first line of the immune defense
layers of the masticatory mucosa
epithelium (parakeratinized), lamina propria (rests on top of periosteum/bone)
location of masticatory mucosa
gingiva (gums) and hard palate
types of mucous membrane in the oral cavity
masticatory mucosa, lining mucosa, and specialized mucosa
location of the lining mucosa in the oral cavity
lips, cheeks, floor of the mouth, inferior surface of the tongue and soft palate
lies on the surface of skeletal muscle
layers of the lining mucosa
epithelium (stratified, squamous non-keratinized), lamina propria, submucosa, striated muscle
layers of the lining mucosa of the upper lip
- pars mucosa - nonkeratinized or parakeratinized with mixed salivary glands
- rubor labii (vermilion border) - thin keratinzed, no glands
- pars cutanea - skin with sebaceous glands and hair follicles
location of specialized mucosa in the oral cavity
dorsum of the tongue, contains papilla
filiform papilla
- “flames” point backward
- found on the dorsum of the tongue
- keratinzed epithelium
- no taste buds, only mechanical function
foliate papilla
- leaf shaped
- found on the lateral margins of the tongue
- slightly keratinized epithelium
- decrease with age
circumvallate papilla
- dome shaped
- found at the sulcus terminalis of the tongue
- only 8-12 present
- taste buds in the side
- Von Ebner’s serous glands open into the clefts
fungiform papilla
- mushroom shaped
- found on the dorsum and tip of the tongue
- slightly keratinized epithelium
- taste buds in the side
composition and function of the intercalated duct
- low cuboidal epithelial cells
- secrete bicarbonate and absorb chlorine
composition and function of the striated duct
- simple cuboidal epithelium that gradually becomes columnar
- reabsorption of sodium and secretion of potassium and bicarbonate
composition and function of the excretory duct
- from pseudostratified columnar to stratified cuboidal and columnar
- parotid (Stensen’s duct) and submandibular (Wharton’s duct)
characteristics of serous acinous glands
- small acinus and lumen
- spheroid central nucleus
- basophilic cytoplasm (rER)
characteristics of mucous acinus glands
- large acinus and lumen
- flattened basal nucleus
- “empty” cytoplasm with H&E (mucous)
serous demilune
serous cap on a mucous acinus and is typically found in the submandibular and sublingual glands
epithelial tissue in the nasopharynx
pseudostratified respiratory epithelium with goblet cells
epithelial tissue in the oropharynx and laryngopharynx
nonkeratinized stratified squamous
location and function of the mucosal glands in the esophagus
- located in lamina propria at the the terminal part of the esophagus, at the esophageo-cardiac junction, and frequently at the beginning of the esophagus
- produce neutral mucous lubricating the cardia to prevent pyrosis (heartburn)
location and function of the submucosal glands in the esophagus
- located in the submucosa scattered along the entire esophagus
- produce slightly acidic mucous lubricating the lumen
shape of fundic glands (fundus, corpus)
simple, branched, tubular
shape of pyloric glands (pylorus)
coiled, branched, tubular
shape of cardiac glands (cardia)
similar to the pyloric glands but shorter, coiled, branched, and tubular
fundic glands cell types
mucous neck cells, chief, parietal, and enteroendocrine
location and function of mucous neck cells
- located at the neck of the glands
- provides soluble mucous
location and function of chief cells
- mainly on the base of the glands
- secrete pepsinogen and weak lipase
location and function of parietal cells
- mainly in the middle third of the glands
- secrete HCl and intrinsic factor
location and function of enteroendocrine cells
- rest on the basal lamina
- produce gastrointestinal hormones
pyloric glands
- located in the pyloric antrum
- coiled, branched, tubular glands
- cells are mainly surface mucous cells and few enteroendocrine cells, no chief or parietal cells
cardiac glands
- surround the esophageal orifice
- secretion protects the mucosa of the esophagus
- coiled, branched, tubular but shorter than pyloric glands
- cells are mainly surface mucous cells and few enteroendocrine cells, no chief or parietal cells
