Comprehensive Physiology and Thermoregulation: Key Concepts and Mechanisms

What is physiology?

The biological study of the functions of living organisms and their parts.

What are emergent properties?

A characteristic that a complex system has, but which the individual parts don't possess.

What does physiology examine?

All different aspects of biological function in one context.

What is the foundation for understanding the function of all organisms?

Physiology.

What processes does physiology include?

Chemical and physical processes.

What are an organism's parts?

Cells, extracellular structures, and organelles.

What is the operational definition of physiology?

The study of how organisms/cells interact with their environment to obtain things required for life and maintain homeostasis.

What are the vital substances for life?

Water, salts, oxygen, nutrients, heat, etc.

What is homeostasis?

A state of relative constancy of the internal environment of an organism.

What is the conceptual definition of physiology?

The collective mechanisms through which an organism maintains homeostasis.

What do all organisms use physiological processes for?

To maintain homeostasis.

What mechanisms help maintain homeostasis?

Obtaining vital substances, molecular interactions, metabolism, function of organ systems, sensory monitoring, feedback loops, etc.

What do all organic molecules contain?

Carbon.

What are biomolecules?

Organic molecules living in organisms.

What are biomolecules made of?

Repeating units of polymers.

Why is carbon important for organic molecules?

It can form multiple bonds, is very flexible, and can create various shapes.

What is compartmentalization?

The organization of every living system into bound spaces that separate internal chemistry from the external environment.

How does compartmentalization aid reactions?

It creates controlled environments where reactions can occur safely and effectively.

How does compartmentalization optimize function conditions?

It allows compartments to create specialized conditions to optimize their functions.

How does compartmentalization aid energy production?

Separations and boundaries allow concentration gradients to drive energy conversion and provide regulation.

How is compartmentalization protective?

It buffers regions against harmful reaction intermediates or enzymes.

What is the smallest unit of structure capable of carrying out all life processes?

Cells/organelles.

What are tissues?

Groups of cells with common structure and function.

What are organs?

Groups of different tissues organized to perform specific functions.

What are organ systems?

Groups of different organs organized to carry out major body functions.

What is the relationship between the internal and external environment of a cell?

They are all within the body.

What does the digestive system exchange?

Wastes and H2O go out and nutrients come in.

What does the respiratory system exchange?

CO2 and H2O go out and O2 goes in.

What does a cell exchange between its intracellular and extracellular space?

Nutrients, H2O, O2, and ions go in; wastes, CO2, H2O, and salts go out.

What percent of molecules are water?

99%.

What percent of body weight is water?

75%.

What are essential physiological parameters that need to be balanced?

Excretion, anabolism vs catabolism, blood glucose, concentrations of CO2 and O2, pH, body temp, concentration of ions, water balance, osmotic balance.

What does all life need energy for?

To take in water, nutrients, gases, heat, and ions; build and disassemble substances; dispose of excess; move substances in and out of cells and through the body; generate energy; and maintain gradients.

How is homeostasis regulated?

Within a range of values, not a single value, using mechanisms to adjust deviations.

What is the state of homeostasis?

Dynamic disequilibrium.

What are critical variables for maintaining internal stability?

Environmental factors that affect cells, materials necessary to meet cells' needs, and factors cells use to communicate with one another.

What are critical requirements for maintaining internal stability?

Energy, cell-cell communication, mass balance, and feedback.

What starts the homeostasis process?

An external change.

What does an external change cause in homeostasis?

An internal change.

What happens after a loss of homeostasis?

The organism attempts to compensate.

What results if the organism succeeds at compensation?

Wellness.

What results if the organism fails at compensation?

Illness or disease.

What does the input signal/sensor do in homeostasis?

Measures the internal environment.

What does the integrating center/integrator do in homeostasis?

Compares the sensor measurement to the set point.

What does the output signal/effect do?

Takes action to change the internal environment.

What is negative feedback?

The response counteracts the stimulus, shutting off the response loop.

What is positive feedback?

The response reinforces the stimulus, sending the variable farther from the setpoint until an outside factor shuts off the feedback loop.

What is the steady state for ions?

Asymmetric distribution between compartments.

What is ECF?

Extracellular fluid.

What is ICF?

Intracellular fluid.

What is the concentration of Na+ inside the cell?

Low.

What is the concentration of K+ inside the cell?

High.

What is the concentration of Ca+ inside the cell?

Very low.

What is the concentration of Na+ outside the cell?

High.

What is the concentration of K+ outside the cell?

Low.

What is the concentration of Ca+ outside the cell?

Low.

What is chemical work?

Work required to make and break bonds.

What is transport work?

Energy required to create concentration gradients by moving ions, molecules, and larger particles.

What is mechanical work?

Energy required to move organelles, change cell shape, beat flagella and cilia, and contract muscles.

What is potential energy?

The energy acquired from an object's position, giving it potential to do work.

What is kinetic energy?

Energy from motion.

What is energy?

The potential to do work.

How do animals get energy?

Must import energy through ingestion of plants or other animals.

What is activation energy?

The 'push' needed to start a reaction.

What are exergonic reactions?

Reactions that produce energy.

What are endergonic reactions?

Reactions that use energy.

What are enzymes?

Biological catalysts made by protein or RNA.

What are catalysts?

Anything that lowers the activation energy to speed up the rate of a reaction.

What is catabolism?

An energy-releasing breakdown.

What is anabolism?

Energy-utilizing synthesis.

What is metabolic rate (MR)?

The sum of all energy-requiring biochemical reactions.

What is the enzyme for ATP?

ATPase.

What is the ATP cycle?

Nutrients, food, and energy provide and restore ATP; ATP is then hydrolyzed and broken down into ADP, organic molecules, and energy.

How much energy is given per mole of ATP?

-30 kJ.

Where does aerobic catabolism occur?

In the mitochondria.

What is aerobic respiration?

Glucose goes through glycolysis to become pyruvate, then is transported to the mitochondria and becomes Acetyl CoA, going through the Krebs cycle to produce high energy electrons, resulting in H2O, CO2, and restoring ATP.

What is anaerobic respiration?

Glucose goes through glycolysis to become pyruvate, making lactate and 2 ATP.

What is the basal metabolic rate?

The rate of energy expenditure at rest.

What do kilocalories measure?

Energy released or stored in chemical bonds.

How do pH and temperature affect proteins?

They alter the 3D shape of protein by disrupting hydrogen or ionic bonds.

What are ectotherms?

Cold-blooded animals.

What types of isozymes do ectotherms have?

Temperature-adapted isozymes.

How do isozymes of an ectotherm vary?

They vary by temperature changes.

What are endotherms?

Warm-blooded animals.

What type of isozymes do endotherms have?

Tissue-specific isozymes.

How do isozymes of an endotherm vary?

They vary by metabolic needs.

What happens to a protein if the pH is very low or high and the temperature is high?

The protein is stable and properly folded.

What happens to a protein at very low temperatures?

The protein would be unfolded and denatured.

What is thermoregulation?

The regulation of transfer of heat and energy across the surface of an organism.

What is heat loss from an animal proportional to?

Surface area.

How does the temperature of a small animal compare to a big animal?

The temperature of a small animal drops more quickly.

What is surface area proportional to in relation to radius?

r².

What is volume proportional to in relation to radius?

r³.

What is heat exchange per unit volume in a large animal?

Low.

What is heat exchange per unit volume in a small animal?

High.

What is temperature?

The average kinetic energy (the index of molecular motion).

What type of energy is heat?

Kinetic energy (molecular motion).

What happens to molecular motion and temperature when it's hot?

They are high.

What happens to molecular motion and temperature when it's cold?

They are low.

What are the principles of heat transfer?

Conduction, convection, evaporation, and radiation.