The digestive system 1 Flashcards
Heterotrophs and 3 groups
feed from other organsims
1-herbivores: plant ie cattle
2-carnivores: other animals ie shark
3-Omnivores: plant and animals ie humans
Constitution adéquaté diet
1-chemical energy
2-building blocks (for macromolecules)
3-essential nutrients (to synthesize)
Essential nutrients
aa
fa
vitamins
minerals
What are essential amino acids
aa that come from food, other half is synthesized by body
what are essential fatty acids and where do they come from
fatty acids that cant be synthesized by animals like unsaturated fatty acids that have double bonds
come from grains, seeds, vegetables
What are vitamins and major required by humans
organic molecules required in small amounts like B2, B12, C, D
What are minerals
inorganic molecules required in small amounts like sodium, potassium, chloride
Vitamin D difficiency
crooked leggs
Vitamin B2 dificiency
red eyes
Vitamin c difficiency
scurvy (recall teeth, bruising picture…)
Vitamin B12 difficiency
Anemia (fainting, chest pains, heart attack)
4 main stages of food processing
1- mechnaical digestion (break food down into small molecules for absorbtion)
2- chemical digestion (enzymatic hydrolysis)
3-absorbtion (uptake nutrients)
4- elimination (undigested material out of digestive)
How does primitive animals digest their food
intrecaellularly
Cnidarian digestion and example
Extracellularly: gastrovascular cavity that has one opening for mouth and anus and no specialization
ie hydra
Platyhelminthes digestion
extracellularly: gastrovascular cavity that has one opening for mouth and anus
ie planarian
digestive tube of more complex organisms
complete digestive tract or alimentary canal that has 2 openings for anus and mouth
specialization: different parts for digestion and absorbtion
what phylum has a complete digestive tract (one way transport of food)
phylum Arthropoda
complete digestive tract or alimentary canal divided into
foregut
midgut
hindgut
Digestive tract of Annelida
Tract specialized for: ingestion, digestion, absorbtion, storage, fragmentation
digestive tract of chordata (birds) and whats special about it
complete alimentary canal
some gizzard for fragmentationa nd others specialized regions
what do birds lack in digestive tract
teeth: so mouth, oesophagus, cropm stomac, gizzard, intestine, anus
vertebrates digetsive tract (anatomy) and what does digetsion involve
tract specialized: mouth/pharynx, esophagus, stomach, small intetsine (villi and microvilli cover wall (brush border)), large intetsine, rectum
digetsion involves physical fragmentation and chemical fragmentation
accessory gland secreting digestive juice
salivary glands, pancreas, liver, gallbladder
chemical and mechanical digetsion in oral cavity
chewing and salivary amylase (glucose breakdown)
types of teeth
incisors, premolars, canines, molars
how many pairs of salivary glnd
3
role of saliva
lubricate food
tongue does what
mixes saliva with food
mechanical digestion in esophagus
peristalsis (food from pharynx to stomach)
swallowing process
food pushed back mouth, larynx rise, epiglottis seals larynx, bolus forced down esophagus instead trachea and evetually larynx relaxes
what prevents food from going back in esophagus after entering stomach
sphincter
role of stomach
stores food and secrets gastric juice that will convert meal to acid chyme
mechanical and chemical digestion in stomach
mechanical: churning
chemical: chief cells secrete HCl and Pepsinogen=pepsin enzyme in stomach (constitutes gastric juice) and parietal cells secrete H and CL ions
