Foundations of Anatomy & Physiology: Methods, Variation, and Key Concepts (Video Notes)

Physiology is the foundation course for all health-related programs (nursing, physical therapy, dental hygiene). It underpins understanding across programs.
Expected learning outcomes accompany each section and are available in videos, PowerPoints, textbook, and study guides to guide assessment.
Key definitions:
- Anatomy: examining the structure of the human body.
- Physiology: examining the functioning of those structures.
The two disciplines are complementary and inseparable in practice.
- Example: joint (synovial joint) anatomy determines possible movements; the bone shapes dictate the physiology (movement).

Anatomy determines structure; Physiology explains function; they inform each other.
Techniques in anatomy:
- Exploratory surgery
- Medical imaging (relevant to radiologic techs and imaging specialists)
Subfields within anatomy:
- Gross anatomy: structures visible to the naked eye
- Histology: tissue study under the microscope
- Histopathology: tissue changes with disease (e.g., cancer)
- Cytology: cellular structure and function; ultrastructure (details at the cell level)
Visual overview categories: histology, cytology, exploratory surgery (as practical approaches).
Physiological sub-disciplines mentioned:
- Neurophysiology (nervous system)
- Endocrinology (endocrine system and hormones)
- Pathophysiology (mechanisms of disease)

Physiology is studied across species as many processes are conserved.
Historical note: much human physiology knowledge originated from animal studies.
Examples in dogs:
- Glaucoma occurs in dogs
- Diabetes occurs in dogs
Real-world relevance: cross-species studies have enabled drug development and medical procedures.

Two main pathways for obtaining scientific knowledge:
- Inductive method
- Hypothetico-deductive method
Experimental design considerations also play a crucial role.

Process: make many observations to form generalizations and predictions.
Most anatomical knowledge originated via this method.
Concept of proof in science via induction:
- A body of repeated, reliable observations that are not falsified by credible counter-observations can be considered reliable"beyond a reasonable doubt".
Important caveat: truth is tentative and subject to change when credible contradictory observations arise.

Process: formulate a hypothesis, then derive an educated, testable answer.
Hypothesis should be consistent with existing knowledge and testable.
Falsifiability: a claim is scientific only if there exists evidence that could falsify it; if no such evidence exists, the claim is not scientific.
This method drives the majority of physiological knowledge generation.

Sample size: larger samples increase confidence in results.
- Example contrast: drug study with n = 10 vs n = 5,000 subjects.
Controls: essential to compare treatment vs no treatment under identical conditions.
Placebo control: controls for psychosomatic effects (subject expectations influencing outcomes).
Double-blind design: neither subjects nor experimenters know group assignments to minimize bias.
Statistical testing: provides a probability about the effectiveness of a treatment (e.g., significance testing).
Peer review: critical evaluation by experts before funding and publication to ensure design integrity, reproducibility, honesty, and quality.
Ethical considerations: history of false publications funded by external interests (e.g., drug companies); such cases are rare but illustrate the need for integrity and verification.

Scientific fact: something that can be independently verified and is reliable.
Law of nature: a verbal statement or mathematical formula describing matter/energy behavior; often arises from inductive reasoning and repeated observations.
- Example: the law of gravity. An illustrative mathematical form for gravity is F = G \frac{m1 m2}{r^2}, where $G$ is the gravitational constant.
Theory: a broad set of statements derived from facts, laws, and confirmed hypotheses; it summarizes what is known and suggests directions for further study.
In AMP 1, you encounter references to:
- Self theory (likely cell theory), fluid mosaic model of the plasma membrane, and the sliding filament theory of muscle contraction.

Hierarchy (from most complex to least, as described):
- Organism → Organ systems → Organs → Tissues → Cells → Organelles → Molecules → Atoms
The diagram described places the organism as most complex and the atom as least complex.
Anatomical variation: no two humans are exactly alike; AMP emphasizes the most common structures rather than every individual variance.
- Examples of common characteristics you’ll study include:
- Variation in muscles (some individuals may lack certain muscles)
- Vertebral counts can vary between individuals
Kidneys variations:
- Pelvic kidney (kidney located in the pelvis)
- Horseshoe kidney (kidneys fused at the lower poles forming a horseshoe shape)
Aorta anatomy and bifurcation:
- Aorta typically bifurcates above the hips; occasionally there is a kink and bifurcation occurs a bit lower in the pelvis.
This section prepares you to recognize common anatomical patterns while acknowledging variations.

The discussion sets the stage for the next video, which will focus on human functions (physiology) rather than structure.
Emphasis on how foundational knowledge of anatomy supports understanding physiology and clinical applications.

Always consider both structure and function when analyzing a biological system.
In experimental design, prioritize sample size, proper controls, placebo effects, randomization, and blinding to reduce bias.
Peer review serves as a quality checkpoint to maintain scientific integrity.
Be mindful of how scientific knowledge is built: inductive observations establish facts and laws; hypothetico-deductive reasoning tests theories and hypotheses.
Expect natural variation in anatomy but focus on the most common patterns relevant to clinical practice.
Cross-species studies are valuable for discovery and translation but require careful interpretation when applying to humans.

Be able to define and distinguish anatomy vs physiology and explain their interdependence with a concrete example (synovial joint).
List and describe the main anatomical and physiological subfields and techniques.
Explain the inductive vs hypothetico-deductive methods and what constitutes falsifiability.
Identify key features of good experimental design and why each feature matters (sample size, controls, placebo, double-blind, peer review).
Define scientific fact, law of nature, and theory, with examples.
Describe the hierarchy of biological organization and give examples at each level.
Recognize common anatomical variations and their potential clinical significance.
Recall the cross-species rationale for learning physiology and provide examples from veterinary observations.
Prepare to connect today’s content to human functions discussed in the next video.