Anatomy & Physiology: Foundational Concepts, Cells, and Tissues Study Guide

Chapter 1: Introduction to Anatomy & Physiology

Levels of Organization

The human body is organized in a hierarchical manner, from the smallest chemical units to complex organ systems.

• Atom: The basic unit of matter.

• Molecule: Two or more atoms bonded together.

• Organelle: Specialized structures within cells.

• Cell: The basic unit of life.

• Tissue: Groups of similar cells performing a common function.

• Organ: Structures composed of two or more tissue types.

• Organ System: Groups of organs working together for a common purpose.

Organ Systems

Each organ system has a specific overall function essential for maintaining homeostasis and supporting life.

• Examples: Nervous system (control), cardiovascular system (transport), digestive system (nutrient absorption).

Homeostasis

Homeostasis refers to the body's ability to maintain a stable internal environment despite external changes.

• Components: Receptor (detects change), Control Center (processes information), Effector (responds to change).

• Feedback Mechanisms:

  • Negative Feedback: Reduces the effect of the stimulus (e.g., body temperature regulation).

  • Positive Feedback: Enhances the effect of the stimulus (e.g., blood clotting).

Survival Needs

The body requires certain conditions to survive, known as the 5 Survival Needs:

• Nutrients

• Oxygen

• Water

• Normal Body Temperature

• Atmospheric Pressure

Anatomical Terminology

Understanding anatomical terminology is essential for describing locations and directions in the body.

• Regional Terms: Refer to specific areas (e.g., brachial for arm).

• Directional Terms: Describe positions (e.g., superior, inferior, anterior, posterior).

• Body Cavities: Dorsal (cranial, vertebral) and ventral (thoracic, abdominopelvic).

Chapter 2: Chemistry of Life

Atomic Structure

Atoms are composed of subatomic particles: protons, neutrons, and electrons. Atomic number and mass are used to determine the number of each particle.

• Atomic Number: Number of protons.

• Mass Number: Number of protons plus neutrons.

Electron Shells

Electrons are arranged in shells around the nucleus. The number of electrons in each shell determines chemical reactivity.

• First shell: Up to 2 electrons.

• Second shell: Up to 8 electrons.

Chemical Bonds

Atoms bond to achieve stability. The main types of chemical bonds are:

• Ionic Bonds: Transfer of electrons between atoms.

• Covalent Bonds: Sharing of electrons between atoms.

• Polar and Nonpolar Bonds: Polar bonds have unequal sharing; nonpolar bonds have equal sharing.

Properties of Water

Water is essential for life due to its polarity, high heat capacity, and solvent properties.

• Polarity: Allows water to dissolve many substances.

• Hydrogen Bonds: Contribute to water's unique properties.

Inorganic Compounds

Inorganic compounds do not contain carbon-hydrogen bonds. Examples include water, salts, and acids/bases.

• Salts: Ionic compounds that dissociate in water.

• Acids and Bases: Affect pH; acids release H+, bases accept H+.

pH Scale

The pH scale measures the concentration of hydrogen ions in a solution.

• Acidic: pH < 7

• Neutral: pH = 7

• Basic: pH > 7

Formula:

$pH = -\log_{10}[H^+]$

Organic Compounds

Organic compounds contain carbon and are essential for life. The main types are carbohydrates, lipids, proteins, and nucleic acids.

• Carbohydrates: Provide energy; include monosaccharides, disaccharides, and polysaccharides.

• Lipids: Include triglycerides and phospholipids; important for energy storage and membrane structure.

• Proteins: Made of amino acids; function as enzymes, structural components, and more.

• Nucleic Acids: DNA and RNA; store and transmit genetic information.

Chapter 3: Cells and Their Environment

Membrane Composition

Cell membranes are composed of phospholipids, proteins, and cholesterol, which provide structure and regulate transport.

• Phospholipid Bilayer: Forms the basic structure.

• Proteins: Serve as channels, carriers, and receptors.

• Cholesterol: Stabilizes membrane fluidity.

Membrane Junctions

Cells are connected by specialized junctions:

• Tight Junctions: Prevent leakage between cells.

• Desmosomes: Provide mechanical strength.

• Gap Junctions: Allow communication between cells.

Membrane Transport

Substances move across cell membranes by passive or active transport.

• Passive Transport:

  • Diffusion: Movement from high to low concentration.

  • Facilitated Diffusion: Uses carrier proteins.

  • Osmosis: Diffusion of water across a membrane.

• Active Transport: Requires energy to move substances against a concentration gradient.

• Vesicular Transport: Includes endocytosis (into cell) and exocytosis (out of cell).

Tonicity

Tonicity describes the effect of a solution on cell volume.

• Isotonic: No net movement of water.

• Hypertonic: Water moves out; cell shrinks.

• Hypotonic: Water moves in; cell swells.

Organelles and Cell Structures

Cells contain specialized organelles for various functions.

• Nucleus: Contains genetic material.

• Mitochondria: Produce ATP.

• Endoplasmic Reticulum: Synthesizes proteins and lipids.

• Golgi Apparatus: Modifies and packages proteins.

• Lysosomes: Digest cellular waste.

Cell Cycle and Division

Cells reproduce by mitosis and meiosis.

• Mitosis: Produces two identical daughter cells.

• Phases: Prophase, metaphase, anaphase, telophase.

DNA Replication and Protein Synthesis

DNA replication ensures genetic continuity; protein synthesis involves transcription and translation.

• DNA Replication: DNA makes a copy of itself before cell division.

• Transcription: DNA is transcribed into mRNA.

• Translation: mRNA is translated into a protein.

Example: If the DNA sequence is ATG-CAG, the mRNA sequence will be UAC-GUC.

Characteristics of Epithelial Tissue

Epithelial tissue covers body surfaces and lines cavities.

• Functions: Protection, absorption, filtration, secretion.

• Types: Simple (single layer), stratified (multiple layers).

• Locations: Skin, lining of digestive tract, respiratory tract.

Characteristics of Connective Tissue

Connective tissue supports, protects, and binds other tissues.

• Components: Cells, fibers (collagen, elastic, reticular), and extracellular matrix.

• Types: Loose, dense, cartilage, bone, blood.

Chapter 4: The Integumentary System

Body Membranes

Body membranes cover surfaces, line cavities, and form protective sheets.

• Types: Cutaneous (skin), mucous, serous, synovial.

• Serous Membranes: Have two layers—parietal (lines cavity) and visceral (covers organ).

Skin Structure and Function

The skin consists of two main layers: epidermis and dermis.

• Epidermis: Stratified squamous epithelium; contains keratinocytes, melanocytes, dendritic cells, tactile cells.

• Dermis: Connective tissue; contains blood vessels, nerves, glands.

Layers of the Epidermis

The epidermis is organized into distinct layers:

• Stratum basale: Deepest layer; cell division occurs here.

• Stratum spinosum

• Stratum granulosum

• Stratum lucidum: Only in thick skin.

• Stratum corneum: Outermost layer; dead, keratinized cells.

Hair and Nails

Hair and nails are accessory structures of the skin.

• Hair Structure: Shaft, root, bulb; composed of keratin.

• Nail Structure: Free edge, body, root; composed of hard keratin.

Glands of the Skin

Skin contains several types of glands:

• Sudoriferous (Sweat) Glands: Eccrine (thermoregulation), apocrine (odor).

• Sebaceous (Oil) Glands: Secrete sebum to lubricate skin and hair.

Homeostatic Imbalances

Disorders of the skin include infections, allergies, and cancer.

• Types of Skin Cancer: Basal cell carcinoma, squamous cell carcinoma, melanoma.

• ABCDE Rule: Asymmetry, Border, Color, Diameter, Evolving (used to identify melanoma).

Burns

Burns are classified by depth and severity.

• Types: First-degree (epidermis), second-degree (epidermis and part of dermis), third-degree (full thickness).

• Rule of Nines: Used to estimate the percentage of body surface area affected by burns.

Type of Membrane	Location	Main Function
Cutaneous	Skin	Protection
Mucous	Lines body cavities open to exterior	Secretion, absorption
Serous	Lines closed body cavities	Lubrication
Synovial	Joints	Reduces friction

Additional info: Some details, such as the full list of organ systems and expanded examples of homeostatic mechanisms, were inferred for completeness.