Digestive System

Question 1

Herbivore

Answer 1

Plant-eaters. Horses, rabbits, sheep, goats. High fiber. Large flat premolars/molars for grinding. Minimum/absent canine teeth. Ruminant or non-ruminant

Question 2

Carnivore

Answer 2

meat-eaters. Dogs and cats. small or absent cecum. Minimal fermentation, large canine teeth for ripping and tearing flesh, pointed molars for sheering/minimally chewing food

Question 3

Omnivore

Answer 3

Plant and meat. Pigs and humans. Cecum small or absent. Teeth for ripping and grinding

Question 4

Morphology

Answer 4

structure and function of the digestive tract

Question 5

Ruminants

Answer 5

sheep’s and goats. Large fermentation capacity in stomach

Question 6

Non-ruminants

Answer 6

horses and rabbits, large fermentation capacity in cecum and colon

Question 7

Prehension

Answer 7

bringing food to mouth

Question 8

Mastication

Answer 8

chewing

Question 9

Deglutination

Answer 9

swallowing

Question 10

Peristalsis

Answer 10

smooth muscle contraction to move food

Question 11

Mesentary

Answer 11

suspends intestines from abdominal wall. Lined with blood vessels and nerves. Passage of digested nutrients from lumen of gut across mucosa into bloodstream for transport to tissues

Question 12

Omentum

Answer 12

links stomach to abdominal wall/other organs. Less/greater omentum depending on abdomen location. Store fat, assist in insulating abdomen

Question 13

Ligaments

Answer 13

connective tissue

Question 14

Monogastric

Answer 14

one stomach, size/shape varies. Temporary storage of digesta

Question 15

Rugae

Answer 15

lines interior of stomach, increases surface area for secretion of gastric juices/absorption of some nutrients

Question 16

Pyloric Sphincter

Answer 16

band of smooth muscle. Controls movement of partially digested food and juices

Question 17

Recticulum

Answer 17

smallest, most cranial chamber. Honeycomb to increase surface area, heavy objects get stuck here. Prevention of hardware disease

Question 18

Rumen

Answer 18

main site of fermentation, small bumps (papillae) to increase surface area for microbial digestion. Mixes stomach content (mixing = mechanical or physical digestive process)

Question 19

Omasum

Answer 19

muscular chamber with many folds. Important for water absorption and removal of bicarbonate buffer. Participates in absorption of energy products from digestion, microbial fermentation

Question 20

Abomasum

Answer 20

“true stomach,” lined with glandular epithelium, secretes mucus and enzymes. Anything not digested from microbial digestion absorbed here before going to small intestine

Question 21

Bile

Answer 21

made in liver, stored in gallbladder. Good for digestion and emulsification of fats into small lipid droplets (further digested by lipases)

Question 22

Goblet Cells

Answer 22

Secrete mucus for lubrication of dried feces

Question 23

Defecation

Answer 23

pooping. Feces moving into the rectum stimulates sensory receptors that initiate defecation reflex. Colon/rectum contracts/relaxes. Some animals can control it, others can’t

Question 24

Cephalic Phase

Answer 24

1) stimulation of neurotransmitter (ACh) release
2) ACh binds to receptors that cause the release of gastric juices into the stomach (HCl and pepsinogen)
3) ACh triggers hormone histamine release which further stimulates ACh

Question 25

Gastric Phase

Answer 25

1) formation of peptides from protein (enzymatic digestion) triggers vagal nerve (cranial nerve 10)
2) stimulation of hormone gastrin release from G cells
3) gastrin triggers more histamine and HCl stomach acid to be produced
4) stomach acidity lowers (gets more acidic for enhanced digestion)

Question 26

Intestinal Phase

Answer 26

1) ACh triggers vagal nerve (cranial nerve 10) stimulation that increases hormones, CCK and secretin
2) most enzymatic digestion happens in duodenum of small intestine

Question 27

Gastric Motility

Answer 27

rate of passage of digesta through stomach. Neurohormonal control

Question 28

Enteroendocrine cells

Answer 28

dispersed in gradient fashion.