Anatomy and Physiology Overview

Anatomy and Physiology

• Anatomy: Study of the structure of the body.
• Physiology: Study of the body's functions.
• Macroscopic Anatomy (Gross Anatomy): Study of structures visible to the naked eye.
• Microscopic Anatomy: Study of structures only visible with a microscope.

Hierarchy of Structural Organization

• Ascending Order:

  • Chemical Level: Atoms combine to form molecules.
  • Cellular Level: Molecules form organelles, which make up cells.
  • Tissue Level: Groups of similar cells performing a common function.
  • Organ Level: Two or more tissues working together for a common purpose.
  • Organ System Level: Groups of organs that cooperate for a major function.
  • Organismal Level: All organ systems working together to maintain life.

• Descending Order: Organism, Organ System, Organ, Tissue, Cellular, Chemical

Homeostasis and Feedback Loops

• Homeostasis: Maintenance of a stable internal environment.
• Feedback Loops: Mechanisms used to maintain homeostasis.
• Positive Feedback Loop: Amplifies the initial stimulus, pushing the body further away from homeostasis. Example: Childbirth
• Negative Feedback Loop: Counteracts the initial stimulus, bringing the body back to homeostasis. Example: Body temperature regulation.

Components of a Feedback Loop

• Receptor: Detects the stimulus.
• Control Center: Processes the information and sends instructions.
• Effector: Carries out the instructions to bring the body back to homeostasis.

Organ Systems

• Integumentary System: Skin, hair, nails; protects the body, regulates temperature.
• Skeletal System: Bones, cartilage, joints; provides support, protection, movement, mineral storage, and blood cell production.
• Muscular System: All muscles; movement, posture, heat production.
• Endocrine System: Glands that produce hormones; regulates body functions.
• Nervous System: Brain, spinal cord, nerves; regulates rapid communication and body functions.

Anatomical Position and Directional Terms

• Anatomical Position: Standing erect, palms facing forward, feet together.
• Directional Terms: Describe the position of body parts relative to each other.
  • Superior: Above.
  • Inferior: Below.
  • Anterior (Ventral): Front.
  • Posterior (Dorsal): Back.
  • Medial: Toward the midline.
  • Lateral: Away from the midline.
  • Proximal: Closer to the point of attachment.
  • Distal: Further from the point of attachment.
  • Superficial: Close to the surface.
  • Deep: Away from the surface.
• Anatomical Landmarks: Specific body locations.
  • Antebrachial: Forearm.
  • Antecubital: Front of elbow.
  • Lumbar: Lower back.
  • Cephalic: Head.

Body Planes and Sections

• Transverse Plane: Divides the body into superior and inferior portions.
• Sagittal Plane: Divides the body into left and right portions.
  • Midsagittal Plane: Divides the body into equal left and right portions.
  • Parasagittal Plane: Divides the body into unequal left and right portions.
• Frontal (Coronal) Plane: Divides the body into anterior and posterior portions.

Body Cavities

• Dorsal Body Cavity: Houses the central nervous system.
  • Cranial Cavity: Contains the brain.
  • Spinal (Vertebral) Cavity: Contains the spinal cord.
• Ventral Body Cavity: Houses the internal organs.
  • Thoracic Cavity:
    • Pleural Cavities: Contain the lungs.
    • Mediastinum: Contains the heart, trachea, and esophagus.
  • Abdominopelvic Cavity:
    • Abdominal Cavity: Contains the stomach, liver, intestines, and other organs.
    • Pelvic Cavity: Contains the urinary bladder, reproductive organs, and rectum.

Serous Membranes

• Serous Membranes: Double-layered membranes that line body cavities and cover organs.
  • Parietal Layer: Lines the body cavity wall.
  • Visceral Layer: Covers the organ.
• Pericardial Membrane: Surrounds the heart.
• Pleural Membrane: Surrounds the lungs.
• Peritoneal Membrane: Surrounds the abdominopelvic organs.

Abdominal Regions and Quadrants

• Abdominal Regions: Nine regions used to describe locations of abdominal organs.
• Abdominal Quadrants: Four quadrants used to describe locations of abdominal organs.

Atoms and Elements

• Atom: Smallest unit of an element that maintains the properties of that element.
• Element: A pure substance consisting of only one type of atom.
• Electron: Negatively charged particle that orbits the nucleus.
• Neutron: Neutral particle found in the nucleus.
• Proton: Positively charged particle found in the nucleus.
• Atomic Number: Number of protons in an atom's nucleus.
• Mass Number: Total number of protons and neutrons in an atom's nucleus.
• Isotope: Atoms of the same element with the same number of protons but a different number of neutrons.
• Major Elements in the Human Body: Oxygen, Carbon, Hydrogen, Nitrogen.

Solutions and Suspensions

• Solution: A homogeneous mixture where one substance is dissolved into another.
• Suspension: A heterogeneous mixture where particles are suspended in a liquid.

Chemical Bonds

• Valence Electrons: Electrons in the outermost shell of an atom, involved in chemical bonding.
• Octet Rule: Atoms tend to gain, lose, or share electrons to achieve a stable outer shell with eight electrons.
• Ionic Bonds: Formed by the transfer of electrons between atoms, resulting in ions with opposite charges.
• Covalent Bonds: Formed by the sharing of electrons between atoms.
  • Polar Covalent Bond: Unequal sharing of electrons, resulting in a partial positive and partial negative charge within the molecule.
  • Non-polar Covalent Bond: Equal sharing of electrons.
• Hydrogen Bonds: Weak bonds formed between a partially positive hydrogen atom and a partially negative atom in another molecule.

Chemical Reactions

• Anabolic Reactions: Build larger molecules from smaller ones, requiring energy.
• Catabolic Reactions: Break down larger molecules into smaller ones, releasing energy.
• Exchange Reactions: Involve both the breaking and formation of chemical bonds.
  • Dehydration Synthesis: Removal of water to form a bond.
  • Hydrolysis: Addition of water to break a bond.
• Endergonic Reactions: Require energy input.
• Exergonic Reactions: Release energy.

Enzymes

• Enzymes: Biological catalysts that speed up chemical reactions without being consumed in the process.
• Properties of Enzymes: Specific to their substrate, affected by temperature and pH.
• Function of Enzymes: Lower activation energy, allowing reactions to proceed faster.
• Denaturation: Loss of an enzyme's shape and function due to changes in temperature or pH.

Water

• Water as a Polar Molecule: The uneven sharing of electrons in the water molecule creates a partial positive charge on the hydrogen atoms and a partial negative charge on the oxygen atom.
• Hydrogen Bonding in Water: Hydrogen bonds between water molecules give water its unique properties.

pH Scale

• pH Scale: Measures the acidity or alkalinity of a solution.
• Acidic Solutions: Have a pH less than 7.
• Neutral Solutions: Have a pH of 7.
• Basic (Alkaline) Solutions: Have a pH greater than 7.
• Each unit on the pH scale represents a tenfold change in acidity or alkalinity.

Buffer Systems

• Buffer Systems: Help to maintain a stable pH in body fluids.

Organic Molecules

• Carbohydrates: Composed of carbon, hydrogen, and oxygen.
  • Monosaccharides: Simple sugars (e.g., glucose, fructose).
  • Disaccharides: Two monosaccharides linked together (e.g., sucrose, lactose).
  • Polysaccharides: Many monosaccharides linked together (e.g., starch, glycogen).
• Lipids: Primarily composed of carbon, hydrogen, and oxygen.
  • Triglycerides: Fats and oils, important energy storage molecules.
  • Phospholipids: Major component of cell membranes.
  • Steroids: Include hormones, cholesterol.
• Proteins: Composed of amino acids.
  • Monomers of Proteins: Amino acids.
  • Functions of Proteins: Structural support, enzymatic activity, transport, movement, defense, etc.
  • Denaturation of Proteins: Loss of shape and function due to changes in temperature or pH.
  • Fibrous Proteins: Long, fibrous strands that provide structural support.
  • Globular Proteins: Spherical or globular shapes, often involved in biological processes.
• Nucleic Acids: Composed of nucleotides.
  • Monomers of Nucleic Acids: Nucleotides.
  • Components of a Nucleotide: Sugar, phosphate group, nitrogenous base.
  • DNA (Deoxyribonucleic Acid): Genetic material that stores the instructions for building and maintaining an organism.
  • RNA (Ribonucleic Acid): Transports and translates genetic information.
  • ATP (Adenosine Triphosphate): Energy carrier in cells.

Cells

• Cell: Basic unit of life.
• Plasma Membrane: Outer boundary of the cell.
  • Phospholipid Bilayer: Two layers of phospholipids, with hydrophobic tails facing inward and hydrophilic heads facing outward.
  • Proteins: Embedded in the phospholipid bilayer, involved in transport, communication, and other functions.
• Cytoplasm: Everything inside the cell except the nucleus.
  • Cytosol: Fluid portion of the cytoplasm.
  • Organelles: Specialized structures within the cytoplasm, performing specific functions.
• Microvilli: Finger-like projections that increase surface area.
• Cilia: Hair-like projections that move fluids.
• Flagella: Long, whip-like projections that propel the cell.

Organelles

• Ribosomes: Sites of protein synthesis.
• Mitochondria: Powerhouse of the cell, producing ATP.
• Lysosomes: Contain enzymes that break down waste products.
• Peroxisomes: Detoxify harmful substances.
• Nucleus: Control center of the cell, containing DNA.
  • Nucleolus: Produces ribosomes.
• Endoplasmic Reticulum (ER): Network of interconnected membranes.
  • Rough ER: Contains ribosomes, involved in protein synthesis.
  • Smooth ER: Lacks ribosomes, involved in lipid synthesis and detoxification.
• Golgi Apparatus: Modifies, packages, and sorts proteins.

Membrane Transport

• Passive Transport: Movement of substances across the plasma membrane without requiring energy.
  • Simple Diffusion: Movement of substances from an area of higher concentration to an area of lower concentration.
  • Facilitated Diffusion: Movement of substances across the membrane with the help of a transport protein.
• Active Transport: Movement of substances across the plasma membrane requiring energy.
  • Endocytosis: Bringing substances into the cell.
  • Exocytosis: Releasing substances out of the cell.
• Osmosis: Diffusion of water across a semipermeable membrane from an area of high water concentration to an area of low water concentration.
  • Isotonic Solution: Same concentration of solutes as the cell.
  • Hypertonic Solution: Higher concentration of solutes than the cell, causing water to move out of the cell.
  • Hypotonic Solution: Lower concentration of solutes than the cell, causing water to move into the cell.

Cell Cycle

• Interphase: Period of growth and preparation for cell division.
  • G1 Phase: Cell grows and synthesizes proteins.
  • S Phase: DNA is replicated.
  • G2 Phase: Cell continues to grow and prepares for mitosis.
• Mitosis: Division of the nucleus, resulting in two daughter cells with identical genetic material.
  • Prophase: Chromatin condenses into chromosomes, nuclear envelope breaks down, spindle fibers form.
  • Metaphase: Chromosomes line up at the equator of the cell.
  • Anaphase: Chromosomes separate and move to opposite poles.
  • Telophase: Chromosomes uncoil, nuclear envelope reforms, cytoplasm divides.
• Cytokinesis: Division of the cytoplasm, resulting in two daughter cells.
• Mitosis and Meiosis
  • Mitosis: Type of cell division used for growth and repair.
  • Meiosis: Type of cell division used for sexual reproduction.

Explore the foundational concepts of anatomy and physiology, including the structural organization of the body. This quiz covers macroscopic and microscopic anatomy, as well as homeostasis and feedback loops. Test your knowledge on how these systems interact to maintain life.