Exam 3 lecture 17 and 18 Flashcards
(12 cards)
Gradient
-Changes in distribution over time or space
-Create different regions
-Provide a driving force for diffusion
-Movement always towards equillibrium
Types of gradients
-Chemical/Concentration (1 type of particle)
-Charge (ions)
-Pressure (fluids and particles)
Concentration (chemical) gradients
-How many particles of a certain type
-Cell pumps particles across the membrane
-Slow takes time
-Needs pathway to move in/out of cell (channel/carrier proteins)
-High to low concentration
Charge gradients
-If charges out vs in cell are not the same, its a gradient
-Opposites attract
Osmotic pressure gradients
-Depends on total # of particles / vol of fluid
-Influences water movement
-Only water moves
-Moves from low to high Osmotic pressure
-mOsm/L
-To make equal remove water
Hydrostatic pressure
-Pressure of fluid inside container
-More fluid = more pressure
-Moves from high pressure to low pressure
Partial pressure gradients
-CO2 waste product, uses O2
-PO2 means partial pressure of O2
-High to low pressure
Daltons law
-Used to find total partial pressure from a mixture of gases
-Equals sum of pressures exerted by each gas
-mmHg
gas 1 / total = partial pressure gas 1
gas 1 + gas 2… = total partial pressure
Form follows function
-Things are designed a certain way because the function works
-Different cells are designed for different things
Laws of physics limit function
-Blood flow through vasculature
-Lever action of skeletal muscle
-Movement of substances across membranes
-Body size
Material exchange and enviroment
Substances exchanged: Must be dissolved, must come into contact with cell
Amount exchanged: amount needed is proportional to volume, amount that can be exchanged is proportional to surface area
Increasing surface area without changing volume
-Villus: Folding, big fold
Microvilli: Flods on top of cell. Absorption
