PSIO BLOCK 2 EXAM Review | July Update
Homeostasis ** Answ** the tendency toward a relatively stable equilibrium between
interdependent elements, especially as maintained by physiological processes
What are the 2 types of feedback circuits? ** Answ** 1. Negative feedback loop
2. Positive feedback loop/cumulative causation
Negative feedback loop ** Answ** changes in monitored parameter cause control
mechanism to work to counteract further changes of the parameter in the same
direction
result: change triggers reversal of detected change
Positive feedback loop ** Answ** changes in monitored parameter cause control
mechanism to word to cause/amplify changes of the parameter in the same direction
result: change triggers amplification of detected change
What are the 3 components of homeostatic control? Functions? ** Answ** 1.
receptors: sense changes in the internal or external environment
2. control center: processes information gathered from receptors and sends a response
to effectors
3. effector: adjusts the regulated parameter
Cell Response pathway ** Answ** 1. stimulus: hormones, nutrients, mental/neuron
activity etc.
2. endocrine cell
3. blood
4. target cell
5. response
What regulates Ca++ in blood? ** Answ** 1. thyroid and parathyroid glands
2. bones
3. kidneys
4. intestines
Roles of Ca++ ** Answ** bone formation, muscle contraction, membrane excitbaility,
blood clotting, intracellular activity
What hormones are involved to regulate Ca++? ** Answ** calcitonin: increased
mineralization of bone & decreased renal reabsorption of Ca++ [decreases Ca++]
PTH: increased demineralization of bond, & increased intestinal absorption and
increased renal reabsorption of Ca++ [increases Ca++]
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, Clacium level in blood ** Answ** 8.5-11 MG
pH level ** Answ** 7.4
Glucose in blood ** Answ** 90 MG
What regulates blood glucose? ** Answ** pancreas
What regulates blood pH? ** Answ** respiratory and renal systems
How does the respiratory system regulate pH? ** Answ** rapid breathing: increases
pH
slow breathing: decrease pH
What regulates breathing? ** Answ** medulla and pons
How does the renal system regulate pH? ** Answ** secretion and/or reabsorption of
H+ and bicarbonate
H+ ions are secreted/bicarbonate is reabsorbed; increase pH
Fick's diffusion equation ** Answ** Rate of diffusion = k x A x (P2-P1)/D
Diffusion rates vary with changes in: ** Answ** 1. area: increasing SA increases
diffusion rate
2. Gradient: increasing concentration gradient of the diffusing solute increases diffusion
rate
3. distance: increasing diffusion distance decreases diffusion rate
Diffusion vs convection ** Answ** diffusion: passive movement of molecules or
particles down a gradient
convection: bulk transport
What are the 4 modes of heat transfer? ** Answ** 1. conduction
2. convection
3. radiation
4. evaporation
Conduction ** Answ** direct molecular transfer of energy from a warmer surface to a
cooler surface
Convection ** Answ** conduction coupled to air or fluid movement (ex: wind chill)
Radiation ** Answ** emission of photons from any surface above a temperature of
absolute zero
For assistance with assignments contact
Homeostasis ** Answ** the tendency toward a relatively stable equilibrium between
interdependent elements, especially as maintained by physiological processes
What are the 2 types of feedback circuits? ** Answ** 1. Negative feedback loop
2. Positive feedback loop/cumulative causation
Negative feedback loop ** Answ** changes in monitored parameter cause control
mechanism to work to counteract further changes of the parameter in the same
direction
result: change triggers reversal of detected change
Positive feedback loop ** Answ** changes in monitored parameter cause control
mechanism to word to cause/amplify changes of the parameter in the same direction
result: change triggers amplification of detected change
What are the 3 components of homeostatic control? Functions? ** Answ** 1.
receptors: sense changes in the internal or external environment
2. control center: processes information gathered from receptors and sends a response
to effectors
3. effector: adjusts the regulated parameter
Cell Response pathway ** Answ** 1. stimulus: hormones, nutrients, mental/neuron
activity etc.
2. endocrine cell
3. blood
4. target cell
5. response
What regulates Ca++ in blood? ** Answ** 1. thyroid and parathyroid glands
2. bones
3. kidneys
4. intestines
Roles of Ca++ ** Answ** bone formation, muscle contraction, membrane excitbaility,
blood clotting, intracellular activity
What hormones are involved to regulate Ca++? ** Answ** calcitonin: increased
mineralization of bone & decreased renal reabsorption of Ca++ [decreases Ca++]
PTH: increased demineralization of bond, & increased intestinal absorption and
increased renal reabsorption of Ca++ [increases Ca++]
For assistance with assignments contact
, Clacium level in blood ** Answ** 8.5-11 MG
pH level ** Answ** 7.4
Glucose in blood ** Answ** 90 MG
What regulates blood glucose? ** Answ** pancreas
What regulates blood pH? ** Answ** respiratory and renal systems
How does the respiratory system regulate pH? ** Answ** rapid breathing: increases
pH
slow breathing: decrease pH
What regulates breathing? ** Answ** medulla and pons
How does the renal system regulate pH? ** Answ** secretion and/or reabsorption of
H+ and bicarbonate
H+ ions are secreted/bicarbonate is reabsorbed; increase pH
Fick's diffusion equation ** Answ** Rate of diffusion = k x A x (P2-P1)/D
Diffusion rates vary with changes in: ** Answ** 1. area: increasing SA increases
diffusion rate
2. Gradient: increasing concentration gradient of the diffusing solute increases diffusion
rate
3. distance: increasing diffusion distance decreases diffusion rate
Diffusion vs convection ** Answ** diffusion: passive movement of molecules or
particles down a gradient
convection: bulk transport
What are the 4 modes of heat transfer? ** Answ** 1. conduction
2. convection
3. radiation
4. evaporation
Conduction ** Answ** direct molecular transfer of energy from a warmer surface to a
cooler surface
Convection ** Answ** conduction coupled to air or fluid movement (ex: wind chill)
Radiation ** Answ** emission of photons from any surface above a temperature of
absolute zero
For assistance with assignments contact
