Introduction to Anatomy and Physiology - Chapter 1

Information credited to Elder Pearl Solomon, author of "Introduction to Human Anatomy and Physiology"

Anatomy and Physiology

• Anatomy: Science of body structure.
• Physiology: Science of body function or how the body works.
• Both fields are interrelated, each body part is adapted for its function.

Scientific Method

1. Observe the world and ask questions.
2. Develop a tentative explanation (hypothesis).
3. Test the hypothesis with an experiment.
4. Collect data and report results in a conclusion.

Levels of Organization within the Human Body

1. Chemical Level: Atoms and molecules.
2. Cellular Level: Organelles and cells.
3. Tissue Level: Cells form tissues (e.g., muscle or bone tissue).
4. Organ Level: Tissues form organs (e.g., stomach, liver).
5. Organ System Level: Organs function together to form systems.
6. Organism Level: Body systems work together to form a human organism.

Human Organ Systems (11 main systems)

1. Integumentary: Skin, hair, nails, sweat glands.
   • Functions: Protects body, regulates temperature, sensory information.
2. Skeletal: Bones, cartilage, ligaments, joints.
   • Functions: Support, protection, movement, stores calcium, produces blood cells.
3. Muscular: Skeletal muscles, cardiac muscle, smooth muscle.
   • Functions: Movement, pumps blood, moves materials.
4. Nervous: Brain, spinal cord, sense organs, nerves.
   • Functions: Regulatory system, transmits impulses, response to stimuli.
5. Endocrine: Glands that produce hormones (e.g., pituitary, adrenal, thyroid).
   • Functions: Regulates metabolism, body chemistry, secretes hormones.
6. Cardiovascular: Heart, blood vessels, blood.
   • Functions: Transports nutrients, gases, hormones, waste, fluid balance.
7. Lymphatic/Immune: Lymph, lymphatic vessels, lymph nodes, spleen.
   • Functions: Collects/Transports fluid, absorbs lipids, defends against pathogens.
8. Respiratory: Lungs, trachea, air passageways.
   • Functions: Gas exchange, oxygen content balance, acid-base balance.
9. Digestive: Mouth, esophagus, stomach, intestines, liver, pancreas, salivary glands.
   • Functions: Ingests, digests, absorbs nutrients.
10. Urinary: Kidneys, bladder, ureter, associated ducts.
    • Functions: Excretes waste, regulates blood/fluid composition.
11. Reproductive: Gonads (testes in males, ovaries in females) and associated structures.
    • Functions: Reproduction, sexual characteristics.

Composition of the Human Body

• Organic Compounds: Large, complex (containing carbon) - carbohydrates, lipids, proteins, nucleic acids.
• Inorganic Compounds: Small, simple (e.g., water, salts, acids, bases).

Electrolytes and pH

• Electrolytes: Inorganic salts, acids, bases form charged particles (ions).
  • Cations (+), Anions (-)
• Acids: Produce hydrogen ions (H+) and an anion.
• Bases: Produce hydroxide ions (OH-) and a cation.
• pH Scale: Measures hydrogen ion concentration.
  • Example: Pure water (pH 7), Blood (pH 7.4)
• Acid-Base Reaction: H+ from acid + OH- from base → Water + Salt

Organic Compounds and Chemical Bonds

• Carbohydrates: Sugars and starches - fuel and energy storage.
• Lipids: Fats, phospholipids, steroids - energy storage, cell membranes, hormones.
• Proteins: Amino acids - enzymes, structural components (e.g., meat, fish, eggs).
• Nucleic Acids: DNA and RNA - genetic information and protein synthesis.

Metabolism

• Metabolism: Chemical activities in the body (food to energy).
• Catabolism: Breakdown phase, provides energy.
• Anabolism: Building phase, uses energy to create compounds.
• Cellular Respiration: Catabolic process converting nutrients to energy stored in ATP.

Homeostasis and Feedback Mechanisms

• Homeostasis: Maintains internal environment (steady state).
• Negative Feedback: Response opposes the initial change (e.g., body temperature regulation).
• Positive Feedback: Response amplifies the initial change (e.g., during labor).

Anatomical Position and Directional Terms

• Anatomical Position: Erect, eyes forward, arms at sides, palms and toes forward.
• Directional Terms:
  • Superior: Above
  • Inferior: Below
  • Anterior (Ventral): Front
  • Posterior (Dorsal): Back
  • Medial: Toward midline
  • Lateral: Away from midline
  • Proximal: Toward reference point
  • Distal: Away from reference point
  • Superficial: Near surface
  • Deep: Far from surface
  • Cranial (Cephalic): Toward head
  • Caudal: Toward feet
  • Rostral: Toward nose
  • Ipsilateral: Same side
  • Contralateral: Opposite side

Body Planes

• Sagittal Plane: Vertical, divides into left and right.
• Coronal (Frontal) Plane: Vertical, divides into anterior and posterior.
• Axial (Transverse) Plane: Horizontal, divides into superior and inferior.

Body Regions and Cavities

• Axial: Head, neck, trunk.
• Appendicular: Limbs.
• Torso/Trunk: Thorax, abdomen, pelvis.
• Main Cavities:
  • Dorsal: Cranial and spinal cavities.
  • Ventral: Thoracic and abdominopelvic cavities.
• Thoracic Cavity: Pleural cavities, mediastinum.
• Abdominopelvic Cavity: Abdominal and pelvic cavities.

Abdominal Quadrants and Regions

• Four Quadrants: RUQ, LUQ, RLQ, LLQ.
• Nine Regions: Right hypochondrium, epigastrium, left hypochondrium, right lateral, umbilical, left lateral, right inguinal, hypogastrium, left inguinal.

Anatomic Regional Terminology

• Examples:
  • Abdominal: Abdomen
  • Antebrachial: Forearm
  • Axillary: Armpit
  • Brachial: Upper arm
  • Carpal: Wrist
  • Cephalic: Head
  • Cervical: Neck
  • Cubital: Posterior arm/elbow
  • Femoral: Thigh
  • Gluteal: Buttock
  • Inguinal: Groin
  • Plantar: Sole of foot
  • Thoracic: Chest
  • Umbilical: Navel

Body Views and Imaging

• Anterior View: Skin, muscles removed. Rib cage, scrotum exposed.
• Deeper Interior View: Lungs, heart, intestines removed to show deeper structures.
• Posterior View: Skeletal structures and positions of kidneys.
• CT Scans: Show various body regions with different density representations.