Unit 1: Homeostasis: Foundations of Physiology Flashcards
Define the study of Physiology?
-The study of the functions of living systems
Explain the difference between a Teleological vs. Mechanistic approach to explaining physiology.
Teleological- why events happen, but not how.
ex. Why do we shiver? Ans. To generate heat.
Mechanistic approach- cause and effect.
ex. Why do we shiver? Ans. Our bodies undergo ATP synthase reactions in adipose fat tissues to regenerate heat, thus making us warmer.
Define Homeostasis
The maintenance of a steady state in the body.
How are Anatomy and Physiology complementary?
You can’t explain either one without the use of the other… in other words, we need to explain the anatomical body parts in order to describe bodily functions.
Which 4 elements make up the bulk 96% of the body’s mass?
-Carbon, nitrogen, oxygen and hydrogen.
What is an ionic bond?
- A bond held together by opposite charged ions.
- ->A cation and anion.
ex. Na + and Cl-
What is a covalent bond?
-Most prevalent chemical bonds
Formed when atoms of a molecule share one, two or three pairs of electrons.
-May be polar or non-polar.
What is hydrogen bonding?
- Occurs with the binding of a hydrogen from a polar molecule to the negative end of another polar molecule. (FON)
- Holds DNA strands together.
What is the purpose of a catalyst?
To lower the activation energy of a reaction
–>In the body, typically enzymes!
Molarity?
Describes concentration of solution in mols/ litre.
What is Osmolarity?
The total number of solute particles in a litre of solution instead of the relative weights of specific solutes.
What is a Colloid?
- Contain dispersed-phase particles no larger than 100x the particles of a solution.
- ->Particles in a colloid do not separate out.
What is a Suspension?
-Mixtures of large, dispersed-phase particles that when left undisturbed settle out due to gravity.
Organic vs. Inorganic Molecules?
Organic molecules contain carbon, with the exception of CO and CO2. Inorganic molecules do not contain carbon.
Carbohydrates recap.
-Provide energy for vital processes
Monosaccharides: glucose, fructose, galactose, ribose, ect.
Dissacharides: lactose and sucrose.
Polysaccharides: glycogen, starch, cellulose
Lipids recap
-non polar molecules which are insoluble in water
-ideal of energy storage
-waxy, greasy, oily
Saturated fatty acids= no double bonds
Unsaturated fatty acids= double bonds
What constitutes a Triacylglyeride?
A glycerol backbone with 3 fatty acids
What constitutes a Phospholipid?
A glycerol backbone with 2 fatty acids & a phosphate group
Proteins Recap
- Polymers made up of nucleic acid monomers (20 different amino acids in humans)
- -> changing 3D structure effects function
- Connected through peptide bonds
What is hydrolysis?
- The means by which digestive enzymes break down ingested food into small units that can be absorbed by the digestive lumen.
- adding H20 to peptide bonds to lyse them
What is denaturation?
Adding heat or chemicals to proteins to break down the peptide bonds.
Nucleic Acid recap.
–>Nucleotides are composed of a phosphate group, a 5C sugar and a nitrogenous base. These nucleotides form nucleic acids responsible for storing genetic information.
What is the body’s main energy carrier?
ATP!
ATP –> Pi + ADP
How is ATP converted into cAMP?
Under the influence of an enzyme, ATP is converted into cAMP (loses a phosphate), which is one of the bodies intracellular messengers & precursors.
What is cellular differentiation?
From meiosis, cells are uniquely different after each division.
What are the three types of muscle tissue?
-Cardiac, skeletal, and smooth muscle
What constitutes Nervous Tissue?
Cells that can initiate and transmit nerve impulses
*Found in the brain, spinal cord & nerves
What constitutes Epithelial Tissue?
-Cells specialized for exchanging materials between the cell and it’s environment
What are Glands?
Glands are specialized epithelial cells used for secretory purposes.
2 types: Exocrine (secrete externally) & Endocrine (secrete hormones)
What constitutes Connective Tissue?
- Connects & supports various tissues
- ->Includes loose connective tissue, blood & bones
What is the key to homeostasis?
-The watery internal environment in which cells make their exchanges (ECF)
What is ECF?
- Extracellular fluid
- Cells reside here
- Composed of plasma, the fluid portion of the blood, and interstitial fluid which surrounds & bathes the cell
List at least 5 factors that are homeostatically regulated.
-Nutrients, CO2 and O2, waste products, pH, concentration of water & salt, volume/ pressure, temperature.
Homeostatic control systems must:
- Detect deviations from the normal internal environment that are kept within narrow limits.
- Integrate & relay information
- Make appropriate adjustments back to the restoring factor
What is negative feedback?
-A change in a homeostatic controlled factor triggers a response that seeks to reverse or restore the factor by moving in the opposite direction of it’s initial change
Feedback loops have 4 components. What are they?
- Deviation in controlled variable
- Sensor
- Integrator
- Effector which brings about a compensatory response
What is positive feedback?
A change in a homeostatic controlled factor which triggers to move the deviation of the controlled variable in the same direction as the change.
What are feed forward mechanisms?
- Response in anticipation of a change in a regulated variable
- Less common than feedback mechanisms
What is pathophysiology?
The abnormal functioning of the body associated with disease.
