Unit 1: Homeostasis: Foundations of Physiology

Question 1

Define the study of Physiology?

Answer 1

-The study of the functions of living systems

Question 2

Explain the difference between a Teleological vs. Mechanistic approach to explaining physiology.

Answer 2

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.

Question 3

Define Homeostasis

Answer 3

The maintenance of a steady state in the body.

Question 4

How are Anatomy and Physiology complementary?

Answer 4

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.

Question 5

Which 4 elements make up the bulk 96% of the body’s mass?

Answer 5

-Carbon, nitrogen, oxygen and hydrogen.

Question 6

What is an ionic bond?

Answer 6

• A bond held together by opposite charged ions.
• ->A cation and anion.
  ex. Na + and Cl-

Question 7

What is a covalent bond?

Answer 7

-Most prevalent chemical bonds
Formed when atoms of a molecule share one, two or three pairs of electrons.
-May be polar or non-polar.

Question 8

What is hydrogen bonding?

Answer 8

• Occurs with the binding of a hydrogen from a polar molecule to the negative end of another polar molecule. (FON)
• Holds DNA strands together.

Question 9

What is the purpose of a catalyst?

Answer 9

To lower the activation energy of a reaction

–>In the body, typically enzymes!

Question 10

Molarity?

Answer 10

Describes concentration of solution in mols/ litre.

Question 11

What is Osmolarity?

Answer 11

The total number of solute particles in a litre of solution instead of the relative weights of specific solutes.

Question 12

What is a Colloid?

Answer 12

• Contain dispersed-phase particles no larger than 100x the particles of a solution.
• ->Particles in a colloid do not separate out.

Question 13

What is a Suspension?

Answer 13

-Mixtures of large, dispersed-phase particles that when left undisturbed settle out due to gravity.

Question 14

Organic vs. Inorganic Molecules?

Answer 14

Organic molecules contain carbon, with the exception of CO and CO2. Inorganic molecules do not contain carbon.

Question 15

Carbohydrates recap.

Answer 15

-Provide energy for vital processes
Monosaccharides: glucose, fructose, galactose, ribose, ect.
Dissacharides: lactose and sucrose.
Polysaccharides: glycogen, starch, cellulose

Question 16

Lipids recap

Answer 16

-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

Question 17

What constitutes a Triacylglyeride?

Answer 17

A glycerol backbone with 3 fatty acids

Question 18

What constitutes a Phospholipid?

Answer 18

A glycerol backbone with 2 fatty acids & a phosphate group

Question 19

Proteins Recap

Answer 19

• Polymers made up of nucleic acid monomers (20 different amino acids in humans)
• -> changing 3D structure effects function
• Connected through peptide bonds

Question 20

What is hydrolysis?

Answer 20

• 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

Question 21

What is denaturation?

Answer 21

Adding heat or chemicals to proteins to break down the peptide bonds.

Question 22

Nucleic Acid recap.

Answer 22

–>Nucleotides are composed of a phosphate group, a 5C sugar and a nitrogenous base. These nucleotides form nucleic acids responsible for storing genetic information.

Question 23

What is the body’s main energy carrier?

Answer 23

ATP!

ATP –> Pi + ADP

Question 24

How is ATP converted into cAMP?

Answer 24

Under the influence of an enzyme, ATP is converted into cAMP (loses a phosphate), which is one of the bodies intracellular messengers & precursors.

Question 25

What is cellular differentiation?

Answer 25

From meiosis, cells are uniquely different after each division.

Question 26

What are the three types of muscle tissue?

Answer 26

-Cardiac, skeletal, and smooth muscle

Question 27

What constitutes Nervous Tissue?

Answer 27

Cells that can initiate and transmit nerve impulses

*Found in the brain, spinal cord & nerves

Question 28

What constitutes Epithelial Tissue?

Answer 28

-Cells specialized for exchanging materials between the cell and it’s environment

Question 29

What are Glands?

Answer 29

Glands are specialized epithelial cells used for secretory purposes.
2 types: Exocrine (secrete externally) & Endocrine (secrete hormones)

Question 30

What constitutes Connective Tissue?

Answer 30

• Connects & supports various tissues

- ->Includes loose connective tissue, blood & bones

Question 31

What is the key to homeostasis?

Answer 31

-The watery internal environment in which cells make their exchanges (ECF)

Question 32

What is ECF?

Answer 32

• Extracellular fluid
• Cells reside here
• Composed of plasma, the fluid portion of the blood, and interstitial fluid which surrounds & bathes the cell

Question 33

List at least 5 factors that are homeostatically regulated.

Answer 33

-Nutrients, CO2 and O2, waste products, pH, concentration of water & salt, volume/ pressure, temperature.

Question 34

Homeostatic control systems must:

Answer 34

1. Detect deviations from the normal internal environment that are kept within narrow limits.
2. Integrate & relay information
3. Make appropriate adjustments back to the restoring factor

Question 35

What is negative feedback?

Answer 35

-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

Question 36

Feedback loops have 4 components. What are they?

Answer 36

1. Deviation in controlled variable
2. Sensor
3. Integrator
4. Effector which brings about a compensatory response

Question 37

What is positive feedback?

Answer 37

A change in a homeostatic controlled factor which triggers to move the deviation of the controlled variable in the same direction as the change.

Question 38

What are feed forward mechanisms?

Answer 38

• Response in anticipation of a change in a regulated variable
• Less common than feedback mechanisms

Question 39

What is pathophysiology?

Answer 39

The abnormal functioning of the body associated with disease.