Histology Flashcards
The oral cavity, oropharynx and laryngopharynx is covered by …..
stratified squamous epithelium which is generally not keratinised
The anterior 2/3 of the tongue has …..
stratified squamous epithelium which is thin on the ventral surface (top) and thick with papillae on the dorsal surface
The posterior 1/3 of the tongue is covered by…
smooth, stratified squamous epithelium
What are the four types of papillae on the tongue?
filiform, fungiform, circumvallate and foliate papillae
On entrance to the oropharynx there is a ring of lymphoid tissue composed of …
palatine tonsils, lingual tonsils, tubal tonsils and pharyngeal tonsils
Explain the four major layers of the GI tract
1) Mucosa (epithelium, lamina propria, muscularis mucosa)
2) Submucosa of loose connective tissue
3) Muscularis externa which is two thick layers of muscle- an inner circular and an outer longitudinal
4) Serosa or adventitia which is an outer layer of connective tissue
The oesophagus contains _____
Its distinctive characteristic is _______
non-keratinised stratified squamous epithelium
distinctive characteristic is mucous glands contained within the submucosa
Type of epithelium in the stomach is
simple columnar epithelium with spaces between for gastric pits and glands
In the stomach parietal cells are
specialised cells that secrete hydrochloric acid
In the stomach chief cells are
cells that produce digestive enzymes
In the cardia and pylorus of the stomach the gastric pits are ______ than in the body of the stomach
deeper
What is special about the muscular externa of the stomach?
it contains an additional layer internal to the circular layer thought to aid the churning action of the stomach
What is the difference in the mucosa of the small intestine
It changes to villi- finger like projections for absorption
The duodenum of the small intestine contains __1___ glands in the __2____ which when stimulated by the presence of ___3__ produce a thin ___4___ mucous to ____5_____
1) Brunner’s
2) submucosa
3) chyme
4) alkaline
5) neutralise the acidic chyme
The jejunum of the small intestine contains the ___1___ villi which are located on the _____2_______ which are ___3_____
1) tallest
2) plicae circularis
3) permanent circular folds on the mucosa
The ileum of the small intestine is characterised by ___1___ villi and aggregations of lymphoid follicles called ______2_______ found in the ____3_____
1) shorter
2) Peyer’s patches
3) submucosa often extending into the lamina propria
In the small intestine the most common epithelial cell is _________ these are ________
enterocytes- simple columnar epithelium with a brush border
The two principle types of large intestinal epithelium are … and their purpose…
absorptive cells for removal of salts and water
goblet cells for secretion of mucus to lubricate the colon
In the large intestine how are the goblet cells arranged?
straight tubular glands referred to as crypts that extend down to the muscular mucosae
Explain the difference in the smooth muscle of the large intestine
it is not continuous but is found in 3 muscular strips called teniae coli
Structure of the appendix?
This is similar to the rest of the colon
Crypts are less abundant and there is typically a circular arrangement of lymphoid tissue in the submucosa and often the lamina proprietary
Structure of the rectum?
Similar in structure to the rest of the large bowel
What happens at the rectoanal junction?
Abrupt transition to become stratified squamous epithelium in the anal canal
What happens at the anal sphincter?
The stratified squamous epithelium undergoes a gradual transition to that of skin.
