Chapter 41: Animal Nutrition Flashcards
How can animals extract the nutrients they
need from food while not digesting their own tissues?
An animal digests food using
compartmentalized processing in a tubelike system
why is the tubelike system important
protects body tissues
while allowing enzymes and acids to
break down nutrients.
what are the 3 needs of an animal
- chemical energy
- organic building blocks
- essential nutrients
what the 4 classes of essential nutrients
- essential amino acids
- essential fatty acids
- vitamins
- minerals
what does food processing involve
- ingestion
- digestion
- absorption
- elimination
what is ingestion and digestion
ingestion is when you eat
digestion is the process of breaking down the food
what is absorption
uptake of small molecules by body cells
what is elimination
the passage of undigested material out of the digestive system
what are the 4 main feeding mechanisms
- filter feederss
- substrate feeders
- fluid feeders
- bulk feeders
what do filter feeders do
sift small food particles from the water
what are substrate feeders
live in or on their food source
what do fluid feeders do
suck nutrient rich fluid from a living host
what do bulk feeders do
eat relatively large pieces of food most animals including humans feed this way
what are the 2 processes of digestion
- mechanical digestion
- chemical digestion
what is mechanical digestion
chewing or grinidng
what is chemical digestion
enzymes breakdown food into small molecules that can pass through membranes
what are the two digestive compartments
- intracellular digestion
2. extracellular digestion
what is intracellular digestion
food particles are engulfed by phagocytosis(solid) or pinocytosis(liquid)
examples of intracellular digestion
- cellular organelles (food vacuoles) fuse with lysosome containing hydrolytic enzymes
- sponges digest their food entirely by this mechanism
what is extracellular digestion
:breakdown of food particles outside
of cells
where does extracellular digestion occur
in compartments that are continuous with the outside
of the animal’s body
what digestive compartment do animals with simple body plans have
digestvie compartment gastrovascular cavity that functions in both the distribution and distribution of nutrients throughout the body
what digestive compartment do animals with complex body plan have
digestive tube with two openings, a mouth and an anus
what is the digestive tube called for complex animals
alimentary canal
how does food move through the alimentary canal
Food moves in one direction, encountering a
series of specialized compartments that carry
out digestion and nutritarian absorption
what do accessory glands do
secrete digestive juices through ducts into the alimentary canal
what are the mammalian accesory glands
salivary glands
pancreas
liver
gallbladder
where does food processing begin
oral cavity
what do the 3 pairs of salivary glands do and what enzymes do they use
deliver saliva (contains mucus and amylase (which breaks down starch))
what is the pharynx
the junction that opens to both the esophagus and the trachea
what is the trachea
leads to the lungs
what is the esophagus
connects to the stomach
how does swallowing affect the epiglottis and the bolus
causes the epiglottis to block entry to the trachea, and the bolus is guided by the larynx, the upper part of the respiratory tract
when does coughing or choking occur
when the swallowing reflex fails and the food or liquids reach the windpipe
what is peristalsis
rhythmic contractions of muscles in the wall of the canal
what are the major roles of the stomach
storage of food and process food into a liquid suspension
what is chyme
mixture of ingested food and gastric juice
what is the longest compartment of the alimentary canal
small intestine
what happens in the small intestine
enzymatic hydrolysis of macromolecules from food
what is the pH of gastric juice
low pH of 2 and it dentures the proteins
what is gastric juice made up of
hydrochloric acid and pepsin
what is pepsin
protease which breaks peptide bonds to cleave proteins into smaller peptides
what do parietal cells do
secrete hydrogen and chloride ions separately into the lumen of the stomach
what do chief cells secrete
inactive pepsinogen which is activated to pepsin when mixed with hydrochloric acid in the stomach
what is the job of mucus in the stomach
protects the stomach lining from gastric juice
how does cell division affect the epithelial layer
adds a new epithelial layer every three days