Exam I Flashcards
List basic differences between intracellular and extracellular fluid compartments.
Intracellular (in the cell): more K+, Mg+2, protein, and PO4- and other organic anions.
Extracellular (outside of the cell): more Cl-, Na+, Ca+2 (not too much), and HCO3-
Compare negative vs positive feedback loops.
Negative feedback loop senses a change in a parameter and and responds in order to get back within the optimum parameters. It is stabilizing and diminishes the change.
Positive feedback is a change in a parameter that causes a response that continues to change in the same direction as before. Can be dangerous and can lead to runaway effects.
Give an example of a negative feedback loop.
Regulation of arteriole blood pressure: baroreceptors sense increase in blood pressure -> send inhibitory signals to vasomotor in medulla -> heart pumping decreases and blood vessels dilate -> bp decreases
Give an example of a positive feedback loop.
Stretch of the cervix sends signals that increase the force of uterine contractions that increases stretch on the cervix -> natural end to process, so not dangerous
Explain gain and know how to calculate.
Gain is the degree of effectiveness with which a control system maintains constant conditions.
Calculate difference of uncontrolled and controlled system.
Correction(Uncon-con diff.)/error(difference of controlled from initial amount)
List and describe the major organelles of a eukaryotic cell.
nucleus- protects DNA, replication, transcription
endoplasmic reticulum- produces proteins, lipids, carbs, etc for transport within and out of the cell.
Golgi apparatus- receives, packages, and sends cellular products to correct area within cell
mitochondria- provides a majority of the ATP within the cell
lysosome- breaks down unwanted materials within the cell
peroxisomes- involved in metabolism
endosome- involved in sorting and transport of substances
Describe the universal structure of the cell membrane and explain how structure allows for passage of materials through the membrane.
The membrane is composed of a phospholipid bilayer, cholesterol (rigidity and fluidity in different conditions), proteins (integral and peripheral). Passive vs active transport
Define homeostasis and explain it’s significance in understanding physiological processes.
Homeostasis- the maintenance of nearly constant conditions in the internal environment.
These mechanisms allow the internal environment of the body to remain within liveable limits through adaptive responses. Maintains optimum conc. of ions, water, gases, and nutrients. optimum temp and pressure for healthy cells to live
The sodium-potassium pump is an example of which of the following kinds of transport?
primary active transport -> ATP is directly involved in the process
Glucose transporters (GLUT) involve what type of transport system?
facilitated diffusion
Sodium-calcium pump os an example of what type of transport?
secondary active transport
The sodium-glucose pump is an example of which kind of transport?
secondary active transport
Define kinetic and thermal energy and relate it to molecular movement.
Kinetic energy is the energy an object possesses due to motion.
Thermal energy is the energy that comes from heat and determines how fast the molecule is moving.
Define diffusion and osmosis. How do these relate to semipermeable membranes?
Diffusion is the random movement through spaces. This can be through a semipermeable membrane from high to low levels.
Osmosis is the diffusion of solution (water in the human body) through a membrane from high conc to low conc.
Explain how osmotic pressure is generated.
Osmotic pressure is generated rushes to one side of the membrane. Water will eventually create a pressure on one side of the membrane, usually the one with more ions.
What is the equation for osmotic pressure?
pi = gCRT
pi= osmotic pressure g= # of particles in solution C= conc (mol/L) R= gas constant T= temp
What equation refers to the ease in which a solute permeates a membrane?
effective osmotic pressure (multiplied) reflection coefficient
1= impermeable 0= permeable
What are the energy independent mechanisms of transport?
Diffusion, osmosis, and facilitated diffusion
What requires channels (gated vs non gated)?
Gated: ligand and voltage gated
Non-gated: aquaporins and ion channels
What are the differences in mechanisms between the active transport processes?
Primary- ATPase is utilized directly with the channel.
Secondary- requires multiporters (complexes that transport multiple substances across) and don’t use ATP directly
symporter
2+ molecules are transported into the same direction
antiporter
2+ molecules are transported to opposite side of the pump
Factors that affect the rate of diffusion
- pressure difference
- membrane electric potential
- proportional to conc difference across membrane
What is the diffusion equation?
J=-PA(C1-C2)
J= flow/flux
P=permeability
A= area
C1 and C2= concentration