Bio315 Exam #1 Study Guide

1. Organization of the Body

a. Definitions:

  • Cell: The basic structural and functional unit of all living organisms.

  • Primary Tissue: A group of similar cells that perform a specific function. The four primary tissues are epithelial, connective, muscle, and nervous.

  • Organs: Structures composed of two or more tissue types that work together to perform a specific function.

  • Organ Systems: Groups of organs that work together to perform major functions (e.g., digestive system, nervous system).

b. Pluripotent Stem Cell:

  • A stem cell that has the potential to differentiate into any cell type in the body (except extraembryonic tissues like the placenta).

c. Primary Tissues and Their Functions:

  1. Epithelial Tissue: Covers body surfaces, lines cavities, and forms glands. Functions include protection, secretion, and absorption.

  2. Connective Tissue: Supports and binds other tissues. Functions include structural support, storage, and transport.

  3. Muscle Tissue: Responsible for movement. Functions include contraction and generating force.

  4. Nervous Tissue: Transmits electrical impulses. Functions include communication and control.



2. Body Regions and Cavities

a. Axial Regions:

  • Includes the head, neck, and trunk (thorax, abdomen, pelvis).

  • Appendicular Region: Refers to the limbs (arms and legs).

b. Body Cavities and Organs:

  1. Cranial Cavity: Brain.

  2. Thoracic Cavity: Heart, lungs, esophagus.

  3. Abdominal Cavity: Stomach, liver, intestines.

  4. Pelvic Cavity: Bladder, reproductive organs.



3. Directional Terms

  • Dorsal: Toward the back.

  • Ventral: Toward the front.

  • Superior: Above.

  • Inferior: Below.

  • Medial: Toward the midline.

  • Lateral: Away from the midline.

  • Proximal: Closer to the point of attachment.

  • Distal: Farther from the point of attachment.



4. Planes of Section

  1. Sagittal Plane: Divides the body into left and right.

  2. Frontal (Coronal) Plane: Divides the body into front and back.

  3. Transverse Plane: Divides the body into upper and lower.



5. Tissue Preparation for Microscopy

a. Steps:

  1. Fixation (preserves tissue).

  2. Embedding (in paraffin or resin).

  3. Sectioning (slicing into thin sections).

  4. Staining (e.g., hematoxylin and eosin).

b. Light vs. Electron Microscopy:

  • Light Microscopy: Uses visible light to view stained tissues. Lower resolution.

  • Electron Microscopy: Uses electron beams for higher resolution and detailed ultrastructure.

c. Hematoxylin and Eosin Staining:

  • Hematoxylin: Binds to acidic structures (e.g., DNA) and stains them blue/purple.

  • Eosin: Binds to basic structures (e.g., proteins) and stains them pink.



6. Clinical Imaging Techniques

  • X-ray: Uses radiation to visualize dense structures like bones.

  • CT Scan: Combines X-rays for 3D images.

  • MRI: Uses magnetic fields and radio waves for soft tissue imaging.

  • Ultrasound: Uses sound waves for real-time imaging.



7. Cell Components

a. Organelles and Functions:

  • Nucleus: Contains DNA and controls cell activities.

  • Rough ER: Protein synthesis and modification.

  • Smooth ER: Lipid synthesis and detoxification.

  • Golgi Apparatus: Modifies, sorts, and packages proteins.

  • Lysosomes/Peroxisomes: Digest waste and detoxify.

b. Cytoskeleton:

  • Made of microtubules, microfilaments, and intermediate filaments.



8. Plasma Membrane Components

  • Phospholipid bilayer, proteins, cholesterol, and carbohydrates.



9. Fluid-Mosaic Model

  • Describes the plasma membrane as a fluid structure with embedded proteins that can move laterally.



10. Phagocytosis vs. Pinocytosis

  • Phagocytosis: Engulfment of large particles (e.g., bacteria).

  • Pinocytosis: Uptake of fluids and dissolved substances.

a. Exocytosis Steps:

  1. Vesicle formation.

  2. Transport to the membrane.

  3. Fusion with the membrane.

  4. Release of contents.



11. Epithelium

a. Morphology:

  • Squamous, cuboidal, columnar.

b. Microvilli vs. Cilia:

  • Microvilli: Increase surface area for absorption.

  • Cilia: Move substances along the surface.

c. Basal Lamina:

  • Extracellular matrix layer underlying epithelial cells.

d. Cell Junctions:

  • Tight junctions, desmosomes, gap junctions.

e. Exocrine Glands:

  • Simple: Unbranched ducts.

  • Compound: Branched ducts.

f. Exocrine vs. Endocrine Glands:

  • Exocrine: Secrete products into ducts.

  • Endocrine: Secrete hormones into the bloodstream.



12. Connective Tissue Features

  1. Extracellular matrix.

  2. Protein fibers (collagen, elastin, reticular).

  3. Cells (fibroblasts, macrophages, etc.).



13. Loose Connective Tissue

a. Functions:

  1. Supports and binds tissues.

  2. Stores water and salts.

  3. Fights pathogens.

b. Cell Type:

  • Fibroblasts produce the extracellular matrix.

c. Role in Immunity:

  • Macrophages and mast cells fight pathogens.



14. Cartilage Types

  1. Hyaline: Found in joints, ribs.

  2. Elastic: Found in ears, epiglottis.

  3. Fibrocartilage: Found in intervertebral discs.



15. Bone Tissue

a. Classifications:

  1. Compact bone.

  2. Spongy bone.

b. Bone Structures:

  • Trabeculae: Spicules in spongy bone.

  • Periosteum: Outer bone covering.

  • Endosteum: Inner bone lining.

c. Osteons:

  • Structural units of compact bone.

  • Lamellae: Concentric rings of bone matrix.

  • Volkman’s Canals: Connect blood vessels.

  • Canaliculi: Allow nutrient exchange.

d. Bone Composition:

  • Inorganic: Hydroxyapatite (calcium phosphate).

  • Organic: Collagen fibers.

e. Function:

  • Compact bone resists compression; spongy bone resists tension.



16. Bone Development

a. Endochondral Ossification:

  1. Cartilage model forms.

  2. Bone replaces cartilage.

  • Intramembranous Ossification: Bone forms directly from mesenchymal tissue.

b. Examples:

  • Intramembranous: Flat bones (skull).

  • Endochondral: Long bones (femur).

c. Bone Remodeling:

  • Osteoclasts remove bone; osteoblasts form new bone.



17. Muscle Tissue Types

  1. Skeletal.

  2. Cardiac.

  3. Smooth.



18. Skeletal Muscle Organization

a. Filaments:

  1. Actin (thin filaments).

  2. Myosin (thick filaments).

b. Sarcomeres:

  • Functional units of muscle contraction.

c. Myofibrils:

  • Long protein bundles in muscle cells.

d. T Tubules:

  • Conduct electrical signals.

e. Sarcoplasmic Reticulum:

  • Stores and releases calcium for contraction.



19. Smooth Muscle

  • Smaller, spindle-shaped cells.

  • No sarcomeres.

  • Dense Bodies: Anchor actin filaments (analogous to Z-discs in skeletal muscle).



20. Cardiac Muscle

  • Striated, branched cells.

  • Intercalated Discs: Connect cells and allow synchronized contraction.



21. Fascicles

  • Bundles of muscle fibers in skeletal muscle.



22. Connective Tissue Layers in Muscle

  • Endomysium: Surrounds individual muscle fibers.

  • Perimysium: Surrounds fascicles.

Epimysium: Surrounds entire muscle.