AP03 - Histology of the digestive tract and togopraphy of the small and large intestines

Question 1

What defines the bounderies of he small intestine?

Answer 1

pylorus

ileocaecal-junction

Question 2

What are the 3 main sections to the intestine?

Answer 2

duodenum
jejunum
ileum

Question 3

What is the general function of the large intestine?

Answer 3

delaying passage of liquid to allow more time for absorption

Question 4

In embryological development of the GIT, what help relocate the gut on its’ return to the abdominal cavity?
Where are they?

Answer 4

retention bands

duodenal-jejunal flexure
splenic flexure

Question 5

Whch parts of the intestine are fused to the posterior abdominal wall?

Answer 5

ascending and decening colon

Question 6

What are the 5 main phases in the GIT functino?

Answer 6

ingestion
fragmentation
digestion
absorption
elimination

Question 7

What are the layers to the GIT?

Answer 7

Mucosa
Submucosa
muscularis propria
serosa or adventitia

Question 8

What are the sub layers to the mucosa?

Answer 8

epithelium
lamina propria
muscularis mucosa

Question 9

What are the sub layers to the muscularis propria?

Answer 9

circular muscle
auerbach’s myenteric plexus
longitudinal muscle

Question 10

What is the function of the lamina propria?

Answer 10

has blood and lymph vasculature

supports the epithelium, which is avascular

Question 11

What is the structure of hte lip?

Answer 11

Vermillion zone is keratinized stratified squamous epithelia

underneath is thick in sensory bits and capillaries, making it pink

Question 12

Where and what is contained within the circumvalate papillae?

Answer 12

8-12 just before tongue terminal sulcus

salivary von Ebner glands hae entry into surrounding grooves

Question 13

What is the structure of taste buds?

Answer 13

gustatory cells and gustatory microvilli connect the taste pore to the underlying sensory nerve

Question 14

What does the pulp cavity of a tooth contain?

what is another name for it?

Answer 14

capillaries and sensory fibres

perioduntium

Question 15

What is the main chemical constituent of enamel, and whihc cell type forms this?

Answer 15

calcium hydroxypatite, formed in the developing tooth by ameloblasts

Question 16

What type of epithelium lines the oesophagus?

What protects it?

Answer 16

nonkerainized stratified squamous epithelium

oesophageal gland secretions

Question 17

What do mucous neck cells secrete?

Answer 17

mucous

bicarbonate

Question 18

What do parietal cells secrete?

Answer 18

gastric acid (HCl)
intrinsic factor (Calcium absorption)

Question 19

What do enterchromaffin like cells secrete?

Answer 19

histamine

Question 20

What do chief cellls secrete?

Answer 20

pepsin

gastric lipase

Question 21

What do D cells secrete?

Answer 21

somatostatin

Question 22

What do G cells secrete?

Answer 22

Gastrin

Question 23

What are enteroendocrine cells?

Answer 23

umbrel term for cells of the GIT and pancreas with endocrine function (doesn’t secrete steroids)

Question 24

by what factor do villi and microvilli increase surface area by?

Answer 24

villi x3
microvilli x10
(combined x30)

Question 25

Where are the crypts of Leiberkuhn and what do they produce?

Answer 25

colon THEY ARE GLANDS lining of the crypts contain stem cells, which differentiate and migrate out, forming goblet cells, enterocytes, and enteroendocrine cells

Question 26

What types of cells are in crypts of Leiberkuhn?

Answer 26

Paneth cells - producing defensin | Stem cells

Question 27

What are Peye's patches?

Answer 27

lymphatic tissue found throughout the ileum | help immunity, monitoring intestinal bacterial populations

Question 28

How might you differentiate between ileum and duodenum?

Answer 28

ileum - peyer's patches in mucosa | duodenum - bicarbonate secreting mucous cells

Question 29

How does lymph in the bowel differ from those draining other tissues?

Answer 29

Lacteals absorbs fats, transporting chyle into Lymph vessels

Question 30

What is the difference between stenosis and atresia?

Answer 30

both are congenital narrowing of spaces atresia is full, stenosis is partial

Question 31

What are taenia coli?

Answer 31

three ribbons of longitudinal muscle, following the ascending, transverse, and descending colons respectively

Question 32

What is a merkel's diverticulum?

Answer 32

congenital bulge in the lower ileum | 2-3% of the population

Question 33

Why might a colonoscopy in women be harder?

Answer 33

their colon is a bit longer

Question 34

What 2 GI structures do we consider when describing defecation?

Answer 34

sigmoid colon | rectum

Question 35

Where are the internal and external anal sphincter located? What lies between them?

Answer 35

right at the end of the rectum anal sinuses

Question 36

Where are the sensory nerves stimulating defecation? | What is theme of this nerve?

Answer 36

sigmoid colon | pelvic nerve

Question 37

What type of nerve stimulates the involuntary defecation reflex, and where are the muscles is stimulates?

Answer 37

autonomic parasympathetic | sigmoid colon and internal anal sphincter

Question 38

What nerve controls the external anal sphincter, what kind of control is this?

Answer 38

pudendal nerve somatic control

Question 39

What is caeliac disease?

Answer 39

AI attack on cells when gliadin from gluten is absorbed

Question 40

What is McBurney's point?

Answer 40

point over the abdomen 1/3 of distance from ASIS to umbilicus marks the attachment of appendix to the colon