The Digestive System

Question 1

What is the Digestive System?

Answer 1

The organ system with associated organs that take in food and liquids, breaking them down into substances that the body can use and discard as waste.

Question 2

What are the organs and accessory organs involved in the digestive system?

Answer 2

1. Oral Cavity
2. Mouth
3. Tongue
4. Salivary Glands
5. Pharynx
6. Esophagus
7. Stomach
8. Gallbladder
9. Liver
10. Pancreas
11. Large Intestine
12. Small Intestine
13. Rectum
14. Anus
15. Sphincter Muscles

Question 3

How does the Digestive System Begin and End? Explain the process.

Answer 3

1. Ingestion at the Mouth
   Teeth (1): Aids Digestion via Mechanical Movement that physically breaks down the food.
   Tongue (2): Helps churn food, allowing it to flow into the esophagus.
   Salivary Glands: Performs chemical digestion by using the salivary amylase (enzymes found within the salivary glands), additionally breaks down food.
2. The esophagus then contract that force the food down
3. The food travels from the esophagus and into the stomach where the acidic environment of the stomach breaks down food physically (peristalis- churning food) and chemically (hydrochloric acid).
4. The body absorbs nutrients from the digested food is via the small intestine- the nutrients diffuse into the bloodstream to go to cells through the microvilli.
5. It is during this time that the the liver creates bile and pancreas creates and releases more enzymes that speed up breakdown of proteins, lipids, and carbohydrates (i.e., the digested food in the small intestine mixes with the digestive enzymes from the pancreas and bile from the liver, efficiently quickening digestion).
6. The gallbladder also stores the bile and transport it to the small intestine when it is ready to emulsify fat.
7. Afterwards, the food passes to the large intestine (colon) for further digestion and water absorption- this process turns the food into solid waste.
8. The Anus is an orfice that then allows waste to exit the body.

Question 4

Define Peristalis

Answer 4

Peristalsis is a series of wave-like muscle contractions that move food through the digestive tract.

Physical Digestion

Question 5

What are the parts of the Large Intestine?

Answer 5

Cecum: The first part of the large intestine, which looks like a pouch
Colon: The main part of the large intestine, which includes the ascending colon, transverse colon, and descending colon
Rectum: Stores feces until they are expelled through the anus as a bowel movement

Question 6

Enzymes

How does the amylase enzyme work for digestion?

Answer 6

It turns starch and carbohydrates into small sugars.

Question 7

Enzymes

Where are amylase enzymes found in the body?

Answer 7

In the salivary glands of the mouth (starch into small sugars) and the small intestine (carbohydrates into small sugars).

Question 8

Enzymes

How does the pepsin enzyme work for digestion?

Answer 8

It breaks down proteins.

Question 9

Enzymes

Where are the pepsin enzyme located?

Answer 9

Stomach

Question 10

Enzymes

How does the trypsin enzyme work for digestion?

Answer 10

Breaks down proteins into amino acids.

Question 11

Enzymes

Where are the trypsin enzymes located?

Answer 11

Small intestine

Question 12

Enzymes

How does the lipase enzyme work for digestion?

Answer 12

Turns lipids into fatty acids and glycerol.

Question 13

Enzymes

Where are the lipase enzymes located?

Answer 13

Small intestine

Question 14

Specialized Cells of the Digestive System

What are absorptive cells?

Answer 14

A dense array of microvilli, visible microscopically as the brush border.

Question 15

Specialized Cells of the Digestive System

What are goblet cells?

Answer 15

Scattered among the absorptive cells in the epithelium of the small intestine and colon. These epithelial cells are specialized for the secretion of mucus which facilitates a passage of material through the bowel.

Goblet refers to the cell’s shape, narrow-based and apically bulging

Question 16

Specialized Cells of the Digestive System

What are taste cells?

Answer 16

The sensation of taste is mediated by columnar epithelial sensory cells.
- sensory cells are normally replaced every 10-14 days by division and differentiation of stem cells, which is handy since they are exposed and easily damaged

Question 17

Clarification

Epithelial cells are?

Answer 17

Type of Tissue cells that make up the epithelium (tissue made up of tightly bound epithelial cells that form sheets which ocver the body’s surfaces.

Question 18

Clarification

What are hepatocytes?

Answer 18

Cells that predominantly make up the liver.

80% to be specific

Question 19

Clarification

Functions of Hepatocytes:

Answer 19

• form and secrete bile
• store glycogen and buffer blood glucose
• synthesize urea (colourless substance formbed by the breakdown of protein in the liver)
• metabolize cholesterol and fat
• synthesize plasma proteins
• detoxify many drugs and other poisons
• process several steroid hormones and vitamin D
• offer splendid and numerous examples of most cellular organelles.

Question 20

Difference between Villi and Microvilli

Answer 20

Villi are covered with even smaller hairlike structures called microvilli. Microvilli are projections smaller than villi. Their job is to also increase the surface area so each villus can absorb the maximum amount of nutrients.

Question 21

What is the brush border?

Answer 21

Specialized structure that lines the small intestine- made up of tightly packed microvilli.

Question 22

Function of the Oral Cavity?

Mouth, Tongue, Salivary Glands, etc.

Answer 22

The mouth is where food enters- its teeth chew food (a physical component of digestion)
Its tongue aids in breaking down food into smaller parts.
The Salivary Glands employs enzymes contained in the glands that break down food

Question 23

What is the function of the pharynx?

Answer 23

Swallows food, muscle contractions push food into the esophagus.

Question 24

What is the function of the esophagus?

Answer 24

Tubular structure that leads food into the stomach through peristalsis (muscle contractions).

Question 25

What is the function of the stomach?

Answer 25

An acidic environment where food breaks down physically and chemically via digestion.

Question 26

What are Sphincter Muscles and what do they do?

Answer 26

Ring-shaped muscles that relaxes or tightens to open or close a passage or opening in the body.

Question 27

Examples of Sphincter Muscles

Answer 27

The anal sphincter (around the opening of the anus) and the pyloric sphincter (at the lower opening of the stomach).

Question 28

What is the function of the liver?

Answer 28

Process and stores nutrients from food that is digested; produces bile to break down fats and stores harmful chemicals in blood

Question 29

What is the function of the gallbladder?

Small pear-shaped sac located under the liver

Answer 29

Stores and concentrates bile, a digestive fluid produced by the liver.

Question 30

What is the function of the pancreas?

Answer 30

Creates and releases more enzymes/chemicals that help speed up breakdown of proteins, lipids, and carbohydrates.
Produce hormones (including insulin) helping food digestion processes and enabling appetite, and regulation of blood sugar (connected to diabetes).

Question 31

What is the function of the small intestine?

Answer 31

Place where absorption happens - Where nutrients diffuse into the bloodstream to go to cells through microvilli.

Question 32

What is the function of the large intestine?

Answer 32

Absorbs water and electrolytes from digested food, which solidifies it into stool.
Producing and absorbing vitamins, and forming and propelling feces toward the rectum for elimination.

Question 33

What is the function of the rectum?

Answer 33

Stores stool

Question 34

What is the function of the anus?

Answer 34

Controls when stool is released from the body.

Question 35

What is the difference between bile and stool?

Answer 35

Bile is a yellow-green fluid fluid produced by the liver that helps digest fats and carries waste out of the body, while stool is the waste that passes through the digestive system.