Chapter 1 Lecture 1

Basic Physiological Principles

• Biology: The scientific study of living things.

• Anatomy: (Greek ana=“up” and tomos=“cutting”) Science of the structure of an organism and the relationship of its parts.

• Physiology: (Greek physis=“nature” and logos=“study”) Science of the functions of organisms.

Physiology

• Physiology is the study of the functions of organisms using methods of experimental science.

• Comparative physiology studies these functions in different species, providing a basis for new drugs and medical procedures.

• Physiology can be classified by:

  • Organism involved (e.g., human or plant physiology).

  • Organizational level (e.g., molecular or cellular physiology).

  • Systemic function (e.g., respiratory, neurovascular, or cardiovascular physiology).

Elements of Physical Examination

• Anatomy can provide clues about physiological function.

• Clinical assessments:

  • Palpation: Touching to examine the body.

  • Percussion: Tapping to evaluate internal organs and structures.

  • Note: The transcript asks for the difference but does not provide it. Palpation uses touch to feel for abnormalities, while percussion uses tapping to assess density and location of structures based on the sounds produced.

  • Auscultation: Listening to body sounds (e.g., heart murmurs).

• Histology and histopathology: Microscopic examination of tissues to assess cell structure and organization.

• Imaging techniques: In-depth assessment without invasive procedures.

Clinical Assessment Methods

• Listening for a heart murmur: Auscultation.

• Examining liver structure under a microscope for pathology like cirrhosis: Histology.

• Performing a breast self-exam: Palpation.

Pathophysiology

• Study of the underlying physiological processes associated with disease.

• Diseases: Disturbances to homeostasis (the relative constancy of the body's internal environment) beyond normal fluctuations.

• Acute conditions: Body quickly recovers homeostatic balance.

• Chronic diseases: Normal balance may not be restored.

• Death: May occur if disturbances are too severe or prolonged.

Analyzing Medical Terms

• Scientific terms:

  • Root (stem): Core meaning, e.g., “cardio” in cardiology.

  • Prefix: Modifies core meaning, e.g., hypogastric (prefix: hypo-).

  • Suffix: Modifies core meaning, e.g., gastroenterology (suffixes: -gastric and -entero).

• Acronyms:

  • First few letters of words, e.g., DNA (deoxyribonucleic acid).

Disease Terminology

• Epidemiology: Study of the occurrence, distribution, and transmission of diseases in human populations.

• Endemic: Disease native to a local region.

• Epidemic: Disease spreads to many individuals simultaneously.

• Pandemic: Epidemic affecting large geographic regions, possibly worldwide.

Disease Terminology (cont.)

• Chronic: Develops slowly and lasts a long time.

• Etiology: All factors causing a disease.

• Pathogenesis: Pattern of disease development.

• Idiopathic: Disease with undetermined cause(s).

• Communicable: Disease transmitted from person to person.

• Incubation: Latent stage of infection.

• Remission: Reversal of a chronic disease.

Characteristics of Life (Biological)

• Organization

• Cellular composition

• Metabolism: digestion, absorption, excretion, secretion

• Responsiveness: stimuli, conductivity, movement

• Development: differentiation & growth

• Reproduction

• Evolution: genetic changes (mutations) seen in the population not in the individual

• Homeostasis

Organization

• Organisms are complex and highly organized, often hierarchically.

• Cells focus on maintaining this order.

• Loss of organization leads to adverse effects like illness.

Cellular Composition

• Eukaryotic cells are compartmentalized, forming organelles that provide micro-environments for specialized division of labor to benefit the organism.

• Organisms are made of one or more cells with specialized functions.

Metabolism

• Encompasses all chemical activities of the cell.

• Two broad classes of metabolic activities:

  • Anabolic (biosynthesis)

  • Catabolic (breakdown/digestion)

• Waste products result from metabolic reactions, necessitating excretion.

Responsiveness

• Also called irritability or excitability.

• Ability to sense and react to environmental factors/stimuli.

• Occurs at cellular (e.g., hormone secretion) or organismal level (e.g., escaping a predator).

• Facilitated by nervous and muscular systems.

Development

• Changes in form and/or function over time.

• Begins during embryogenesis and continues throughout life.

• Involves:

  • Growth

  • Differentiation/specialization

Reproduction

• Production of offspring with genetic information from parents.

• All organisms have this capacity.

Evolution

• Genetic change within species from generation to generation.

• Characteristic of a population, not an individual.

• Arises from mutations in DNA, leading to adaptations influenced by environmental factors.

Homeostasis

• Ability to maintain constant internal conditions despite external fluctuations (e.g., thermoregulation).

Characteristics of Life (Clinical)

• Clinical and legal criteria for being alive:

  • Brain activity (waves)

  • Reflexes (evoked)

  • Respiration (independent of artificial means)

  • Heartbeat (independent of artificial means)

• Paradox: Clinically dead person can still have biologically alive organs suitable for donation.

Human Origins and Adaptations

• Cell Theory:

  • All organisms are made of one or more cells (Theodor Schwann).

  • The cell is the basic structural unit of all organisms.

  • Cells arise only from preexisting cells (Rudolf Virchow).

• Theory of Natural Selection:

  • Populations with useful/advantageous characteristics persist.

  • These characteristics are passed to offspring and become more common over generations.