tissue:: a collection of cells, usually held together by cell junctions, that work together to perform a specific function

organ:: two or more tissues that function together

organ system:: a group of functionally integrated organs

evolution is:: an undercurrent of all biological concepts

diffusion versus bulk transport is a:: scaling issue

bulk transport example:: breathing air using a pump system, moving nutrients using the cardiovascular system

Ohm’s law:: the relationship between voltage, current, and resistance wrt membrane potential

homeostasis:: dynamic steady state of the constituents in and properties of the internal fluid environment that surrounds and exchanges materials with cells

negative feedback:: stimulus>sensor>integrator>effector>stop stimulus

homeostasis/osmolarity values are:: always a ballpark/average value that fluctuates within and between individuals

main fluid compartments:: plasma, interstitial fluid, intracellular fluid

extracellular fluid:: plasma and interstitial fluid

regulated internal fluid properties:: pH, ion concentration, temperature, volume and pressure, water

diffusion happens between:: circulatory system and all others

nutrients/products are transferred between:: all body systems

negative feedback def:: the output of a process inhibits the process that created it

positive feedback def:: the output of a process stimulates the process that created it

feed-forward def:: a process is up or down regulated in anticipation of an event

neg feedback example:: thermostat, insulin

pos feedback example:: birth (until end with negative feedback)

feed-forward example:: smell food, stomach rumbles and prepares

reflex arc functions as:: an involuntary negative feedback control system

reflex definition:: simple, involuntary response to a stimulus

afferent pathway:: carries signal away (sensory receptor to integrating center)

efferent pathway:: carries a signal around (integrating center to effector), generates a response

chemically/ligand gated channels:: specific molecule binds to a channel to open or close it

voltage gated channels:: change in membrane potential opens and closes the channel

mechanically gated channel:: deformation of the membrane opens and closes the channel

leak channel:: always open

channels:: select what gets through a pore in the membrane based on size and charge

carriers:: select what gets through based on binding specificity

carrier protein:: transported substances bind to specialized sites and cause a change in conformation

pumps are:: primary active transport

primary active transport:: direct input of energy via ATP

pumps:: transport proteins use direct input energy to move substances against energetically favorable direction

secondary active transport:: harnesses potential energy of an ion gradient to drive another substance in energetically unfavorable direction

secondary active transport example:: electron transport chain

pump example:: sodium-potassium pump

opening and closing channels changes:: membrane permeability of the membrane to specific ions

cells expend energy on ion gradients because:: they use the stored potential energy to do work

ICF and ECF generally:: osmotic equilibrium/total amount of solute or volume of fluid is the same

extra negative ions in ICF and positive ions in ECF creates:: membrane potential

Day 2

osmosis:: the diffusion of water across a semipermeable membrane up a solute concentration gradient

osmosis depends on:: the number of particles in a given volume of solution

osmolarity:: = molarity * particles/molecule

hyperosmotic:: higher osmolarity in relation to another solution

hypoosmotic:: lower osmolarity in relation to another solution

isosmotic:: the same osmolarity in relation to another solution

tonicity:: describes a solution based on its effects on the volume of a cell placed in the solution

hypertonic:: water diffuses out, shrinking

hypotonic:: water diffuses in, swelling

lysis:: a very hypotonic solution causes _____

isotonic:: water diffuses normally, no effect to the cell

nonpenetrating solutes:: only solutes that effect osmolarity and tonicity

body fluid osmolarity:: 300 mOsm

nonpenetrating:: assume that all intracellular solutes are _____