Digestive System: Mouth, Esophagus, Stomach

Question 1

Ingestion

Answer 1

act of eating (starts at mouth)

Question 2

Digestion

Answer 2

process of food breakdown (enzymatic hydrolysis)
Breaking down polymoners into monomers

Question 3

Absorption

Answer 3

the uptake of small molecules, Go into blood stream, cells turn into monomers

nutrients from digested food are taken up by the cells lining the digestive tract and transported into the bloodstream

Question 4

Egestion

Answer 4

elimination of indigestible and unabsorbed food residues from the body in the form of feces

Question 5

Basic Sequence:

Answer 5

Mouth → Esophagus → Stomach → Small Intestine → Large Intestine → Rectum → Anus

Question 6

Mechanical [Physical] Digestion:

Answer 6

involves physically breaking the food into smaller pieces. Mechanical digestion includes chewing (mastication), churning of food in the stomach, and segmentation in the small intestine.

Question 7

Chemical Digestion:

Answer 7

involves breaking down the food into simpler nutrients with enzymes. mouth, saliva contains salivary amylase, which begins the breakdown of starches into simpler sugars.

Question 8

There are three sets of salivary glands:

Answer 8

Parotid glands
Submandibular glands
Sublingual glands

Question 9

Pharynx

Answer 9

The back of the mouth, Common area for BOTH food and air inhaled to pass to their respective areas.

Question 10

Pharynx categories

Answer 10

Esophagus → for food to stomach
Trachea → for air to lungs

Question 11

Epiglottis

Answer 11

Flap that prevents food from
entering the lungs.

Question 12

Peristalsis

Answer 12

Food is moved by peristalsis, which are rhythmic contractions that force food down to the stomach.

Question 13

Lower esophageal sphincter (LES)

Answer 13

End of the esophagus there is a sphincter that leads to the stomach.

Including acid, into the esophagus. This helps protect the esophagus from damage due to stomach acid and ensures that food moves in the correct direction.

Question 14

Pyloric Sphincter

Answer 14

Food remains in the stomach for about 2-4 hours, before exiting into small intenstine

Located between the stomach and the duodenum (the first part of the small intestine). It controls the passage of partially digested food (chyme) from the stomach into the small intestine and prevents backflow of intestinal contents into the stomach.

Question 15

Mechanical digestion:

Answer 15

food is further ground up as the stomach contracts, squeezes, and churns the food (remember the stomach is a muscle!)

Question 16

Chemical digestion:

Answer 16

Secretions from walls of stomach AKA Gastric Secretions

Question 17

Chyme

Answer 17

The food is called Chyme which is a liquified food slurry

Question 18

Hydrochloric Acid

Answer 18

does not break food down very well, despite having a pH of 2-3. The acid has 2 functions
Kill organisms that enter the stomach
Activate pepsin

Question 19

Pepsin

Answer 19

an enzyme that is used to break down proteins
breaks down proteins (stomach. Originates as pepsinogen, which needs to be activated by the low pH in the stomach)

Question 20

Salivary amylase

Answer 20

enzyme found in saliva, begins the breakdown of starches (carbohydrates) into simpler sugars. breaks down carbohydrates (saliva & small intestine)

Question 21

Rennin (Chymosin)

Answer 21

a milk clotting protein that is important in digestion for babies (tapers off early in place of pepsin)

Question 22

Ulcers

Answer 22

caused by a bacterial infection by the Helicobacter pylori (or commonly referred to as H. pylori) bacterium.

protective mucous stomach lining is broken, the capillary network is exposed to stomach acid.