Physiological Principles Notes

Module 1: Introduction to Physiological Principles

Learning Objectives

  • Understand the importance of physiology.

  • Explain the two central questions of physiology.

  • Identify the levels of organization in organisms.

  • Understand the basic mechanisms and enhancements in homeostasis.

  • Describe the positive and negative feedback mechanisms.

Organisms: Common Characteristics and Processes

  • Cells: Basic structural and functional units.

  • Organization: Hierarchical arrangement.

  • Large molecules: Proteins, carbohydrates, lipids, nucleic acids.

  • Responsiveness: Ability to react to stimuli (e.g., painful stimulus).

  • Regulation: Maintaining internal stability (e.g., body temperature homeostasis).

  • Growth and Development: Increase in size and complexity.

  • Reproduction: Production of offspring.

  • Metabolism: Sum of all chemical reactions.

    • Catabolic chemical reaction: CD→C+D+EnergyCD \rightarrow C + D + Energy

Anatomy and Physiology

  • Anatomy: Study of structure.

    • Derived from "a cutting open."

    • Study of internal and external structures and their relationships.

    • Gross anatomy (macroscopic).

    • Microscopic anatomy.

    • Methods of examination: inspection, auscultation, palpation, percussion.

  • Physiology: Study of function.

    • How living organisms perform vital functions.

    • Heartbeat coordinated by electrical events.

    • Electrocardiogram (ECG): Record of electrical events.

    • Blood pressure in major arteries must be maintained within normal limits.

Interrelationship of Structure and Function

  • Example: The elbow joint. Humerus interacts with ulna and radius to allow hinge-like movement.

    • Ulna: Larger bone with a deep depression for humerus.

    • Humerus: Cylindrical surface that is part of the elbow joint.

    • Ligaments and surrounding muscles stabilize the joint.

Hierarchical Organization of Living Systems

  • Cellular level: Atoms, molecules, macromolecules, organelles, cells.

    • Examples: Atoms (H), Molecules (H2H_2), Organelles (mitochondria, nucleus).

  • Organismal level: Tissues, organs, organ systems, and organism.

  • Populational level: Population, species, community, ecosystem, biosphere.

Structural Hierarchy in the Body

  1. Atom

  2. Molecule

  3. Macromolecule

  4. Organelle

  5. Cell

  6. Tissue

  7. Organ

  8. Organ System

  9. Organism

Cells: The Smallest Units of Life

  • Examples:

    • Smooth muscle cells: Long and slender, support digestion.

    • Blood cells: Flattened discs (red blood cells) or spherical (white blood cells).

      • Red blood cells: Transport oxygen and carbon dioxide.

      • White blood cells: Fight infection and combat disease.

    • Bone cells: Maintain bone and recycle calcium and phosphate.

    • Fat cells: Spherical storage containers for excess energy.

  • Cell division and growth.

  • Cell differentiation: Specialized cell types.

    • Epithelial, connective, nervous, and muscle tissues.

  • Tissues form organs (e.g., kidney).

  • Organs form organ systems (e.g., urinary system).

Levels of Anatomy and Physiology Study

  • Atomic and molecular levels: Membrane protein in neurons regulates ion flow.

  • Cellular level: Electrical signal travels down neuron.

  • Tissue level: Signals travel from cell to cell in nervous tissue.

  • Organ level: Nervous and connective tissue in brain aid in sight, smell, memory, and thought.

  • Organ system level: Brain and nerves control breathing, digestion, movement, etc.

  • Organism level: Nervous system coordinates functions to support life.

Integrative Nature of Physiology

  • Ecological and evolutionary levels: Pheasant escaping predator.

    • Muscle cell structure determines escape speed.

    • Failure to escape = death; success = life and reproduction.

  • Biochemical level: Krebs cycle for ATP production in muscle contraction.

  • Evolution: Genetic differences between salmon populations.

  • Chemistry and physics: Thrust - Drag = Mass x Acceleration.

    • C<em>6H</em>12O<em>6+6O</em>2→6CO<em>2+6H</em>2O+energyC<em>6H</em>{12}O<em>6 + 6O</em>2 \rightarrow 6CO<em>2 + 6H</em>2O + energy

  • Physiology depends on all levels of organization.

    • Cell physiology: Voltage across nerve cell membrane.

    • Biochemistry: ATP production by enzymes in muscle cells.

    • Systems physiology: Nerve impulses activate swimming muscles.

    • Morphology and Biomechanics.

Physiology within an Ecological Context

  • Example: Salmon adapting to saltwater and freshwater by modifying ion-transport proteins in gill epithelium (Cell-membrane protein).

Physiology's Two Central Questions

  1. Mechanism: How does it work?

  2. Origin: How did it evolve?

Mechanism in Physiology

  • Refers to the components of living organisms and their interactions that enable them to perform.

Evolutionary Origin & Natural Selection

  • Natural selection: Genes producing phenotypes that increase survival and reproduction become more frequent.

Homeostasis: Claude Bernard

  • Claude Bernard's work on digestion (pancreas, gastric juices, intestines).

  • Proposed the concept of “homeostasis” - controlled stability of the internal milieu.

  • "The fixity of the internal environment is the condition for free life."

Homeostasis: Walter Bradford Canon

  • Coined the term "fight or flight."

  • Expanded on Bernard's concept of homeostasis.

  • Described the balancing and rebalancing of physiological processes.

Types of Environments

  • External environment: Everything outside the body.

  • Internal environment: Cells, tissues, fluids, and organs.

Potential Changes in the Internal Environment

  • Materials from the environment surrounding cells (oxygen, nutrients, salts).

  • Changes in response to the external environment.

Homeostatic Regulation

  • Adjustment of physiological systems to preserve homeostasis in inconsistent, unpredictable, and dangerous environments.

Regulation of Temperature

  • Sensors detect changes in body temperature and send signals to the hypothalamus.

  • Hypothalamus signals effectors for corrective action to maintain range.

Negative Feedback

  • The response of the integrator is opposite to the input of the sensor.

  • Example:

    • Receptors detect a rise in body temperature above 37.2°C(99°F)37.2°C (99°F).

    • Control center (hypothalamus) receives information and sends commands to effectors.

    • Effectors: Smooth muscle in blood vessels dilate, sweat glands secrete.

    • Homeostasis is restored at normal body temperature (37°C37°C or 98.6°F98.6°F).

Positive Feedback

  • Changes increase the deviation from the set point.

  • Conditions move away from the normal range.

  • Example:

    • Damage to blood vessel wall releases chemicals.

    • Chemicals start chain reactions to form a clot.

    • Clotting process accelerates as each step releases more chemicals.

    • Positive feedback loop ends with the formation of a blood clot.

    • he body responds to this potential catastrophe by releasing substances in the injured blood vessel wall that begin the process of blood clotting. As each step of clotting occurs, it stimulates the release of more clotting substances. This accelerates the processes of clotting and sealing off the damaged area. Clotting is contained in a local area based on the tightly controlled availability of clotting proteins. This is an adaptive, life-saving cascade of events.

Cells

  • cell theory, fundamental scientific theory of biology according to which cells are held to be the basic units of all living tissues. First proposed by German scientists Theodor Schwann and Matthias Jakob Schleiden in 1838.

  • Cellular physiology

  • Cell is the smallest unit of life that can function independently

Cell Theory

  • All organisms are made of one or more cells

  • The cell is the fundamental unit of life

  • All cells come from preexisting cells

  • All cells have the same basic chemical composition

  • All cells use energy

  • All cells contain DNA that is duplicated and passed as each cell divides.

Prokaryotes and Eukaryotes

  • Bacterial Cell
    * DNA and RNA
    * Ribosomes
    * Cytoplasm
    * Cell membrane

  • Eukaryotic Cell.

Anatomy of a Bacterial Cell

  • They lack membrane-bounded organelles and their ribosomes and DNA are free in the cytoplasm.

Anatomy of an Animal Cell

  • Components Include
    * Centrosome
    * Centriole
    * Peroxisome
    * Nucleus
    * Nuclear pore
    * Nuclear envelope
    * Nucleolus
    * DNA
    * Cytoskeleton
    * Microtubule
    * Intermediate filament
    * Micro filament
    * Cell membrane
    * Lysosome
    * Cytosol
    * Mitochondrion
    * Smooth endoplasmic reticulum
    * Golgi apparatus
    * Cytoplasm
    * Ribosomes
    * Rough endoplasmic reticulum

Anatomy of Plant Cell

  • Components Include
    * Nucleus
    * Nuclear pore
    * Nuclear envelope
    * Nucleolus
    * DNA
    * Ribosomes
    * Cell wall
    * Vacuole
    * Chloroplast
    * Mitochondrion
    * Golgi apparatus
    * Smooth endoplasmic reticulum
    * Peroxisome
    * Cell membrane
    * Plasmodesma
    * Cytoplasm
    * Cytosol
    * Central vacuole
    * Cytoskeleton
    * Intermediate filament
    * Microtubule
    * Micro Filament

Microscopy Ranges

*Microscope and Magnifications
* Microscopes
* Atomic force microscope, 0.1nm-10nm
* Transmission electrom microscope, 10pm-100 micrometers
* Scanning electron microscope, 10nm- 1mm
* Light microscope, 200nm-10mm
* Unaided eye, greater than 200 micrometers

Small Cells and Microscopes

  • Range of human eye

  • Range of the light microscope

  • Range of the electron microscope

Light Microscope

  • Visible spectrum of light

TEM Microscopy

  • View cells

SEM Microscopy

  • View Cells

Parts of A Cell

Nucleus

  • Stores and transmits information.

  • The genetic, or hereditary, information is encoded in DNA, which is apart of the chromosomes inside the nucleus.

  • Nucleolus: RNA molecules in ribosomes are manufactured and the large and small ribosomal subunits are assembled.

Ribosomes

  • Sites of protein synthesis

  • Eukaryotic ribosomes are not only scattered free in the cytosol, but are also associated with the endoplasmic reticulum

  • Proteins manufactured by free ribosomes either remain in the cytosol or are imparted into other organelles, such as the nucleus

Endoplasmic Reticulum

  • Site of synthesis processing, and storage.

  • ER is continuous with the nuclear envelope and possesses two distinct regions: system of membrane bound sacs and tubules with ribosomes attached, the system of membrane bound sacs and tubules that lacks ribosomes

Golgi Apparatus

  • site of protein processing, sorting and shipping.

  • A collection of flattened sacs called cisternae.

Lysosomes

  • Recycling centers.

  • Oval or globular organelles that contain enzymes to digest macromolecules.

  • Contains about 40 different enzymes, each specialized for hydrolyzing different types of macromolecules- proteins, nucleic acids, lipids, or carbohydrates.

Vacuoles

  • Storage centers in Plant and fungal cells

  • Vary in size and function

  • Some contain digestive enzymes and serve as recycling centers

  • Most are large storage containers

Peroxisomes

  • Site of oxidation reactions

  • Globular Organelles that contain enzymes involved in detoxifying reactive molecules, such as hydrogen peroxide

  • Centers for reduction - oxidation (Redox) reactions

Mitochondria

  • Power- generating stations

  • Vary in size and shape, but all have two membranes with sac- like cristae formed from the inner membrane that are involved in producing ATP

  • Copies of a small, circular or in some species, called mitochondrial DNA(mtDNA) that is independent of the nuclear chromosomes.

Chloroplast

  • Sugar manufacturing centers in plants and algae.

  • Many of the enzymes and other molecules required for photosynthesis are located in the membranes inside the chloroplast

  • Membranes from thylakoids that consist of discs stacked into grana.

Chemical Foundations of Life

  • Sodium

  • Water

  • Oleic Acid

  • D-serine

  • L-glucose

Chemical level of Organization

  • Atoms, ions, and molecules: building blocks of chemical evolution

Atoms

  • Protons (p+) have a positive electrical charge.

  • Neutrons (n or n0) are electrically neutral, which means they are uncharged.

  • Electrons (e-) are much smaller and about 1/1836th the mass of either protons or neutrons.
    The have a negative electrical charge

Types of Chemical Reactions

*Synthesis - Occurs when subunits bond during a dehydration reaction (removal of H<em>2OH<em>2O). *Degradation- Occurs when the subunits separate during a hydrolysis reaction (addition of H</em>2OH</em>2O).

Carbon And Life:

*Lipids that store energy in the canola plant.
*Carbohydrates that provide structures for the tree.
*Proteins that form the hemoglobin of red blood cells.
*Genetic material that the lioness has passed on to her offspring.

Properties of water

  • Partial chargers on water molecules can form up to four hydrogen bonds the oxygen can form two -each hydrogen can form one polar covalent bonds in water give the oxygen a partial negative charge and each hydrogen atom a partial positive charge.

Three forms of water

  • Ice (solid)

  • Water (liquid)

  • Steam becoming water vapor (gas)

Regulation of body fluid PH

  • Vital or homeostasis.

*PH formula
*Acidic and basic numbers on pH

Hydrogen bonds

* Give water its emergent properties.
Water

  • Cohesion- tendency of water molecules to stick to one another

  • Adhesion- Water molecules also form hydrogen bonds with other molecules

  • Solvent-The polarity of water molecules helps water dissolve most biologically important molecules, science many of them are hydrophilic

  • Temperature regulation- Hydrogen bonds make water resist changes in temperature

  • Water expands - when it freezes

Organic Molecules

  • Are biologically important.
    Are categorized into four main types:
    * Carbohydrates
    * Proteins
    * Nucleic acids
    * Lipids

Carbohydrates

Monosaccharides

  • Are simple sugars and the monomers that make up larger carbohydrates

Carbohydrates
* Synthesis reactions binds tow monosaccharides together, forming a disaccharide.
* Hydrolysis separates disaccharides into monosaccharides
Complex Carbohydrates
*Leafs
*Potatoes
*Liver
    *Cellulose
    *Starch
    *Glycogen
Major group of Carbs Based of Structure
*Simple sugars
    *Monosaccharides- Glueclose, galactose, mannose.
    *Disaccharides- Sucorse, maltosse, lactose
    *Oligosacchardies: milk oligosacchardies, raffinoss
*Polysaccharides
    *Glusoce homoplymers- cellulose, starch, glycogen
    *Disaccharide
*glycoconjugates
    *Glycoprotiens- Antibodes
    *Proteoglycans- aggrecan, syndecan, glypican
    *Glycolipids- Blood antigens, membrane anchors

Amino Acids, Peptides, and Proteins

  • Proteins are at the center of action in most biological processes

  • Nearly all the molecular transformation that define cellular metabolism are mediated by protein catalysts.

Protein Associations

  • Protein association with membranes

General Structure of Amino Acids
    *R group
    *Central Carbon
    *Amino Group
    *Carboxyl Group
Proteins
*Synthesis-Binds two amino acids together, forming a dipeptide
*Hydrolysis
Polypeptides fold up into protiens
*Chain of amino acids folds  into a unique three d shape to become a protien
*Function of a protien depends on its shape of tertiary structure
    *Protien is functional
    *Protien is not functional
The two structure of Amino Acid:
    *Primary and secondary
*Tertiary and quaternary

Nucleic acids Carry

  • the genetic information

The structure of Nucleic Acids including
*DNA
*Gene
*Base pair
*Cell
*Nucleus
*Chromosome
NUelic Acids
    *Include DNA and RNA
*The primary structure of each protein in a cell is determined by the nucleic acids
The monomers of Nucleic Acid are NUcleotides
* The three parts of a nucleotide are a phosphate group, a 5-carbon sugar and a nitrogenous base.
DNA AND RNA
*Use Thymine
*Uses uracil
Acids Synthesis
*Synthesis acids into individuals nucleic acids
*Hydrolysis
Important role Of Acids
* Storage moleucules
*  Hydrophobics
* endoctrine
Lipids Three Roles
1. Energy storage molecules and are either obtained directly from the diet or synthesized from carbohydrates
2. Form the hydrophobic barriers of cell membranes.
3. Function in the endocrine system and activate a variety of signaling pathways

Collection Ofmolecules

*Hydrophobic Molecules

The three classes of lipids:

*Triglycerides
    *This is formed by covalently attaching 3 fatty acid melecules to a glycerol moleucle.

Waxes
*This is composed of fatty acids combined with alchols. This is particularly hydrophobic.
Steriods
This regulates the fluidity of cells and membrane and helps synthesize hormones. . This is the 3rd class of lipids.