ch. 34 Flashcards
what are herbivores?
plant eaters
what are carnivores?
meat eaters
what are omnivores?
plant and meat animals
what is a gastrovascular cavity?
a type of digestive system that consists of a single opening
what are some examples of phylums that have a gastrovascular cavity?
- Cnidarians
- Platyhelminthes
what is an alimentary canal?
a tubular digestive system with a mouth and an anus
what is aminopeptidase? what is it secreted by?
protease that breaks down peptides to single amino acids; secreted by the brush border of small intestine
what is the anus?
the exit point for waste material
what is bile?
digestive juice important for the digestion of lipids
what organ produces bile?
the liver
what is a bolus?
a mass of food resulting from chewing action and wetting by saliva
what is caboxypeptidase? what is it secreted by?
a protease that breaks down peptides to single amino acids; secreted by the brush border of the small intestine
what is the cephalon phase?
the first phase of digestion, controlled by the neural response to the stimulus provided by food
what is cholecystokinin?
a hormone that stimulates the contraction of the gallbladder to release bile
what is chylomicron?
a small lipid globule
what is chyme?
a mixture of partially digested food and stomach juices
what is chymotrypsin?
pancreatic protease
what is digestion?
the mechanical and chemical breakdown of food into small organic fragments
what is dipeptidase? what is it secreted by?
protease that breaks down peptides to single amino acids; secreted by the brush border of small intestine
what is the duodenum?
the first part of the small intestine
what does the duodenum digest?
carbohydrates and fats
what is elastase?
pancreatic protease
what does the endocrine system control?
the responses of various glands in the body and the release of hormones at appropriate times
what does the esophagus connect?
mouth to the stomach
what are essential nutrients?
nutrients that cannot be synthesized by the body and must be obtained from food
what does the gallbladder do?
stores and concentrates bile
what organ are gastric inhibitory peptides secreted by? when is it secreted?
the small intestine when its in the presence of fatty acids and sugars
what do gastric inhibitory peptides inhibit? why?
it inhibits acid production and peristalsis in order to slow down the rate at which food enters the small intestine
what happens during the gastric phase?
gastric acids and enzymes process the ingested materials
what begins the gastric phase?
food entering the stomach
what is gastrin?
hormone which stimulates hydrochloric acid secretion in the stomach
what is a gastrovascular cavity?
digestive system consisting of a single opening
what is a gizzard?
muscular organ that grinds food
what is the ileum?
the last part of the small intestine
what is the purpose of the ileum?
connects the small intestine to the large intestine; important for the absorption of B-12
what is ingestion?
the act of taking in food
what begins the intestinal phase?
chyme entering the small intestine
what is the third digestive phase?
the intestinal phase
what happens during the intestinal phase?
chyme enters the small intestine triggering digestive secretions and controlling the rate of gastric emptying
what is the second part of the small intestine?
the jejunum
what does lipase break down?
lipids
what does the liver produce? why?
produces bile for digestion
what does the liver process?
vitamins and lipids
what does maltase break down? into what?
breaks down maltose into glucose
what is a mineral? what does it do?
inorganic, elemental molecule that carries out important roles in the body
what does a monogastric digestive system consist of?
a single-chambered stomach
what is the pancreas? what does it secrete?
a gland that secretes digestive juices
what is pepsin? where is it found?
an enzyme found in the stomach
what is the main role of pepsin?
protein digestion
what is the inactive form of pepsin called?
pepsinogen
what is peristalsis?
wave-like movements of muscle tissue
what is the proventriculus?
glandular part of a bird’s stomach
what is the purpose of the rectum?
where feces is stored until elimination
what is roughage low in? what is it high in?
low in energy and high in fiber
what is a ruminant?
animal with a stomach divided into four compartments
what is salivary amylase?
an enzyme found in saliva
what does salivary amylase convert? to what?
converts carbohydrates to maltose
what does secretin stimulate? where?
stimulates sodium bicarbonate secretion in the small intestine
what is digested in the small intestine?
protein, fats, and carbohydrates
why is somatostatin released?
to stop acid secretion when the stomach is empty
what is the sphincter? what does it control?
band of muscle that controls movement of materials throughout the digestive tract
what does the stomach contain?
acidic digestive juices
what does sucrose break down? into what?
sucrose into fructose and glucose
what is trypsin? what does it break down?
pancreatic protease that breaks down protein
what are villi? what is their role?
folds on the inner surface of the small intestine whose role is to increase absorption area
what is a vitamin? why is it necessary?
organic substance necessary in small amounts to sustain life
why is an incomplete digestive system inefficient?
- because there is no way to distribute broken down nutrients to all the cells they need to reach; this means that all calls have to be in contact with where food is located
- can’t departmentalize anything
what does extracellular digestion mean?
absorbing things from outside the cell
what are two examples of phylum’s that have incomplete digestive systems/a gastrovascular cavity?
- cniderians
- playthelminthes
what type of digestive system is a gastrovascular cavity?
incomplete
what type of digestive system is an alimentary canal?
complete
how does the circulatory system work with the digestive system?
the DS breaks down foods so that the CS can absorb and transport them across the body
where does most absorption happen during digestion?
the small intestine
the small intestine absorbs nutrients directly into the blood to be transported. What is the exception to this? what system does this nutrient have to go through before being distributed?
fats because they have to go through the lymphatic system first; they are transported to the neck and then distributed across the body
how many chambers does a bird stomach have?
two
what does digestion break down? into what?
polymers into monomers
what organ’s function is storage in birds?
the crop
what do ruminants need for digestion?
bacterial symbioses
what does the small intestine absorb? into where?
monomers into the blood stream
what does the large intestine absorb?
water and minerals
what is always involved in chemical digestion?
enzymes
why are we supposed to have fiber in our diets?
even though we can’t digest it, it helps remove things we don’t want in our digestive system
what is eliminated in feces/stool?
- undigested food (most)
- bacteria
- dead cells
- mucus
what body parts does fragmentation consist of?
tongue, teeth, and mouth
what does sublingual mean?
under tongue
what organ is responsible for bile production?
the liver
what is the largest internal organ?
the liver
what organ is responsible for bile storage/concentration?
the gallbladder
what organ is responsible for nutrient absorption?
the small intestine
what are the three parts of the small intestine?
duodenum, jejunum, and ileum
what part of the small intestine does the most nutrient absorption?
the ileum
what organ is responsible for holding beneficial bacteria?
the appendix
what is the main site of chemical digestion?
the stomach
what are the two purposes of pancreatic juice?
enzyme and being a buffer to bring down pH from stomach (acidic to basic)
what organ is responsible for water and mineral absorption?
the large intestine
what are the three parts of the large intestine?
the transverse colon, descending colon, and ascending colon
what organ is responsible for holding waste?
the rectum
what organ is responsible for expelling waste?
the anus
what enzyme does saliva contain?
amylase
what does amylase break down? into what?
polysaccharides into maltose
