Fundamental Concepts in Anatomy & Physiology: Cells, Chemistry, and Biological Processes

Study Guide - Smart Notes

Tailored notes based on your materials, expanded with key definitions, examples, and context.

Physiology and Levels of Organization

Definition of Physiology

Physiology is the study of how living organisms perform their vital functions. It encompasses the mechanisms and processes that allow organisms to survive, grow, and reproduce.

Physiology: Examines the function of cells, tissues, organs, and organ systems.

Levels of Organization

Biological systems are organized into hierarchical levels, each with increasing complexity.

Chemical/Molecular Level: Atoms and molecules essential for life.
Cellular Level: Basic structural and functional units of life.
Tissue Level: Groups of similar cells performing a common function.
Organ Level: Structures composed of different tissues working together.
Organ System Level: Groups of organs that perform related functions.
Organism Level: The complete living being.

Homeostasis and Regulation

Homeostasis

Homeostasis refers to the maintenance of a stable internal environment, essential for the survival of cells and organisms.

Homeostasis: Stable internal environment.

Regulatory Mechanisms

Auto-regulation: Local process where cells, tissues, or organs adjust in response to environmental changes.
Extrinsic Regulation: Regulation by nervous or endocrine systems, often involving signals sent to adjust activity.

Components of Regulatory Systems

Receptor: Structure sensitive to stimuli or environmental changes.
Control Center: Receives and processes information from receptors and sends commands.
Effector: Cell or organ that responds to commands from the control center.

Feedback Mechanisms

Negative Feedback: Counteracts changes, maintaining homeostasis (e.g., temperature regulation).
Positive Feedback: Amplifies changes, often seen in processes like blood clotting or childbirth.

Chemistry of Life

Atoms and Molecules

Atom: Smallest stable unit of matter.
Nucleus: Central region of the atom, contains protons and neutrons.
Isotope: Atoms of the same element with different numbers of neutrons.
Molecule: Chemical structure of atoms held together by chemical bonds.
Compound: Pure chemical substance made of atoms of two or more elements in fixed proportion.

Ions

Cation: Ion with a positive charge.
Anion: Ion with a negative charge.

Enzymes and Metabolism

Enzyme: Protein that speeds up chemical reactions without being consumed.
Metabolite: Substance involved in or produced by metabolism.

Solutions and Electrolytes

Solution: Uniform mixture of two or more substances.
Solvent: Liquid in which atoms, ions, or molecules are dissolved.
Solute: Dissolved substances in a solution.
Electrolyte: Soluble inorganic substance whose ions conduct electrical current in solution.

Acids, Bases, and Buffers

Acids and Bases

Acid: Substance that releases hydrogen ions (H+).
Base: Substance that removes hydrogen ions, raising pH.

Salt and Buffers

Salt: Electrolyte whose cation is not H+ and whose anion is not OH-.
Buffer: Compound that stabilizes pH by removing or replacing hydrogen ions.

Carbohydrates and Lipids

Types of Carbohydrates

Monosaccharides: Simple sugars with three to seven carbon atoms (e.g., glucose).
Disaccharides: Two monosaccharide monomers joined together (e.g., sucrose).
Polysaccharides: Large molecules formed by repeated dehydration synthesis of monosaccharides (e.g., starch, glycogen).

Functions and Examples

Carbohydrates: Main energy source for humans.

Lipids

Lipids: Contain carbon, hydrogen, and oxygen; include fats, oils, and waxes.
Triglyceride: Glycerol plus three fatty acids, formed by dehydration synthesis.

Proteins

Structure and Function

Proteins: Most abundant organic molecules in the human body; composed of amino acids containing carbon, hydrogen, oxygen, and nitrogen.
Functions: Structural support, transport, enzymes, movement, and defense.

Cells and Cellular Structure

Cell Theory

Cells are the building blocks of all organisms.
All cells come from the division of preexisting cells.
Cells are the smallest units that carry out essential physiological functions.
Each cell maintains homeostasis at the cellular level.

Types of Cells

Sex Cells: Sperm (males) and oocytes (immature ova, females).
Somatic Cells: All other body cells except sex cells.

Cytology

Cytology: Study of cellular structure and function.

Plasma (Cell) Membrane

Plasma Membrane: Outer boundary of a cell.
Physical Isolation: Separates inside of cell from extracellular fluid.
Regulation of Exchange: Controls entry and exit of substances.
Sensitivity to Environment: Responds to changes in extracellular fluid.
Structural Support: Provides stability and support.
Phospholipid Bilayer: Main component of plasma membrane.

Membrane Proteins

Integral Proteins: Embedded in the membrane, cannot be easily separated.
Anchoring Proteins: Attach membrane to other structures and stabilize position.
Receptor Proteins: Sensitive to specific extracellular ligands.
Carrier Proteins: Bind and transport substances across the membrane.

Cytoplasm

Cytoplasm: Includes cytosol and organelles.
Cytosol: Intracellular fluid.
Organelles: Structures suspended in cytosol, performing specific functions.

Cellular Organelles and Functions

Major Organelles

Ribosomes: Contain rRNA and proteins; site of protein synthesis.
Rough Endoplasmic Reticulum (RER): Has ribosomes; synthesizes and stores proteins.
Smooth Endoplasmic Reticulum (SER): Synthesizes lipids and carbohydrates.
Golgi Apparatus: Modifies, sorts, and packages proteins and lipids.
Lysosomes: Contain digestive enzymes; break down waste.
Peroxisomes: Contain enzymes that break down hydrogen peroxide.
Autolysis: Destruction of cell via lysosomal enzymes.
Mitochondria: Generate most ATP required for cellular operations.
Nucleus: Contains DNA, RNA, and proteins; control center for cellular operations.

Transport Across Membranes

Diffusion and Osmosis

Diffusion: Passive movement of molecules from high to low concentration.
Osmosis: Movement of water across a selectively permeable membrane.

Osmotic and Hydrostatic Pressure

Osmotic Pressure: Pressure required to prevent water movement by osmosis.
Hydrostatic Pressure: Fluid pressure exerted by a liquid.

Tonicity

Tonicity: Description of how a solution affects the shape of a cell.
Isotonic Solution: Solution with osmolarity that does not result in water movement across plasma membranes.

Carrier-Mediated and Vesicular Transport

Carrier-Mediated Transport: Integral proteins bind specific ions or molecules and carry them across the membrane.
Vesicular Transport: Movement of materials into or out of the cell in vesicles.
Endocytosis: Movement of extracellular material into the cytoplasm by vesicle formation.
Exocytosis: Ejection of cytoplasmic materials by fusion of vesicle with plasma membrane.
Phagocytosis: Engulfing of extracellular materials or pathogens.

Cellular Potentials and Reproduction

Membrane Potential

Membrane Potential: Potential difference across plasma membrane due to uneven distribution of ions.

Cell Division

Cell Division: Form of cellular reproduction.
Somatic Cells: Produced by division of preexisting cells.
Mitosis: Division of somatic cells (non-sex cells).
Meiosis: Division that produces gametes (sex cells) with half the normal chromosome complement.
Cell Differentiation: Development of specific cellular characteristics and functions.
Apoptosis: Genetically programmed cell death.

Key Table: Types of Carbohydrates

Type	Description	Example
Monosaccharide	Single sugar molecule, 3-7 carbon atoms	Glucose
Disaccharide	Two monosaccharides joined	Sucrose
Polysaccharide	Many monosaccharides joined by dehydration synthesis	Starch, Glycogen

Key Table: Types of Membrane Proteins

Protein Type	Function
Integral	Embedded in membrane, structural and functional roles
Anchoring	Attach membrane to other structures, stabilize position
Receptor	Bind specific extracellular ligands
Carrier	Transport substances across membrane

Key Equations

Osmotic Pressure: Where i is the van 't Hoff factor, M is molarity, R is the gas constant, and T is temperature in Kelvin.
pH Calculation:

Summary

This guide covers essential concepts in anatomy and physiology, including cellular structure, chemical principles, biological molecules, and processes such as homeostasis, transport, and cell division. Understanding these fundamentals is crucial for further study in human biology and health sciences.