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1. Organizational Hierarchy of an Organism

  • Cell: Basic unit of life; performs all essential functions.

  • Tissue: Group of similar cells working together; types include epithelial, connective, muscle, and nervous.

  • Organ: Structure composed of multiple tissue types; performs specific functions (e.g., heart, lungs).

  • Organ System: Group of organs that work together for complex functions (e.g., digestive system).

  • Organism: Individual living being made up of various organ systems.

2. The 11 Organ Systems

  • Integumentary: Protects body; includes skin, hair, nails.

  • Skeletal: Provides structure; supports and protects organs; produces blood cells.

  • Muscular: Facilitates movement; maintains posture; generates heat.

  • Nervous: Controls body activities; processes information; includes brain, spinal cord, nerves.

  • Endocrine: Regulates bodily functions through hormones (e.g., glands).

  • Cardiovascular: Transports nutrients, gases, and waste; includes heart and blood vessels.

  • Lymphatic: Returns fluid to blood; protects against infection; includes lymph nodes and vessels.

  • Respiratory: Facilitates gas exchange (oxygen and carbon dioxide); includes lungs and airways.

  • Digestive: Breaks down food; absorbs nutrients; includes stomach and intestines.

  • Urinary: Removes waste; regulates water and electrolytes; includes kidneys and bladder.

  • Reproductive: Produces offspring; includes reproductive organs.

3. Terms of Direction

  • Superior: Above; e.g., the head is superior to the abdomen.

  • Inferior: Below; e.g., the stomach is inferior to the heart.

  • Medial: Closer to the midline; e.g., the nose is medial to the eyes.

  • Lateral: Further from the midline; e.g., the ears are lateral to the head.

  • Proximal: Closer to the point of attachment; e.g., the elbow is proximal to the wrist.

  • Distal: Further from the point of attachment; e.g., the fingers are distal to the wrist.

  • Anterior: Front; e.g., the sternum is anterior to the spine.

  • Posterior: Back; e.g., the spine is posterior to the sternum.

4. Surface Regions of the Body

  • Key regions include:

    • Abdominal: Related to the abdomen.

    • Axillary: Armpit region.

    • Brachial: Arm region.

    • Buccal: Cheek area.

    • Cervical: Neck region.

    • Cubital: Elbow area.

    • Femoral: Thigh region.

    • Orbital: Eye socket.

    • Patellar: Knee region.

    • Pubic: Genital region.

    • Thoracic: Chest area.

    • Tibial: Shin area.

    • Calf: Lower leg.

    • Gluteal: Buttocks.

    • Lumbar: Lower back.

    • Occipital: Base of the skull.

    • Popliteal: Back of the knee.

    • Scapular: Shoulder blade region.

    • Vertebral: Spinal column.

5. Planes of the Body

  • Sagittal Plane: Divides the body into left and right parts.

  • Frontal (Coronal) Plane: Divides the body into anterior and posterior parts.

  • Transverse (Horizontal) Plane: Divides the body into superior and inferior parts.

6. Subatomic Particles

  • Protons: Positively charged; found in the nucleus.

  • Neutrons: Neutral charge; also in the nucleus.

  • Electrons: Negatively charged; orbit around the nucleus.

7. Types of Chemical Bonds

  • Ionic Bonds: Formed when electrons are transferred from one atom to another, resulting in charged ions.

  • Covalent Bonds: Involve the sharing of electrons between atoms.

    • Nonpolar Covalent Bonds: Electrons are shared equally.

    • Polar Covalent Bonds: Electrons are shared unequally, creating partial charges.

  • Hydrogen Bonds: Weak attractions between a hydrogen atom covalently bonded to one electronegative atom and another electronegative atom.

8. Chemical Reactions

  • Synthesis Reaction: Two or more reactants combine to form a larger product (A + B → AB).

  • Decomposition Reaction: A single compound breaks down into two or more simpler products (AB → A + B).

  • Exchange Reaction: Atoms or molecules exchange places (AB + CD → AC + BD).

  • Reversible Reaction: Can proceed in both forward and reverse directions (A + B ⇌ AB).

9. Parts of the Cell

  • Cytoplasm: Gel-like substance where organelles are suspended.

  • Nucleus: Contains genetic material (DNA); controls cellular activities.

  • Endoplasmic Reticulum (ER):

    • Rough ER: Studded with ribosomes; synthesizes proteins.

    • Smooth ER: Synthesizes lipids and detoxifies.

  • Ribosomes: Sites of protein synthesis; can be free in cytoplasm or attached to ER.

  • Golgi Complex: Modifies, sorts, and packages proteins for secretion or use within the cell.

  • Lysosomes: Contains digestive enzymes to break down waste.

  • Peroxisomes: Contains enzymes that detoxify harmful substances.

  • Mitochondria: Powerhouse of the cell; site of ATP production.

  • Centrioles: Involved in cell division.

10. Transport Mechanisms

  • Passive Transport: Movement of molecules without energy use.

    • Diffusion: Movement from high to low concentration.

    • Osmosis: Movement of water across a membrane.

    • Facilitated Diffusion: Requires transport proteins.

  • Active Transport: Requires energy (ATP) to move substances against their concentration gradient.

    • Examples: Sodium-potassium pump, endocytosis, and exocytosis.

11. DNA and RNA in Protein Synthesis

  • DNA: Double-stranded molecule; stores genetic information.

  • RNA: Single-stranded; involved in protein synthesis.

    • mRNA (Messenger RNA): Carries genetic information from DNA to ribosomes.

    • rRNA (Ribosomal RNA): Structural component of ribosomes.

    • tRNA (Transfer RNA): Brings amino acids to the ribosome during protein synthesis.

12. Mitosis Stages

  • Prophase: Chromatin condenses into visible chromosomes; nuclear membrane breaks down.

  • Metaphase: Chromosomes align at the cell's equator.

  • Anaphase: Sister chromatids are pulled apart to opposite poles of the cell.

  • Telophase: Nuclear membranes re-form around each set of chromosomes; cell begins to divide.

13. ATP Structure and Energy Use

  • ATP (adenosine triphosphate) consists of adenine, ribose (a sugar), and three phosphate groups. The energy stored in the high-energy phosphate bonds is released when ATP is hydrolyzed to ADP (adenosine diphosphate) and inorganic phosphate.

14. Metabolic Energy Systems

  • ATP: Immediate energy source; lasts seconds.

  • Phosphocreatine (PCr): Provides energy for short bursts; lasts about 10 seconds.

  • Glycolysis: Anaerobic breakdown of glucose; lasts 30 seconds to 2 minutes; produces 2 ATP per glucose molecule.

  • Krebs Cycle: Aerobic process; occurs in mitochondria; produces 2 ATP and high-energy carriers per glucose molecule.

  • Electron Transport Chain: Produces the most ATP (up to 34 ATP) through aerobic respiration.

15. Calories in Macromolecules

  • Carbohydrates: 4 calories per gram; primary energy source.

  • Proteins: 4 calories per gram; used for repair and growth.

  • Fats: 9 calories per gram; dense energy source.

  • In a pound: Approximately 3,500 calories.

16. Bone Types/Features

  • Types of Bones:

    • Long (e.g., femur), short (e.g., carpals), flat (e.g., skull), irregular (e.g., vertebrae).

  • Surface Features:

    • Condyle: Rounded knob; fits into a joint.

    • Head: Prominent rounded end.

1. Types of Muscles

  • Skeletal Muscle:

    • Voluntary muscle; striated appearance due to alternating light and dark bands.

    • Attached to bones; responsible for body movement.

    • Multinucleated.

  • Cardiac Muscle:

    • Involuntary muscle; found only in the heart.

    • Striated but branched; contains intercalated discs for synchronized contraction.

    • Single nucleus per cell.

  • Smooth Muscle:

    • Involuntary muscle; non-striated.

    • Found in walls of hollow organs (e.g., intestines, blood vessels).

    • Single nucleus; contracts slowly and rhythmically.

2. Anatomy of Skeletal Muscle Fibers

  • Sarcolemma:

    • The cell membrane of a muscle fiber; encloses the muscle cell and transmits electrical impulses.

  • Sarcoplasmic Reticulum (SR):

    • Specialized endoplasmic reticulum; stores calcium ions necessary for muscle contraction.

  • Transverse Tubules (T-tubules):

    • Extensions of the sarcolemma that penetrate into the muscle fiber; help transmit electrical signals deep into the cell.

  • Myofilaments:

    • Thin (actin) and thick (myosin) filaments that slide past each other during contraction.

  • Sarcomere:

    • The basic functional unit of muscle; the region between two Z-discs. Contains organized myofilaments responsible for contraction.

3. Sliding Filament Theory

  • Explains how muscles contract. When a muscle fiber is stimulated, myosin heads attach to actin, pulling the filaments past each other, which shortens the sarcomere. This process requires ATP and calcium ions.

4. Motor Unit

  • A motor unit consists of a motor neuron and all the muscle fibers it innervates. When a motor neuron fires, all muscle fibers in the unit contract simultaneously, allowing for coordinated movement.

5. Ligament vs. Tendon

  • Ligaments: Connect bone to bone; provide stability to joints.

  • Tendons: Connect muscle to bone; transmit force generated by muscles to move bones.

6. Types of Tissues: Structure and Functions

  • Epithelial Tissue:

    • Covers body surfaces and lines cavities; involved in protection, absorption, and secretion.

    • Simple: Single layer of cells (e.g., simple squamous, cuboidal, columnar).

    • Stratified: Multiple layers (e.g., stratified squamous for protection).

  • Connective Tissue:

    • Supports, binds, and protects other tissues; diverse in structure and function.

    • Loose Connective Tissue: Provides support and elasticity (e.g., areolar tissue).

    • Dense Connective Tissue: Provides strength and resistance (e.g., tendons, ligaments).

    • Fluid Connective Tissue: Includes blood; transports nutrients, gases, and waste.

  • Muscular Tissue:

    • Responsible for movement; types include skeletal, cardiac, and smooth muscle.

  • Nervous Tissue:

    • Composed of neurons and glial cells; transmits signals and processes information.

7. Types of Membranes

  • Mucous Membranes:

    • Line passages that open to the exterior (e.g., respiratory, digestive tracts); contain goblet cells for mucus secretion.

  • Serous Membranes:

    • Double-layered; cover organs and line cavities.

    • Visceral Layer: Covers organs.

    • Parietal Layer: Lines the cavity walls.

  • Cutaneous Membrane:

    • Skin; provides protection and is waterproof.

  • Synovial Membrane:

    • Lines joints; produces synovial fluid for lubrication.

8. Structure of Skin

  • Epidermis:

    • Outermost layer; composed of keratinized stratified squamous epithelial cells.

    • Avascular (lacks blood vessels).

    • Contains hair follicles.

    • Layers of the Epidermis:

      • Stratum Basale: Innermost layer; site of mitosis producing new keratinocytes.

      • Stratum Spinosum: Contains keratinocytes that begin to produce keratin.

      • Stratum Granulosum: Cells undergo keratinization; begin to die.

      • Stratum Lucidum: Present only in thick skin (e.g., palms, soles); provides additional protection.

      • Stratum Corneum: Outermost layer; consists of dead, keratinized cells that protect underlying layers.

  • Dermis:

    • Innermost layer; known as “true skin.”

    • Divided into two regions:

      • Papillary Layer: Contains dermal papillae (finger-like projections) with blood vessels and touch receptors; forms fingerprints.

      • Reticular Layer: Dense network of collagen and elastic fibers; contains pressure, touch, pain, and temperature receptors.

  • Hypodermis (Subcutaneous Layer):

    • Beneath the dermis; consists of loose connective tissue and adipose tissue; attaches skin to underlying structures and provides insulation.