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.