Histology Flashcards
Which epithelium is in the oral cavity, oropharynx and laryngopahrynx?
Stratified squamous
Which epithelium is in the nasal cavity and nasopharynx?
Respiratory epithelium
Which epithelium and features are found on the anterior 2/3rds of the tongue?
Stratified squamous epithelium and papillae
Which epithelium is posterior 1/3rd of the tongue?
Smooth stratified squamous (no papillae)
What are the 4 kinds of papillae and their functions?
1) Filiform - for gripping with no tast buds (majority) 2) Fungiform - taste buds 3) Foliate (laterally) 4) Circumvallate (large papillae at the back) - taste buds
What are the 4 layers of the digestive tract (lumen outwards)?
1) Muscosa (made up of epithelium, lamina propria and muscular mucosal) 2) Submucosa (loose CT) 3) Muscular externa/propria (inner circular and obture longitudinal m. layers) 4) Serosa or adventitia (Ct for attaching to stuff)
What are the muscle types in different parts of the oesophagus?
Upper third- skeletal Middle third - mixture of skeletal and smooth Lower third - smooth muscle
Histologically, what is the gasto-oeosphageal junction?
Abrupt change from stratified squamous of oesophagus to columnar epithelium of the stomach (Z line)
What are unique features to the stomach epithelium?
Flat mucosa but containing gastric pits, with 1-7 gastric glands at the bottom
Which cells are mostly at in the isthmus of the gastric pits of the stomach?
Parietal cells
What is the function of parietal cells in the stomach?
Produce HCL and intrinsic factor
Which cells are found on the surface of the stomach?
Surface mucous cells
What is the function of surface mucous cells in the stomach?
Secrete mucous into the lumen
Which cells are found at the neck of the gastric pits?
Mucous neck cells and stem cells
What is the function of mucous neck cells in the stomach?
Secrete mucous only on vagal stimulation
What is the function of gastric stem cells?
This epithelium is being renewed at a vast rate, so need stem cells to replace these
Which cells are found at the base of the gastric glands?
Chief cells and enteroendocrine cells
What is the function of chief cells in the stomach?
Produce pepsinogen and gastric lipase
What is the function of enteroendocrine cells?
Release signals to control lots of GI motility, secreting serotonin an other hormones
How do the gastric pits/glands differ between stomach regions?
• Cardia: Deep gastric pits that branch into loosely packed, tortuous glands. • Body: Shallow gastric pits with long straight gastric glands. • Pylorus: Deep gastric pits with branched, coiled gastric glands at a higher density than in the cardia.
What cells are subtypes of enteroendocrine cells in the stomach?
G cells and enterochromaffin-like cells
What is the function of G cells in the stomach and duodenum?
Secrete gastrin