Foundations of Anatomy & Physiology: Organization, Tissues, and Integumentary System

Basic Concepts in Anatomy & Physiology

Definitions and Scope

• Anatomy: Study of body structures.

• Physiology: Study of body functions.

• Cytology: Study of the internal structure of individual cells.

• Histology: Study of tissues (groups of specialized cells).

• Relationship: Structure exists to perform function.

Levels of Organization

Hierarchical Structure of the Human Body

• Chemical/Molecular: Atoms combine to form molecules (e.g., proteins, water).

• Cellular: Molecules form cells, the smallest living units.

• Tissue: Similar cells grouped for specific function (four primary types).

• Organ: Two or more tissues form an organ (e.g., heart, stomach).

• Organ System: Multiple organs work together (e.g., digestive system).

• Organism: All systems maintain life and health.

Key Terms in Physiology

Essential Functional Concepts

• Responsiveness (Irritability): Ability to respond to changes.

• Adaptability: Ability to adjust to environmental changes.

• Differentiation: Specialization of cells (e.g., stem cells).

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

• Catabolism: Breaking down complex molecules to release energy.

Branches of Anatomy

Types of Anatomical Study

• Gross (Macroscopic) Anatomy: Large structures visible to the naked eye.

• Systemic Anatomy: Study of organ systems.

• Microscopic Anatomy: Structures requiring magnification (cells, tissues).

Anatomical Language

Body Landmarks and Directional Terms

• Anatomical Position: Standing upright, feet forward, palms forward.

• Directional Terms:

  • Superior/Inferior: Above/below

  • Anterior (ventral)/Posterior (dorsal): Front/back

  • Medial/Lateral: Toward/away from midline

  • Proximal/Distal: Closer/farther from trunk

  • Superficial/Deep: Closer/farther from surface

• Body Planes:

  • Sagittal: Left/right

  • Frontal (coronal): Anterior/posterior

  • Transverse: Superior/inferior

  • Oblique: Angled cut

Body Cavities and Membranes

Major Cavities and Their Membranes

• Ventral Body Cavity: Separated by diaphragm.

  • Thoracic cavity: Heart, lungs

  • Pleural cavities: Lungs

  • Mediastinum: Pericardial cavity (heart)

  • Abdominopelvic cavity: Stomach, liver, intestines, bladder

• Membranes:

  • Parietal: Lines cavity walls

  • Visceral: Covers organs

Abdominopelvic Quadrants

Quadrant	Main Organs
RUQ	Liver, gallbladder
LUQ	Stomach, spleen
RLQ	Cecum, appendix, right ureter, right ovary, right spermatic cord
LLQ	Left ureter, left ovary, left spermatic cord

Vocabulary Highlights

Key Terms and Movements

• Lamina: Layer

• Confluence: Joining

• Papillae: Nipple-like

• Septum: Divider

• Afferent: Toward

• Efferent: Away

• Osteo-: Bone

• Myo-: Muscle

• Neuro-: Nerves

• Supinate: Rotate arm upward

• Pronate: Rotate arm downward

Tissue Types

Epithelial Tissue

• Functions: Protection, selective permeability, secretion, sensation.

• Characteristics: Cellularity (tight cells), polarity (apical/basal), avascular, innervated, high regeneration.

• Arrangement: Sheets (single or multiple layers).

• Types:

  • Simple Squamous: Single flat layer; diffusion/filtration (lungs, capillaries).

  • Simple Columnar: Single tall cells; absorption/secretion (digestive tract).

  • Stratified Squamous: Multiple layers; protection (skin, oral cavity).

  • Pseudostratified: Appears layered but single layer; secretion/mucus propulsion (respiratory tract).

Connective Tissue

• Components: Cells, protein fibers (collagen, elastic, reticular), ground substance.

• Functions: Support, protection, energy storage, transport, defense.

• Types:

  • Loose Connective Tissue: Fewer fibers, more ground substance (framework of lymphatic organs).

  • Dense Connective Tissue:

    • Dense Regular: Parallel collagen fibers; strength in one direction (tendons, ligaments).

    • Dense Irregular: Random collagen fibers; strength in all directions (dermis).

    • Elastic: Elastic fibers; stretch and recoil (large arteries).

  • Supporting Connective Tissue:

    • Cartilage:

      • Hyaline: Reduces friction. Most common, smooths joints (articular cartilage).

      • Elastic: Flexible (ear, nose).

      • Fibrocartilage: Shock absorber (intervertebral discs).

    • Bone:

      • 2/3 inorganic (calcium phosphate) for hardness.

      • 1/3 organic (collagen) for flexibility.

      • Covered by periosteum (dense irregular CT).

      • Compact bone arranged in osteons (functional units).

Muscle Tissue

• Skeletal, Cardiac, Smooth.

Nervous Tissue

• Conducts impulses.

Body Membranes

Types and Functions

• Mucous Membranes: Line passages open to outside; stay moist.

• Serous Membranes: Line ventral cavities; parietal and visceral layers; secrete friction-reducing fluid.

• Cutaneous Membrane: Skin.

• Synovial Membranes: Line joint cavities; secrete lubricating fluid.

Integumentary System

Functions and Components

• Functions: Protection, temperature regulation, sensation, waste excretion, vitamin D synthesis.

• Components: Skin (epidermis, dermis), hair, nails, sweat glands, sebaceous glands, mammary glands.

Skin Layers

• Epidermis:

  • Keratized, avascular.

  • Cell types: Keratinocytes (produce keratin), Melanocytes (produce melanin), Merkel cells (touch receptors).

  • Layers (deep to superficial): Boys Say Girls Like Cookies

    1. Stratum Basale (mitosis, melanocytes)

    2. Stratum Spinosum (keratinocytes, Langerhans cells)

    3. Stratum Granulosum (keratin production)

    4. Stratum Lucidum (palms, soles)

    5. Stratum Corneum (dead keratinized cells)

• Dermis:

  • Papillary layer: Thin, superficial; nutrients, Meissner's corpuscles (light touch).

  • Reticular layer: Thick, deep; hair follicles, glands, Pacinian corpuscles (pressure).

  • Composed of dense irregular connective tissue.

  • Contains blood vessels and nerves.

• Hypodermis (Subcutaneous):

  • Not part of skin.

  • Made of adipose and connective tissue.

  • Stabilizes skin, insulates, stores energy.

Skin Color Factors

• Blood supply, stratum corneum thickness, carotene, melanin (genetic control).

• Cyanosis: Bluish tint from low oxygen.

• Melanin protects against UV radiation.

Glands of the Skin

• Sweat Glands:

  • Eccrine: All over body; cooling by evaporation.

  • Apocrine: Axilla, nipples, groin; odorous secretions; activated at puberty.

• Sebaceous Glands: Produce sebum; lubricate skin and hair.

• Mammary glands: Milk production.

• Ceruminous glands: Earwax production.

Nails

• Protect finger and toe tips.

• Parts: Free edge, lateral fold, lunula, cuticle (eponychium), hyponychium.

• Hair types: Vellus (fine), Intermediate, Terminal (thick).

Aging Effects on Skin

• Thinner epidermis and dermis.

• Fewer immune cells, less vitamin D and melanin.

• Dryer skin, slower repair.

• Hair thins and lightens.

• Fat distribution decreases.

Additional Notes

• Gap Junctions: Allow communication between adjacent epithelial cells.

• Basement Membrane: Anchors epithelial tissue.

• Arrector Pili Muscle: Small muscle attached to hair follicles; causes goosebumps.

• Mesenchyme: Stem cell origin for connective tissue.

• Tendon: Connects muscle to bone.

• Ligament: Connects bone to bone.