Anatomy & Physiology: Foundational Study Notes

Chapter 1: The Human Body

Definitions

Anatomy and physiology are foundational sciences for understanding the human body. Anatomy focuses on the structure, while physiology examines function.

• Anatomy: Study of structure.

• Physiology: Study of function.

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

  • Regional: Structures in one area.

  • Systemic: One system at a time.

  • Surface: External features and landmarks.

• Microscopic Anatomy:

  • Histology: Study of tissues.

  • Cytology: Study of cells.

• Pathology: Study of disease.

Levels of Structural Organization

The human body is organized into hierarchical levels, each building upon the previous.

1. Chemical: Atoms and molecules.

2. Cellular: Basic unit of life.

3. Tissue: Groups of cells.

4. Organ: Two or more tissues working together.

5. Organ System: Organs with a common function.

6. Organism: Entire body.

Life Functions

All living organisms perform essential life functions to maintain homeostasis and survival.

• Maintain boundaries: Skin, membranes separate internal from external environments.

• Movement: Muscles, cilia, blood transport.

• Responsiveness: Sense and respond to stimuli.

• Digestion: Breakdown and absorption of nutrients.

• Metabolism: Chemical reactions for energy and synthesis.

• Excretion: Removal of waste products.

• Growth: Increase in size or number of cells.

• Reproduction: Cellular (mitosis) and organismal reproduction.

Homeostasis

Homeostasis is the maintenance of stable internal conditions despite external changes. It is regulated by control systems.

• Definition: Stable internal conditions despite outside changes.

• Control System Parts:

  1. Receptor: Detects change.

  2. Control Center: Processes and sets response (e.g., brain, spinal cord).

  3. Effector: Carries out response.

• Negative Feedback: Reverses change (e.g., body temperature, blood glucose).

• Positive Feedback: Amplifies change (e.g., childbirth, blood clotting).

Anatomical Terms

Standard anatomical terms describe locations, planes, and cavities in the body for clarity and precision.

• Planes: Sagittal, midsagittal, parasagittal, frontal, transverse, oblique.

• Directional Terms: Superior/inferior, anterior/posterior, medial/lateral, proximal/distal, superficial/deep.

• Cavities:

  • Dorsal: Cranial, vertebral.

  • Ventral: Thoracic (pleural, pericardial, mediastinum), abdominopelvic.

• Serous Membranes:

  • Parietal: Lines cavity.

  • Visceral: Covers organ.

  • Examples: Pleura, pericardium, peritoneum.

Medical Imaging

Medical imaging techniques allow visualization of internal structures for diagnosis and treatment.

• CT: Detailed cross-section imaging.

• MRI: Soft tissue imaging.

• PET: Metabolic activity.

• Ultrasound: Safe, commonly used in pregnancy.

Chapter 2: Chemistry of Life

Atoms

Atoms are the basic units of matter, composed of protons, neutrons, and electrons.

• Atomic number: Number of protons.

• Mass number: Protons + neutrons.

• Isotopes: Same element, different number of neutrons.

Bonds

Chemical bonds hold atoms together in molecules and compounds.

• Ionic bond: Transfer of electrons (e.g., NaCl).

• Covalent bond: Sharing of electrons.

  • Nonpolar: Equal sharing (e.g., O2).

  • Polar: Unequal sharing (e.g., H2O).

• Hydrogen bond: Weak attraction, important in water and DNA structure.

Water Properties

Water is essential for life due to its unique chemical properties.

• High heat capacity: Absorbs and releases heat slowly.

• Universal solvent: Dissolves polar molecules.

• Cohesion and adhesion: Water molecules stick to each other and other surfaces.

• Cushions/protects: Provides protection to organs.

pH

pH measures the concentration of hydrogen ions in a solution, indicating acidity or basicity.

• Scale: 0–14.

• Acidic: pH < 7.

• Basic: pH > 7.

• Buffer systems: Maintain blood pH at 7.35–7.45.

Organic Molecules

Organic molecules are carbon-based compounds essential for life.

• Carbohydrates: Provide energy.

  • Monosaccharides: Glucose.

  • Disaccharides: Sucrose.

  • Polysaccharides: Glycogen, starch.

• Lipids: Long-term energy, membrane structure.

  • Triglycerides

  • Phospholipids: Bilayer structure.

  • Steroids: Cholesterol, hormones.

• Proteins: Structural and functional roles.

  • Made of amino acids.

  • Levels: Primary, secondary, tertiary, quaternary.

  • Enzymes: Biological catalysts.

• Nucleic Acids:

  • DNA: Genetic information.

  • RNA: Protein synthesis.

  • Nucleotide: Sugar + phosphate + base.

Chapter 3: The Cell

Plasma Membrane

The plasma membrane controls the movement of substances in and out of the cell.

• Phospholipid bilayer: Polar heads out, nonpolar tails inside.

• Proteins: Transport, receptors.

• Carbohydrates: Cell recognition.

Membrane Transport

• Passive (no ATP required):

  • Simple diffusion

  • Facilitated diffusion (channel/carrier)

  • Osmosis (water)

• Active (ATP required):

  • Primary (Na+/K+ pump)

  • Secondary (uses gradient)

• Vesicular transport: Endocytosis, exocytosis

Organelles

Organelles are specialized structures within cells that perform distinct functions.

• Nucleus: DNA storage.

• Rough ER: Protein synthesis.

• Smooth ER: Lipid synthesis, detoxification.

• Golgi apparatus: Packages proteins.

• Mitochondria: ATP production.

• Lysosomes: Digestion of cellular waste.

• Cytoskeleton: Microtubules, microfilaments for structure and movement.

Protein Synthesis

Protein synthesis involves transcription and translation, converting genetic information into functional proteins.

1. Transcription (nucleus): DNA → mRNA.

2. Translation (ribosome): mRNA → protein.

   • tRNA carries amino acids.

Cell Cycle

The cell cycle describes the stages a cell goes through to grow and divide.

• Interphase:

  • G1: Growth

  • S: DNA replication

• Mitosis:

  • Prophase: Chromosomes condense

  • Metaphase: Chromosomes align in middle

  • Anaphase: Chromosomes pulled apart

  • Telophase: Nuclei reform

• Cytokinesis: Cytoplasm divides

Chapter 4: Tissues (Main Focus)

4 Major Tissue Types

Tissues are groups of cells with similar structure and function. There are four major types in the human body.

1. Epithelial: Covering/lining, glands.

2. Connective: Support, binding, transport.

3. Muscle: Movement.

4. Nervous: Control, communication.

Characteristics of Epithelial Tissue

Epithelial tissue has distinct features that enable its protective and absorptive functions.

• Cellularity: Tightly packed cells.

• Polarity: Apical (top) and basal (bottom) surfaces.

• Avascular: No blood vessels.

• Regeneration: High rate of cell replacement.

• Basement membrane: Attaches to connective tissue.

Classification of Epithelia

Epithelia are classified by the number of layers and cell shape.

• By layers:

  • Simple: 1 layer

  • Stratified: Multiple layers

  • Pseudostratified: Appears layered but is not

• By shape:

  • Squamous: Flat

  • Cuboidal: Cube-shaped

  • Columnar: Tall

Types of Epithelia (ALL you need)

Each epithelial type has specific functions and locations in the body.

• Simple squamous: Diffusion/filtration

  • Location: Alveoli (lungs), kidneys, lining blood vessels

• Simple cuboidal: Secretion/absorption

  • Location: Glands, kidney tubules

• Simple columnar: Absorption, secretion

  • Location: Digestive tract (stomach to rectum)

• Pseudostratified columnar: Secretion, cilia move mucus

  • Location: Trachea, upper respiratory tract

• Stratified squamous: Protection

  • Location: Skin (keratinized), mouth, esophagus (non-keratinized)

• Stratified cuboidal: Rare, secretion

  • Location: Sweat/mammary glands

• Stratified columnar: Rare, protection/secretion

  • Location: Male urethra

• Transitional epithelium: Stretch

  • Location: Bladder, ureters

Chapter 28: Genetics (Basic)

Genes and Inheritance

Genetics is the study of heredity and variation in organisms. Genes are segments of DNA that code for proteins.

• Gene: Segment of DNA coding for protein.

• Phenotype: Physical traits expressed.

• Inheritance patterns:

  • Dominant: Only one allele needed for trait expression.

  • Recessive: Two alleles needed for trait expression.

  • Sex-linked: Carried on X chromosome.

Key Genetics Equations

• Genotype Ratio (Monohybrid Cross): $1:2:1$ (homozygous dominant : heterozygous : homozygous recessive)

• Phenotype Ratio (Monohybrid Cross): $3:1$ (dominant : recessive)

Additional info: These notes expand on the original bullet points with academic context, definitions, and examples for clarity and completeness.