Digestive Tract

Question 1

To maintain homeostasis, nutrient molecules are needed for 2 things:

Answer 1

• fuel

* building blocks

Question 2

What are the four basic processes of digestion?

Answer 2

• motility
• secretion
• digestion
• absorption

Question 3

Motility is?

Answer 3

Muscular contractions

Question 4

Secretion is?

Answer 4

Digestive juices secreted by exocrine glands

Question 5

Digestion is?

Answer 5

Breaking down structurally complex foodstuffs (carbs,fats, proteins) into nutrients that can pass the plasma membrane

Question 6

Absorption is?

Answer 6

Blood or body cavity

Question 7

Mastification

Answer 7

• to break up food

- facilitate swallowing and increase food surface

Question 8

Teeth necessary for mastification?

Answer 8

Incisors (front)
Molars (back)
Diastoma

Question 9

Salivary glands two cell types?

Answer 9

• watery fluid

• parotid gland
• high in enzymes

• mucus

• sublingual
• lubrication
• submandibular
• both

Question 10

Salivary glands functions?

Answer 10

Moistening 
Digestion
Defense
Taste
Neutralization 
Thermoregulation
Pheromones

Question 11

Pharynx

Answer 11

Acts as a passageway for food between mouth and esophagus

Question 12

Esophagus

Answer 12

• straight muscular tube
Ruminants and dogs- skeletal structure
Birds and humans- smooth muscle
Horses and cats- bottom third is smooth muscle

Question 13

Sphincter

Answer 13

• pharyngoesophageal sphincter- upper

* gastroesophageal sphincter- (cardiac sphincter) lower

Question 14

Stomach (monogastric)

Answer 14

• simple, muscular, sac-like chamber between the esophagus and the small intestine

Question 15

Functions of the stomach for monogastrics

Answer 15

Storage
• rate optimal for digestion and absorption
Digestion
• hydrochloric acid and enzymes: protein digestion
Chyme formation
• mixed up food and gastric juices= thick liquid known as chyme

Question 16

Cardia

Answer 16

• immediately surrounding opening of esophagus

* produces mucus

Question 17

Fundus

Answer 17

• ingested food
• can change in volume
• thin smooth muscle

Question 18

Corpus or body

Answer 18

(Biggest part of stomach)
• digesta is mixed with gastric secretions
• thin smooth muscle

Question 19

Antrum

Answer 19

• regulates expulsion of food into SI
• regulates HCl acid levels in the stomach
• thick musculature

Question 20

Pyloric sphincter

Answer 20

• barrier between stomach and SI

* Regulates movements of chyme

Question 21

Oxyntic mucosa

Answer 21

Lines the fundus and the body

Question 22

Pyloric gland (PGA)

Answer 22

Lines the antrum

Question 23

Oxyntic mucosa 3 types of secretory cells

Answer 23

• Mucous cells- lines the pits and entrance of the gland
• Chief cells- line the deeper portions of the gastric glands ( produce pepsinogen)
• Parietal cells- locates on the outer wall of the gastric (produce hydrochloric acid and gastric intrinsic factor)

Question 24

Enterochromaffin- like cells (ECL)

Answer 24

• dispersed among the parietal and chief cells
• secrete histamine
• stimulates the parietal cells

Question 25

G cells

Answer 25

• dispersed in pyloric gland
• secretes gastrin into the blood
• stimulates the parietal, chief, and ECL cells

(On)

Question 26

D cells

Answer 26

• dispersed in pyloric gland
• secretes somatostatin
• inhibits parietal, G, and ECL cells

(Off)