Test #1 Flashcards
Define physiology.
The study of function in living organisms.
Define homeostasis.
The internal environment maintains a relatively stable condition, even if the external environment changes.
Define negative feedback control system.
Tries to reverse an initial change to keep a variable at homeostasis. The controlled variable shuts off its own production by shutting off the effector.
Define positive feedback control system.
Amplifies the initial change by stimulating its own production “self-amplifying system”.
Define the different components of the feedback systems (set point, controlled variable, sensor/or receptor, control center, effector).
The set point is the value that your body wants to maintain with the controlled variable being the variable that your body is trying to maintain.
The sensor (or receptor) monitors the controlled variable and signals the control center to communicate about the actual environment.
The control center compares the value that the sensor sent out to the set point. If there’s a difference, the control center activates the effector.
The effector are organs and systems that change the controlled variable.
What are the levels of organization of the body?
Atoms
Molecules
Macromolecules
Cellular Organelles
Cells
Tissues
Organs
Organ Systems
Organism
Define the intracellular (ICF) and extracellular (ECF) fluids.
Intracellular Fluid (ICF): Inside all the cells.
Extracellular Fluid (ECF): Everything outside the cells.
The extracellular fluid (makes up the internal environment of the body) can be divided into the interstitial fluid—the fluid directly outside, bathing the cells— and the plasma—watery portion of the blood.
What makes up the most body water and the least body water out of the intracellular fluid, interstitial fluid, and the plasma? The least?
Intracellular fluid makes up the most body water, then the interstitial (extracellular), then the plasma (extracellular) makes up the least body water.
Define plasma and what its components.
Plasma is apart of the blood and made up of mostly water and a small amount of other substances (proteins, ions, nutrients, gases, waste) like proteins albumins, globulins, and fibrinogen.
What are the ratio of concentrations for Na+, Cl-, Ca++ and K+ in and out of the cell?
Na+: High (extracellular) & low (intracellular).
Cl-: High (extracellular) & low (intracellular).
Ca++: High (extracellular) & low (intracellular).
K+: High (extracellular) & low (intracellular).
Why are there differences in the ionic concentration of the ICF and ECF?
Due to the selective permeability of the plasma membrane. These differences set up a net negative membrane charge (-70 mV) for action potential.
Define the Golgi apparatus.
Responsible for packaging proteins from the rough ER into membrane-bound vesicles.
Two Types: secretory vesicles to transport proteins to the cell membrane for release into the extracellular environment through secretion and storage vesicles (e.g., lysosome) whose contents are stored within the cell.
Define secretory vesicle.
Produced by the Golgi apparatus and are used to transport various types of proteins out of the cell to use in other parts of the body.
Define ribosomes.
Dense granules of RNA and protein that are responsible for manufacturing proteins from amino acids under the control of the cell’s DNA.
Two Types: fixed ribosomes that are attached to the ER and free ribosomes that float in the cytoplasm (can form in groups of 10-20, called polyribosomes).
Define lyosome.
A type of storage vesicle produced by the Golgi apparatus that act as a digestive system of the cell. They contain several kinds of enzymes that the cell uses to destroy damaged organelles, kill bacteria, and break down other kinds of biomolecules.
Define the mitochondrian.
The “powerhouse” of the cell. Where most of the body’s adenosine triphosphate (ATP) is generated, which is used for energy storage and transfer. Note: The mitochondrian can replicate themselves even if the cell is not undergoing division based on the cell’s energy needs.
Define the endoplasmic reticulum (ER).
A continuation of the cell’s nuclear membrane and the site for synthesis, storage, and transport of proteins and lipid molecules.
Two Types: the rough or granular ER is covered with rows of ribosomes and is the site for protein synthesis, while the smooth or agranular ER lacks ribosomes and is the site for lipid and fatty acid synthesis.
Proteins manufactured in the rough ER are packaged into vesicles that transport them to the Golgi apparatus.
Define the cell membrane.
The plasma membrane regulates the passage of substances in and out of the cell (allows certain molecules, excludes others). It regulates transport, detects chemical signals from other cells and forms physical links with adjacent cells.
Define the centriole.
Cylindrical bundles of microtubules that direct the movement of DNA strands during cell division.
Define the nucleolus.
A dense body in the nucleus that contains the specific DNA to produce the RNA in ribosomes.
Further explain the cell membrane.
Separates the intracellular and extracellular environments. It is selectively permeable, giving two-way traffic for nutrients and waste needed for metabolism, while preventing passage of other substances between the intracellular and extracellular compartments.
Explain hydrophilic phosphate “head” and hydrophobic fatty acid (or lipid) “tails”.
When phospholipids are thrown into water, they align themselves into a lipid bilayer where the heads are facing out towards the water and the tails are facing in and away from the water.
Because the fatty acid tails are hydrophobic, they can be a major barrier to water and water-soluble substances like ions, glucose, urea and most other molecules.
Fat-soluble substances like oxygen, carbon dioxide, and steroid hormones can penetrate easily because they dissolve through the lipid region of the membrane.
Define each type of membrane protein and what each does.
Receptors help with the attachment of chemical hormones and neurotransmitters.
Enzymes help with chemical reactions or the breakdown of molecules.
Pores allow water soluble substances into the cell.
Carriers transport molecules across the cell membrane.
Identity markers help the body distinguish between normal cells and foreign particles.
Define diffusion.
The movement of molecules from an area of high concentration to low concentration down its concentration gradient.
Define facilitated diffusion.
Similar to diffusion in the way that it does not require energy and is powered by the concentration gradient of the molecule, however, it is limited by the number of available proteins. Once all carriers are occupied, the system becomes saturated and cannot operate any faster.
Define active transport.
Requires energy and moves molecules up their concetration gradients from low concentration to high concentration.
Define a solute, a solvent, and a solution.
Solute: what’s being dissolved
Solvent: what’s doing the dissolving (water)
Solute + Solvent = Solution
Define osmosis.
The net movement of water down its concentration gradient (from high concentration to low concentration).
Water will always move into the area with a higher solute concentration (it will always try to dilute it)!
Define an osmole and give example(s).
The unit used to describe the number of particles in a solution that causes osmosis or “osmotically active particle.”
E.g., Na+, Cl-, K+, and glucose.
Explain how to calculate the concentration of osmoles.
Concentration = number of osmotic particles (osmol)/volume of solution
Define osmolality.
Osmolality = number of osmoles per kilogram (kg) of water
Define osmolarity.
Osmolarity = number of osmoles per liter of solution
