Introduction to Anatomy & Physiology

Definition and Scope

Anatomy and Physiology are foundational sciences in understanding the structure and function of the human body. Anatomy focuses on the structure (morphology) of body parts, while Physiology studies their functions and interactions.

• Anatomy: Study of body structure, including cytology (cells), histology (tissues), regional, systemic, and surface anatomy.

• Physiology: Study of how body parts function and work together to sustain life.

Homeostasis

Homeostasis is the maintenance of a stable internal environment despite external changes. It is vital for survival and proper function.

• Feedback Loops: Mechanisms that maintain homeostasis.

• Negative Feedback: Reduces the effect of a stimulus (e.g., body temperature regulation).

• Positive Feedback: Enhances the effect of a stimulus (e.g., blood clotting).

• Examples: Regulation of blood glucose (negative), childbirth contractions (positive).

Major Themes in Anatomy & Physiology

• Structure and function are closely related.

• Levels of organization: chemical, cellular, tissue, organ, organ system, organism.

• Adaptation, natural selection, and evolution shape physiological processes.

Levels of Organization

Hierarchical Structure

The human body is organized into increasing levels of complexity:

• Chemical Level: Atoms and molecules

• Cellular Level: Cells and their organelles

• Tissue Level: Groups of similar cells

• Organ Level: Two or more tissue types

• Organ System Level: Organs working together

• Organism Level: The complete living being

Major Tissue Types

• Epithelial: Covers surfaces, lines cavities

• Connective: Supports, protects, binds tissues

• Muscle: Produces movement

• Nervous: Transmits impulses

Cytology vs. Histology

• Cytology: Study of cells

• Histology: Study of tissues

Basic Chemistry for Anatomy & Physiology

Atoms, Elements, and Molecules

• Atom: Smallest unit of matter

• Proton: Positively charged particle

• Neutron: Neutral particle

• Electron: Negatively charged particle

• Atomic Number: Number of protons

• Atomic Mass: Protons + Neutrons

Bonding and Chemical Properties

• Ionic Bonds: Transfer of electrons

• Covalent Bonds: Sharing of electrons

• Hydrogen Bonds: Weak attractions between polar molecules

• Octet Rule: Atoms tend to have 8 electrons in their valence shell

Macromolecules

• Carbohydrates: Monosaccharides, disaccharides, polysaccharides

• Lipids: Triglycerides, phospholipids, steroids

• Proteins: Amino acids, peptide bonds, four levels of structure

• Nucleic Acids: DNA, RNA, nucleotides

Cell Structure and Function

Cell Theory and Components

• All living things are composed of cells.

• Cells are the basic unit of life.

• Cells arise from pre-existing cells.

Major Organelles:

• Nucleus: Control center, contains DNA

• Mitochondria: ATP production

• Ribosomes: Protein synthesis

• Endoplasmic Reticulum: Protein and lipid synthesis

• Golgi Apparatus: Modifies, sorts, packages proteins

• Lysosomes: Digestion of macromolecules

• Cytoskeleton: Structural support, movement

Cell Membrane and Transport

• Fluid Mosaic Model: Phospholipid bilayer with embedded proteins

• Passive Transport: Diffusion, osmosis, facilitated diffusion

• Active Transport: Requires energy (e.g., sodium-potassium pump)

• Tonicity: Hypertonic, hypotonic, isotonic solutions

Energy, Chemical Reactions, and Enzymes

Types of Energy and Reactions

• Endergonic: Absorb energy

• Exergonic: Release energy

• Anabolism: Building up molecules

• Catabolism: Breaking down molecules

Enzymes and Reaction Rates

• Enzymes: Biological catalysts that speed up reactions

• Factors affecting rate: temperature, pH, substrate concentration

• Hydrolysis: Breaking bonds with water

• Dehydration Synthesis: Forming bonds by removing water

Genetics and Molecular Biology

DNA, RNA, and Protein Synthesis

• Central Dogma: DNA → RNA → Protein

• Transcription: DNA to mRNA

• Translation: mRNA to protein

• Replication: DNA copying

• Gene: Segment of DNA coding for a protein

• Genome: Complete set of genes

Cell Cycle and Mitosis

• Phases: Interphase (G1, S, G2), Mitosis (prophase, metaphase, anaphase, telophase), Cytokinesis

• Checkpoints: Ensure proper division

• Programmed Cell Death (Apoptosis): Controlled cell death, prevents cancer

• Benign vs. Malignant Tumors: Benign are non-cancerous, malignant are cancerous and can metastasize

Sample Table: Comparison of Major Tissue Types

Key Equations and Concepts

• Metabolism Equation:

• pH Calculation:

• ATP Hydrolysis:

Summary

This guide covers the essential concepts in Anatomy & Physiology, including structural organization, basic chemistry, cell biology, genetics, and physiological processes. Mastery of these topics provides a strong foundation for further study in health and biological sciences.