Digestive I

Question 1

The digestive system is a basically a tube from the ____ ____ to the rectal area.

Answer 1

oral cavity

rectal area

Question 2

What are some accessory structures of the GI system?

Answer 2

teeth
tongue
salivary glands
liver
gallbladder
pancreas

Question 3

Voluntary sphincters are made from ______ muscle, involuntary from _______ muscle.

Answer 3

skeletal

smooth

Question 4

The tube is open to the environment at both ends, so anything in it is considered _______ to the body until it is absorbed by epithelial cells lining the gastrointestinal tract

Answer 4

external

Question 5

What 4 general things happen in the digestive system?

Answer 5

Ingestion
Digestion
Absorbtion
Defacation

Question 6

What are the three processes used by the digestive system?

Answer 6

Motility
Secretion
Membrane transport

Question 7

What is motility? What 2 mechanisms allow for it?

Answer 7

Muscular contraction with smooth muscle

Peristalsis and Segemnetation

Question 8

How do peristalsis and segmentation provide motility in the digestive system?

Answer 8

Peristalsis- propels chyme (a semi-fluid material produced by gastric digestion)
Segmentation- mix chyme

Question 9

What is chyme?

Answer 9

A semi-fluid material produced by gastric digestion

Question 10

What is secreted in the digestive system?

Answer 10

Secretion of enzymes

Sends hormones- they control the process of secretion

Question 11

How do cells absorb nutrients?

Answer 11

By membrane transport

Question 12

Once inside the GI cells, carbohydrates and proteins go into blood capillaries, and lipids are absorbed by the _______.

Answer 12

blood

lacteal (lymph capillaries)

Question 13

What are the two types of digestion? How doe they work?

Answer 13

Mechanical digestion- Teeth which masticate food
Smooth muscle- churns chyme in stomach and small intestine
Chemical digestion- Enzymes
They split carbohydrates, lipids, and protein molecules so they can be absorbed into the simple columnar mucosal cells

Question 14

What are the three types of glands in the GI system?

Answer 14

Unicellular
Multicellular under epithelium
Multicellular glands outside digestive tract

Question 15

Which unicellular gland is in the GI tract?

Answer 15

Goblet cells

Question 16

Which multicellular glands are in the GI tract?

Answer 16

Have ducts leading into lumen of tract- Eg salivary gland in mouth, pancreas, liver

Question 17

Which 4 tunics are in the GI tract?

Answer 17

Submucosa
Mucosa
Muscularis
Serosa OR adventitia

Question 18

Why is the innermost layer a “mucosa”?

Answer 18

Because it’s a membrane that lines a body cavity open to the outside

Question 19

Which three sublayers are in the mucosa tunic?

Answer 19

Epithelium
Lamina propria
Muscularis mucosa

Question 20

What kinds of cells are in the epithelium of the mucosa tunic? Why?

Answer 20

Stratified squamous at both ends, simple columnar in the middle
In direct contact with the contents of the GI tube

Question 21

What is the lamina propria of the mucosa tunic?

Answer 21

Loose connective tissue layer- room for lymphocytes, blood, macrophages etc

Question 22

What is the muscularis musosa?

Answer 22

There is a thin layer of smooth muscle that throws the mucosa into folds, to increase surface area

Question 23

What kind of lymph tissue is present in the mucosa tunic?

Answer 23

MALT- mucosa-associated lymphatic tissue

Question 24

What tissues are present in the submucosa?

Answer 24

Loose CT, highly vascular

Question 25

What kind of nerve ending is present in the submucosa? What nervous system is it part of?

Answer 25

Submucosal plexus of ANS- plexus of Meissner- controls secretions of nearby glands This is part of the general enteric nervous system (PNS) that regulates digestive tract motility, secretion, and blood flow

Question 26

What is the muscularis tunic made from? What does it do?

Answer 26

Made from 2 sheets of smooth muscle throughout the tube that are responsible for peristalsis and segmentation of the chyme

Question 27

In general, the 2 layers of the muscularis are : 1- _____ _____, and 2- _____ ________

Answer 27

inner circular | outer longitudinal

Question 28

What nerve is in the muscularis? Where is it and what does it do?

Answer 28

Plexus of Auerbach- myenteric plexus of the ANS Located between the 2 muscle layer Controls mostly GI tract motility

Question 29

What composes the tunic serosa?

Answer 29

1- Simple squamous epithelium next to space of abdominal cavity 2- A thin, underlying, supporting layer of CT between the muscle and epithelium

Question 30

What does a "serosa" do?

Answer 30

Lines a cavity not open to the outside

Question 31

What is the diffrence between a serosa and an adventita?

Answer 31

Is an adventitia, and not serosa when it is CT that blends into surrounding tissue instead of a smooth lining. Eg when other organs are nearby such as with pharynx, trachea, or rectal area.

Question 32

What does retroperitoneal mean?

Answer 32

External to the peritoneal lining of the abdominal cavity

Question 33

What are some retroperitoneal organs?

Answer 33

kidneys, adrenals, duodenum, pancreas, ascending and descending colon, rectum, and bladder.

Question 34

What is two serous membranes with connective tissue in between that generally extend from the body wall to the digestive organs?

Answer 34

Mesentery

Question 35

What binds and holds the abdominal organs to each other and the back wall?

Answer 35

Mesentery

Question 36

What is contained within the mesentery?

Answer 36

blood vessels, lymph vessels, and nerves

Question 37

What provides a route by which the vessels and nerves can pass from the back of the abdominal wall to the organs?

Answer 37

Mesentery

Question 38

What organs have mesentery?

Answer 38

Small intestine, transverse colon

Question 39

What is the mesocolon?

Answer 39

Folds of mesentery that covers the large intestine (colon), but only the part that isn’t retroperitoneal, the transverse colon.

Question 40

What is the falciform ligament?

Answer 40

A sheet of mesentery that suspends the liver from the abdominal wall.

Question 41

What is the lesser omentum?

Answer 41

A smaller mesentery that connects the liver to the lesser curvature of the stomach.

Question 42

What is the greater omentum?

Answer 42

This forms a long double fold of mesentery that extends from the greater curvature of the stomach inferiorly over the surface of the small intestines and back up to the transverse colon.

Question 43

Which mesentery folds back upon itslef?

Answer 43

Greater omentum

Question 44

What is the greater omentum also known as?

Answer 44

The "fatty apron"