Comprehensive Study Notes on Anatomy and Physiology
Fundamentals of Anatomy and Physiology
Definitions and Core Concepts
Anatomy
Derived from the Greek word anatome, meaning "to cut apart or dissect."
The study of structure and form.
Anatomists examine the relationships among body parts as well as the structure of individual organs.
Physiology
The study of function of body parts.
Physiologists examine how organs and body systems typically function and how their functioning may be altered via medication or disease.
Interrelationship of Form and Function
Form and function are intrinsically interrelated.
Capillary Structure and Function Example:
An anatomist describes the composition of the thin wall of blood capillaries (the smallest blood vessels).
A physiologist explains how that thin wall allows for effective gas and nutrient exchange between blood within the capillary and tissue cells external to the capillary.
The Scientific Method in Anatomy and Physiology
Anatomists and physiologists use the scientific method as a systematic and rigorous process to explain and understand body workings.
Steps of the Scientific Method:
Examine natural events (or phenomena) through observation.
Develop a hypothesis (a possible explanation) for explaining these phenomena.
Experiment and test the hypothesis through the collection of data.
Determine if the data support the hypothesis, or if the hypothesis needs to be rejected or modified.
Applications:
Early scientists used the scientific method to explain how blood circulates through the body.
Modern applications include understanding how the brain stores memories and explaining how cancer spreads throughout the body.
Subdivisions of Anatomy
Microscopic Anatomy
Examines structures that cannot be seen by the unaided eye.
Requires preparing individual cells or thin slices of body structures to examine under a microscope.
Cytology (si-tol'ō-jē; kytos = a hollow [cell], logos = study):
Also termed cellular anatomy.
The study of body cells and their internal structure.
Histology (his-tol'o-jē; histos = web, tissue):
The study of body tissues.
Gross Anatomy (Macroscopic Anatomy)
Investigates the structure and relationships of body parts visible to the unaided eye (such as the intestines, stomach, brain, heart, and kidneys).
Involves dissecting (cutting open) specimens or their parts for examination.
Systemic Anatomy:
Studies the anatomy of each functional body system.
Urinary System Example: Involves examining the kidneys (where urine is formed), organs of urine transport (ureters and urethra), and the organ of urine storage (urinary bladder).
Approach used in most undergraduate anatomy and physiology classes.
Regional Anatomy:
Examines all structures in a particular region of the body as a complete unit.
Axillary (Armpit) Region Example: Examines blood vessels (axillary artery and vein), nerves (branches of the brachial plexus), lymph nodes (axillary lymph nodes), musculature, connective tissue, and skin.
Approach used in most medical school gross anatomy courses.
Surface Anatomy:
Focuses on superficial anatomic markings and internal body structures that relate to the skin covering them.
Used by healthcare providers to identify and locate landmarks, such as pulse locations or the proper body region for cardiopulmonary resuscitation (CPR).
Comparative Anatomy:
Examines similarities and differences in the anatomy of different species.
Example: Comparing limb structures across humans, chimps, dogs, and cats.
Embryology (em'brē-ol'o-jë; embryon = young one):
Focuses specifically on developmental changes occurring from conception to birth.
Specialized Diagnostic and Research Branches
Pathologic Anatomy (path-o-loj'ik; pathos = disease):
Examines all anatomic changes resulting from disease.
Investigates both gross anatomic changes and microscopic structures.
Radiographic Anatomy:
Investigates relationships among internal structures visualized by specific scanning procedures.
Modalities include radiography (x-ray), ultrasound, and magnetic resonance imaging (MRI).
Dynamic Nature of Anatomy
Anatomy is not a static, unchanging science; it is a dynamic, changing science.
Ongoing anatomical studies continuously generate new information that displaces traditional thinking regarding organ function.
Significant Historical Figures in Anatomy
Andreas Vesalius
Sixteenth-century Belgian physician and anatomist who taught at the University of Padua.
Championed human dissection over animal dissection to understand the human body.
Authored the landmark 1543 text De Humani Corporis Fabrica.
De Humani Corporis Fabrica contained anatomically accurate illustrations of organs, bones, and dissections.
Vesalius's human dissections and documented findings corrected anatomical misconceptions that had persisted for thousands of years.
Subdivisions of Physiology
Foundations of Physiology
Focuses primarily on the molecular or cellular level.
Requires a foundational knowledge of chemistry and cellular biology to understand physiologic concepts.
Systemic Physiology Subdisciplines
Cardiovascular Physiology:
Examines the functioning of the heart, blood vessels, and blood.
Investigates how the heart pumps blood, parameters for healthy blood pressure within blood vessels, and cellular exchange mechanisms moving respiratory gases, nutrients, and wastes between blood and body structures.
Neurophysiology:
Examines how nerve impulses are propagated throughout the nervous system.
Respiratory Physiology:
Studies how respiratory gases are transferred via gas exchange between the lungs and blood vessels.
Reproductive Physiology:
Explores how sex hormone regulation drives the reproductive cycle and influences sex cell production and maturation.
Pathophysiology
Investigates the relationship between the functioning of an organ system and disease or injury to that system.
Heart Disease Example: Examines how heart disease alters the contractile force of the heart, blood pressure, and gas and nutrient exchange.