BIO 203 Final Exam Study Guide
Basic Principles of Physiology
What is Physiology?
- “How things work”
- Formal definition: the biological study of the functions of living organisms and
their parts
- Operational Definition: The study of how cells interact with their “environment” to
obtain the things required for life (“vital substances”)
Exchange Systems
- Any system that allows for the exchange of material (“vital substances”) from external
environment to internal environment, vice versa
- Examples:
- Respiratory system (O2/CO2)
- Digestive system (nutrients/H2O)
- Urinary system (excretion/H2O)
- Circulatory System (distribution)
- Vital substances = water, salts, oxygen, nutrients, heat, etc.
Organization of Complex Biological Organisms
- Cellular level
- Most basic
- Four general cell types
- Epithelial, connective tissue, nerve, muscle
- Tissue level
- Groups of cells with common structure and function
- Ex: epithelial tissue
- Organ level
- Organization of different tissues to perform specific functions
- Ex: heart
- System level
- Most complex
- Several organs organized carry out major body functions
- Ex: cardiovascular system
Basic Principles of Life
1. All life is aquatic
- Body fluids of animals have the same general composition
- Water and salts
- Water is the major component and is 75% of body weight and 99% of all
molecules in humans
- Salts are simple inorganic substances and make up 0.75% of molecules
- Na+, K+, Cl-, Ca++, Mg++, Zn++, Po4-
, - Biochemical substances are proteins, nucleic acids, etc. and make up 0.25% of
molecules
2. All life is compartmentalized
- Separation of substances in different compartments
- The cell is the basic unit (compartment)
- There are 2 major fluid compartments
- Intracellular fluid (ICF) - inside the cell
- Extracellular fluid (ECF) - outside the cell
- Interstitial fluid - ECF that is not in the circulatory system
- Plasma - liquid portion of blood
- There is an asymmetric distribution of ions between different
compartments
- Sodium:
- High in the ECF (100-140 mM)
- Low in the ICF (1-10 mM)
- Potassium
- Low in the ECF (1-10 mM)
- High in the ICF (100-140 mM)
- Calcium
- Low in the ECF (1-3 mM)
- Very low in the ICF
3. All life deals with same fundamental problems
- Many animals have solved fundamental problems in interesting ways
- Comparative physiology
- Ex: all life requires the input of energy
- Life is energetically unfavorable (need energy to survive)
- ATP is principal form of energy used by cells
- Aerobic respiration
- Oxygen
- More efficient
- Produces more energy
- Anaerobic respiration
- No oxygen
- Less efficient
- Produces less energy
- Ex: reproduction
- Ex: defense
- Ex: maintain asymmetric distribution of ions
- Hard to transport substances selectively between compartments
- Trade offs (lose water during respiration, lose water during
thermoregulation)
4. All life is constrained by laws of physics and chemistry
- Ohm’s law, boyle’s law, ideal gas law, gravity, kinetic and potential energy, inertia,
momentum, velocity, and drag
, - Physical environment goversn what cells can and cannot accomplish
- Cells can utilize laws to their advantage
- Cell signaling
- Ex: Size principle is the relationship between surface area and volume
- SA/V is an index of relative surface area for exchange
- As the radius gets bigger (larger animal), the SA/V ratio gets smaller and
relative surface are for exchange decreases
- Ex: relationship between animal size and heat exchange with environment
- Large animal: low rate of heat exchange per unit volume, and good heat
retention per unit volume
- Small animal: high rate of heat exchange per unit volume, and poor heat
retention per unit volume
5. All life can tolerate only a limited range of conditions
- Conditions include:
- Salts, water, oxygen, carbon dioxide, nutrients, waste elimination,
temperature, pH….
- The process of maintaining these conditions with tolerable ranges is
homeostasis
- Homeostasis: maintenance of relatively constant internal environment; it
fluctuates
- Requires cell-to-cell communication
- Nervous system, hormonal system, intrinsic system
- Requires negative feedback
Metabolic Rate
- Definition: the amount of energy an animal uses in a unit amount of time
- Measured as oxygen consumption in units of calories or kilocalories (1000 calories)
- Consume more oxygen when expending more energy
- Sum of all energy-requiring biochemical reactions
- Basal metabolic rate (energy to sustain life)
- Movement
- Heat production
- Anabolic pathways (building biomass)
Feedback Systems
- Components:
- Sensor: measures some aspect of the internal environment
- Integrator: compares the sensor measurement to a reference valeu (set point)
- effector : the output of the system that changes the internal environment
- Negative feedback: effector counteracts (is opposite to) stimulus
- Critical for maintaining homeostasis
- Ex: an increase in temperature measured by the sensor results in the effector
causing a decrease in temperature
- Positive feedback: the effector increases the initial sensor stimulus
- Leads to rapid change
, - Ex: an increase in temperature measured by the sensor results in the effector
causing a further increase in temperature
- Ex: action potential
Body Temperature
Energy Production and Utilization
- Macromolecules: metabolize energy
- Carbohydrates, proteins, fats
- They go in the system to produce energy
- Macromeolcules produce energy that forms ATP, water, carbon dioxide, and nitrogenous
waste products (from proteins)
- The ATP is then used for biosynthesis (increase biomass), cellular work (defending
asymmetry), and external work (activity cost)
- Increase in biomass leads to growth of new tissue and fat storage
- Increase in cellular work leads to signaling, transport, secretion, and muscle
contraction
- Increase in external work leads to locomotion
- Biosynthesis, cellular work, and external work all lead to heat production
Nitrogenous Waste
- Metabolic breakdown of proteins produce ammonia (NH3)
- Nitrogenous waste
- The nitrogenous waste are:
- Salvaged for amino acid synthesis
- Excreted (high levels if ammonia are lethal)
- In some animals, converted to less toxic forms of nitrogen
- Urea and uric acid
- Excretion of nitrogenous waste
- Ammonia:
- Advantages: no energy required
Basic Principles of Physiology
What is Physiology?
- “How things work”
- Formal definition: the biological study of the functions of living organisms and
their parts
- Operational Definition: The study of how cells interact with their “environment” to
obtain the things required for life (“vital substances”)
Exchange Systems
- Any system that allows for the exchange of material (“vital substances”) from external
environment to internal environment, vice versa
- Examples:
- Respiratory system (O2/CO2)
- Digestive system (nutrients/H2O)
- Urinary system (excretion/H2O)
- Circulatory System (distribution)
- Vital substances = water, salts, oxygen, nutrients, heat, etc.
Organization of Complex Biological Organisms
- Cellular level
- Most basic
- Four general cell types
- Epithelial, connective tissue, nerve, muscle
- Tissue level
- Groups of cells with common structure and function
- Ex: epithelial tissue
- Organ level
- Organization of different tissues to perform specific functions
- Ex: heart
- System level
- Most complex
- Several organs organized carry out major body functions
- Ex: cardiovascular system
Basic Principles of Life
1. All life is aquatic
- Body fluids of animals have the same general composition
- Water and salts
- Water is the major component and is 75% of body weight and 99% of all
molecules in humans
- Salts are simple inorganic substances and make up 0.75% of molecules
- Na+, K+, Cl-, Ca++, Mg++, Zn++, Po4-
, - Biochemical substances are proteins, nucleic acids, etc. and make up 0.25% of
molecules
2. All life is compartmentalized
- Separation of substances in different compartments
- The cell is the basic unit (compartment)
- There are 2 major fluid compartments
- Intracellular fluid (ICF) - inside the cell
- Extracellular fluid (ECF) - outside the cell
- Interstitial fluid - ECF that is not in the circulatory system
- Plasma - liquid portion of blood
- There is an asymmetric distribution of ions between different
compartments
- Sodium:
- High in the ECF (100-140 mM)
- Low in the ICF (1-10 mM)
- Potassium
- Low in the ECF (1-10 mM)
- High in the ICF (100-140 mM)
- Calcium
- Low in the ECF (1-3 mM)
- Very low in the ICF
3. All life deals with same fundamental problems
- Many animals have solved fundamental problems in interesting ways
- Comparative physiology
- Ex: all life requires the input of energy
- Life is energetically unfavorable (need energy to survive)
- ATP is principal form of energy used by cells
- Aerobic respiration
- Oxygen
- More efficient
- Produces more energy
- Anaerobic respiration
- No oxygen
- Less efficient
- Produces less energy
- Ex: reproduction
- Ex: defense
- Ex: maintain asymmetric distribution of ions
- Hard to transport substances selectively between compartments
- Trade offs (lose water during respiration, lose water during
thermoregulation)
4. All life is constrained by laws of physics and chemistry
- Ohm’s law, boyle’s law, ideal gas law, gravity, kinetic and potential energy, inertia,
momentum, velocity, and drag
, - Physical environment goversn what cells can and cannot accomplish
- Cells can utilize laws to their advantage
- Cell signaling
- Ex: Size principle is the relationship between surface area and volume
- SA/V is an index of relative surface area for exchange
- As the radius gets bigger (larger animal), the SA/V ratio gets smaller and
relative surface are for exchange decreases
- Ex: relationship between animal size and heat exchange with environment
- Large animal: low rate of heat exchange per unit volume, and good heat
retention per unit volume
- Small animal: high rate of heat exchange per unit volume, and poor heat
retention per unit volume
5. All life can tolerate only a limited range of conditions
- Conditions include:
- Salts, water, oxygen, carbon dioxide, nutrients, waste elimination,
temperature, pH….
- The process of maintaining these conditions with tolerable ranges is
homeostasis
- Homeostasis: maintenance of relatively constant internal environment; it
fluctuates
- Requires cell-to-cell communication
- Nervous system, hormonal system, intrinsic system
- Requires negative feedback
Metabolic Rate
- Definition: the amount of energy an animal uses in a unit amount of time
- Measured as oxygen consumption in units of calories or kilocalories (1000 calories)
- Consume more oxygen when expending more energy
- Sum of all energy-requiring biochemical reactions
- Basal metabolic rate (energy to sustain life)
- Movement
- Heat production
- Anabolic pathways (building biomass)
Feedback Systems
- Components:
- Sensor: measures some aspect of the internal environment
- Integrator: compares the sensor measurement to a reference valeu (set point)
- effector : the output of the system that changes the internal environment
- Negative feedback: effector counteracts (is opposite to) stimulus
- Critical for maintaining homeostasis
- Ex: an increase in temperature measured by the sensor results in the effector
causing a decrease in temperature
- Positive feedback: the effector increases the initial sensor stimulus
- Leads to rapid change
, - Ex: an increase in temperature measured by the sensor results in the effector
causing a further increase in temperature
- Ex: action potential
Body Temperature
Energy Production and Utilization
- Macromolecules: metabolize energy
- Carbohydrates, proteins, fats
- They go in the system to produce energy
- Macromeolcules produce energy that forms ATP, water, carbon dioxide, and nitrogenous
waste products (from proteins)
- The ATP is then used for biosynthesis (increase biomass), cellular work (defending
asymmetry), and external work (activity cost)
- Increase in biomass leads to growth of new tissue and fat storage
- Increase in cellular work leads to signaling, transport, secretion, and muscle
contraction
- Increase in external work leads to locomotion
- Biosynthesis, cellular work, and external work all lead to heat production
Nitrogenous Waste
- Metabolic breakdown of proteins produce ammonia (NH3)
- Nitrogenous waste
- The nitrogenous waste are:
- Salvaged for amino acid synthesis
- Excreted (high levels if ammonia are lethal)
- In some animals, converted to less toxic forms of nitrogen
- Urea and uric acid
- Excretion of nitrogenous waste
- Ammonia:
- Advantages: no energy required
