Structure + Fnc of Upper GI

Question 1

In the stomach, food is churned in the presence of digestive juices to generate a semi-fluid mass of partially digested food called chyme which leaves the stomach via the_____ and enters the duodenum

Answer 1

pylorus

Question 2

Chyme leaves the stomach via the pylorus and enters the duodenum where it encounters

Answer 2

pancreatic digestive enzymes and bile from the liver

Question 3

is completed in the small intestine, and digestive products are absorbed.

Answer 3

Digestion

Question 4

The liquid residue enters the _____ where water is absorbed. As water is absorbed, the residue becomes solid generating fecal material that is collected in the rectum.

Answer 4

large intestine

Question 5

• Initially _______ muscle action in the oral cavity and upper 1/3rd of the esophagus moves food into the alimentary canal.

Answer 5

voluntary

Question 6

_______muscle action (peristalsis) takes over after the upper 1/3 of the esophagus to propel the food and products of digestion through the remainder of the GI tract.

Answer 6

Involuntary

Question 7

• Four tunics define separate functional layers in the GI system:

Answer 7

• Mucosa • Submucosa • Muscularis externa • Adventitia / Serosa

Question 8

The mucosa consists of three distinct tissue layers.

Answer 8

epithelium lamina propria muscularis mucosae

Question 9

major site of mucosal function, varies in type depending upon function; stratified squamous or simple columnar

Answer 9

epithelium (part of mucosa)

Question 10

loose connective tissue that supports the epithelium, which is rich in lymphatic and blood capillaries and contains lymphocytes and plasma cells

Answer 10

Lamina propria (part of mucosa)

Question 11

• thin layer of smooth muscle required for local movements of the mucosa and folding of the mucosa

Answer 11

Muscularis mucosae (MM)

Question 12

Layer of loose collagenous and adipose tissue that supports the mucosa. Contains large blood vessels and lymphatic vessels

Answer 12

Submucosa

Question 13

What is present in the submucosa?

Answer 13

Mucous-secreting glands present in SM of esophagus and duodenum Nervous tissue; submucosal (Meissner’s) plexis (PG, parasympathetic ganglia) Control muscularis mucosae movement, blood flow and gland secreation

Question 14

mixes luminal contents and propels contents along GI tract

Answer 14

Muscularis externa

Question 15

Muscularis externa (ME) surrounds the submucosa with a thick layer of smooth muscle except in the

Answer 15

esophagus and anal sphincter, which also contain skeletal muscle

Question 16

How is the muscularis externa arranged?

Answer 16

as an inner circular layer and outer longitudinal layer; responsible for peristalsis.

Question 17

What kind of nervous tissue resides in the muscularis externa?

Answer 17

Myenteric (Auerbach’s) plexus resides between the muscle layers, and it controls peristalsis.

Question 18

What protects the GI tract?

Answer 18

adventitia/serosa; outermost covering of GI tract

Question 19

– loose connective tissue layer surrounding the GI tract located outside of the peritoneal cavity.

Answer 19

Adventitia

Question 20

simple squamous epithelium (mesothelium) along with connective tissue covers the GI tract within the peritoneal cavity

Answer 20

Serosa

Question 21

What is the purpose of the epithelial component in the adventitia/serosa?

Answer 21

secretes serous fluid to lubricate the interface between the visceral and parietal peritoneum allowing movement of the GI tract organs

Question 22

Enteric nervous system - “the second brain” is composed of _______ neurons and is a division of the ______ system but can operate independent of the brain and spinal cord

Answer 22

~ 100 x 10 to the 6th neurons autonomic nervous system

Question 23

What can regulate the enteric NS besides the brain and sp cd?

Answer 23

hormones secreted by enteroendocrine cells

Question 24

Enteric neurons mediate their action through the standard repertoire of neurotransmitters and neuromodulators found in the brain including

Answer 24

acetylcholine, norepinephrine, and serotonin.

Question 25

_________ system stimulates secretion and peristalsis.

Answer 25

Parasympathetic

Question 26

________ represses peristalsis and activates activity of sphincters.

Answer 26

Sympathetic

Question 27

Be able to identify layers of GI

Answer 27

Note layers in GI

Question 28

Controls mucosal movement, secretory activity and blood flow

Answer 28

Submucosal (Meissners Plexus)

Question 29

Controls peristaltic gut movements

Answer 29

Myenteric (Auerbach’s) plexus

Question 30

Mucosal types vary throughout the G.I.
Tract depending on

Answer 30

function

Question 31

Function of stratified squamous epithelium mainly found in the _upper G.I. and anus. _

Answer 31

Protective

Question 32

Function of the mucosa: found in the stomach, this mucosa contains an abundance of tubular glands.

Answer 32

Secretory

Question 33

Function of the mucosa is folded into villi to maximize surface area; found throughout
the small intestine.

Answer 33

Absorptive

Question 34

Function of mucosa that lines the large intestine; produces mucin to help fecal movement
and absorbs water.

Answer 34

Absorptive/protective

Question 35

What is included in the Mucosa of the esophagus?

Answer 35

• Epithelium (E): stratified nonkeratinized
squamous epithelium with Langerhans cells (antigen presenting cells)
• Lamina propria: narrow with lymphoid aggregates (Ly)

Question 36

narrow with lymphoid aggregates (Ly)

Answer 36

lamina propria in the mucosal layer of the esophagus

Question 37

Epithelium (E): stratified________
squamous epithelium with _________cells (antigen presenting cells)

Answer 37

nonkeratinized

Langerhans

Question 38

clusters of mucosal glands that
secrete mucous to help propel food =

Location?

Answer 38

esophageal cardiac glands

Question 39

can be
difficult to identify because it consists
of a single layer of smooth muscle
cells; more substantial near stomach

Answer 39

Muscularis mucosae (MM)

(layer in mucosa of esophagus)

Question 40

What does the submucosa of the esophagus contain?

Answer 40

Esophageal glands arragned as acini. Has two cell types; mucous cells and serous cells that secreate pepsinogen and lysoxyme.

Question 41

2. Submucosa:
   Esophageal glands (G) are abundant in
   the submucosa. Only the______ and
   _______contain glands in their
   submucosal layers.

Answer 41

esophagus

duodenum

Question 42

Esophageal glands contain what two cell types?

Where are their nucleus’s located?

Answer 42

They contain two cell types - mucous
cells that have a basally located nucleus
and the less abundant serous cells that
have a centrally located nucleus.

Question 43

Major secretory products of serous
cells are____ and______ that
are deposited via ducts into the lumen.

Answer 43

pepsinogen

lysozyme

Question 44

What is included in the muscularis externa in the esophagus?

Answer 44

— inner layer of circular smooth
muscle (CM) and an outer layer of
longitudinal smooth muscle (LM)

Question 45

upper the 1/3rd of the esophagus
has _______ interspersed
with the smooth muscle. Initial
swallowing is under_____ control
and so utilizes skeletal muscle

Answer 45

skeletal muscle (Sk)

voluntary

Question 46

Prior to reaching the diaphragm, the
esophagus is encased with an
_______. Once it traverses the
diaphragm, it is covered with a_____.

Answer 46

adventitia

serosa