Intro/Quiz 1 Flashcards
Physiology
Concerns the function of the body’s structural machinery; how all the body parts work and carry out their life-sustaining activities
3 critical ideas
1) Hierarchy of structural
2) Complementarity of function
3) Homeostasis
Positive feedback
Causes change in state from increase of positive stimulus, output of system is further accelerated
Negative feedback
Action of effector returns the variable to a more normal value, therefore reducing the intensity of the original stimulus
Intrinsic controls
When the function of an organ or tissue is regulated by factors originating from within the organ or tissue itself
Extrinsic controls
Regulatory mechanisms initiated outside of organ, involves nervous and/or endocrine system
Effector
Enabling the control center response or output to stimulus; allows change on variable to take effect
Variable
Factor or event being regulated
Receptor
Some type of sensor that monitors the environment and responds to changes in stimuli by sending info (input) to the CONTROL CENTER
Control center
Determines the set point (level or range) at which a variable is to be maintained
AND
Analyzes input it receives and determines the appropriated response course of action
Control system
A group of components that maintains a desired result by manipulating the value of another variable in the system
Anatomy
Studies the structure of body parts and their interrelationship
What are forms of carrier mediated transport?
1) facilitated diffusion
2) active transport
3) secondary active transport
Tonicity
Ability of a solution to affect fluid volume and pressure within a cell
– Depends on concentration and permeability of solute
Hypotonic solution
- Has low concentration of nonpermeating solutes (high water concentrations)
- Cells in this solution would absorb water, swell and may burst (lyse)
Hypertonic solution
- has high concentration of nonpermeating solutes (low water concentration)
- cells in this solution would lose water + shrivel (crenate)
Isotonic solution
Solution that doesn’t alter cell volume; normal saline
What are the types of intercellular communication?
1) gap junctions
2) paracrine secretion
3) hemocrine secretion
4) transient direct linkup of cells
5) neurotransmitter secretion
6) neurohormone secretion
What is the hierarchy of structural organization?
Atom, molecule, macromolecule, organelle, cell, tissue, organ, system, organism
What are necessary life functions?
MaMoRD MERG
1) Maintaining boundaries, 2) movement, 3) responsiveness (irritability), 4) digestion, 5) metabolism, 6) excretion, 7) reproduction and 8) growth
Survival needs of the body
NOW NAed
1) Nutrients, 2) oxygen, 3) water, 4) normal body temperature, 5) atmospheric pressure
Homeostasis
A dynamic state of equilibrium, balance pr status quo which internal conditions vary, but always within relatively narrow limits
Factors of the internal environment that must be homeostatically maintained
concentration of nutrient molecules concentration of O2 and CO2
concentration of water products
pH
concentration of water salt and other electrolytes
temperature
volume and pressure
What are the divisions of body water?
- total body water
- intracellular
- extracellular
a. plasma
b. interstitial fluid
What are the 3 functions of the plasma membrane?
- Defines cell BOUNDARIES
- It controls INTERACTIONS with other cells
- It controls PASSAGE of material in and out of the cell
Factors of the internal environment that must be homeostatically maintained
Concentration of nutrient molecules
Concentration of O2 and CO2 Concentration of waste products
pH
Concentration of water, salt and other electrolytes
temperature and pressure
Two properties that determine plasma membrane permeability
- Relative solubility of the particle in lipid
- The size of particle
Tight junctions
Integral membrane proteins called occludins FUSE adjacent cells together to form a nearly IMPERMEABLE barrier to the movement of substances between cells
I.e. Epithelial tissue
Desosome
A FILAMENTOUS junction between two adjacent cells that provide STRENGTH so that the cells do not tear apart when the tissue is subject to stress
I.e. Muscles in heart, uterus and skin
“Deal with it! Desosome with it!”
Gap junctions
Areas where two adjacent cells are connected by membrane proteins called connexons
Provide DIRECT electrical and metabolic coupling of adjacent cells
I.e. Smooth muscle
Phagocytosis
Engulfing large particles by pseudopods
Pinocytosis
Taking in fluid droplets
Receptor-mediated endocytosis
Taking in specific molecules
Carrier mediated transport
For transfer of small water-soluble substances across the membrane
Vesicular transport
For movement of large molecules and even multimolecular particles b/n the ECF and ICF
3 characteristics for carrier mediated transport
1) specificity
2) saturation
3) competition
Factors that influence rate of net diffusion across membrane - FICK’S LAW OF DIFFUSION
1) magnitude or STEEPNESS of conc. gradient
2) PERMEABILITY of membrane to substance
3) SURFACE AREA of membrane which diffusion is taking place
4) MOLECULAR WEIGHT of substance
5) DISTANCE thru which diffusion must take place
What is secondary active transport?
It couples the transport of 2 solutes, one moving down its concentration gradient (favorable) and the other is moving up its concentration (unfavorable).
Involves indirect usage of ATP.
Describe the principle of saturation in relation to carrier mediated transport.
- As [solute] ^ on 1 side of membrane, transport rate will ^ until all transporters are saturated.
- Afterwards, further ^ in [solute] won’t change transport rate. Rate hits max, all transporters are full.
What is membrane potential (how to establish and maintain it)?
- Separation of charges across membrane
- relative permeability of Na and K across membrane & is counterbalance of their competing equilibrium potentials
- maintained by Na and K pump
Why do cells use signaling cascades?
Signaling cascades allow for amplification of a signal from one initial binding event to a large response.
What is equilibrium potential for an ion?
It’s when electrical and chemical gradients are balanced in magnitude and there is no net movement of ions across the membrane.
Plasma membrane
Phospholipid bilayers with proteins dispersed throughout
Facilitated diffusion
- carrier mediated transport
- does not require energy
- passive, works only if there’s a concentration gradient
