Prelim 3 Flashcards
Leave absorb…
CO2 (from air)
Roots absorb…
H2O and some minerals (from soil)
Cation exchange
+ cation bonded to - soil particle
+ ion (H+) exchanged for cation
4 stages of food processing
- Ingestion
- Digestion
- Absorption
- Elimination
Alimentary canal
Main organs responsible for digestion (mouth, esophagus, stomach, small and large intestine, rectum)
Accessory glands
Salivary, pancreas, liver, gallbladder
Adaptation of an herbivore
Longer posterior digestive tract (cecum, colon)
*not ruminant
Adaptation of a carnivore
Longer small intestine
Mono gastric
Simple chambered (ex. Human, dog, cat, pig)
Ruminant
Multi chambered stomach (goat, cow, deer)
Hindgut fermentor
Simple stomach, complex intestine (horse, ostrich)
What do the salivary glands secrete?
Amylase to breakdown carbohydrates
Pepsin
Enzyme to digest protein
How is the stomach layer protected
Mucus layer (physical) and bicarbonate secretion (chemical)
Gastric phase
1) Pepsinogen and HCl - secreted into lumen
2) HCl - converts pepsinogen into pepsin
3) pepsin activates more pepsinogen (pos. feedback loop)
Where does most digestion occur
Phase 3: small intestine
Adaptation to increase absorption
Microvillar surface (inc. surface area)
Is transport across the epithelium active or passive
Both
Endosymbiots
Reside within the body or cells of an organism
Relationship between plants and rhyzobacteria
Symbiotic
Plants provide nutrients
Rhyzobacteria provide chemicals to promote growth, produce antibiotics, absorb toxic metals, inc. nutrient availability
Nitrogen cycle
Converts nitrogen/compounds into NO3- or NH4+
Nitrogen fixing bacteria
Generate NH4+ from N2
Nitrifying bacteria
Generate NO3- from NH4+
Ammonifying bacteria
Generate NH4+
Where are most microbes
Large intestine preferred site, >70% in colon
Microbes ____ in number from proximal to distal
Increase
Microbia main functions
Maintain intestinal homeostasis by
1) immunity
2) metabolic role
3) chemical modulator
How to microbes impact behavior?
Microbia are affected by the body’s experiences -> send chemical signals that affect memory, emotions, behavior
Initial exposure to Microbia occurs…
In the birth canal
What happens to Microbia abundance and diversity as you age?
Age 0-1 increase in abundance
Age 0-3 increase in diversity/development of composition
Dysbiosis
Microbial imbalance
What do Microbia do for the human body?
1) synthesize neurotransmitters
2) metabolize undigested food
3) inhibit pathogens from colonizing (disease prevention)
4) synthesize vitamins and amino acids
FAST cell communication by…
Neurotransmitters
FAST cell communication range
Short range, by axons
SLOW cell communication by…
Hormones
SLOW cell communication range
Long range, by diffusion through circulatory system
Ranges of hormone diffusion…
1) short : autocrine
2) medium : paracrine
3) long : endocrine
Autocrine diffusion
Acts on the same cell
Paracrine diffusion
Acts on neighbors
Endocrine diffusion
Requires circulation
Negative feedback loop
Regulates homeostasis. Acts on stimulus and brings it back to normal. RESPONSE COUNTERACTS CHANGE.
Positive feedback loop
Enhances the affect of stimulus. RESPONSE AMPLIFIES CHANGE.
Ex. Childbirth (explain)
