Cell Physiology Flashcards
Autoregulation
Myogenic - local baroreceptors react to vascular stretching/relaxing by constricting/dilating vessel
Metabolic - local chemoreceptors constrict/dilate in response to high metabolic waste/low O2
Cellular components
Nucleus Ribosome - translation Golgi apparatus - modifies and packages proteins Rough ER - makes proteins, attached to ribsome Smooth ER - makes lipids Mitochondira - ATP production Lysosome - cell digestion Cytoskeleton Membrane
Eukaryotic vs Prokaryotic
Pro - no nucleus, slime capsule, complex cell wall, no carbs/sterols in membrane, small ribosome
Euk - nucleus, complex glycocalyx, simple cell wall, carbs/sterols in membrane, large ribosome
Cellular composition
H20 - 80%
Protein - 10-20%
Carbs - 1-5%
ICF electrolyte levels Na+ K+ Ca+2 Cl- HCO3- pH
Na+ - 14 K+ - 120 Ca2+ - 1*10-4 HCO3- - 10 pH - 7.1 Protein - 16
Osmotic pressure
Pressure required to stop the flow of H20 across a membrane
Oncotic pressure/colloid osmotic pressure
Osmotic pressure across a blood vessel
Resting membrane potential
~-70mv
Diffusion potential
Potential created when an ion crosses a membrane while diffusing down its concentration gradient
Equilibrium potential
Charge at which an ion stops diffusing
Threshold
~-60 mv
Types of cell transport
Simple - diffusion across membrane
Facilitated (passive) - diffusion through channels
Primary active - pumped up gradient, ATP used at pump
Secondary active - pumped up gradient, ATP used elsewhere
Cotransport/symport vs Countertransport/antiport
Sym - moving in same direction
Anti - moving in opposite directions
Saturation kinetics
Can’t increase transport rate when all transporters are in use
Partition coefficient
Oil vs H2O solubility - higher equals more lipid soluble
What determines diffusion?
Concentration gradient
Surface area
Diffusion coefficient (solute shape/size)
Partition coefficient (lipid/H20 solubility)
Membrane thickness
Hyperpolarization
K+ lowers membrane potential below resting potential (~-85) before K+ gates close
Absolute refractory period
Na+ gates are open but inactivated, occurs during repolarization, no additional AP possible
Atrophy
Loss of cell mass
Hypertrophy
Increase in cell mass
Hyperplasia
Increase in cell number
Dysplasia
Abnormal change in size, shape or arrangement of cells; often associated w/ cancer
Metaplasia
Replacement of one cell type by another
Ways to influence synaptic transmission
Block neurotransmitter release Block receptor Prevent neurotransmitter production Use up transmitter Increase transmitter esterase Bind and change transmitter Prevent reuptake of transmitter