Lecture 20

Question 1

What is the role of the GI system?

Answer 1

To bring nutrients and water into the internal environment to be used by the body

Question 2

What are the four functions of the GI system?

Answer 2

Motility, secretion, digestion, absorption

Question 3

What is the function of the motility of the GI tract?

Answer 3

To transport food into and through the body, mixing luminal contents and transporting waste out

Question 4

What is the function of the secretion of the GI tract?

Answer 4

To synthesise and release enzymes, mucus and serous fluid into the lumen

Question 5

What is the function of the digestion of the GI tract?

Answer 5

To break nutrients into smaller pieces, mechanically and chemically

Question 6

What is the function of the absorption of the GI tract?

Answer 6

To bring nutrients and water from the lumen to the internal environment

Question 7

What are the sphincters and what is their function in the GI system?

Answer 7

Rings of smooth muscle that close off ends and separate sections of the tube

Question 8

What do the sphincters allow?

Answer 8

Different environments within different organs

Question 9

What is the GI system lined by?

Answer 9

Epithelium

Question 10

What type of epithelia is found in the mouth, oral cavity and esophagus?

Answer 10

Stratified squamous to protect from abrasions

Question 11

What type of epithelia is found in the stomach, small and large intestines?

Answer 11

Simple columnar for secretion and absorption

Question 12

What type of epithelia is found in the anus?

Answer 12

Stratified squamous to protect from abrasion

Question 13

What are unicellular glands?

Answer 13

Glands with single cells to perform a function. Columnar, goblet-shaped, mucous-producing cells with apical mucous granules and a basal nucleus.

Question 14

What are the two functions of the unicellular glands?

Answer 14

Lubrication and protection

Question 15

What are multicellular glands?

Answer 15

Invaginated epithelium to form glands, this increases the surface area for more secretion

Question 16

What are the two types of multicellular glands?

Answer 16

Simple and Compound

Question 17

What is a simple multicellular gland?

Answer 17

A gland with a single duct

Question 18

Where are the simple multicellular glands found?

Answer 18

In the stomach and small intestine

Question 19

What is a compound multicellular gland?

Answer 19

A gland with 2 or more ducts

Question 20

Where are the compound multicellular glands found?

Answer 20

Salivary glands

Question 21

What are the four layers of the gut tube, deep to superficial?

Answer 21

Mucosa, submucosa, muscularis, adventitia

Question 22

What does the mucosa consist of?

Answer 22

Epithelium, basement membrane, lamina propria (FCT), muscularis mucosae and sometimes glands

Question 23

What does the submucosa consist of?

Answer 23

FCT, glands, blood vessels and submucosal plexus

Question 24

What is the function of the submucosal plexus?

Answer 24

To regulate secretion through the enteric nervous system (ENS)

Question 25

What is the muscularis?

Answer 25

A layer of smooth muscle

Question 26

What are the two main layers of the muscularis?

Answer 26

Inner circular and outer longitudinal

Question 27

How is the inner circular muscularis structured?

Answer 27

Cells wrap around the tube

Question 28

How is the outer longitudinal muscularis structured?

Answer 28

Cells run up and down the tube

Question 29

What is the myenteric plexus?

Answer 29

Part of the ENS, located between the inner circular and outer longitudinal muscle layers. It regulates motility (contractions)

Question 30

What is the adventitia composed of?

Answer 30

Fibrous connective tissue to hold things together

Question 31

Where does digestion begin?

Answer 31

The mouth and oral cavity

Question 32

What are the two forms of digestion?

Answer 32

Mechanical and chemical

Question 33

Where does food flow through to get to the stomach?

Answer 33

The fauces, into oropharynx and laryngopharynx and then into the esophagus

Question 34

What does the mouth and oral cavity need?

Answer 34

Lubrication

Question 35

How is the mouth and oral cavity lubricated?

Answer 35

Through salivary glands

Question 36

What are the three salivary glands?

Answer 36

Parotid, sublingual, submandibular

Question 37

What does the parotid salivary gland secrete?

Answer 37

Serous fluid with amylase

Question 38

What does the sublingual salivary gland secrete?

Answer 38

Mucous only

Question 39

What does the submandibular salivary gland secrete?

Answer 39

Mixed of mucous and serous fluid

Question 40

Where is the parotid glad positioned?

Answer 40

In front of the ear

Question 41

Where is the sublingual gland located?

Answer 41

Below the tongue

Question 42

Where is the submandibular gland located?

Answer 42

Around the mandible

Question 43

What type of glands are the salivary glands?

Answer 43

Compound secretory glands

Question 44

What is an acinus?

Answer 44

Cluster of cells

Question 45

What do acinus cells secrete? | In the salivary glands

Answer 45

Serious fluid, enzymes and mucus

Question 46

What do duct cells secrete? | In the salivary glands

Answer 46

Bicarbonate, a pH buffer

Question 47

What is the esophagus?

Answer 47

Long tube of about 25cm made from stratified squamous epithelium

Question 48

Where is the esophagus located?

Answer 48

Posterior to the trachea and extends from the pharynx to the stomach

Question 49

What does the epiglottis ensure?

Answer 49

Food does not enter the trachea

Question 50

What is the function of the muscularis externa?

Answer 50

To move food bolus

Question 51

What is the composition of muscle along the muscularis externa? (In the esophagus)

Answer 51

First 1/3 = skeletal muscle Second 1/3 = mixture Third 1/3 = smooth muscle

Question 52

What component of the esophagus is highly folded?

Answer 52

The submucosa and mucosa which expands for food passage

Question 53

How does the esophagus secrete mucus without goblet cells?

Answer 53

Through glands with ducts in submucosa and the mucosa close to the stomach

Question 54

Why does the esophagus need mucus?

Answer 54

For lubrication and protection

Question 55

Why is the structure of the esophagus so different to the stomach?

Answer 55

To preform different functions