KW

Integrated Human Anatomy and Physiology I — Introductory Notes (copy)

Course logistics and study expectations

  • Materials: You should download the first lecture set and the second lecture set. There is a recurring pattern of new material being posted each Monday and Wednesday by 9 PM; check for updates by that deadline. If you find out in the morning, there is still time before the class starts in late morning to download.
  • Lecture outlines: Outlines are posted before the lecture and serve as scaffolding for taking your best notes. Merely downloading the outline and not attending class is a huge mistake; it will not prepare you well for exams.
  • Note-taking philosophy: The best way to take notes is the method that works for you. People have different preferences (typing, iPad, paper), and you should use the approach that you find most effective.
  • Office hours and meetings:
    • The instructor had a small office-hour turnout (one student visited, four people chatted on another day).
    • You are welcome to come by or make appointments.
    • A standing weekly time for a few students (e.g., every Friday at 3 PM) cannot be guaranteed due to other commitments; the schedule is flexible throughout the week.
    • If you need consistent weekly help, discuss options and be flexible with timing.
  • Administrative note: If you arrive late, important information may have been said before you arrived. It’s good to connect with classmates or approach the instructor after class to catch up.

What is anatomy? Structure (one-word definition) and related concepts

  • One-word definition of anatomy: structure.
  • Anatomy focuses on the structure of the body and its components: mass, shape, attachments, and location relative to other objects.
  • Example: urinary bladder (part of the urinary system) has a quantifiable mass, a specific shape, defined components, and a definite location/attachments.
  • Anatomy as a field is extensive; to manage it, it is divided into logical categories and subcategories to aid comprehension.

Gross anatomy and its approaches

  • Gross anatomy: study of body structure at a level visible to the naked eye; traditionally involves cadaver dissection.
  • Etymology: gross (German) means large, hence gross anatomy refers to large-scale structures visible without magnification.
  • Approaches to studying gross anatomy:
    • Systemic approach: study by organ systems (e.g., integumentary, skeletal, muscular, nervous, etc.). There are 12 systems in total.
    • Regional approach: study by body regions (e.g., chest, abdomen, pelvis) focusing on all systems present in that region.
    • Most courses use a combination of both approaches; our course leans toward a systemic orientation but includes regional elements.
  • In this course, the order typically follows systemic anatomy (e.g., integumentary first, then skeletal, muscular, nervous, etc.), with some regional context.
  • Regional labeling is also used in labs (axial skeleton vs. appendicular skeleton) to emphasize different regional perspectives.

Levels of study: structure at multiple scales

  • Anatomy levels (visible to the naked eye) vs. microscopic levels:
    • Gross anatomy (macroscopic): structures visible without a microscope.
    • Histology (microscopic anatomy): study of tissues under a light microscope.
    • Cellular ultrastructure: detailed organelle-level structure (requires an electron microscope).
  • Tissues: four basic tissue types (spelled out below) but with many subtypes in practice.
  • Structure-function relationship: physiology (function) explains how structures work; these two are interdependent and integrated in this course.

Tissues and the four basic tissue types

  • The four basic tissue types are:
    • Epithelial tissue
    • Connective tissue
    • Muscle tissue
    • Nervous tissue
  • Note: these are broad categories; there are many subtypes within connective and epithelial tissues.
  • Cells form tissues; tissues aggregate into organs. Tumbling down to the cellular level provides more detail (ultrastructure) and helps explain function.

Organ definition and examples

  • An organ is a collection of at least two tissue types that are associated with one another, encapsulated and self-contained, with a specific function or set of functions.
  • Examples and clarifications:
    • Urinary bladder: a hollow organ with a specific function (holding urine) and several tissue types (epithelial lining, connective tissue, smooth muscle).
    • Bones (206 bones) are organs within the skeleton; each bone is predominantly composed of bone tissue but includes other tissues as well.
    • A single biceps muscle is an organ; a humerus bone is an organ; a tooth is an organ.
    • Visceral organs (viscera) refer to the organs within the abdominal cavity as a collective group.
  • The urinary bladder serves as a canonical example of structure tailored to function: it has a hollow space, a lining, connective tissue that allows expansion, and smooth muscle to expel urine.
  • Basic functional description of the urinary system:
    • Kidneys (2) filter blood and produce urine.
    • Ureters (2) transport urine from kidneys to the bladder.
    • Urinary bladder (1) stores urine and expands/contracts to expel urine.
    • Urethra (1) conducts urine out of the body.
    • Total organs in the urinary system: 2\text{ kidneys} + 2\text{ ureters} + 1\text{ bladder} + 1\text{ urethra} = 7 organs.
    • Overall function: get rid of waste, regulate water and ion balance, and manage urine transport and excretion.
    • The excretory system = urinary system.
  • Interdependence of systems: disease in one tissue or organ can compromise the entire system; metaphorical “house of cards” analogy.

The chemical and cellular basis of life (atoms, elements, macromolecules, cells)

  • Elements and atoms:
    • Humans are built from a subset of the periodic table; there are about 100 elements on Earth; atoms are the smallest units of elements that retain element properties.
    • The four most abundant elements in the body (by mass or atom count, depending on metric): ext{C}, ext{O}, ext{H}, ext{N} (carbon, oxygen, hydrogen, nitrogen).
  • Commonly cited mass composition:
    • Water comprises about 60\% - 65\% of body mass (roughly two-thirds).
  • The four major macromolecules (the core components of biology):
    • Lipids
    • Proteins
    • Nucleic acids (DNA and RNA)
    • Carbohydrates
  • Phosphorus and sulfur occurrences:
    • DNA has a phosphodiester backbone (phosphorus).
    • Some amino acids contain sulfur.
  • From atoms to cells:
    • Cells are the basic living units; all life emerges from cells.
    • In humans, common cell types include smooth muscle cells (example used in lecture).

Cells, tissues, and microstructure (examples from the lecture)

  • A smooth muscle cell example:
    • Smooth muscle cells are smaller than skeletal muscle cells and typically have one nucleus (unlike skeletal muscle cells, which may have many nuclei).
    • Smooth muscle tissue forms part of various organs (e.g., the urinary bladder) and works within tissues to create functional structures.
  • Tissues are aggregates of like cells that connect and function together as a unit.
  • An organ contains at least two tissue types and is encapsulated with a defined function; organs are often comprised of multiple tissue types working together.

Structure-function: integration and examples

  • Integrating anatomy and physiology (the course title): Integrated Human Anatomy and Physiology I
    • The course emphasizes learning both structure and function together, rather than in isolation.
    • Some universities separate anatomy and physiology into two courses (an unintegrated approach), but this course advocates integration for a holistic understanding.
  • The integrated approach provides an immediate context for how structure enables function and how function reinforces structure.
  • The lecture notes also compare approaches across institutions to illustrate there is no single “right” method; there are preferences and historical precedents.

Physiology: the study of function (the other side of the coin)

  • One-word definition of physiology: function.
  • How things work concept:
    • Example with an engine: the engine block (structure) houses a piston (structure); fuel-air mixture and ignition drive a controlled explosion that moves the piston and ultimately turns wheels.
    • This illustrates that function arises from the coordinated interaction of multiple structural components.
  • The relationship between structure and function: they are interdependent and interrelated; one largely determines the other; they are not synonymous but are tightly linked.
  • The concept of control systems in the body is introduced (nervous vs endocrine) and will be explored further in the course.

The 12 body systems: overview and starting points

  • The body is organized into 12 systems; the lecture begins with an overview of the first few:
    • Integumentary system: consists of one organ—skin; the largest organ of the body (roughly 11\text{ pounds} on average).
    • Skin functions: protection, regulation of body temperature, and hydration maintenance (among other roles discussed later).
    • Skeletal system: consists of 206 bones; bones form a rigid framework, protect organs, and interact with muscles for movement; bone marrow produces blood; bones store calcium and phosphorus; bones also serve as a reserve of fat in adulthood.
    • Muscular system: about 650 skeletal muscle organs; enables movement and posture maintenance; generates heat (e.g., shivering).
    • Nervous system: composed of central nervous system (brain and spinal cord) and peripheral nervous system (nerves); responsible for sensing internal/external environments, initiating movements, and coordinating physiology; one of the two main body control systems (the other being the endocrine system).
    • Endocrine system: introduced as the second major body control system; more details will be covered in Biology 320.
  • The instructor emphasizes that most of the rest of the systems will be covered in 3/20, with early exposure to a broad, integrated overview in this course.

Practical guidance for learning and class participation

  • Emphasize timely attendance and note how late arrivals can miss important information.
  • Build study communities: make friends, check with peers for what was discussed earlier in class.
  • The instructor’s aim is to provide the core, essential points that will appear on exams; students should use lectures to ground and connect with lab material.

Quick recap of key relationships presented in this lecture

  • Anatomy = structure; physiology = function; and in this course they are integrated.
  • There are multiple levels of structural analysis: gross anatomy (visible to the naked eye), histology (t tissues under microscope), and cellular ultrastructure (ultra-fine details seen with electron microscopy).
  • Tissues are the building blocks of organs; organs are the functional units of organ systems; organ systems work together to sustain the organism.
  • The urinary bladder exemplifies how form (hollow, expandable chamber with transitional epithelium and smooth muscle) is perfectly matched to function (holding and expelling urine).
  • Body content basics: about 60\% - 65\% of body mass is water; four major macromolecules drive biology: ext{lipids}, ext{proteins}, ext{nucleic acids}, ext{carbohydrates}; the four key elements in the body’s bulk composition are ext{C}, ext{O}, ext{H}, ext{N}.

End of Day note

  • The lecturer signs off at around 12:25 PM after outlining the plan for the next lectures and reiterating the 12-system framework and integrated teaching approach.