Histology Flashcards
Columnar and cuboidal cells are involved in ————–
secretion and obsorption
Functions of epithelium
stratified → ————-
Squamous → ——————
Keratinised → —————
stratified → protective (lots of layers)
Squamous → thin for diffusion (squashed cells
Keratinised → skin (mechanical stress)
Ends of epithelial cells
apical end = ———————-
basal end = ———————–
Ends of epithelial cells
apical end = upper end (exposed to outside of body, or internal cavity)
basal end = attached to basement membrane, anchored to connective tissue
——— are the absorptive cells of the intestine
enterocytes
GALT
Gut Associated Lymphoid Tissue = lymphocytes in the GI tract wall, part of the immune system
Myenteric plexus location
Between the two muscle layers of the muscularis externa
Layers of GI tract wall
M,S,M,S
Mucosa»_space; epithelium (enterocytes), lamina propria (loose connective tissue + GALT), muscularis mucosae (thin SM)
Submucosa»_space; loose connective tissue, submucous plexus (part of ENS)
Muscularis externa»_space; inner circular layer, myenteric plexus (part of ENS), outer longitudinal layer
Serosa/adventitia»_space; connective tissue
The enteric nervous system has two nervous plexuses in the GI tract wall. They are ———-
1) Submucous plexus (in submucosa) - controls LOCAL intestinal secretion, absorption and contraction of submucosal muscle
2) Myenteric plexus (between muscle layers) - increased muscle tone, increased rhythmic contractions, increased conduction velocity of slow wave activity
In the mouth and pharynx, stratified squamous epithelium covers the ———— and respiratory epithelium covers ————–
In the mouth and pharynx, stratified squamous epithelium covers the oral cavity, oropharynx, laryngopharynx, and tongue, and respiratory epithelium covers the nasopharynx and nasal cavity.
———- papillae cover most of the dorsal surface of the tongue
Filiform papillae (no taste buds)
The pharynx houses the tonsils (4) =
1) Pharyngeal tonsils (adenoids)
2) Palatine tonsil (tonsils)
3) Lingual tonsil
4) Tubal tonsil (leads to ear - covered in ENT)
Tonsils are ——– tissue
Lymphoid tissue (part of the immune system)
Stratified squamous epithelium covers the mouth because ——–
it comes into contact with food which may abrase the surface of these structures so needs a protective function (also these cells are easily replaced)
There is —— AND ——– epithelium present in the nasal cavity.
Olfactory AND respiratory
Gastro-oesophageal junction: ——— epithelium»_space; ——– epithelium
stratified squamous epithelium»_space; simple columnar epithelium (of the stomach)
Mucosa of stomach - key differentiators
Gastric pits → mucus cells (produce mucus + bicarbonate to protect against the acidic environment)
Gastric glands → stomach secretions
Isthmus → the point where the pit becomes the gland
Cells in the gastric glands of the stomach
Parietal cells → HCl
Stem cells → make more cells
Chief cells → secrete digestive enzymes
Enteroendocrine cells → produce hormones to control secretions and motility
In Barrett’s oesophagus ——– epithelium of the oesophagus changes to ———- epithelium because ——–
This can predispose to ———
In Barrett’s oesophagus the stratified squamous epithelium changes of the oesophagus changes to the simple columnar epithelium in order to protect the oesophagus from increased exposure to gastric acid. This change in cell type can predispose to cancer development.