Intro to Structure, Organization, and Planes in A&P

Structure and Function

  • Core principle: Structure equals function; everything is designed with a specific structure to carry out a particular function.
  • We will cover core study strategies and how to use the book; expect a quiz with some questions on these topics; review during breaks.
  • Read the textbook and the lecture slides; the lecture schedule mirrors lab; use the PowerPoints during class; take notes and study from them.
  • Class schedule (lecture): 50-minute lectures with short breaks:
    • Lecture block: 09:50–10:00 break, then 10:00–10:50 lecture, then 10:50–11:00 break, then 11:00–11:55 lecture.
  • You should print or have access to the PowerPoints if you don’t have a computer in class.
  • The aim is to understand how to study for anatomy and physiology; the same approach applies to lecture and lab.
  • Emphasis on active studying rather than passively reading slides.

Characteristics of Living Organisms

  • One defining feature: living organisms are composed of cells.
    • The human body contains trillions of cells.
  • A cell is the smallest functional unit that can carry out all the functions of life.
  • Other key characteristics of life include metabolism, growth, excretion, responsiveness, movement, and reproduction.

Metabolism: Anabolism and Catabolism

  • Metabolism: sum of all chemical reactions in an organism; most metabolic activities occur at the cellular level.
  • Anabolism: building larger molecules from smaller subunits; typically energy input-required.
    • Example: amino acids assembled into proteins; anabolic steroids (historical analogy) build up muscle by promoting synthesis of complex molecules.
    • Definition: smaller units → larger, energy input needed.
  • Catabolism: breaking large molecules into simpler components; energy is released.
    • Example: digestion of food; nutrients are broken down to release energy.
  • Energy flow: energy released by catabolic reactions is captured and used for anabolic reactions to build and repair tissues.
    • Summary relation: catabolic reactions provide the energy for anabolic reactions to occur.
  • Notation: we can express energy changes as:
    • \Delta E_{\text{input}} > 0 for anabolic processes (net energy input).
    • \Delta E_{\text{released}} < 0 for catabolic processes (net energy release).

Growth, Excretion, Responsiveness, Movement, Reproduction

  • Growth: increase in size and/or number of cells.
    • E.g., hair and nails grow continuously; chairs do not grow.
  • Excretion: elimination of wastes (defecation, urination) to maintain homeostasis.
  • Responsiveness/irritability: organisms respond to environmental stimuli (external and internal).
    • Examples: moving away from heat, hunger signals trigger eating, breathing rate changes with blood oxygen levels.
  • Movement: organisms can move; in humans, this includes both external movement and internal movement (e.g., blood flow, digestion).
  • Reproduction: genetic information passed to offspring; can be sexual or cellular (e.g., skin cell turnover or hair growth as a form of cell replication).

Structural Organization and Emergent Properties

  • The hierarchy of life (in humans) begins with the chemical level and proceeds upward, with emergent properties at each level:
    • Chemical level: atoms and chemicals form the basis of matter.
    • Macromolecules: proteins, carbohydrates, lipids, and nucleic acids (DNA) are unique to living organisms and organize into cells.
    • Cells: the basic unit of life with emergent properties not present in individual molecules; cells perform specialized functions.
    • Tissues: groups of similar cells form tissues (emergent properties beyond the cells themselves).
    • Organs: composed of two or more tissues; organs have properties beyond those of their constituent tissues.
    • Organ systems: groups of organs working together (e.g., digestive system, cardiovascular system).
    • Organism: the complete living being (the human) composed of multiple organ systems functioning together; the whole is greater than the sum of its parts.
  • Emergent properties: as complexity increases, new properties arise that individual components do not have (the whole is more than the sum of its parts).
    • Example: a phospholipid is an emergent property formed when carbon and hydrogen assemble into lipids; phospholipids are amphipathic and have properties that individual carbon/hydrogen atoms do not.
    • Similarly, a cell has properties that a single macromolecule cannot exhibit.
  • Cells do not exist in isolation; they come together to form tissues.
  • Four basic tissue types (the next unit in study):
    • Epithelial tissue (epithelial)
    • Connective tissue (connective)
    • Muscle tissue (muscle)
    • Nervous tissue (nervous)
  • Each tissue type has emergent properties distinct from its component cells and macromolecules, and each cell, macromolecule, and tissue has specialized structure and function.

Macromolecules and Cells

  • Four macromolecules important to living organisms: proteins, carbohydrates, lipids, and nucleic acids (DNA).
    • Represented as: proteins,carbohydrates,lipids,nucleic acids{\text{proteins}, \text{carbohydrates}, \text{lipids}, \text{nucleic acids}}
  • Macromolecules assemble to form cells; a cell has emergent properties greater than the individual molecules.
  • Cells come in various types and perform specialized functions; not all cells are identical.

Tissues

  • Four basic tissues:
    • Epithelial tissue
    • Connective tissue
    • Muscle tissue
    • Nervous tissue
  • Each tissue type has its own structure-function relationship and emergent properties beyond the properties of individual cells.

Organs and Organ Systems

  • Organs: a higher level of organization consisting of two or more tissue types that work together to perform a specific function.
    • Example: stomach contains epithelial, connective, muscle, and nervous tissues; it stores and digests food and secretes digestive juices.
    • Brain is an organ that does not include muscle tissue; it contains epithelial, connective, nervous tissues, but not muscle tissue.
  • Organs do not exist in isolation; they are part of organ systems.
  • Organ systems (examples):
    • Integumentary system
    • Skeletal system
    • Muscular system
    • Nervous system
  • In BIO 141, these four systems are studied.
  • In BIO 142, this expands to include: Endocrine, Cardiovascular, Lymphatic, Respiratory, Digestive, Urinary, Reproductive systems.
  • Digestive system example: mouth, esophagus, stomach, small intestine, large intestine, liver, gallbladder, pancreas, all working to bring nutrients into bloodstream.
  • Cardiovascular/ circulatory system example: heart is part of this system and delivers blood; nervous system controls the brain/spinal cord.
  • Organ systems together maintain homeostasis and support life; the organism is the sum of these systems working in harmony.

Types of Anatomy and Physiology and Subfields

  • Types of anatomy:
    • Systemic anatomy: studies each organ system individually (e.g., structure of the heart or a system-wide view).
    • Regional anatomy: examines body regions (e.g., head and neck; thoracic region) and all their organs.
    • Surface anatomy: studies surface markings; used for understanding bone markings and where muscles/tendons attach.
    • Gross anatomy: structures visible to the unaided eye.
    • Microscopic anatomy: study of cells and tissues with a microscope; will include lab work on tissues starting soon.
  • Plan to study tissues in lecture and lab; the four tissue types will be examined in depth.
  • Physiology: how structures function; subfields are often organized by organ or organ system (e.g., bone physiology, nervous system physiology).
  • Note: The skeleton (bone) physiology is studied in BIO 141; senses and nervous system physiology are also studied; skin physiology (integumentary system) is explored for its protective roles, vitamin D synthesis, thermoregulation, and sensory monitoring.
  • Terminology: medicine uses Latin and Greek roots; understanding word roots helps interpret terms; this is reinforced throughout lecture and lab.
  • Aikos on terminology class: NOVA offers Medical Terminology; the instructor emphasizes understanding word meaning from roots rather than memorizing all vocabulary; this course helps interpret terms encountered in anatomy and physiology.

Anatomical Position, Directional Terms, and Regional Terms

  • Anatomical position: standing upright, feet shoulder-width apart, upper limbs at the sides, head and palms facing forward.
  • Directional terms: anterior (ventral), posterior (dorsal), superior (cranial), inferior (caudal), proximal, distal, medial, lateral, superficial, deep; cranial is synonymous with cephalic in some contexts.
  • Regional terms: a set of terms used to describe regions of the body (head, neck, thorax, abdomen, etc.).
  • Study tips for directional/regional terms:
    • Create blank diagrams of the human figure and practice labeling without the words to test yourself.
    • Use the Pearson study resources, including flashcards and practice tests, to reinforce the terms.
    • Expect quiz questions on directional and regional terms in lab and exams.

Planes of Section

  • Planes of section define how anatomy can be cut or viewed in a cross-section:
    • Sagittal plane: divides body into right and left portions.
    • Midsagittal plane: divides into equal right and left halves.
    • Parasagittal plane: divides into unequal right and left portions.
    • Frontal (coronal) plane: divides body into anterior (ventral) and posterior (dorsal) parts.
    • Transverse (horizontal) plane: divides body into superior and inferior parts; also called cross-sectional.
    • Oblique plane: cuts at an angle; used less frequently (e.g., angled cuts through the heart).
  • Example: midsagittal brain section from an MRI shows the medial right half of the brain; a frontal section shows front/back view; a transverse section shows superior/inferior view.
  • Study boost: Flashcards (via Pearson) and study area resources help memorize terms and planes.
  • Study approach recommendations: read each chapter 3–4 times before the first exam; use Pearson homework mastery and practice quizzes; utilize the study area for extra practice.

Study Tools and Exam Preparation

  • Study tools mentioned:
    • Pearson eText and study area
    • Flashcards (digital or paper) for terminology and planes
    • Practice quizzes and master homework assignments
  • Recommended study plan:
    • Read Chapter 1 today, Chapter 1 again next week, start Chapter 2 next week; repeat through the term.
    • Use the