Anatomy & Physiology: Foundational Concepts and Systems

Chapter 1: An Introduction to Anatomy and Physiology

Overview of Anatomy and Physiology

Anatomy is the study of the structure of the human body, while physiology explores how those structures function to support life. These disciplines are deeply interconnected and form the basis for understanding health and disease.

• Diagnostic anatomy: Utilizes imaging technologies (e.g., x-rays, CT scans, MRI) to visualize and examine structures in a living body.

• Pathological anatomy: Focuses on anatomical changes that occur due to disease.

• Homeostasis: The body's ability to maintain a stable internal environment, essential for health.

• Anatomy can be gross (macroscopic) or microscopic (cytology and histology).

• Physiology includes subfields: cell physiology, systemic physiology, and pathological physiology.

Levels of Organization

• Chemical level: Atoms and molecules.

• Tissue level: Groups of similar cells working together.

• Organ level: Organs composed of different tissues.

• Organ system level: Organs with a common function.

• Organism level: A complete living being.

Life Functions

• Responsiveness, growth, reproduction, movement, metabolism.

• Metabolism: Includes catabolism (breakdown) and anabolism (synthesis).

• Homeostasis: Maintains stable internal conditions.

Organ Systems Overview

• Nervous system: Rapid communication and control.

• Endocrine system: Long-term regulation via hormones.

• Integumentary system: Protects and regulates body temperature.

• Muscular system: Produces movement, generates heat.

• Skeletal system: Provides support, stores minerals, forms blood cells.

• Cardiovascular system: Distributes blood, nutrients, and wastes.

• Lymphatic system: Defends against infection, returns tissue fluids to blood.

• Respiratory system: Delivers air, exchanges gases.

• Digestive system: Processes food, absorbs nutrients, eliminates waste.

• Urinary system: Eliminates wastes, regulates fluid balance.

• Reproductive system: Produces sex cells and hormones.

Anatomical Terminology

• Standard reference position: Anatomical position (standing upright, palms forward).

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

• Directional terms: Anterior/posterior, superior/inferior, proximal/distal, medial/lateral.

Chapter 2: The Chemical Level of Organization

Atoms, Elements, and Molecules

The chemical level includes atoms, elements, and molecules, which form the basis of all matter in the body.

• Atoms: Consist of protons, neutrons, and electrons.

• Elements: Substances composed of one type of atom (major elements: C, H, O, N, P, Ca).

• Molecules: Two or more atoms bonded together.

• Ionic bonds: Transfer electrons; covalent bonds: Share electrons.

Water, Acids, Bases, and Salts

• Water: Most abundant compound in the body; solvent for chemical reactions.

• Acids, bases, salts: Dissociate into ions in water.

• pH scale: 0 (acidic) to 14 (basic); 7 is neutral.

• Buffers: Stabilize pH in body fluids.

Organic Molecules

• Carbohydrates: Provide quick energy. Types: monosaccharides (e.g., glucose), disaccharides, polysaccharides.

• Lipids: Include fats, oils, phospholipids, steroids.

• Proteins: Composed of amino acids; functions include enzymes, structure, transport, communication.

• Nucleic acids: DNA and RNA; store genetic information.

• ATP: The energy currency of the cell.

Chapter 3: The Cellular Level of Organization

Cell Structure and Function

Cells are the structural and functional units of life, varying in shape and size to suit their functions.

• Cell types: Epithelial, connective, muscle, nervous.

• Plasma membrane: Lipid bilayer with proteins; controls entry/exit.

• Transport mechanisms: Diffusion, facilitated diffusion, osmosis, active transport, endocytosis, exocytosis.

• Organelles: Nucleus (contains DNA), mitochondria (ATP production), ribosomes (protein synthesis), endoplasmic reticulum (protein/lipid synthesis), Golgi apparatus (modifies/packages proteins), lysosomes (digestive enzymes).

• Cell cycle: Interphase (G1, S, G2), mitosis (PMAT), cytokinesis.

• Apoptosis: Programmed cell death.

Chapter 4: The Tissue Level of Organization

Types of Tissues

The body contains four primary tissue types, each with specialized functions.

• Epithelial tissue: Covers surfaces, lines cavities, forms glands; tightly packed cells, polarity, avascular.

• Connective tissue: Supports, binds, protects; cells (fibroblasts, adipocytes, macrophages, mast cells), matrix (fibers: collagen, elastic, reticular).

• Muscle tissue: Contracts to produce movement; types: skeletal (voluntary), cardiac (involuntary, heart), smooth (involuntary, organs).

• Nervous tissue: Conducts electrical impulses; neurons (transmit signals), neuroglia (support).

Chapter 5: The Integumentary System

Structure and Function of Skin

The integumentary system includes the skin, hair, nails, and glands, providing protection and other vital functions.

• Skin layers: Epidermis (stratified squamous epithelium), dermis (connective tissue), hypodermis (subcutaneous layer).

• Functions: Protection, thermoregulation, sensation, vitamin D synthesis.

• Epidermis: Layers—stratum corneum, lucidum, granulosum, spinosum, basale.

• Dermis: Papillary (areolar CT), reticular (dense irregular CT).

• Skin color: Determined by melanin, carotene, hemoglobin.

• Glands: Sebaceous (oil), sweat (eccrine, apocrine), ceruminous (earwax), mammary (milk).

• Hair: Protection, sensation; nails: Protection, manipulation.

• Conditions: Cyanosis (blue), jaundice (yellow), erythema (redness).

Chapter 6: Osseous Tissue and Bone Structure

Bone Structure and Function

Osseous tissue forms the rigid framework of the body, supporting movement, protecting organs, and storing minerals.

• Functions: Support, movement, protection, mineral storage, blood formation.

• Matrix: Collagen fibers (flexibility), calcium salts (hardness).

• Bone types: Long, short, flat, irregular, sesamoid.

• Bone cells: Osteocytes (maintain), osteoblasts (form), osteoclasts (resorb), osteoprogenitors (stem cells).

• Compact bone: Dense, forms outer layer; spongy bone: Lattice-like, contains marrow.

• Periosteum: Covers bone; endosteum: Lines marrow cavity.

• Ossification: Intramembranous (flat bones), endochondral (long bones).

• Growth plates: Epiphyseal plates allow longitudinal growth.

Chapter 7: The Axial Skeleton

Components and Key Features

The axial skeleton includes the skull, vertebral column, and thoracic cage, providing central support and protection for vital organs.

• Skull: 22 bones (8 cranial, 14 facial).

• Cranial bones: Frontal, parietal, occipital, temporal, sphenoid, ethmoid.

• Facial bones: Maxillae, palatine, nasal, zygomatic, lacrimal, vomer, mandible.

• Sutures: Coronal, sagittal, squamous, lambdoid.

• Hyoid bone: Not articulated with other bones; supports tongue.

• Vertebral column: 7 cervical, 12 thoracic, 5 lumbar, sacrum, coccyx.

• Curvatures: Cervical/lumbar (concave), thoracic/sacral (convex).

• Vertebrae: Body, vertebral arch, spinous/transverse processes.

• Thoracic cage: Sternum (manubrium, body, xiphoid), 12 pairs of ribs.

• Key landmarks: Foramen magnum, sella turcica, mastoid process.

• Common injuries: Scaphoid fracture, stress fractures in athletes.