Exam 1 Study Guide: Foundations of Anatomy & Physiology

Chapter 1: Introduction to Anatomy & Physiology

Principles of Homeostasis

Homeostasis is the process by which living organisms maintain a stable internal environment despite changes in external conditions. This principle is fundamental to understanding how physiological systems function.

• Definition: Homeostasis refers to the dynamic equilibrium of the body's internal environment.

• Key Components: Sensors (receptors), control center, effectors.

• Example: Regulation of body temperature through sweating or shivering.

• Feedback Mechanisms: Negative feedback (most common, e.g., blood glucose regulation) and positive feedback (e.g., childbirth).

Chapter 2: Chemistry of Life

Organic Compounds

Organic compounds are molecules containing carbon and are essential for life. They include carbohydrates, lipids, proteins, and nucleic acids.

• Lipids: Hydrophobic molecules important for energy storage, membrane structure, and signaling.

• Saturated vs Unsaturated Fats:

  • Saturated Fats: No double bonds between carbon atoms; solid at room temperature (e.g., butter).

  • Unsaturated Fats: One or more double bonds; liquid at room temperature (e.g., olive oil).

• Example: Triglycerides are a common form of lipid found in adipose tissue.

• Additional info: Unsaturated fats are generally considered healthier for cardiovascular health.

Chapter 3: The Cell

Organelles

Organelles are specialized structures within cells that perform distinct functions necessary for cellular life.

• Names and Function: Includes nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, etc.

• Structure of DNA in Nucleus: DNA is organized into chromosomes within the nucleus, serving as the genetic blueprint.

• Transport of Endomembrane System: The endomembrane system (ER, Golgi, vesicles) is responsible for protein and lipid transport within the cell.

• Example: Mitochondria are the site of ATP production via cellular respiration.

Cellular Transport

Cellular transport refers to the movement of substances across the cell membrane, essential for maintaining cellular homeostasis.

• Structure and Function of Plasma Membrane: Composed of a phospholipid bilayer with embedded proteins, it regulates entry and exit of substances.

• Passive vs Active Transport:

  • Passive Transport: Movement down a concentration gradient without energy input (e.g., diffusion, osmosis).

  • Active Transport: Movement against a concentration gradient requiring energy (ATP), e.g., sodium-potassium pump.

• Examples of Each Type:

  • Simple Diffusion: Oxygen and carbon dioxide moving across the membrane.

  • Facilitated Diffusion: Glucose transport via carrier proteins.

  • Active Transport: Na+/K+ pump.

• Osmosis: Movement of water across a semipermeable membrane.

• Types of Solutions:

  • Hypertonic: Higher solute concentration outside the cell; cell shrinks.

  • Hypotonic: Lower solute concentration outside the cell; cell swells.

  • Isotonic: Equal solute concentration; no net water movement.

• Additional info: Osmosis is a type of passive transport specific to water molecules.

Protein Synthesis

Protein synthesis is the process by which cells build proteins, involving transcription and translation.

• Steps:

  1. Transcription: DNA is copied into messenger RNA (mRNA) in the nucleus.

  2. Translation: mRNA is decoded by ribosomes in the cytoplasm to assemble amino acids into a protein.

• Components: Enzymes (e.g., RNA polymerase), ribosomes, tRNA, mRNA.

• Example: Hemoglobin synthesis in red blood cells.

• Additional info: Protein synthesis is regulated by both genetic and environmental factors.

Cell Cycle

The cell cycle is the series of events that cells go through as they grow and divide. It ensures proper replication and division of genetic material.

• Interphase Steps: G1 (cell growth), S (DNA synthesis), G2 (preparation for division).

• Mitosis Steps:

  1. Prophase: Chromosomes condense, spindle forms.

  2. Metaphase: Chromosomes align at the cell equator.

  3. Anaphase: Sister chromatids separate.

  4. Telophase: Nuclear membranes reform.

  5. Cytokinesis: Division of cytoplasm.

• Division of Chromosomes: Each cell starts with a diploid set and ends with two identical diploid cells after mitosis.

• Cancer/Cell Cycle Checkpoints: Cancer results from uncontrolled cell division due to failure of cell cycle checkpoints (G1, G2, M).

• Comparison to Normal Cell Division: Normal cells obey checkpoints; cancer cells bypass them, leading to tumor formation.

• Additional info: Cell cycle checkpoints are regulated by proteins such as cyclins and CDKs.