Ch. 1 The Human Body: An Orientation

Homeostasis and Feedback Mechanisms

Homeostasis is the body's ability to maintain a stable internal environment despite changes in external conditions. It is essential for normal body functioning and survival.

• Negative Feedback: A process that reverses a change in a controlled condition, bringing the body back to its set point. Example: Regulation of body temperature.

• Positive Feedback: A process that amplifies a change, moving the body further from its set point. Example: Blood clotting, labor contractions.

Levels of Organization & Essential Life Processes

The human body is organized into hierarchical levels, each with specific functions.

• Chemical Level: Atoms and molecules

• Cellular Level: Cells and their organelles

• Tissue Level: Groups of similar cells

• Organ Level: Structures composed of at least two tissue types

• Organ System Level: Organs working together

• Organismal Level: The whole body

• Essential Life Processes: Maintaining boundaries, movement, responsiveness, digestion, metabolism, excretion, reproduction, growth.

• Living vs. Non-living: Living things carry out all essential life processes; non-living things do not.

Directional & Regional Terms/Planes

Directional terms describe the positions of structures relative to other structures or locations in the body.

• Superior (cranial): Toward the head

• Inferior (caudal): Away from the head

• Anterior (ventral): Toward the front

• Posterior (dorsal): Toward the back

• Medial: Toward the midline

• Lateral: Away from the midline

• Proximal: Closer to the origin of the body part

• Distal: Farther from the origin

• Body Planes: Sagittal (left/right), Frontal (anterior/posterior), Transverse (superior/inferior)

Symptoms vs. Signs

• Symptoms: Subjective changes not observable by others (e.g., pain, fatigue)

• Signs: Objective changes that can be observed or measured (e.g., fever, rash)

Metabolism, Anabolism, Catabolism

• Metabolism: All chemical reactions in the body

• Anabolism: Building up complex molecules from simpler ones (requires energy)

• Catabolism: Breaking down complex molecules into simpler ones (releases energy)

Ch. 3 Cells: The Living Units

Cell Division: Mitosis vs. Meiosis & Interphase

• Mitosis: Cell division producing two identical daughter cells (for growth and repair)

• Meiosis: Cell division producing four genetically unique gametes (for reproduction)

• Interphase: Period of cell growth and DNA replication before division

Cell Organelles & Functions

• Mitochondria: Site of ATP (energy) production

• Ribosomes: Synthesize proteins

• Lysosomes: Contain digestive enzymes to break down waste

• Other organelles: Endoplasmic reticulum, Golgi apparatus, etc.

Transport Processes: Passive vs. Active

• Passive Transport: No energy required; substances move down their concentration gradient

• Active Transport: Requires energy (ATP); substances move against their concentration gradient

• Examples of Passive: Diffusion, osmosis, facilitated diffusion

• Examples of Active: Sodium-potassium pump, endocytosis, exocytosis

Diffusion vs. Osmosis & Vesicular Transport

• Diffusion: Movement of molecules from high to low concentration

• Osmosis: Diffusion of water across a selectively permeable membrane

• Vesicular Transport: Movement of large particles via vesicles (endocytosis, exocytosis)

Ch. 4 Tissue: The Living Fabric

The Four Basic Tissue Types

• Epithelial Tissue: Covers surfaces, lines cavities, forms glands. Examples: Skin epidermis, lining of GI tract.

• Connective Tissue: Supports, protects, binds other tissues. Examples: Bone, blood, adipose, cartilage.

• Muscle Tissue: Contracts to cause movement. Examples: Skeletal, cardiac, smooth muscle.

• Nervous Tissue: Transmits electrical impulses. Examples: Brain, spinal cord, nerves.

Examples, Functions, and Locations

• Epithelial: Protection (skin), absorption (intestines), secretion (glands)

• Connective: Support (bone), transport (blood), insulation (fat)

• Muscle: Movement (skeletal), pumping blood (cardiac), moving food (smooth)

• Nervous: Communication (neurons), support (neuroglia)

Tissue Repair & Regeneration

• Steps: Inflammation, organization, regeneration/fibrosis

• Regenerative Capacity: Epithelial and connective tissues regenerate well; muscle and nervous tissues regenerate poorly

Membranes

• Cutaneous Membrane: Skin

• Mucous Membranes: Line body cavities open to exterior

• Serous Membranes: Line closed body cavities

Ch. 5 The Integumentary System

Skin Layers & Associated Tissues

• Epidermis: Stratified squamous epithelium; includes stratum corneum (outermost) and stratum germinativum (basal layer)

• Dermis: Dense irregular connective tissue

• Hypodermis: Adipose tissue (not technically part of skin)

Skin Color & Clinical Signs

• Cyanosis: Bluish skin due to low oxygen

• Erythema: Redness due to increased blood flow

• Jaundice: Yellowing due to bilirubin buildup

Functions & Properties of Skin

• Protection, temperature regulation, sensation, metabolic functions, blood reservoir, excretion

• Melanin: Pigment for UV protection

• Keratin: Protein for waterproofing and strength

• Collagen: Provides structure and elasticity

Aging, Glands, and Disorders

• Aging: Thinner skin, less elasticity, fewer melanocytes, slower healing

• Glands: Sebaceous (oil), sweat (eccrine/apocrine), ceruminous, mammary

• Skin Cancer: Basal cell carcinoma, squamous cell carcinoma, melanoma

• Burns: Classified by depth (first, second, third degree)

Ch. 6 Bones and Skeletal Tissues

Components of Bone Tissue

• Collagen Fibers: Provide flexibility and tensile strength

• Ground Substance: Contains hydroxyapatite (calcium phosphate crystals), water, and other minerals

• Bone Cells: Osteocytes (maintain bone), osteoblasts (build bone), osteoclasts (break down bone)

Bone Structure & Classification

• Spongy Bone: Porous, contains trabeculae

• Compact Bone: Dense, contains osteons (Haversian systems)

• Parts of Long Bone: Diaphysis (shaft), epiphyses (ends), medullary cavity, periosteum (outer covering)

• Bone Shapes: Long (femur), short (carpals), flat (sternum), irregular (vertebrae)

Bone Functions & Ossification

• Support, protection, movement, mineral storage, blood cell formation (hematopoiesis), fat storage

• Ossification: Process of bone formation

• Endochondral Ossification: Bone forms by replacing hyaline cartilage

• Intramembranous Ossification: Bone develops from fibrous membrane

Hormonal Regulation & Bone Markings

• PTH (Parathyroid Hormone): Increases blood calcium by stimulating osteoclasts

• Other Hormones: Calcitonin, growth hormone, sex hormones

• Bone Markings: Projections, depressions, and openings for muscle attachment and passage of vessels/nerves

Bone Tissue Vitality & Periosteum

• Bone tissue is living and has a rich blood supply

• Periosteum: Double-layered membrane covering bone; essential for growth, repair, and nutrition

Table: Classification of Bones by Shape

Key Equations

• General Equation for Metabolism:

• Osmosis (Water Potential):

where is water potential, is solute potential, and is pressure potential.

• Calcium Homeostasis (PTH effect):

Additional info: Some explanations and examples were expanded for clarity and completeness based on standard A&P textbooks.