Introduction and Orientation

Anatomical Position and Planes

The anatomical position is a standardized stance used as a reference in describing the locations and relationships of body parts. Understanding anatomical planes and directional terms is essential for accurate communication in anatomy.

• Anatomical Position: The body stands upright, facing forward, arms at the sides with palms facing forward, and feet parallel.

• Anatomical Planes:

  • Sagittal Plane: Divides the body into right and left portions. The midsagittal (median) plane divides it into equal halves.

  • Frontal (Coronal) Plane: Divides the body into anterior (front) and posterior (back) portions.

  • Transverse Plane: Divides the body into superior (upper) and inferior (lower) portions.

• Directional Terms: Used to describe the location of one body part relative to another. Examples include:

  • Medial/Lateral: Toward/away from the midline.

  • Anterior (Ventral)/Posterior (Dorsal): Front/back of the body.

  • Superior/Inferior: Above/below.

  • Cranial (Cephalic)/Caudal: Toward the head/tail.

  • Superficial/Deep: Toward the surface/away from the surface.

  • Proximal/Distal: Closer to/farther from the point of attachment (usually used for limbs).

• Body Movements: Terms describing joint and body part movements:

  • Flexion/Extension

  • Abduction/Adduction

  • Medial/Lateral Rotation

  • Elevation/Depression

  • Protraction/Retraction

  • Pronation/Supination

  • Plantarflexion/Dorsiflexion

  • Eversion/Inversion

  • Circumduction

  • Opposition

Safety

Lab Safety and Pathogen Procedures

Safety in the laboratory is paramount. Students must be able to identify and use safety data sheets (SDS) and understand procedures for handling bloodborne pathogens.

• SDS: Documents that provide information on the properties of chemical products, including hazards and safe handling.

• Bloodborne Pathogens: Procedures include wearing gloves, proper disposal of sharps, and immediate cleaning of spills.

Metric System

Units, Prefixes, and Conversions

The metric system is the standard for scientific measurement. Understanding units, prefixes, and conversions is essential for lab work.

• Base Units: Meter (length), liter (volume), gram (mass).

• Prefixes: kilo- (103), hecto- (102), deca- (101), deci- (10-1), centi- (10-2), milli- (10-3), micro- (10-6).

• Conversions: Move the decimal point according to the prefix change.

• Temperature Conversion:

  • From Celsius to Fahrenheit:

• Measuring Length, Mass, and Volume: Use appropriate lab equipment (meter stick, balance, graduated cylinder).

Graphing

Data Interpretation and Presentation

Graphing is a key skill for visualizing and interpreting scientific data.

• Reading Graphs: Identify axes, units, and the relationship between variables.

• Dependent vs. Independent Variables: The independent variable is manipulated (x-axis); the dependent variable is measured (y-axis).

• Direct vs. Indirect Relationships: Direct: both variables increase/decrease together. Indirect: one increases as the other decreases.

• Graph Preparation: Label axes, include units, provide a title and key if necessary.

pH and Chemistry

Acids, Bases, and Hydrogen Ion Concentration

pH is a measure of hydrogen ion concentration in a solution. It is crucial for understanding chemical reactions in biological systems.

• pH Scale: Ranges from 0 (acidic) to 14 (basic), with 7 as neutral.

• Hydrogen Ion Concentration:

  • As pH increases, [H+] decreases.

  • As pH decreases, [H+] increases.

  • Each step on the pH scale represents a tenfold change in [H+].

• Acids and Bases: Acids donate H+; bases accept H+.

• Serial Dilution: A stepwise dilution of a substance in solution, often used to achieve a desired concentration.

Biological Molecules and Bonds

• Major Elements: Carbon, nitrogen, hydrogen, oxygen.

• Valence Electrons: Determine bonding capacity and stability ("happy" atoms have full outer shells).

• Bonds in Water:

  • Covalent Bonds: Hold H and O together within a water molecule.

  • Hydrogen Bonds: Form between the H of one water molecule and the O of another.

• Saturated vs. Unsaturated Fatty Acids: Saturated have no double bonds; unsaturated have one or more double bonds in the hydrocarbon chain.

• Glucose Molecule: C6H12O6 (6 carbons, 12 hydrogens, 6 oxygens).

• Peptide Bonds: Formed by dehydration synthesis between amino acids; broken by hydrolysis. Proteins are the resulting macromolecules.

Cells and Microscope

Microscope Parts and Use

Microscopy is essential for studying cells and tissues. Proper use and care of the microscope are fundamental lab skills.

• Parts of a Light Microscope: Ocular lens (eyepiece), objective lenses, stage, coarse and fine focus knobs, light source, diaphragm, base, arm.

• Care and Storage: Carry with two hands, clean lenses with lens paper, store with low power objective in place.

• Focusing Procedure: Start with lowest magnification, use coarse focus, then fine focus as needed.

• Immersion Oil: Used with high-power (usually 100x) objective to increase resolution by reducing light refraction.

• Total Magnification:

Cell Structure and Identification

• Visible Cell Parts: Nucleus, plasma membrane, cytoplasm.

• Cell Types Observed: Cheek cells, blood cells (from blood smear slide).

• Mitosis vs. Interphase: Mitosis is cell division; interphase is the resting/growth phase.

Tissues

Types and Identification

Tissues are groups of similar cells performing specific functions. Four main types are identified by their structure and function.

• Main Tissue Types: Epithelial, connective, muscle, nervous.

• Specific Tissue Identification: Use prepared slides to observe distinguishing features.

  • Example: Main tissue type: muscle; specific type: skeletal muscle (characterized by striations and multinucleated fibers).

• Characteristic Features: At least two specific features are required for identification (e.g., striations, cell shape, arrangement).

• Note: Vague terms like "lots of lines" or "dots" are not acceptable for tissue identification.

Diffusion, Osmosis, and Tonicity

Definitions and Principles

Diffusion and osmosis are passive transport processes essential for maintaining cellular homeostasis.

• Definitions:

  • Solution: Homogeneous mixture of solute and solvent.

  • Solute: Substance dissolved in a solvent.

  • Solvent: Substance that dissolves the solute (usually water in biological systems).

  • Soluble/Insoluble: Ability/inability to dissolve in a solvent.

  • Permeable/Semi-permeable/Impermeable: Describes membrane's ability to allow substances to pass through.

  • Concentration Gradient: Difference in concentration across a space.

  • Diffusion: Movement of molecules from high to low concentration.

  • Osmosis: Diffusion of water across a semi-permeable membrane.

  • Tonicity: Effect of a solution on cell volume (isotonic, hypertonic, hypotonic).

Factors Affecting Diffusion and Osmosis

• Solute Concentration, Temperature, Molecular Weight: Higher concentration, higher temperature, and lower molecular weight increase diffusion rate.

• Carrier Proteins: Some solutes (e.g., glucose, amino acids, ions) require proteins to cross membranes due to size or charge.

• Osmosis: Passive process dependent on water concentration gradient.

• Tonicity and Cell Volume:

  • Isotonic Solution: No net water movement; cell volume remains constant.

  • Hypotonic Solution: Water enters cell; cell swells.

  • Hypertonic Solution: Water leaves cell; cell shrinks.

Experimental Application

• Compare weight gain/loss in osmosis experiments to understand the effect of solute concentration on water movement.

• Key concepts: solute concentration, osmolarity, osmotic pressure, tonicity.