Chapters 29, 37 Flashcards
incomplete digestive system
food enters and leaves through the same hole (e.g. flatworms)
ruminants
several stomach chambers where cellulose is digested
digestion: accessory organs
salivary glands liver gallbladder pancreas
digestion: major components
mouth pharynx esophagus stomach small intestine colon rectum anus
saliva
contains an enzyme (salivary amylase), a buffer (bicarbonate), mucins, and water
sphincter
ring of smooth muscles whose contractions close off a passageway
start digestion of polysaccharides
saliva
carbohydrate digestion
- salivary amylase- in mouth,stomach
- pancreatic amylase- in small intestine
- disaccharidases- in small intestine
to monosaccharides (e.g. glucose)
protein digestion
- pepsin-stomach
- trypsin-intestine
- aminopeptidase-intestine
to amino acids
fat digestion
- lipase-pancreas-smallintestine
- free fatty acids, monoglycerides
- also bile
- emulsification-> bile salts accelerate fat digestion
nucleic acid digestion
pancreatic/intestinal nucleases in small intestine
to nucleotides, monosacch.
open circulatory system
blood moves via hearts and large vessels but also mixes with interstitial fluid
homeostasis
- detect change and direct responses
- most control based on negative feedback
effectors
carry out the response (muscles, glands)
tissue
integrated group of similar cells performing a common function
interstitial fluid
fluid that bathes all cells (where solute exchange occurs)
epithelial tissue
- sheets of tightly-packed cells that cover body surfaces
- cell-to-cell contacts: tight, adhering, gap junctions
- glandular: exocrine, endocrine
connective
- scattered via extracellular matrix
- soft- loose, dense (regular, irregular)
- specialized: adipose, bone, cartilage, blood
muscle tissue
- bundles of long cells; most abundant kind in animals
- skeletal, cardiac, smooth
nervous
- senses stimuli and transmits info
- greatest control over responses
- neuron: excitable cell; communication
digestive tasks
- mech processing/motility
- secretion
- digestion
- absorption
- elimination
intestinal absorption
- folded lining
- villi
- brush border cells (absorb monomers of eaten food)
leptin
hormone: controls glands which control hunger in animals
PYY
hormone: acts in brain to suppress appetite