Anatomy & Physiology: Foundational Concepts and Cell Structure

Chapter 1: Foundational Concepts in Anatomy & Physiology

Anatomy vs. Physiology: Structure vs. Function

Anatomy and physiology are closely related disciplines that form the basis of understanding the human body. Anatomy focuses on the structure of body parts, while physiology explores their functions.

• Characteristics of living matter: Includes organization, complementary functions, and signaling pathways in living systems.

• Homeostasis: The process by which organisms maintain stable internal conditions. Examples include temperature regulation and blood glucose control.

• Negative feedback: A mechanism that counteracts changes in a physiological variable, helping maintain homeostasis.

Example: Regulation of body temperature through sweating or shivering.

Body Systems: Names, General Functions, and Representative Organs

The human body is organized into systems, each with specific functions and representative organs.

• Examples: The cardiovascular system (heart, blood vessels), respiratory system (lungs, trachea), digestive system (stomach, intestines).

• General function: Each system contributes to the characteristics of life in the human organism, such as movement, responsiveness, and metabolism.

Additional info: The major body systems include the integumentary, skeletal, muscular, nervous, endocrine, cardiovascular, lymphatic, respiratory, digestive, urinary, and reproductive systems.

Body Cavities and Membranes

Body cavities house internal organs and are lined by membranes that provide protection and compartmentalization.

• Types of cavities: Dorsal (cranial and vertebral) and ventral (thoracic and abdominopelvic).

• Membranes: Serous membranes (e.g., pleura, pericardium, peritoneum) and their functions.

• Lab exercises: Identification and description of cavities and membranes.

Additional info: Serous membranes secrete fluid to reduce friction between organs.

Chapter 3: Cell Anatomy and Physiology

Cell Structure: Compartmentalization and Contents

Cells are the basic units of life, with specialized structures that perform distinct functions.

• Extracellular space/fluid vs. intracellular space/fluid: The extracellular space surrounds cells, while the intracellular space is within the cell membrane.

• Cell (Plasma) Membrane: Composed of a phospholipid bilayer with embedded proteins, carbohydrates, and cholesterol.

• Organic compounds/macromolecules: Proteins, lipids, carbohydrates, and nucleic acids are essential for cell structure and function.

Example: The plasma membrane regulates the movement of substances into and out of the cell.

Membrane Function: Regulation and Transport

Cell membranes control the passage of materials and facilitate communication between cells.

• Selective permeability: Only certain substances can cross the membrane.

• Transport mechanisms: Include passive (diffusion, osmosis) and active (pumps, vesicular transport) processes.

• Na+/K+ Pump: An active transport mechanism that maintains ion gradients across the membrane.

Equation:

$\text{Na}^+/\text{K}^+ \text{ Pump:} \, 3\, \text{Na}^+ \text{ out}, \, 2\, \text{K}^+ \text{ in}$

Additional info: Vesicular transport includes endocytosis and exocytosis, which move large molecules or particles.

The Organelles: Names and General Functions

Organelles are specialized structures within cells that perform specific tasks essential for cell survival.

Organelle	Main Function
Nucleus	Contains genetic material (DNA); controls cell activities
Mitochondria	Produces ATP through cellular respiration
Endoplasmic Reticulum (ER)	Synthesizes proteins (rough ER) and lipids (smooth ER)
Golgi Apparatus	Modifies, sorts, and packages proteins and lipids
Lysosomes	Digests cellular waste and foreign material
Ribosomes	Site of protein synthesis

Additional info: Table 4.1 in lab text provides further details on organelle structure and function.

Structures and Functions Common to All Cells

All cells share certain structures and functions, but may specialize through differentiation.

• Cell differentiation: The process by which cells become specialized for specific functions.

• The Cytoskeleton: Provides structural support and facilitates movement. Includes microfilaments, intermediate filaments, and microtubules.

Example: Microtubules are involved in cell division and intracellular transport.

The Cell Cycle: Division, Purpose, Events

The cell cycle is the series of events that cells go through as they grow and divide.

• Phases: Interphase (G1, S, G2) and M phase (mitosis and cytokinesis).

• Purpose: Growth, repair, and reproduction of cells.

• Events: DNA replication, chromosome segregation, and division into two daughter cells.

Equation:

$\text{Cell Cycle:} \, G1 \rightarrow S \rightarrow G2 \rightarrow M$

Additional info: Proper regulation of the cell cycle is essential for tissue health and prevention of diseases such as cancer.