Anatomy and Physiology

Anatomy and Physiology

• Anatomy is the study of the body's structure and the relationships between its parts.
• Gross anatomy involves studying body parts visible to the naked eye.
• Microscopic anatomy studies structures too small to see with the naked eye.
• Developmental anatomy studies changes from conception to adulthood.
• Physiology is the study of how the body functions to sustain life.
• Cell physiology focuses on the functions of individual cells.
• Systemic physiology explains how different organs work together.

Principle of Complementarity

• A structure's form is directly related to its function.
• An organ's anatomy dictates how it functions.
• Red blood cells lack a nucleus, increasing flexibility and oxygen-carrying capacity.

Levels of Structural Organization

• The human body is organized into chemical, cellular, tissue, organ, organ system, and organismal levels.
• Molecules form cells, which form tissues, which form organs, which form organ systems, which form an organism.

Functional Characteristics of Life

• Maintaining boundaries separates internal and external environments.
• Movement involves motion of the body, organs, or cells.
• Responsiveness is the ability to react to stimuli.
• Digestion breaks down food into absorbable molecules.
• Metabolism involves chemical reactions in the body.
• Excretion removes waste products.
• Reproduction produces offspring.
• Growth increases body size.
• Homeostasis maintains stable internal conditions.

Survival Needs

• Nutrients provide energy and building blocks.
• Water is essential for chemical reactions and transport.
• Oxygen is needed for metabolic processes.
• Temperature must be maintained within a narrow range.
• Atmospheric pressure is necessary for breathing.

Homeostasis

• Homeostasis is the body's ability to maintain a stable internal environment.
• It allows the body to function at a set point.
• The body reacts to deviations from the set point to restore normal function.

Feedback Systems

• Positive feedback enhances the initial change (e.g., childbirth).
• Negative feedback reverses the initial change to restore balance (e.g., temperature regulation).

Homeostatic Imbalance and Disease

• Homeostatic imbalance occurs when the body fails to regulate internal conditions.
• This can lead to disease and dysfunction.
• Maintaining homeostasis through lifestyle choices helps prevent disease.

Major Forms of Energy

• Chemical energy is stored in molecular bonds.
• Electrical energy is from moving charged particles.
• Mechanical energy directly moves matter.
• Radiant energy travels in waves.

Types of Reactions

• Synthesis combines smaller molecules into larger ones, requires energy (anabolic).
• Decomposition breaks down larger molecules, releases energy (catabolic).
• Exchange swaps parts of molecules, can store or release energy.

Oxidation-Reduction Reactions

• Oxidation-reduction (redox) reactions transfer electrons between molecules.
• Oxidation involves the loss of electrons.
• Reduction involves the gain of electrons.
• Redox reactions are critical for energy production, such as ATP generation from glucose.

Reversible Reactions

• Chemical reactions in the body are reversible.
• This allows the body to adapt to changing conditions, regulate metabolism, and maintain homeostasis.

Factors Affecting Reaction Rates

• Temperature affects reaction rates; higher temperatures usually increase the rate.
• Higher reactant concentrations typically increase reaction rates.
• Enzymes speed up reactions by lowering activation energy.

Importance of Water

• Water acts as a universal solvent.
• Aids in temperature regulation.
• Assists in lubrication.
• Plays a role in metabolic reactions.
• Transports substances within the body.

Importance of Salts

• Salts are essential for nerve impulses.
• They are needed for muscle contraction.
• They are important for fluid balance.

Acids and Bases

• An acid releases H+ ions in solution.
• A base removes H+ ions from solution.
• pH measures H+ concentration, controlling biological functions and maintaining homeostasis.

Carbohydrates and Lipids

• Carbohydrates are composed of monosaccharides (C, H, O).
• Carbohydrates are water-soluble and provide quick energy.
• Lipids are composed of glycerol and fatty acids (mostly C and H).
• Lipids are hydrophobic and provide long-term energy storage.

Enzyme Function

• Enzymes are essential for life.
• They enable reactions efficiently.
• Biological processes would be too slow to sustain life without enzymes.

DNA vs. RNA

• DNA contains deoxyribose, is double-stranded, uses A, T, G, C, stores genetic information, and is stable.
• RNA contains ribose, is single-stranded, uses A, U, G, C, aids in protein synthesis, and is less stable.

Cell Definition

• A cell is the basic structural and functional unit of life.
• The smallest unit capable of carrying out life functions.
• Cells form tissues, organs, and organisms.

Major Cell Regions

• Plasma membrane: outer boundary, regulates movement, provides protection and communication.
• Cytoplasm: includes cytosol and organelles, site for cellular activities.
• Nucleus: control center, houses DNA, regulates gene expression.

Plasma Membrane Composition and Function

• Phospholipid bilayer with proteins, cholesterol, and carbohydrates.
• Selectively permeable due to composition.
• Controls what enters and exits the cell.

Cell Junctions

• Tight junctions seal cells together to prevent leakage.
• Desmosomes provide strong connections to resist mechanical stress.
• Gap junctions allow communication via passage of ions and molecules.

Membrane Structure and Transport

• Plasma membrane structure regulates movement.
• Passive transport requires no energy.
• Active transport requires energy.

Passive Transport Types

• Simple diffusion: small, nonpolar molecules move from high to low concentration.
• Facilitated diffusion: uses membrane proteins for larger/polar molecules.
• Osmosis: water moves from high to low water concentration.

Active Transport Types

• Primary active transport: uses ATP directly.
• Secondary active transport: uses ion gradients.

Endocytosis and Exocytosis

• Endocytosis: brings substances into the cell.
• Exocytosis: releases substances out of the cell.

Endocytosis Types

• Pinocytosis: uptakes fluids and solutes.
• Phagocytosis: engulfs large particles.
• Receptor-mediated endocytosis: targets specific particles.

Membrane Potential

• Electrical charge difference across the membrane.
• Established by ion gradients and selective permeability.
• Maintained by Na+/K+ pump.
• Essential for nerve impulses and muscle contractions.

Glycocalyx Role

• Carbohydrate-rich layer covering the plasma membrane.
• Facilitates cell-to-cell binding.
• Aids in cell communication and identification.

Membrane Receptors and Channels

• Membrane-bound receptors bind to specific signals and trigger responses.
• Voltage-sensitive channels open/close in response to voltage changes.
• Aid in electrical signaling.

Cytosol Composition

• Intracellular fluid surrounding organelles.
• Contains water, ions, proteins, nutrients, and waste products.

Mitochondria

• Double-membrane organelle that generates ATP.
• Inner membrane is highly folded.
• Site of cellular respiration.

Ribosomes, ER, Golgi Apparatus

• Ribosomes: aid in protein synthesis.
• ER: network for protein and lipid synthesis (rough ER has ribosomes, smooth ER does not).
• Golgi Apparatus: modifies and packages proteins.
• These organelles work together to handle protein production and distribution.

Lysosomes vs. Peroxisomes

• Lysosomes function in digestion and waste removal.
• Peroxisomes function in detoxification and lipid metabolism.

Cytoskeletal Elements

• Microfilaments: provide support and aid in muscle contraction.
• Intermediate filaments: provide structural support.
• Microtubules: act as tracks for motor proteins.

Cilia vs. Microvilli

• Cilia: move substances across the cell surface.
• Microvilli: increase surface area for absorption.

Nuclear Components

• Nuclear envelope: protects DNA and regulates transport.
• Nucleolus: synthesizes ribosomes.
• Chromatin: stores genetic information.

Cell Cycle Phases

• Interphase: growth and preparation.
• Mitotic phase: division of the cell.
• Key events include DNA replication, chromosome condensation, and cell division.

DNA Replication

• Initiation: DNA unwinds.
• Elongation: RNA primase adds primer; DNA polymerase synthesizes new strands.
• Termination: replication completes, resulting in two identical DNA molecules.

Genes and Genetic Code

• A gene is a DNA segment that codes for a specific protein or RNA molecule.
• Genetic code converts DNA/RNA into proteins; triplet bases and codons.
• Genes play a crucial role in protein synthesis and cell regulation.

Protein Synthesis Phases

• Transcription (nucleus): mRNA carries genetic instructions from DNA.
• Translation (ribosome): tRNA delivers amino acids, rRNA catalyzes peptide bonds.

Triplets, Codons, Anticodons

• Triplet: DNA sequence coding for mRNA codon.
• Codon: mRNA sequence coding for an amino acid.
• Anticodon: tRNA sequence pairing with mRNA codon.

Ubiquitin-Dependent Degradation

• Ensures protein quality control.
• Breaks down misfolded or unneeded proteins.

Extracellular Materials

• Extracellular fluid provides a medium for nutrient/waste exchange.
• Extracellular matrix provides structural support and cell adhesion.
• Cell secretions include mucus, enzymes, and hormones.

Apoptosis Value

• Controlled cell death that removes old, damaged, or unnecessary cells.
• Essential for development, maintenance, and protection.