GI Tract I & II

Question 1

what is the digestive system made of?

Answer 1

alimentary canal and associated organs (tongue.. teeth etc.)

Question 2

what does the sulcus terminalis do?

Answer 2

divides the tongue into anterior 2/3 and posterior 1/3

Question 3

what do extrinsic tongue muscles do?

Answer 3

attach tongue to other structures

move the entire tongue

Question 4

what do the intrinsic tongue muscles do?

Answer 4

alters the shape of the tongue

good for speech and swallowing

Question 5

what are the 4 types of lingual papillae?

Answer 5

filliform, fungiform, circumvallate, foliate

Question 6

what are the 3 types of cells found in taste buds?

Answer 6

neuroepithelial cells, supporting cells, basal cells

Question 7

which stimuli use G protein coupled chemosensory receptors with IP3?

Answer 7

bitter, sweet and umami

Question 8

which stimuli use H+ protons as receptors?

Answer 8

sour

Question 9

which stimuli use Na+ ions as receptors?

Answer 9

salt

Question 10

what makes up the mucosa?

Answer 10

epithelium, lamina propria, muscularis mucosae

Question 11

what does the lamina propria usually contain?

Answer 11

loose CT
blood and lymph vessels
mucosal glands
GALT

Question 12

what does the muscularis mucosae usually have?

Answer 12

2 layers
inner = circular
outer = longitudinal

Question 13

what is found usually in the submucosa?

Answer 13

dense irregular CT
large blood and lymphatic vessels
sometimes glands
submucosal plexus = Meissner’s plexus

Question 14

what does Meissner’s plexus innervate? where is it found?

Answer 14

muscularis mucosae = innervation

submucosa = location

Question 15

what are the 4 layers that make up the alimentary canal?

Answer 15

mucosa, submucosa, muscularis externa, serosa/adventitia

Question 16

whats usually in the muscularis externa layer?

Answer 16

inner layer = circular = forms sphincters
outer layer = longitudinal
myenteric plexus = Auerbach’s plexus

Question 17

where is Auerbach’s plexus found? What does it innervate?

Answer 17

found in between circular and longitudinal layer of muscularis externa and it innervated the muscularis externa for peristalsis

Question 18

Where is serosa commonly found?

Answer 18

mesothelium

Question 19

what parts of the GI tract do NOT have a serosa but DO have adventitia?

Answer 19

esophagus (thoracic)
2nd, 3rd, 4th part of duodenum
asending and descending colon
rectum and anal canal

Question 20

what is special about the submucosa of the esophagus?

Answer 20

esophageal glands proper is there = slightly acidic mucous to lub. lumen - can ID huge duct

Question 21

whats special about the esophagus mucosa?

Answer 21

it has esophageal cardiac glands that produce neutral mucous to protect regurg of gastric juices

Question 22

what is special about the musclaris externa of the esophagus?

Answer 22

upper 1/3 is straited
middle 1/3 is both smootha nd striated
lower 1/3 is smooth

Question 23

what is a distinguishing feature of the duodenum?

Answer 23

submucosal gland = Brunner’s glands - secrete a highly alkaline msolution to neutralize acidic chyme coming from stomach

Question 24

whats a distinguishing feature of the jejunum?

Answer 24

many plicae circulars
long prominent villi
increase in amount of goblet cells
NO submucosal GLANDS

Question 25

What is a distinguishing feature of the ileum?

Answer 25

aggregated nodules of lymphatic tissue in lamina propria of mucosa peyer's patches- very many in ileum

Question 26

what are the distinctive features of the Large intestine?

Answer 26

TC, HC, OM

Question 27

what is different about the mucosa of the large intestine?

Answer 27

its smooth - no villi, no plicae circularis

Question 28

what is a distinguishing feature of the appendix?

Answer 28

numerous lymphatic nodules that extend into submucosa

Question 29

does the rectum have serosa or adventitia?

Answer 29

adventitia

Question 30

what are the 3 zones of the anal canal?

Answer 30

``` colorectal zone (CRZ) - simple columbar epi anal transition zone (ATZ) - transition epi squamous zone (SQZ) - stratified squamous epi ```

Question 31

How are amino acids absorbed?

Answer 31

Secondary active transport | Majority are Na+ dependent

Question 32

How are carbohydrates absorbed?

Answer 32

SGLT -1 transporter - secondary active transport , Na dependent GLUT transporter - facilitated transport

Question 33

How are lipids absorbed?

Answer 33

Diffusion

Question 34

what lingual papillae has highly keratinized stratified squamous epithelium, has no taste buds and works to grip food?

Answer 34

filliform - looks like a flame

Question 35

where are fungiform found and where are their taste buds located?

Answer 35

``` tip of the tongue taste buds (if any) on dorsal surface ```

Question 36

which lingual papillae has von ebners glands?

Answer 36

circumvallate - has moat like invaginations, largest

Question 37

where are circumvallates located?

Answer 37

just anterior to sulcus terminalis

Question 38

what are the characteristics of cardiac glands? - pits, glands, cells

Answer 38

short pits short glands | enteroendocrine and mucous secreting cells

Question 39

what are the characteristics of pyloric glands? - pits, glands, cells

Answer 39

long pits, short glands | enteroendocrine, mucous secreting and parietal

Question 40

what are the characteristics of the fundic glands - pits, glands, cells

Answer 40

``` short pit, long gland mucous neck cells enteroendocrine cells parietal chief stem ```

Question 41

what is an intestinal gland?

Answer 41

crypts of leiberkauhn

Question 42

what do enterocytes do?

Answer 42

absorption simple columnar - Mv, tight junctions, lateral plications secretory - dig enzymes, water, electrolytes

Question 43

what do paneth cells do?

Answer 43

antimicrobial secretions

Question 44

what do M cells do?

Answer 44

cover large lymph nodules, antigen transporting cells

Question 45

what are the components of gastric juice?

Answer 45

HCL, pepsin, mucous and intrinsic factor