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Flashcards in Digestive 2 Deck (24):
1

What adaptation to (most) Osteichthyes have to increase surface area for digestion & absorption?

Pyloric ceca, at junction of stomach and duodenum

2

Describe ruminants' stomach

Digastric - 2 main chambers:
Rumen - initial storage & foregut fermentation (helps break down cellulose to simpler carbs, fatty acids, amino acids, peptides)
Abomasum - reached after regurgitation & rechewing, used for chemical & mechanical digestion like a monogastric stomach (+ helps recover some bacteria & nutrients)

3

What are the component(s) of the hindgut?

Caecum, large intestine

4

What happens to material digested in the caecum?

Either re-enters ileum for absorption, or excreted as semi-solid feces and reconsumed (because small intestine has the absorptive surface, so want to go through there)

5

Who has a spiral valve?

non-teleost fishes (Chondrichthyes, Sarcopterygii, non-teleost Actinopterygii)

6

Describe rugae & their function

Folds in stomach, allow expansion without distension

7

Function of taste sense in buccal cavity

Assess food quality

8

Define monogastric stomach

Stomach is 1 connected chamber

9

What comprises the midgut?

small intestine

10

What is the structure of the caecum?

Blind-end chamber at small/large intestine junction, with high surface area

11

Functions of stomach

- food storage
- glandular secretions (HCl, enzymes) for chemical digestion
- mechanical digestion

12

What kind of stomach do most animals have? Who are the exceptions?

Most: monogastric
Archosaurs: proventriculus & gizzard
Ruminants: digastric
Agnathans: none

13

What is the function of the small intestine, and how is it adapted for this?

Chemical digestion (esp anterior) - bacteria to help (esp w/cellulose) & provide nutrients; secretions + from pancreas, bile; longer if lower quality food

Absorption (esp posterior) - thin epithelium is easy to cross; v. high SA by plicae -> villi -> microvilli (brush border)

14

Function of the large intestine

- consolidates undigested material
- prepares for defecation
- specifically reabsorbs remaining water, even without nutrient uptake creating an osmolar gradient

15

Function of esophagus

- transport food to stomach
- keep water out of stomach

16

Secretions found in buccal cavity? (content & where they are made)

- mucus, digestive enzymes, toxins/anticoagulants/analgesics
- from salivary glands

17

Describe the stomach in archosaurs

2 chambers:
Proventriculus - glandular stomach
Gizzard - grinding stomach (may contain rocks or sand)

18

What comprises the foregut?

Esophagus, stomach (+ crop, if present)

19

What are pyloric ceca & who has them?

Pouch at junction of small intestine & stomach for DIGESTION & ABSORPTION, NOT fermentation; in most osteichthyes

20

Function of the caecum & how it accomplishes it

- cellulose digestion
- lots of bacteria to do hindgut fermentation; lots of surface area

21

What are the two functions of the buccal cavity?

Breathing, eating (structure is a compromise)

22

What adaptation do non-teleost fishes (Chondrichthyes, Sarcopterygii, non-teleost Actinopterygii) have to increase small intestine surface area?

Spiral valve

23

Who is the large intestine particularly important in?

Species in dry environments that must conserve water - large intestine is specialized for water reabsorption

24

Function of crop

- store food for controlled digestion or regurgitation
- may secrete crop milk (nutrient-rich, for young)