Introduction to Anatomy and Physiology PDF

# Introduction to Anatomy and Physiology ## Chapter One ### Levels of Organization - **Organ System Level:** Many organs interact together to produce the function of a specific system, such as the cardiovascular system, which consists of the heart, blood, and blood vessels. - **Organism Level:**...

# Introduction to Anatomy and Physiology ## Chapter One ### Levels of Organization - **Organ System Level:** Many organs interact together to produce the function of a specific system, such as the cardiovascular system, which consists of the heart, blood, and blood vessels. - **Organism Level:** All of the organ systems of the body work together to maintain life and health. ### Homeostasis - **Homeostasis** is the existence of a stable internal environment. - **Homeostatic Regulation** is the adjustment in physiological systems that preserve homeostasis. Homeostatic regulation involves: - **Receptor:** Is sensitive to a particular environment change or stimulus. - **Control Center:** Receives and processes information from the receptor. - **Effector:** Responds to the commands of the control center and either opposes or reinforces the stimulus. ### Negative Feedback - Variation outside normal limits triggers an automatic response that corrects the situation. ### Positive Feedback - The initial stimulus produces a response that reinforces that stimulus. ### The Language of Anatomy - **Surface Anatomy** - **Anatomical Landmarks:** - **Supine** (face up) - **Prone** (face down) - **Anatomical Regions:** - **Abdominopelvic Quadrants (4)** - **Abdominopelvic Regions (9)** ### Anatomical Direction - **Anterior** (front) - **Ventral** (front) - **Posterior** (back) - **Dorsal** (back) - **Lateral** (side) - **External** (outside) - **Medial** (middle) - **Internal** (inside) - **Proximal** (toward an attached base) - **Distal** (away from an attached base) - **Superior** (above) - **Inferior** (below) ### Body Cavities Covered - All body cavities are covered by serous moist membrane, those which lines organs "viscera" called the visceral layers, and the opposing layer that lines the inner surface, or the body wall or chamber is called the parietal layer. - The function of visceral and parietal layers: - They permit expansion and limited movement. - They prevent friction. ## Chapter Two ### The Chemical Level of Organization - **Chemistry** is the science that investigates matter and its interactions. - **Matter** is anything that takes up space and has mass. All matter is composed of substances called elements. - **Elements** are a part of matter that cannot be changed or broken down into simpler substances. ### Structure of an Atom - **Atoms** are the smallest stable unit of matter. - Atoms contain three major types of subatomic particles: - **Neutrons:** Have a neutral electrical charge. - **Protons:** Have a positive electrical charge. - **Electrons:** Have a negative electrical charge. ### Isotopes - Isotopes are atoms of an element that differ in the number of neutrons in the nucleus. - Some isotopes are unstable. Unstable isotopes are radioactive and spontaneously emit subatomic particles or radiation. ### Atomic Weight - The average mass of an element's atoms, taking into account the mass of the subatomic particles and the relative proportions of any isotopes. ### Chemical Bonds - **Ionic Bonds:** Occur when one atom loses and another atom gains an electron. Atoms or molecules with an electrical charge are called ions. Atoms with a positive charge are called cations. Atoms with a negative charge are called anions. - **Covalent Bonds:** Created by sharing electrons with other atoms. If the sharing of one pair of electrons creates a single covalent bond, sharing two pairs creates a double covalent bond. Covalent bonds are very strong because the electrons tie the atoms together. ### Types of Chemical Reactions - **Decomposition Reaction:** Breaks molecules into smaller fragments, as in digestion. - **Synthesis Reaction:** Assembles larger molecules from smaller components. - **Exchange Reaction:** The components of reactions and products are present in different combinations. - **Reversible Reaction:** Occurs when a synthesis reaction and a decomposition reaction happen simultaneously, and at equilibrium, the rate of both reactions is balanced. ### Enzymes - **Enzymes** are very important proteins that catalyze the reactions that sustain life. - The reactants in an enzymatic reaction are called **substrates**, which interact to form a specific product. The substrates must bind to a specific region of the enzyme called the **active site**. The fit depends on the complementary shapes of the two molecules. ## Chapter Three ### Cell Structure and Function - **Cells** are the building blocks of the human body. About trillions of human body cells form and maintain anatomical structures, and they perform physiological functions. - **Cell Anatomy:** A cell is surrounded by **extracellular fluid**. The cell's outer boundary, called the cell membrane, separates the **cytoplasm** (cell contents) from the extracellular fluid. - **Organelles:** Specialized structures within a cell. ### Organelles: - **Cytoplasm:** Main substance that fills the cell and holds the organelles - **Nucleus:** Control center of the cell, which contains genetic material. - **Endoplasmic Reticulum (ER):** Complex organelle composed of membrane-bound flattened sacs, elongated canals, and fluid-filled sacs. It communicates with the cell membrane, nuclear envelope, and other organelles. - **Rough ER:** Ribosomes are attached. Serves as a site for protein synthesis. - **Smooth ER:** No ribosomes are attached. Contains enzymes important in lipid synthesis. ### Vesicular Transport - Material moves into or out of cells in membranous sacs that form at, or fuse with, the cell membrane. - **Endocytosis:** Movement of extracellular material into the cell. - **Receptor-mediated endocytosis:** Active process includes receptors at the surface membrane that bind with specific molecules; then form vesicles. - **Phagocytosis:** "Cell eating". Cell engulfing of large particles, such as bacteria. - **Pinocytosis:** "Cell drinking". Cell engulfing of smaller particles, such as proteins. - **Exocytosis:** The reverse of endocytosis. A vesicle inside the cell fuses with the cell membrane and discharges its contents into the extracellular environment. ## Chapter Five ### The Integumentary System - **Thermoregulation:** The skin maintains normal body temperature. - **Synthesis and storage of nutrients:** The stratum germinativum synthesizes Vitamin D3, a steroid building block for a hormone that aids calcium uptake. The dermis stores large reserves of lipids. - **Sensory Reception:** Receptors in the skin detect touch, pressure, pain, and temperature. - **Excretion & Secretion:** Integumentary glands excrete salts, water, and organic wastes. ### The Epidermis - Stratified squamous epithelium. - Several cell layers (strata): - **Stratum Germinativum** (deepest) - **Stratum Spinosum** - **Stratum Granulosum** - **Stratum Lucidum** (palms and soles) - **Stratum Corneum** (superficial) ### The Dermis - Superficial **papillary layer:** Loose connective tissue that supports the epidermis and contains blood vessels and nerves. - Deeper **reticular layer:** Dense, irregular connective tissue with elastic fibers that provide flexibility and collagen fibers that limit flexibility. Also contains blood vessels and nerves. - Epidermal accessory organs (hair follicles, sweat glands) extend into the dermis. ### Hypodermis (Subcutaneous Tissue) - Consists of loose connective tissue with many fat cells. - Provides energy reserves, reduces heat loss, and connects the skin to underlying tissue. ### Accessory Structures - **Hair and Hair Follicles:** - **Hair shaft** (exposed) - **Hair root** - **Hair follicle** (sheath) - **Sebaceous glands:** Secrete sebum, an oily substance. - **Sweat glands:** Produce sweat. ## Chapter Six ### The Skeletal System - Contains 206 separated bones. ### Functions - **Support:** Provides structure and a framework for the attachment of soft tissues and organs. - **Storage:** Bones store calcium, phosphate ions, and energy reserves (as lipids). - **Blood Cell Production:** Occurs in the red bone marrow. - **Protection:** Skeletal elements protect soft tissues and organs. - **Movement:** Skeletal muscles are attached to bones. ### Bone Structure - **Bone Matrix:** Consists of extracellular protein fibers and ground substances. - **Calcium phosphate** makes up most of the bone matrix. - **Collagen fibers** make up the rest. - Osteocytes and other cell types are also present. ### Bone Types - **Compact Bone:** Solid. - **Spongy Bone:** A network of bone rods separated by space. ### Long Bones - **Diaphysis (shaft)** - **Epiphysis** - **Bone Marrow** ### Bone Covers - **Periosteum:** Outer surface bone cover. - Attaches muscles to bones. - Isolates the bone. - Provides a route for blood vessels and nerves. - Participates in bone growth and repair. - **Endosteum:** Lines the marrow cavity and other inner coverings. - Functions in bone growth and repair.