Exotics

Question 1

list the 9 general structures of the avian digestive tract

Answer 1

1. mouth/oral cavity (bill/beak and tongue)
2. esophagus
3. crop
4. proventriculus
5. gizzard
6. small intestine
7. ceca
8. large intestine
9. cloaca

Question 2

describe avian bill/beak

Answer 2

wide variability in size and shape; useful for different diet such as fish or other meat, fruit, nuts, nectar, etc.

Question 3

describe the avian crop (2)

Answer 3

1. first chamber after the esophagus; storage chamber before food gets to stomach
2. birds eat as much as they can when they have the opportunity, so the corp functions like a to go box of the GI tract for later digestion

Question 4

describe the avian proventriculus (3)

Answer 4

1. first chamber of the 2-chambered stomach; glandular/true stomach
2. secretes HCl and pepsinogen
3. there is a sphincter between the proventriculus and the gizzard

Question 5

describe the avian gizzard (2)

Answer 5

1. 2nd chamber of 2-chambered stomach; mechanical digestion
2. usually contains grit or small stones called gastroliths to help grind up food

Question 6

describe avian small intestines (3)

Answer 6

1. similar to mammals, but longer or shorter depending on diet
2. birds that eat seed will have longer SI to increase surface area for absorption
3. pancreas in loop of duodenum like in mammals

Question 7

describe bird large intestines

Answer 7

very short compared to mammals

Question 8

describe avian ceca

Answer 8

can have 2, or just one, or none, or 2 pairs of 2 so hella variable

Question 9

describe the avian cloaca (3)

Answer 9

1. common space of passage of fecal waste, urinary waste, eggs or sperm; 3 compartments
2. no urinary bladder or urethra
3. external opening through which everything is excreted is called the vent/cloacal orifice

Question 10

describe the reptile mouth

Answer 10

widely variable; some reptiles will lose teeth ad replace them, some won’t replace them

Question 11

describe snake venom glands

Answer 11

evolved salivary glands; commonly called venom glands

Question 12

describe reptile esophagus and stomach (6)

Answer 12

1. reptiles eat prey whole so don’t chew
2. esophagus can act as a storage space for food before it enters stomach
3. carnivorous reptiles have short guts due to the amount of time their whole prey sits in the stomach, which secretes HCl to decalcify the bones of prey
4. large carnivorous reptiles can go for long periods of time between meals
5. amount of time digestion takes can also be longer if it’s cold
6. some herbivorous reptiles will swallow small rocks to help grind their food like birds

Question 13

describe reptile intestines

Answer 13

similar to mammals; long tubes for absorption of water and nutrients; length varies widely by species

Question 14

describe the reptile cloaca (2)

Answer 14

1. similar to bird cloaca
2. some reptiles have a modified cloaca connected to accessory air bladders which helps with gas exchange in water (helps turtle with diving)