CVA: Digestion

Digestion

the process of converting food into usable energy

Absorption is done by

intestine

Digestive tract

tubular passage form mouth to anus/ cloaca

What is Enegry?

Capacity to do Work

What is Work?

Ability to move stuff

The Alimentary canal consists of:

esophagus, stomach, small inst., and large inst.

Secondary palate is only found in

mammals and crocs

Thecodont

deep sockets w/in bone (Mammals and archosaurians)

Acrodont

shallow sockets, teeth on top (Bony fish, some lizards)

Pleurodont

teeth on medial side of bone. (Most squamates)

Mammals that specialize in grass eating, heavy vegetative diet will have

relatively tall teeth since grass eating wears down teeth

Brachydont

short teeth

Hypsodont

tall teeth

Bunodont

rounded peaks

Lophodont

enamel ridges

Selenodont

crescent-shaped cusps

Sectorial teeth are adapted for

cutting

Deglutition is the ability to

swallow

Rugae

ridges to aid folding, mech. digestion

Absorption is dependent on

surface area

Vili

finger-like projections of intestinal wall on the tissue level

Microvilli

finger-like projections of indv. cells of intestinal wall on the cellular level

Cloaca

shared w urogenital tract that most vertebrates have

Rectum

NOT shared w urogenital tract that most mammals and bony fish have

Increasing lengths allows for

more time for digestion so more nutrients can be liberated

Crop

found in birds: a bag-like expansion of esophagus that temporarily stores food

Gizzard

Pocket of stomach that grinds food against (swallowed) rocks or other bard objects (gastroliths) found in crocs and birds

Agnathans have

straight alimentary canal with NO stomach

Gnathostomes do have a stomach but

their digestion tract is weirdly short and display a diverse digestion tract to improve surface area

Compared to carnivores, herbivores have larger

small intestines due to their diet

Foregut fermenters

(Ruminants) incl. cattle, deer, many artiodactyls;

repeated swallow → ferment → regurgitate → chew → repeat

3 or 4 “stomachs” that most derived from esophagus

Hindgut fermenters

incl. rabbits, horses, many rodents, elephants;

possess a large cecum AFTER small int. so additional absorption limited, meaning not as efficient

Coprophangy

many hindgut fermenters ingest fecal pellets to capture nutrients