Histology

Question 1

The oral cavity, oropharynx and laryngopharynx is covered by …..

Answer 1

stratified squamous epithelium which is generally not keratinised

Question 2

The anterior 2/3 of the tongue has …..

Answer 2

stratified squamous epithelium which is thin on the ventral surface (top) and thick with papillae on the dorsal surface

Question 3

The posterior 1/3 of the tongue is covered by…

Answer 3

smooth, stratified squamous epithelium

Question 4

What are the four types of papillae on the tongue?

Answer 4

filiform, fungiform, circumvallate and foliate papillae

Question 5

On entrance to the oropharynx there is a ring of lymphoid tissue composed of …

Answer 5

palatine tonsils, lingual tonsils, tubal tonsils and pharyngeal tonsils

Question 6

Explain the four major layers of the GI tract

Answer 6

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

Question 7

The oesophagus contains _____

Its distinctive characteristic is _______

Answer 7

non-keratinised stratified squamous epithelium

distinctive characteristic is mucous glands contained within the submucosa

Question 8

Type of epithelium in the stomach is

Answer 8

simple columnar epithelium with spaces between for gastric pits and glands

Question 9

In the stomach parietal cells are

Answer 9

specialised cells that secrete hydrochloric acid

Question 10

In the stomach chief cells are

Answer 10

cells that produce digestive enzymes

Question 11

In the cardia and pylorus of the stomach the gastric pits are ______ than in the body of the stomach

Answer 11

deeper

Question 12

What is special about the muscular externa of the stomach?

Answer 12

it contains an additional layer internal to the circular layer thought to aid the churning action of the stomach

Question 13

What is the difference in the mucosa of the small intestine

Answer 13

It changes to villi- finger like projections for absorption

Question 14

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_____

Answer 14

1) Brunner’s
2) submucosa
3) chyme
4) alkaline
5) neutralise the acidic chyme

Question 15

The jejunum of the small intestine contains the ___1___ villi which are located on the _____2_______ which are ___3_____

Answer 15

1) tallest
2) plicae circularis
3) permanent circular folds on the mucosa

Question 16

The ileum of the small intestine is characterised by ___1___ villi and aggregations of lymphoid follicles called ______2_______ found in the ____3_____

Answer 16

1) shorter
2) Peyer’s patches
3) submucosa often extending into the lamina propria

Question 17

In the small intestine the most common epithelial cell is _________ these are ________

Answer 17

enterocytes- simple columnar epithelium with a brush border

Question 18

The two principle types of large intestinal epithelium are … and their purpose…

Answer 18

absorptive cells for removal of salts and water

goblet cells for secretion of mucus to lubricate the colon

Question 19

In the large intestine how are the goblet cells arranged?

Answer 19

straight tubular glands referred to as crypts that extend down to the muscular mucosae

Question 20

Explain the difference in the smooth muscle of the large intestine

Answer 20

it is not continuous but is found in 3 muscular strips called teniae coli

Question 21

Structure of the appendix?

Answer 21

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

Question 22

Structure of the rectum?

Answer 22

Similar in structure to the rest of the large bowel

Question 23

What happens at the rectoanal junction?

Answer 23

Abrupt transition to become stratified squamous epithelium in the anal canal

Question 24

What happens at the anal sphincter?

Answer 24

The stratified squamous epithelium undergoes a gradual transition to that of skin.

Question 25

What is the liver covered by?

Answer 25

A collagenous connective tissue capsule which is covered by a layer of mesothelium

Question 26

Each liver lobule is approximately ___1_____ and has a branch of hepatic vein (centrolobular vein) at its ___2___
and ____3______ at each corner

Answer 26

1 hexagonal
2 centre
3 portal triads/ tracks

Question 27

Portal triads contain….

Answer 27

hepatic portal vein, hepatic portal artery and the bile duct

Question 28

How does the bile duct differ from the blood vessels?

Answer 28

it is lined by simple cuboidal cells called cholangiocytes

Question 29

The main cells of the liver are? These are?

Answer 29

Hepatocytes- polyhedral epithelial cells

Question 30

Hepatocytes are arranged in ___1___ with spaces between called ___2____ for ___3_____

Answer 30

1 sheets
2 sinusoids
3 blood to flow through

Question 31

Sinusoids are lined by ___1____ there is a narrow space between these and the hepatocytes called _____2_____

Answer 31

1 endothelial cells

2 space of Disse

Question 32

What are portal tracts accompanied by?

Answer 32

collagenous connective tissue

Question 33

Where are hepatic stellate (ito) cells found?

Answer 33

scattered in the space of Disse

Question 34

What are hepatic stellate (ito) cells?

Answer 34

modified fibroblasts that make connective tissue as well as storing vitamin A in their fat droplets.

Question 35

What can happen in some pathological conditions involving hepatic stellate cells?

Answer 35

they transform into myofibroblasts and produce scar tissue in the liver causing cirrhosis

Question 36

What are resident macrophages of the liver called and where are they found?

Answer 36

Kupffer cells found within the sinusoids

Question 37

What cell is bile produced by?

Answer 37

hepatocytes

Question 38

What are bile cannaliculi?

Answer 38

small channels formed by right junctions in the cell membrane of adjacent hepatocytes that allows bile to flow from hepatocytes to the bile duct.

Question 39

The gall bladder is a muscular sac lined by ___1_____

backed by _________________2_______________

Answer 39

1 simple columnar epithelium
2 lamina proprietary of loose connective tissue rich in blood vessels and lymphatic vessels, a coat of smooth muscle and an outer collagenous layer of adventitia

Question 40

What is special about the smallest ducts in the pancreas?

Answer 40

They extend into the acinus and are called centroacinar, they don’t stain as intensely as the cells around them

Question 41

What does the endocrine system of the pancreas consist of?

Answer 41

Small scattered islands of tissue called islets of langerhans which produce a number of hormones including glucagon and insulin