Introduction to Anatomy & Physiology
Overview of Anatomy and Physiology
- Anatomy
- Definition: Study of the structure of body parts and their relationships.
- Branches of Anatomy:
- Gross (Macroscopic) Anatomy: Study of large, visible structures (organs, muscles, bones).
- Microscopic Anatomy: Requires magnification; includes histology (tissues) and cytology (cells).
- Regional Anatomy: Focuses on all structures within a particular body region (e.g., head, chest).
- Systemic Anatomy: Studies specific organ systems (e.g., skeletal, muscular).
- Specialization areas: Microscopic & Gross.
- Study approaches: Regional & Systemic.
- Similarity: All describe the bodyās structure to explain function.
- Physiology
- Definition: Study of the functions of body parts; how structures work.
- Example: Heartās anatomy = 4 chambers; physiology = how it pumps blood.
Homeostasis
- Definition: Maintenance of stable internal conditions despite external changes.
- Involves feedback mechanisms: Balance temperature, pH, glucose, blood pressure, etc.
Structural Organization of the Human Body
Levels of Organization
- Subatomic particles (protons, neutrons, electrons)
- Atoms (C, H, O, N, etc.)
- Molecules (DNA, proteins, glucose)
- Organelles (mitochondria, ribosomes)
- Cells (basic unit of life)
- Tissues (groups of similar cells)
- Organs (heart, lungs)
- Organ systems (digestive, respiratory)
- Organism (human body)
- Biosphere (all life on Earth)
Key Comparisons
- Chemical Level: Subatomic ā Molecules.
- Biological Level: Organelles ā Organism.
Structure Relationships
- Hierarchy: Cells ā Tissues ā Organs ā Organ Systems ā Organism.
- Organ systems consist of: Organs working together.
Organ Systems of the Human Body
| System | Organs | Functions |
|---|
| Integumentary | Skin, hair, nails | Protection, vitamin D, sensation, temperature regulation |
| Skeletal | Bones, joints | Support, protection, blood formation, mineral storage |
| Muscular | Skeletal muscles | Movement, posture, heat production |
| Nervous | Brain, spinal cord, nerves | Rapid communication, coordination |
| Endocrine | Hormone-producing glands | Long-term regulation (growth, metabolism, reproduction) |
| Cardiovascular | Heart, blood vessels | Transport nutrients, gases, hormones, waste |
| Lymphatic | Lymph nodes, vessels, spleen | Immune defense, fluid return |
| Respiratory | Lungs, trachea | Gas exchange (Oā in, COā out) |
| Digestive | Stomach, intestines, liver | Breakdown and absorption of nutrients |
| Urinary | Kidneys, bladder | Waste excretion, fluid balance |
| Male Reproductive | Testes, penis | Sperm production, hormone secretion |
| Female Reproductive | Ovaries, uterus, breasts | Egg production, fetal development |
Functions of Human Life
- First Law of Thermodynamics: Energy cannot be created or destroyed, only transformed.
- Metabolism:
- Catabolism: Breaking down molecules (releases energy).
- Anabolism: Building molecules (uses energy).
- ATP (Adenosine Triphosphate): Cellular "energy currency."
Requirements for Human Life
- Oxygen: Needed for ATP production (aerobic respiration).
- Carbon Dioxide: Byproduct; regulates pH.
- Nutrients:
- Water: Most abundant, solvent, regulates temperature.
- Micronutrients: Vitamins & minerals.
- Macronutrients: Carbs, lipids, proteins.
- Temperature: Optimal ~37Ā°C.
- Controlled hypothermia used in certain surgeries to reduce tissue damage.
- Atmospheric Pressure: Needed for breathing & gas exchange.
- Decompression Sickness: Caused by rapid pressure change ā nitrogen bubbles.
- Acclimation: Short-term adjustment.
- Adaptation: Long-term genetic adjustment.
Homeostasis
- Negative Feedback:
- Definition: Brings system back to balance.
- Example: Blood sugar regulation (insulin lowers, glucagon raises).
- Positive Feedback:
- Definition: Amplifies change.
- Example: Labor contractions (oxytocin release).
Anatomical Terminology
- Directional Terms:
- Superior/Inferior, Anterior/Posterior, Medial/Lateral, Proximal/Distal.
- Body Planes:
- Sagittal (left/right), Frontal (front/back), Transverse (top/bottom).
- Body Cavities:
- Dorsal (cranial, vertebral)
- Ventral (thoracic, abdominal, pelvic)
- Serous Membranes: Double layers that reduce friction.
- Examples: pleura (lungs), pericardium (heart), peritoneum (abdomen).
Medical Imaging
- X-ray: Bones, dense tissues.
- CT Scan: Cross-sectional images, used for trauma.
- MRI: Soft tissues, uses magnetic fields.
- PET Scan: Detects metabolic activity (cancer, brain activity).
- Ultrasound: Safe, uses sound waves (pregnancy, organs).
Chapter 1 Big Picture Summary
- Anatomy = structure; Physiology = function.
- Human body organization is hierarchical from atoms ā biosphere.
- Life requires oxygen, nutrients, temperature, and pressure.
- Homeostasis keeps systems stable using feedback loops.
- Anatomical terminology & imaging provide a shared language and tools for study.
Sample Exam Questions
- Define anatomy and physiology. How do they differ?
- What type of feedback mechanism is blood clotting? Why?
- Arrange the following in order from smallest to largest: organelle, atom, organ, tissue, biosphere.
- Which imaging technique is best for detecting brain tumors? Explain.
- Explain how the integumentary and muscular systems interact to regulate body temperature.