Lecture 11 Alimentary Canal

Question 1

regions of the alimentary canal (6 IN ORDER)

Answer 1

1.mouth/teeth
2.pharynx
3.esophagus
4.stomach
5. intestine
6. anus

Question 2

regions for capture and selection (3)

Answer 2

mouth/teeth
pharynx
esophagus

Question 3

regions for digestion (4)

Answer 3

esophagus
stomach
intestine
anus

Question 4

organs associated with the alimentary canal (3)

Answer 4

Liver
pancreas
spleen

Question 5

pharynx 2 parts

Answer 5

Gill rakers
pharyngeal teeth

Question 6

gill rakers (4)

Answer 6

-prevent loss of food particles
-select food of specific sizes
-especially planktivores
-muscles may control gill arch spacing for additional selection

Question 7

pharyngeal teeth (3)

Answer 7

-on gill arches
-vary in form among species or life stages (cardiform to molarform)
-direct food into the gut
-main site of chewing (especially grinding shellfish) in most species

Question 8

Esophagus (3)

Answer 8

-short, expandable connection between pharynx and stomach
-circular and longitudinal muscles aid in swallowing
-taste buds present

Question 9

Stomach (5)

Answer 9

-lacking in some species such as Agnathans
-begins chemical digestion by
-secretes pepsin & HCL
-maintains a ph of 2 for pepsin activity
-store food & mix ingesta & gastric juices

Question 10

pyloric caeca (2)

Answer 10

branch from intestine near stomach
may secrete digestive enzymes

Question 11

intestine (2)

Answer 11

-further chemical digestion and absorption of nutrients
-neutral to alkaline pH

Question 12

intestine enzymes

Answer 12

from intestine: enzymes to digest carbohydrates
from pancreas: trypsin and other protases
from liver: emulsifiers carried in bile aid in fat digestion, also stores glycogen