Stomachs

Stomach

Esophogus Intestine

Eats other fish

Marine fish

FreshwaterOmnivore

Stomachs

Stomach

IntestineEsophagusPlanktivore

Gizzard-Like Stomach

Gizzard Shad

Mullet

Parts of the Stomach

Cardiac StomachSecretes

Fundic StomachMuscular for Grinding

Fundic

Cardiac

Hydrochloric AcidHydrochloric Acid• decalcifies bones• decalcifies bones

Hydrochloric Acid

• decalcifies bones• breaks down

connective tissue

• decalcifies bones• breaks down

connective tissue

Hydrochloric Acid

•decalcifies bones•breaks down

connective tissue•hydrolyzes proteins

•decalcifies bones•breaks down

connective tissue•hydrolyzes proteins

Hydrochloric AcidHydrochloric Acid

• decalcifies bones• breaks down

connective tissue• hydrolyzes proteins• kills disease

organisms

• decalcifies bones• breaks down

connective tissue• hydrolyzes proteins• kills disease

organisms

Pepsin•Enzyme•Made by stomach glands

•Breaks down protein at low pH

Implications?

Large Intestine?

Variability in Intestine Design

Carp Catfish TroutSturgeon(Spiral Valve)

Stomach

Intestine

Cecae

Definitions

• Planktivore: Eats plankton• Piscivore: Eats fish• Herbivore: Eats plants• Omnivore: Eats a little of everything• Detritivore: Eats bottom goo• Insectivore: Eats insects• Carnivore: Meat (insects and fish too…)

IntestineLength

• Piscivores: 1 x body length

• Herbivores: 2 x body length

• Planktivores: 5-13 x body

• Omnivores: 2-4 x body

• Detritivores: 10-15 x body

Intestinal Secretions

•Bicarbonate to neutralize the acid

•Produces correct pH for other digestive enzymes that come from the…

Pancreas1. Endocrine: Insulin

for blood sugar control (Brockman bodies)

2. Exocrine: Digestive enzymes

Pancreatic Islet: Insulin

ZymogenGranules

ExocrinePancreas

Trypsin: proteinsLipases: fatsTrypsin: proteinsLipases: fats

Adipose Tissue

ExocrinePancreasExocrinePancreas

Trypsin: proteinsLipases: fatsAmylases: starches

Trypsin: proteinsLipases: fatsAmylases: starches

ExocrinePancreasExocrinePancreas

LiverGallBladder

= Liver cells

= Bile ducts

= Blood

Liver cells arranged in plates

= Liver cells

= Bile ducts

= Blood

Liver cells arranged in tubes

The LiverSecretes Bile

Fat Bile

Bile

•Exocrine Pancreas

•Bile•What else?

Liver Functions

• Vitamin storage: A (years worth!), D, B12 (months worth).

• Iron storage: Iron is needed to make hemoglobin and some enzymes. Free iron levels in the blood are kept very low to inhibit the growth of bacteria.

• Detoxification: Toxic compounds from food and blood are metabolized into nontoxic (hopefully!) compounds.

Liver Functions (metabolism)• Carbohydrate metabolism: Storage of sugar

as glycogen, production of sugar from other molecules, conversion of sugar types to other sugar types. Maintains blood sugar levels.

• Fat metabolism: Fat storage, conversion of carbos to fat, production of cholesterol,

• Protein metabolism: Produces plasma proteins (albumen, clotting, immune function), makes egg yolk (vitellogenin), amino acid conversion.

Glycogen Lipid

Liver Functions (energy storage)

Yikes !

Digestive System Design

•Lips•Teeth•Pharyngeal teeth•Gill rakers•Stomach design (acids and enzymes)

•Intestine length•Digestive enzyme emphasis (and

bicarb)