Overview
This lecture introduces the foundational concepts of anatomy and physiology, emphasizing the relationship between structure and function, homeostasis, levels of organization, and the major organ systems.
Defining Anatomy and Physiology
- Anatomy is the study of body structures and their relationships.
- Physiology is the study of the functions and mechanisms in the body.
- Anatomy can be studied at various levels: gross (organs), histology (tissues), and cytology (cells).
- Physiology often involves physics and chemistry to understand body processes.
- "Form and function" summarizes the connection between anatomy (form) and physiology (function).
Grand Themes in Anatomy & Physiology
- Structure determines function: the shape and makeup of organs relate to their roles.
- Examples: Human eyelids are structured for quick movement to protect the eyes; nasal conchae create air turbulence to trap particles.
- Changes in structure (e.g., sickle-cell disease) can impair function (e.g., oxygen transport).
Homeostasis
- Homeostasis is the relative constancy of the body’s internal environment despite external changes.
- Dynamic equilibrium describes how homeostasis involves continuous adjustments above and below a set point (e.g., body temperature).
- Components of homeostasis: receptor (detects change), control center (analyzes and decides response), and effector (carries out response).
- Negative feedback reverses a change to maintain balance, e.g., insulin lowers high blood sugar.
- Positive feedback amplifies a change and is used in processes with a clear endpoint, e.g., childbirth and blood clotting.
Levels of Organization
- Body organization progresses: chemical/molecular → cellular → tissue → organ → organ system → organism.
- Cells are the smallest living units; tissues are groups of similar cells; organs combine different tissues; organ systems are groups of organs with a common function.
- Four main tissue types: epithelial, connective, muscle, and nervous tissue.
- Most organs (e.g., heart) contain all four tissue types.
Organ Systems & Mnemonics
- Eleven major organ systems: muscular, urinary, respiratory, digestive, endocrine, reproductive, skeletal, lymphatic, integumentary, nervous, cardiovascular.
- Mnemonic "MURDERS LINC" helps remember the organ systems.
Key Terms & Definitions
- Anatomy — the study of body structure and relationships among parts.
- Physiology — the study of body function and mechanisms.
- Histology — study of tissues.
- Cytology — study of cells.
- Homeostasis — maintenance of a stable internal environment.
- Negative Feedback — response that counteracts a deviation from set point.
- Positive Feedback — response that intensifies the original stimulus.
- Organ System — group of organs working together for a common function.
- Mnemonic Device — a memory aid, such as a word or phrase.
Action Items / Next Steps
- Learn and memorize the names and functions of the 11 organ systems.
- Review and understand key terms and definitions.
- Explore mnemonic devices for levels of organization and organ systems.