Histology

Question 1

epithelium covering oral cavity, oropharynx and laryngopharnyx

Answer 1

stratified squamous epithelium

not ketarinized

Question 2

epithelium covering nasal cavity and nasopharnyx

Answer 2

respiratory epithelium

Question 3

anterior tongue

Answer 3

stratified squamous epithelium;
thin on ventral surface
thick and with papillae on dorsal surface

Question 4

posterior tongue

Answer 4

smooth stratified squamous epithelium
lacks papillae, with exception of circumvallate papillae
circumvallate papillae has substantial lymphoid aggregates in submucosa

Question 5

papillae of tongue

Answer 5

anterior to posterior;
fungiform
circumvallate
foliate
filiform - no tastebuds

Question 6

lymphoid tissue of the pharnyx

Answer 6

composed of palatine tonsils
lingual tonsils
tubal tonsils
pharyngeal tonsils (adenoids)

Question 7

4 layers of digestive tract

Answer 7

mucosa
submucosa
muscularis externa
serosa/adventitia

Question 8

mucosa

Answer 8

3 parts;
epithelium - sits on basal lamina
lamina propria - loose connective tissue
muscularis mucosae - smooth muscle

Question 9

submucosa

Answer 9

connective tissue

Question 10

muscularis externa

Answer 10

2 thick layers of smooth muscle
inner circular layer
outer longitudinal layer

Question 11

serosa/adventitia

Answer 11

connective tissue - suspends digestive tract or attaches it to other organs

Question 12

variations of oesophagus

Answer 12

contains submucosal glands

Question 13

transition of epithelium from oesophagus to stomach

Answer 13

abrupt transition from stratified squamous epithelium to simple columnar epithelium of the cardia of stomach

Question 14

stomach

Answer 14

contains gastric pits lined by surface mucous cells on epithelium
gastric glands at bottom of gastric pits

Question 15

cells of the gastric glands - isthmus

Answer 15

parietal cells

stem cells

Question 16

cells of the gastric glands - neck

Answer 16

neck mucous cells

parietal cells

Question 17

cells of the gastric glands - fundus (base)

Answer 17

chief cells
few parietal cells
enteroendocrinecells (neuroendocrine cells)

Question 18

chief cells

Answer 18

digestive enzyme secreting cell

Question 19

parietal cell

Answer 19

hydrochloric acid producing cell

Question 20

regions of the stomach

Answer 20

cardia
body
pylorus

Question 21

cardia of the stomach

Answer 21

deep gastric pits that branch into loosely packed, tortuous glands

Question 22

body of the stomach

Answer 22

shallow gastric pits with long straight gastric glands

Question 23

pylorus of the stomach

Answer 23

deep gastric pits with branched, coiled gastric glands at a higher density than in the cardia

Question 24

muscularis externa of stomach

Answer 24

contains additional layer - aids churning of stomach
extra layer is oblique to usual circular and longitudinal muscle layers
located internal to circular layer

Question 25

transition from stomach to duodenum

Answer 25

abrupt transition from stomach mucosa (mucous) to duodenal mucosa (absorptive) inner, circular layer of smooth muscle is thickened to form pyloric sphincter

Question 26

small instestine

Answer 26

``` finger-like projections - villi between bases of adjacent villi are pits drilling downwards - crypts of lieberkuhn made up of; deudenum jejunum ileum ```

Question 27

deudenum

Answer 27

receives acidic, partly digested semifluid --> chyme from stomach differs from other regions of GI tract below the oesophagus as it has glands within the submucosa --> Brunner’s glands when stimulated by the presence of chyme they produce a thin, alkaline mucous to neutralise the chyme. 25cm

Question 28

jejunum

Answer 28

tallest villi, located on permanent circular folds of mucosa and submucosa, the plicae circularis (also contains submucosa) lymphoid follicles infrequent 2m

Question 29

ileum

Answer 29

shorter vili aggregations of lymphoid follicles called Peyer's patches found in submucosa often extending in lamina propria 2.75m

Question 30

cells of small intestine

Answer 30

``` enterocytes goblet cells paneth cells enteroendocrine stem cells ```

Question 31

enterocytes

Answer 31

most numerous tall columnar cells brush border absorptive cell

Question 32

goblet cell

Answer 32

produce mucin to protect epithelium | lubricates passage of material

Question 33

paneth cells

Answer 33

base of crypts of Lieberkuhn defensive function regulates bacterial flora - secrete lysozyme and definsins

Question 34

enteroendocrine (neuroendocrine) cells

Answer 34

produce hormones contributing to control of secretion and motility e.g. gastrin, cholecystokinin, vasoactive intestine peptide

Question 35

stem cells

Answer 35

base of crypts of Lieberkuhn | divide to replenish epithelium

Question 36

large intestinal epithelium

Answer 36

absorptive cells - removal of salts and water goblet cells - secretion of mucus to lubricate the colon arranged into straight, tubular glands that extend down to muscularis mucosae --> crypts

Question 37

teniae of large intestine

Answer 37

outer, longitudinal smooth muscle is distinct | not continuous but found in 3 muscular strips --> teniae coli

Question 38

appendix

Answer 38

blind-ending hollow extension of the cecum. structure is similar to the rest of the colon, but crypts are far less abundant and there is circular arrangement of lymphoid tissue in the submucosa and often the lamina propria. lymphoid tissue declines with age.

Question 39

rectoanal junction

Answer 39

distinct junction between mucosa of the rectum and the non-keratinized stratified squamous epithelium of anal canal 2-3cm long anal canal is continuous with the keratinized stratified squamous epithelium of the surrounding skin.

Question 40

plexuses of enteric nervous system

Answer 40

2 plexuses; one in the submucosa - submucosal) - controls muscle of muscularis mucosae and regulates secretion in epithelium one between the muscle layers of the muscularis externa - myenteric - controls gut motility

Question 41

what is a ganglion

Answer 41

Most neurones live in groups | a group of neurones living outside of the brain and spinal cord is called a ganglion