EXAM 1 Flashcards
To prove I'm not stupid
Greek: Physis
Nature
Greek Logia
“study of”
Physiology Definition:
The study of how animals work
What does it do?
Function
How does it do it?
Mechanism
Physiology is based on_____
physics & chemistry
Phenotypes are influenced by______
genetics & the environment
Physiological processes are usually _______
regulated
Hierarchy of Integration
atoms>molecules>cells>tissues>organs>organ systems> organisms > populations
3 characteristics of Phenotypes
- morphology (structure/anatomy)
- physiology (function)
- behavior
what is phenotypic plasticity?
ability of a phenotype to change in response to environmental conditions
- same genotype may result in multiple phenotypes
- can be reversible or irreversible
- NOT adaptation (no genomic changes)
epigenetics
non DNA changes
homeostasis
you know what homeostasis is you dumb lunk
2 strategies for physiological regulation (facing external conditions) [graph!!]
- Conformer
- allow internal environment to match external environment
- Regulator
- changes to to a set point, maintain zone of stability
- particular to a specific environmental factor
4 types of Regulatory Mechanisms
- Negative feedback
- Positive feedback
- Feed-Forward Action
- Acclimatization
Negative Feedback
Response opposes stimulus
e. g.:
- Increase in body temp: blood vessels dilate, sweat
- Decrease in body temp: blood vessels constrict, no sweating
Antagonistic control
two functions that work in the opposite directions to maintain set point (homeostasis)
e.g.: Blood glucose
Positive Feedback
response amplifies stimulus (until an END POINT)
e.g. childbirth: as muscles in uterine wall contract, contraction leads to further distortion of uterus which is detected by stretch receptors, affects brain, releases oxytocin to cause further contractions.
Feed-Forward (anticipatory) mechanism
anticipation of stimulus
e.g.: stomach growling at lunch time (a.k.a. Pizza Time)
Acclimatization
adjusting physiological function in response to changes in the environment
Typically reversible
e.g.: jet lag, elevation change
Acclimation
laboratory phenomenon - response to change in only one factor
Emergent Properties
a property that complex systems have that the individual members do not
Basic Cell structure
- Nucleus: DNA > gene expression
- Cytoplasm (cytosol)
- Plasma membrane
- mitochondria: makes majority of ATP
Membrane proteins
On the plasma membrane
- Polar heads (hydrophilic)
- Non-polar lipid tails (hydrophobic)
- Small, non-polar molecules can pass through PM
- Large and/or polar/charged molecules can not cross bilayer
Plasma Membrane
- maintain composition of intra and extracellular fluids
- forms framework for protein components
- desmosomes - no transfer of molecules
- tight junctions - some molecular transfer
Types of membrane transport
- simple diffusion
- Facilitated Diffusion
- Active Transport
- Bulk Transport
Characteristics of Simple diffusion
- Movement from a region of high to low concentration
- Powered by random thermal motion
- no ATP required
- FLUX: measure of diffusion rate
Direction and magnitude of net flux depends on_______
- Permeability
- Concentration gradient
- Temperature
- Surface Area
- Size of molecule
- Distance
Facilitated diffusion
Transmembrane proteins facilitate diffusion of some polar or charged molecules
With Facilitated diffusion, molecules move _______ their concentration/electrochemical gradient
Down
ATP is _____ required for facilitated diffusion
NOT
Channel proteins
- Provide corridor for polar or charged molecules to pass through membrane
Channel protein specificity depends on______ and _____
charge & size
Two types of ion channels
Selective (Na+, K+, Cl-)
&
Non-selective (Na+,K+,Li+)
Aquaporins
Facilitated diffusion for water
high concentration of water to low concentration of water
Osmolarity
Total concentration of solutes in a solution
Measured in OSMOLES
1 Osmole =
1 mole of solute/L
Osmolarity depends on______
Total number of molecules NOT individual type
3 ways to compare osmolarity of two solutions
Isomotic: same solute concentration
Hyperosmotic: higher solute concentration
Hyposmotic: lower solute concentration
Isomotic
same solute concentration
Hyperosmotic
higher solute concentration
Hyposmotic
Lower solute concentration
Water moves from ___tonic side to ____tonic side
Hypotonic side to hypertonic side
Osmotic Pressure
Pressure generated by movement of water by osmosis.
No net flux is reached when hydrostatic (gravity) pressure is equal to osmotic pressure
3 different classifications of channel proteins
- Constitutive channels
- Gated Channels
- Special gated channels
Constitutive channels
Always open
- e.g.: Aquaporins
Gated channels
- ligand gated channels
- Voltage-gated channels
- Mechanically gated channels
Ligand gated channels
- signal molecule binds to receptor to open/close channel
- e.g.: acetylcholine regulates entry of Na+ into muscle cells