Chapter 47 Digestion

What consumer levels are Herbivores

Primary consumers

What do Herbivores eat

plants

How much food is required to fill a herbivore

alot, since the food quality is poor

What enzyme are needed to digest plants

cellulose (most animals lack this)

If most animals don’t have cellulose how do they break down plants

having a symbiotic relationship with bacteria or protist to break down cell walls.

What is the cavet to the statement I just made

Animals can break down cellulose by mechanical forces like chewing but we don’t maximize it

Carnivores are in what consumer level

secondary or higher comsumers

How do carnivores obtain their food

they evolved to seize and swallow alive, paralyzed, crush…..

How do carnivores capture prey

tentacles, claws, fangs, poison glands, and teeth

Compare herbivores the digestive tracts to those who are not STRICTLY herbivores

herbivores have a longer digestive tract
non-herbivores have a smaller digestive tract

Why are herbivores digestive tracts longer

cellulose is very hard to break down

Omnivores are what consumer level

They are primary or higher consumer

What do omnivores eat

plants and animals

Many omnivores are…

filter feeders

What do filter feeders do

they remove suspended food particles from fluid (could be from air or liquid)

What is required for filter feeders

they must have a siv

How are the senses of omnivores

well developed, to help distinguish from a wide range of food and smell

(hearing,smell,taste are all good)

What are types of feeding

filter feeder, substrate feeding, fluid feeding, and bulk feeding

What is a substrate feeder

they consume medium in which they are living
(example: leaf minor)

What is a fluid feeder

They eat via fluid no solids
(example: mosquitoes)

What are bulk feeders

they take up large portions of food
(example: snakes, and humans)

What are the process of eating

feeding, ingestion, digestion, absorption, secretion, and egestion/elimination

What is prehension

Getting food to your mouth

What is feeding

the combination of ingestion and prehension

What is ingestion

process of taking food into digestive cavity

What is Digestion

breaking down food

What are the 3 process of digestion

mechanical, chemical, and enzymatic

What is absorption

move nutrients through the lining of digstive tract

What is secretion

movement of materials into lumen or ECF

What is egestion/(elimination)

egestion: getting rid of things we worked on but we can’t absorb all of it (too much)
elimiation: getting rid of things we cannot absorb

Where is the location of digestion

extracellular and intracellular, they both use enzymes

What is intracellular digesting

digesting within the cell
(food vacoule, cytoplasm)

What is example of intracellular digesting

fatty acid breakdown in the liver cell

What is example of extracellular digesting

mouth, stomach, gastrovascular cavity

What invertebrate have no digestive tract

poriferans, protists,

What is a gastrovascular cavity and who has them

an incomplete digestive tract, and seen in inveretebrates

Why is gastrovascular cavity an incomplete digestive tract

there is only one opening, anything comes in and digested must leave the same way

What animal has an incomplete digestive tract (a gastrovascular cavity)

platyhelminthes, and Cnidarians

Animals with a GVS have ___ openings

one, which is the mouth

Where is the location of digestion in Animals with GVC

extracellular, but it’s completed intracellularly in food vacuole (some)

What is a complete digestive tract

digestive tract with a mouth and anus

Animals with a complete digestive tract can constatly…

Eat

What phylums have a compete digestive tract

most invertebrates and all vertebrates

What is the schema of animals with a complete digestive tract

they all have like a mouth, esophagus, stomach/crop,

instead of gizzards/crops humans have stomach

What is accessory structures

projects into tract
(example like teeth and tongue)

What is accessory glands

secrete digestive juices into tract
(example: liver, pancreas, salivary glands)

How can vertebrates species differ in pharnyx

the length of the pharynx in animals with gills are longer then the length of pharynx in animals with lungs

Dogs fun fact

they have greater distance between larynx and entry point of mouth then humans so they rarely choke

How do vertebrates differ in stomach

some can have multiples chambers others have single chambers
(humans:1 cow:multiple)

How do teeth vary in vertebrates

types of teeth will be the same but number and size of a teeth in a specific category differ

How does the gall bladder in vertebrates

only vertebrates that consume fat

How does the gall bladder work

stores bile to break down fat

What are the types of teeth

incisors, canines, premolars, and molars

What do incisors do

they bite and cut food

Can you tell a food diet of animal souley based on teeth

yes

After larynx food goes to the

esophagus

What is the cecum

a past of longer piece of large intestines from herbivores

What ways of digestion happens in the mouth

limite enzymatic and mechanical

Where does enzymatic digestion start

in the mouth

What mouth enzymes are released

amylase, lingual lipase, and salivary glands

What does amylase break down

starch (glucose)

What does lingual lipase break down

fats

How does lingual lipase get activated

by stomach pH (reaches maximizing activity in this pH)

What are the 3 types of salivary glands

parotid, sublingual, and submandibular

What do salivary glands release

enzymes, electrolytes, and water

salivary glands could be mucous or serous secreters

Where does starch break down first start

in the mouth

Is starch a complex glucose moleculue

yes

What’s a virally infected parotid gland

mumps

When our mouth gets dried due to a speech what gets activated and what turns off

sympathetic is activated and serous salivary glands is turned off

(mucous salivary glands are still active)

Is swallowing voluntary or involuntary

both

What is the voluntary part of swallowing

chewing food and getting it back to the top of pharnyx

What is the involuntary part of swallowing

actually swallowing

What does the pharynx do

connect food from mouth to esophagus

What does esophagus connect to

stomach

What kind of movement does esophagus do

peristalsis to move the bolus

How does esophagus regulate moving of food

by lower and upper esophagus sphincter

How do we open and close to esophageal sphincter

by pressure gradient

What does epiglottis do

closes airway during swallowing

What is bolus

concentrated food we swallow

When pressure is too much in the stomach what happens

we vomit

What kind of digesting process happen in the stomach

mechanical: muscles
enzymatic: Pepsin
chemical: HCL

Most of enzymatic activity happens where

small intestines

What sphincters are involved in the stomach

esophageal sphincter and pyloric sphincter

What does pyloric sphincter do

regulate movement of food into from stomach to the duodenum

How much food in volume goes through in one passage from stomach to small intestines

50 mL/1 passage

Why does passage of food from stomach to small intestine must be regulated

so there is a good ratio of enzyme to food

What are the layers of muscles in the stomach called

circular
diagonal
longitudinal

What are stomach rugae

folds of the stomach wall to allow expansion of stomach from 50mL to 1L

What does mechanical breakdown by use of stomach muscles allow for

mixing of food

In walls of stomach there is gastric pits, which hold

mucous cells
parietal cells
chief cell

What do mucous cells do

secrete mucus

What do parietal cells do

secrete HCL and intrinsic factor
(seen in chemical digesting)

What does intrinsic factor do

used for Vitamin B₁₂ absorption

What does Chief cells do

secrete pepsinogen
(seen in enzymatic digestion)

How is pepsinogen activated

in acidic environment of stomach via hydrolysis

what does pepsin do

digestes proteins

How does salivary amylase get inactivated

by acids of stomach

understand how parietal cells release hydrochloric acid

okay

After meal we experience…

an alkaline tide due to bicarbonate movement of parietal cell

What are the 3 phases of breaking down of food in stomach

cephalic, gastric, intestinal phase