Lab Anatomy and Cell Biology Flashcards

Laboratory Safety Protocols, Maintenance Guidelines, and Waste Disposal

• Proper adherence to laboratory safety protocols is mandatory to prevent personal injury and equipment damage.
• Hands must be clean and completely dry before touching electrical equipment.
• All electrical devices must be disconnected from power sources prior to conducting maintenance or troubleshooting.
• When cleaning dissecting instruments, sharp tools (scalpels, scissors, pointed probes) must always be held pointing away from the body.

Waste Management Procedures

• Glassware Disposal: Broken or cracked glass (test tubes, glass slides, cover slips, pasteur pipettes) must never be placed in standard trash receptacles. They must be placed immediately into the designated rigid "Broken Glass" container.
• Biological and Biohazardous Waste: Tissues of animal origin, blood, blood-contaminated gloves, and contaminated plastic items must be disposed of in specified biohazard containers.
• Decontamination of Glassware: Any reusable glassware contaminated with blood or biological fluids must be placed directly into a designated bleach solution bath.
• Workstation Sanitation: Before leaving the laboratory, work areas must be thoroughly wiped down with a $10\%$ bleach solution whenever biological specimens, preserved animals, or fresh animal tissues have been used.
• Personal Hygiene: Hands must be washed thoroughly with antibacterial soap before exiting the lab.
• Accident Reporting: Laboratory instructors must be notified immediately of any accidents, spills, injuries, or broken equipment.

Anatomical Terminology, Body Planes, and Directional Terms

Anatomical Position

• Standard point of reference used by healthcare professionals and scientists to describe body structures precisely.
• Characterized by:
  • Body standing upright, facing directly forward.
  • Feet flat on the floor, shoulder-width apart, with toes pointing directly forward.
  • Upper limbs hanging at the sides with palms facing forward (supinated).

Directional Terms

Directional terms are arranged in pairs of opposite directions to define precise locations of body parts relative to one another:

• Anterior (Ventral) vs. Posterior (Dorsal):

  • Anterior / Ventral: Refers to the front side of the body or a body part (e.g., the nose is on the anterior side of the body; anterior rami travel toward the front).
  • Posterior / Dorsal: Refers to the back side of the body or a body part (e.g., the scapula is posterior to the sternum; posterior rami travel toward the back).

• Superior vs. Inferior:

  • Superior: Toward or closer to the head (e.g., the head is superior to the neck; the superior vena cava lies closer to the head).
  • Inferior: Away from the head or toward the tail/feet (e.g., the abdomen is inferior to the chest; the inferior vena cava lies farther from the head).
  • Axial Restriction: The terms superior and inferior are strictly applied only to the axial region (head, neck, and trunk). They are not used for the appendicular region (limbs).

• Proximal vs. Distal:

  • Proximal: Refers to closeness (proximity) of a structure to its point of origin or point of attachment (the shoulder for the upper limb; the hip for the lower limb).
  • Distal: Refers to farness (distance) of a structure from its point of origin or attachment.
  • Appendicular Restriction: These terms are used exclusively on the appendicular region (upper and lower limbs) because limbs can change position in space. For example, the elbow is proximal to the wrist, while the fingers are distal to the wrist.

• Medial vs. Lateral:

  • Medial: Position closer to the imaginary midline running down the center of the body (e.g., the ulna is medial relative to the radius).
  • Lateral: Position farther away from the midline (e.g., the ears are lateral to the eyes).

• Superficial vs. Deep:

  • Superficial: Position closer to the surface of the body or skin (e.g., the ribs are superficial to the lungs).
  • Deep: Position farther away from the skin surface / internal (e.g., bone is deep to muscle).

Planes of Section

• Sagittal Plane: Vertical plane dividing the body or organ into right and left portions.
  • Midsagittal Plane: Divides the body or organ into equal right and left halves directly down the midline.
  • Parasagittal Plane: Divides the body or organ into unequal right and left parts.
• Frontal (Coronal) Plane: Vertical plane dividing the body or organ into anterior (front) and posterior (back) portions.
• Transverse (Cross / Horizontal) Plane: Horizontal plane dividing the body or organ into superior (proximal) and inferior (distal) portions.

Anatomical Regions, Nouns, and Term Mapping

Regional Adjectives and Definitions

• Antebrachial: Forearm (elbow to wrist).
• Antecubital: Anterior surface of the elbow.
• Axillary: Armpit area.
• Brachial: Upper arm (elbow to shoulder).
• Buccal: Cheek region.
• Cephalic: Head region.
• Cervical: Neck region.
• Frontal: Forehead.
• Gluteal: Buttocks region.
• Inguinal: Groin region.
• Lumbar: Lower back between ribs and pelvis.
• Ophthalmic: Eye region.
• Popliteal: Posterior side of the knee joint.
• Pubic: Area over the pubic bone of the pelvis.
• Scapular: Area over the scapula in the superior back.
• Sternal: Area in the middle of the chest over the sternum.
• Sural: Calf / posterior part of the lower leg.
• Tarsal: Ankle and proximal foot region.
• Thoracic: General chest area.
• Umbilical: Area surrounding the navel (belly button).
• Vertebral: Area overlying the vertebral column (spine).
• Perineum: Region between the anus and external genitalia.

Anatomical Nouns

• Arm: Portion of upper limb from elbow to shoulder.
• Forearm: Portion of upper limb from elbow to wrist.
• Thigh: Portion of lower limb from hip to knee.
• Leg: Portion of lower limb from knee to ankle.
• Upper Limb: Entire structure from shoulder to fingers.
• Lower Limb: Entire structure from hip to toes.

Common-to-Anatomical Term Cross-Reference

Spatial Relationships and Relative Orderings

• Anterior to Posterior: Lips $\rightarrow$ Tongue $\rightarrow$ Vertebrae.
• Proximal to Distal: Thigh $\rightarrow$ Knee $\rightarrow$ Calf $\rightarrow$ Ankle $\rightarrow$ Foot $\rightarrow$ Hallux (great toe).
• Superior to Inferior: Buccal region $\rightarrow$ Cervical region $\rightarrow$ Pectoral region $\rightarrow$ Umbilicus $\rightarrow$ Inguinal region.
• Medial to Lateral: Nose $\rightarrow$ Eye $\rightarrow$ Ear.
• Superficial to Deep: Skin $\rightarrow$ Superficial fascia $\rightarrow$ Muscle.

Body Cavities, Subcavities, and Serous Membranes

Internal spaces containing and protecting organs are classified into two major body cavities:

Body Cavities
├── Posterior (Dorsal) Cavity
│   ├── Cranial Cavity (Brain, CSF)
│   └── Vertebral Cavity (Spinal cord, CSF)
└── Anterior (Ventral) Cavity
    ├── Thoracic Cavity (Superior to Diaphragm)
    │   ├── Pleural Cavities (Lungs)
    │   └── Mediastinum
    │       └── Pericardial Cavity (Heart)
    └── Abdominopelvic Cavity (Inferior to Diaphragm)
        ├── Abdominal Cavity (Viscera)
        ├── Pelvic Cavity (Reproductive, Bladder, Rectum)
        └── Peritoneal Cavity
            ├── Intraperitoneal Organs
            └── Retroperitoneal Organs

Serous Membranes

• Thin, double-layered sheets of tissue lining fluid-filled cavities.
• Layers:
  • Parietal Layer: Outer layer attached to the cavity wall and surrounding structures.
  • Visceral Layer: Inner layer adhering directly to the surface of internal organs (viscera).
• Serous Fluid: Thin, watery lubricating fluid secreted into the potential space (cavity) between parietal and visceral layers to eliminate friction during organ movement.

Posterior (Dorsal) Body Cavity

• Located on the posterior aspect of the body.
• Subdivisions:
  • Cranial Cavity: Formed by the skull; encloses the brain and contains cerebrospinal fluid (CSF).
  • Vertebral (Spinal) Cavity: Formed by the vertebral column; encloses the spinal cord and contains CSF.

Anterior (Ventral) Body Cavity

• Located on the anterior aspect of the body; partitioned by the muscular diaphragm into two main regions:

Thoracic Cavity (Superior to Diaphragm)

Enclosed by the rib cage and divided into:

• Pleural Cavities: Right and left cavities, each enveloping one lung. Lined by the pleural membrane (parietal pleura attached to chest wall/diaphragm; visceral pleura attached to lung surface).
• Mediastinum: Central tissue mass between pleural cavities housing the esophagus, trachea, bronchi, great blood vessels, and the pericardial cavity.
• Pericardial Cavity: Encloses the heart. Lined by the pericardial membrane (parietal pericardium attached to surrounding structures; visceral pericardium attached to heart myocardium).

Abdominopelvic Cavity (Inferior to Diaphragm)

Extends from the diaphragm down into the bony pelvis. Divided into:

• Abdominal Cavity: Superior section bounded by the bony pelvis; houses the stomach, liver, gallbladder, spleen, pancreas, kidneys, adrenal glands, small intestine, and most of the large intestine.
• Pelvic Cavity: Inferior section housed within the bony pelvis; contains internal reproductive organs, urinary bladder, rectum, and lower colon.
• Peritoneal Cavity: Potential space lined by the peritoneal membrane (parietal peritoneum lines abdominal wall; visceral peritoneum covers enclosed organs).
  • Intraperitoneal Organs: Enclosed within the peritoneal cavity (stomach, liver, spleen, most of small intestine, tail of pancreas, transverse/sigmoid colon).
  • Retroperitoneal Organs: Positioned posterior to the peritoneal cavity (kidneys, adrenal glands, ureters, urinary bladder, pancreas head/body, ascending/descending colon, sex organs).

Abdominopelvic Quadrants and Organ Localization

To simplify clinical localization, the abdominopelvic surface is divided into four quadrants by vertical and horizontal lines intersecting at the umbilicus:

• Right Upper Quadrant (RUQ):
  • Primary Organs: Liver (right lobe), gallbladder, duodenum, head of pancreas, right kidney, right adrenal gland, hepatic flexure of colon, section of transverse colon, small intestine.
• Left Upper Quadrant (LUQ):
  • Primary Organs: Stomach, spleen, liver (left lobe), body and tail of pancreas, left kidney, left adrenal gland, splenic flexure of colon, section of transverse colon, small intestine.
• Right Lower Quadrant (RLQ):
  • Primary Organs: Cecum, appendix, ascending colon, small intestine, lower portion of right kidney, right ureter, right ovary and uterine tube (female), right spermatic cord (male).
• Left Lower Quadrant (LLQ):
  • Primary Organs: Descending colon, sigmoid colon, small intestine, lower portion of left kidney, left ureter, left ovary and uterine tube (female), left spermatic cord (male), urinary bladder.

Gross Anatomy and Systemic Dissection of the Rat (Rattus norvegicus)

Dissection Tool Operations

• Surgical Scissors: Features one blunt and one sharp point; used with the blunt tip positioned downward during body wall cuts to prevent puncturing internal organs.
• Iris Scissors: Small, fine-tipped scissors for delicate tissue dissection.
• Forceps: Standard fine forceps, broad forceps, and tooth-tipped tissue forceps for grasping.
• Probes: Blunt and sharp teasing needles used to separate tissues along natural fascial planes.

External and Oral Cavity Examination

• Incisors: Chisel-like anterior teeth adapted for gnawing and cutting.
• Molars: Flat-surfaced posterior teeth adapted for grinding food.
• Palate: Hard palate forms anterior roof of mouth with bony support; soft palate extends posteriorly.
• Pharynx: Muscular passageway at back of mouth serving both respiratory and digestive systems.
• Superficial Fascia: Subcutaneous connective tissue securing skin to underlying body wall muscle; severed during skinning.

Dissection of Thoracic Cavity Structures

• Heart: Median oval organ situated within the pericardial sac in the mediastinum.
• Lungs: Paired, spongy respiratory organs located laterally to heart; covered by visceral pleura.
• Trachea: Rigid tube reinforced with cartilaginous C-rings to maintain airway patency.
• Esophagus: Collapsible muscular tube positioned directly posterior to the trachea, conveying food to stomach.
• Diaphragm: Thin sheet of skeletal muscle separating thoracic and abdominal cavities.

Dissection of Abdominopelvic Cavity Structures

• Stomach: J-shaped/comma-shaped organ in upper left abdominal quadrant responsible for food storage and breakdown.
• Small Intestine: Highly coiled, narrow tube extending from pyloric sphincter of stomach to cecum; held in place by double-layered peritoneal membranes called mesenteries.
• Large Intestine (Colon): Broad tube extending from cecum to rectum.
• Cecum: Large blind pouch at junction of small and large intestines.
• Pancreas: Diffuse, nodular glandular tissue located in the mesentery loop formed between stomach and duodenum.
• Spleen: Elongated, dark-red organ on left lateral aspect of stomach; functions in blood filtering and immune surveillance.
• Liver: Large, multi-lobed dark brown organ directly inferior to diaphragm. Anatomical Difference: Rats lack a gallbladder (bile flows directly from liver to duodenum via bile ducts).
• Kidneys: Paired bean-shaped retroperitoneal organs on dorsal abdominal wall.
• Ureters: Fine tubes extending medially from kidney hilum to urinary bladder.
• Urinary Bladder: Muscular reservoir for urine storage.
• Major Blood Vessels:
  • Inferior Vena Cava: Large venous trunk on dorsal midline carrying deoxygenated blood to heart.
  • Descending Aorta: Thick-walled arterial trunk lying deep/dorsal to inferior vena cava.

Reproductive System Anatomy

• Male System: External scrotal sac superior to anus. Testis located in scrotum; spermatic cord houses blood vessels, nerves, and vas deferens. Vas deferens loops over ureter to enter urethra inferior to bladder; urethra runs through penis.
• Female System: Features a bifurcate (two-horned) uterus / uterine horns (cornua) terminating anteriorly at coiled fallopian tubes (oviducts) and ovaries. Uterine horns join at uterine body, leading into vagina. Functional purpose: Accommodates development of large litter sizes.

Structure-Function Relationships of Organs

• Color vs. Function: Organs with rich, dark red coloration (spleen, liver, kidneys) possess dense vascularization and blood volume necessary for filtration, metabolism, or oxygen exchange. Storage/conduit organs (urinary bladder, esophagus) appear lighter pale-pink due to lower primary blood flow requirements.
• Texture vs. Function: Muscular organs (heart, stomach wall) are firm and dense to generate force for pumping and churning. Gas-exchange organs (lungs) are soft, light, and spongy to allow compliance and surface area expansion.

Microscopy: Optics, Instrumentation, Techniques, and Calculations

          Ocular Lenses (10x)
                   │
            Revolving Nosepiece
                   │
       Objective Lenses (4x, 10x, 40x, 100x)
                   │
             Stage & Clips
                   │
          Condenser & Iris Diaphragm
                   │
            Lamp / Illuminator

Components of the Compound Light Microscope

• Ocular Lens (Eyepiece): Lens system looked through; magnifies image $10\times$.
• Objective Lenses: Mounted on revolving nosepiece:
  • Scanning Objective ($4\times$): Lowest power, used for locating specimen.
  • Low-Power Objective ($10\times$): Medium magnification.
  • High-Power Objective ($40\times$): High detail magnification.
  • Oil-Immersion Objective ($100\times$): Requires immersion oil to eliminate light refraction; highest magnification.
• Stage & Mechanical Stage Adjustment Knob: Flat platform where slide is secured by stage clips; knobs adjust slide along $x$- and $y$-axes.
• Coarse Adjustment Knob: Large wheel moving stage vertically in large increments for initial focusing under low power ($4\times$ and $10\times$ only).
• Fine Adjustment Knob: Small wheel fine-tuning focus; required under high power ($40\times$ and $100\times$).
• Condenser: Substage lens concentrating light beam from illuminator onto specimen.
• Iris Diaphragm: Adjustable aperture controlling amount of light reaching specimen to optimize contrast.
• Light Source / Illuminator: Electric lamp built into base.

Microscope Handling and Maintenance Rules

• Always carry microscope using two hands: one holding the arm, one supporting the base.
• Clean optical glass lenses strictly with dedicated lens paper (never paper towels or lab wipes).
• Always begin focusing on lowest power objective ($4\times$) with stage fully lowered.
• Never use coarse adjustment knob when high-power ($40\times$ or $100\times$) objectives are engaged to avoid cracking slides or damaging optics.
• Wipe immersion oil completely off $100\times$ objective immediately after use.

Magnification Formulas and Optical Physics

$\text{Total Magnification} = \text{Ocular Lens Magnification} \times \text{Objective Lens Magnification}$

Resolution (Resolving Power)

• Definition: Ability of an optical system to distinguish two adjacent points as separate structures.
• Resolution Limits:
  • Unassisted Human Eye: $100\,\mu\text{m}$
  • Compound Light Microscope: $0.2\,\mu\text{m}$
  • Transmission Electron Microscope: $2\,\text{nm}$

Field Dynamics and Image Inversion

• Working Distance: Physical space between bottom of objective lens and slide coverslip. Decreases as magnification increases (greatest at $4\times$, smallest at $100\times$).
• Depth of Field (Focus): Vertical thickness of specimen kept in sharp focus at one time. Decreases as magnification increases.
• Field of View: Total circular area visible through oculars. Decreases as magnification increases. (Maximum field of view and largest structural portion seen occurs at lowest magnification).
• Image Orientation: Microscope lenses invert and reverse images vertically and horizontally. Moving slide left shifts image right; moving slide forward shifts image backward.

Stereomicroscope (Dissecting Microscope)

• Used for viewing large, opaque, three-dimensional specimens or conducting dissections.
• Advantages: Large working distance, stereoscopic (3D) depth perception.
• Disadvantages: Low magnification range ($4\times$ to $50\times$) and lower resolution.

Wet Mount Preparation (Cheek Cell Smear)

1. Collect buccal cell sample by gently scraping inner cheek with clean wooden toothpick.
2. Smear cells onto clean glass slide.
3. Apply one drop of methylene blue stain (stains negatively charged nucleic acids and nuclear components).
4. Apply coverslip at a $45^\circ$ angle to prevent air bubble entrapment.

The Cell Life Cycle, DNA Replication, and Mitosis

Cell Cycle
├── Interphase (G1, S, G2)
│   ├── G1 Phase (Cell growth; G0 checkpoint for amitotic cells)
│   ├── S Phase (DNA synthesis and chromosome replication)
│   └── G2 Phase (Protein synthesis and division preparation)
└── M Phase (Cell Division)
    ├── Mitosis (Nuclear division)
    │   ├── Prophase
    │   ├── Metaphase
    │   ├── Anaphase
    │   └── Telophase
    └── Cytokinesis (Cytoplasmic cleavage)

Interphase

Non-dividing stage comprising $\sim 90\%$ of cell lifespan. Chromatin remains uncondensed.

• $G_1$ Phase (First Gap): Cell metabolic growth, organelle duplication, active protein synthesis. Non-dividing cells exit $G_1$ into non-replicating $G_0$ phase (e.g., mature neurons, skeletal muscle fibers, osteocytes).
• S Phase (Synthesis): DNA replication occurs. Each homologous chromosome duplicates to produce identical sister chromatids joined at a central centromere.
• $G_2$ Phase (Second Gap): Final growth, tubulin synthesis, replication of centrosomes/centrioles in preparation for mitosis.

Mitosis (M Phase - Nuclear Division)

Process dividing duplicated nuclear genome into two identical nuclei:

1. Prophase:
   • Chromatin condenses into visible distinct chromosomes (sister chromatid pairs).
   • Nucleolus disappears and nuclear envelope degenerates.
   • Centrosomes move to opposite cell poles, radiating microtubular mitotic spindles.
   • Spindle fibers attach to kinetochore proteins on centromeres.
2. Metaphase:
   • Spindle fibers pull chromosomes to align along equatorial plane (metaphase plate).
3. Anaphase:
   • Centromeres split as spindle fibers shorten.
   • Sister chromatids separate into individual daughter chromosomes and migrate toward opposite poles.
   • Cell elongates; cytokinesis begins late in anaphase.
4. Telophase:
   • Chromosomes reach opposite poles and uncoil back into chromatin.
   • Nuclear envelopes and nucleoli reassemble around daughter nuclei.
   • Mitotic spindle dissolves.

Cytokinesis (Cytoplasmic Division)

• Division of cytoplasm between daughter cells.
• In animal cells, a contractile ring of actin microfilaments constricts the plasma membrane, forming a cleavage furrow at the former metaphase plate that pinches the mother cell into two genetically identical daughter cells.

Cellular Transport Dynamics: Passive vs. Active

Plasma membranes exhibit selective permeability, governing internal cellular homeostasis:

• Passive Processes: Movement of substances across membrane without expenditure of metabolic cellular energy (ATP). Driven by kinetic energy down concentration or pressure gradients (Simple Diffusion, Facilitated Diffusion, Osmosis, Filtration).
• Active Processes: Require cellular energy (ATP hydrolysis) to transport substances against concentration gradients or via membrane vesicles (Primary Active Transport, Secondary Active Transport, Endocytosis, Exocytosis).

Experimental Analysis of Diffusion Dynamics

Diffusion: Passive net movement of solute molecules from an area of higher concentration to an area of lower concentration down a concentration gradient until dynamic equilibrium is reached.

Factors Governing Diffusion Rate

• Concentration Gradient: Steeper gradient $\rightarrow$ faster diffusion rate.
• Molecular Weight / Particle Size: Smaller mass $\rightarrow$ faster diffusion rate.
• Temperature: Higher thermal kinetic energy $\rightarrow$ faster diffusion rate.

Experiment 1: Agar Gel Matrix Diffusion

• Procedure: Wells cut into agar plate. Equal volumes of dyes placed in separate wells and allowed to diffuse for $120\,\text{min}$.
• Dyes Tested:
  • Orange G: Molecular Weight ($\text{MW}$) = $452\,\text{g/mol}$.
  • Eosin Y: Molecular Weight ($\text{MW}$) = $692\,\text{g/mol}$.
• Experimental Data:

• Conclusions: Orange G diffused faster and further due to lower molecular weight ($452\,\text{g/mol}$ vs. $692\,\text{g/mol}$). Demonstrates an inverse relationship between molecular size and diffusion rate.
• Temperature Effects: Placing agar plates in a warm oven ($37^\circ\text{C}$) accelerates diffusion rate; placing in a refrigerator ($4^\circ\text{C}$) retards diffusion rate.

Experiment 2: Dialysis Sac Selective Permeability

• Membrane Specification: Synthetic dialysis tubing with pore selectivity cutoffs between $12,000$ and $14,000\,\text{MW}$.
• Sac Solution: Mixture of Starch ($\text{MW} > 14,000$), Glucose ($\text{MW} = 180$), and Sodium Chloride (NaCl, $\text{MW} = 58$) placed into sac suspended in distilled water beaker.
• Chemical Indicator Assays:

• Experimental Results:

• Conclusions:
  • Glucose ($\text{MW} = 180$) and NaCl ($\text{MW} = 58$) diffused out through membrane pores down concentration gradients.
  • Starch ($\text{MW} > 14,000$) was retained inside because its molecular dimensions exceeded pore size cutoffs.
  • Relative Molecular Size Ranking (Largest to Smallest): $\text{Starch} > \text{Glucose} > \text{NaCl} > \text{Water}$.

Theoretical Dialysis Transport Scenario

A semipermeable sac (permeable to water, NaCl, glucose; impermeable to starch) containing $4\%$ NaCl, $9\%$ glucose, and $10\%$ starch is placed in a beaker containing $10\%$ NaCl, $10\%$ glucose, and $40\%$ starch:

• Glucose: Diffuses INTO sac (Beaker $10\%$ $\rightarrow$ Sac $9\%$).
• NaCl: Diffuses INTO sac (Beaker $10\%$ $\rightarrow$ Sac $4\%$).
• Water: Moves OUT OF sac via osmosis (Sac $87\%$ water $\rightarrow$ Beaker $40\%$ water / towards higher total solute concentration).
• Starch: DOES NOT MOVE (impermeable due to size).

Experimental Analysis of Osmosis and Tonicity

Osmosis: Passive net diffusion of solvent (water) molecules across a selectively permeable membrane from an area of higher water concentration (lower solute concentration) to an area of lower water concentration (higher solute concentration).

Osmotic Pressure: Force required to stop osmotic water movement across a membrane; proportional to solute concentration (osmolarity).

Experiment 1: Animal Membrane Osmometer Dynamics

• Setup: Y-shaped osmometer fitted with animal membrane bag filled with molasses solution ($25\%$ or $50\%$) immersed in distilled water beaker.
• Experimental Data:

• Diffusion / Osmotic Rate Calculations:

$\text{Rate} = \frac{\text{Distance Moved (mm)}}{\text{Time (min)}}$

$\text{Rate}_{25\%\,\text{Molasses}} = \frac{30\,\text{mm}}{15\,\text{min}} = 2.00\,\text{mm/min}$

$\text{Rate}_{50\%\,\text{Molasses}} = \frac{40\,\text{mm}}{15\,\text{min}} = 2.67\,\text{mm/min}$

• Conclusions: The $50\%$ molasses solution generated a steeper osmotic gradient and higher osmotic pressure than the $25\%$ solution, driving a faster fluid rise rate ($2.67\,\text{mm/min}$ vs $2.00\,\text{mm/min}$).

Experiment 2: De-shelled Egg Osmosis and Tonicity

• Model Setup: Chicken eggs soaked in vinegar (acetic acid) for $24\text{--}48\,\text{hours}$ dissolve calcium carbonate shells ($\text{CaCO}_3$), leaving intact plasma membranes.
• Tonicity Definitions:
  • Hypotonic: Solute concentration lower than cytoplasm. Water enters cell $\rightarrow$ cell swells/gains mass (Hemolysis in RBCs).
  • Hypertonic: Solute concentration higher than cytoplasm. Water leaves cell $\rightarrow$ cell shrinks (Crenation in RBCs).
  • Isotonic: Solute concentration equals cytoplasm. No net water movement $\rightarrow$ mass remains constant.

Egg Mass Changes and Calculations

$\text{Change in Mass (g)} = \text{Final Mass} - \text{Initial Mass}$

$\text{Percent Change in Mass (\%)} = \left( \frac{\text{Change in Mass}}{\text{Initial Mass}} \right) \times 100\%$

• Isotonic Point Determination: Graphing Percent Change in Mass ($y$-axis) versus Corn Syrup Concentration ($x$-axis) reveals an $x$-intercept ($0\%$ mass change) at approximately $6.5\%\text{--}7.5\%$ corn syrup, representing the internal isotonic concentration of the egg.

Principles of Hydrostatic Pressure and Filtration Dynamics

Filtration: Movement of water and dissolved solute molecules across a semipermeable membrane driven by a hydrostatic pressure gradient (from high fluid pressure to low fluid pressure).

• Hydrostatic Pressure: Pressure exerted by liquids due to gravity or mechanical pumping forces (e.g., blood pressure generated by heart contractions).
• Filtrate: Fluid and small soluble substances that pass through membrane pores.
• Anatomical Application: Glomerular filtration in kidney nephrons, where capillary blood pressure forces water and small solutes out of renal capillaries into glomerular capsules to form pre-urine.

Experimental Setup and Results

• Filtered Mixture: Solution containing water, dissolved starch, dissolved blue Copper Sulfate ($\text{CuSO}_4$), and insoluble gray powdered Charcoal.
• Flow Rate Analysis:

• Filtrate Composition Results:

• Conclusions: Higher fluid height increases hydrostatic pressure, thereby increasing filtration rate. Pore dimensions dictate selectivity; particles larger than pores are trapped.

Practical Calculations and Review

Microscope Calculation Examples

1. Total Magnification Problem:

   • Objective Lens: $40\times$
   • Ocular Lens: $10\times$$\text{Total Magnification} = 10 \times 40 = 400\times$

2. Working Distance vs Magnification:

   • Objective with greatest working distance: $4\times$ objective.
   • Objective requiring highest light intensity: $100\times$ objective.

Transport Rate Calculation Examples

1. Osmometer Column Rate:

   • Start height: $10\,\text{mm}$ at $0\,\text{min}$.
   • Final height: $55\,\text{mm}$ at $15\,\text{min}$.    $\text{Distance Moved} = 55\,\text{mm} - 10\,\text{mm} = 45\,\text{mm}$$\text{Rate} = \frac{45\,\text{mm}}{15\,\text{min}} = 3.00\,\text{mm/min}$

2. Percent Mass Change Calculation:

   • Egg Initial Mass: $80.00\,\text{g}$
   • Egg Final Mass: $60.00\,\text{g}$$\text{Change in Mass} = 60.00\,\text{g} - 80.00\,\text{g} = -20.00\,\text{g}$$\text{Percent Change} = \left( \frac{-20.00\,\text{g}}{80.00\,\text{g}} \right) \times 100\% = -25.00\%$

1. Laboratory Safety Protocols, Maintenance, and Waste Disposal

• Laboratory Safety Protocols: Procedures mandated to prevent personal injury and equipment damage.
  • Hands must be clean and completely dry before operating electrical devices.
  • Always disconnect electrical equipment from power sources before conducting maintenance or troubleshooting.
  • Point sharp instruments (scalpels, scissors, pointed probes) away from the body during cleaning.
• Waste Disposal Guidelines:
  • Broken Glass Container: Rigid, dedicated receptacle for non-contaminated broken/cracked glassware (test tubes, slides, coverslips, pasteur pipettes). Never place in standard trash.
  • Biohazard Containers: Designated receptacles for biological waste (animal tissues, blood, blood-contaminated gloves, contaminated plastic items).
  • Bleach Solution Bath: Direct submersion receptacle for reusable glassware contaminated with blood or biological fluids.
• Sanitation and Emergency Procedures:
  • Workstation Sanitation: Decontaminate work areas with a $10\%$ bleach solution before leaving the lab whenever biological specimens or tissues are used.
  • Personal Hygiene: Thoroughly wash hands with antibacterial soap prior to exiting.
  • Accident Reporting: Immediately report any accidents, spills, injuries, or broken equipment to the lab instructor.

2. Anatomical Terminology, Body Planes, and Directional Terms

• Anatomical Position: Standard reference position characterized by an upright posture, facing forward, feet flat and shoulder-width apart, upper limbs hanging at sides with palms supinated (facing forward).
• Directional Terms: Paired descriptors of spatial relationships:
  • Anterior (Ventral) vs. Posterior (Dorsal):
  • Anterior (Ventral): Toward the front aspect of the body.
  • Posterior (Dorsal): Toward the back aspect of the body.
  • Superior vs. Inferior (Axial Restriction):
  • Superior: Closer to the head (applied only to head, neck, and trunk).
  • Inferior: Away from the head or toward the feet.
  • Proximal vs. Distal (Appendicular Restriction):
  • Proximal: Closer to the point of origin or limb attachment (shoulder or hip).
  • Distal: Farther from the point of origin or limb attachment.
  • Medial vs. Lateral:
  • Medial: Position closer to the midline of the body.
  • Lateral: Position farther from the midline.
  • Superficial vs. Deep:
  • Superficial: Closer to the body surface or skin.
  • Deep: Farther internal from the body surface.
• Body Planes of Section:
  • Sagittal Plane: Vertical section dividing body into right and left portions.
  • Midsagittal Plane: Equal right and left halves down the midline.
  • Parasagittal Plane: Unequal right and left portions.
  • Frontal (Coronal) Plane: Vertical section dividing body into anterior and posterior portions.
  • Transverse (Horizontal) Plane: Horizontal section dividing body into superior and inferior portions.

3. Regional Anatomy and Term Mapping

• Regional Adjectives:
  • Antebrachial: Forearm (elbow to wrist).
  • Antecubital: Anterior surface of elbow.
  • Axillary: Armpit region.
  • Brachial: Upper arm (shoulder to elbow).
  • Buccal: Cheek area.
  • Cephalic: Head region.
  • Cervical: Neck region.
  • Frontal: Forehead.
  • Gluteal: Buttocks.
  • Inguinal: Groin.
  • Lumbar: Lower back.
  • Ophthalmic: Eye region.
  • Popliteal: Posterior side of knee joint.
  • Pubic: Region overlying pubic bone.
  • Scapular: Region overlying scapula.
  • Sternal: Middle chest area over sternum.
  • Sural: Calf region.
  • Tarsal: Ankle and proximal foot.
  • Thoracic: Chest area.
  • Umbilical: Navel area.
  • Vertebral: Area overlying the spinal column.
  • Perineum: Region between anus and external genitalia.
• Spatial Ordering Examples:
  • Anterior to Posterior: Lips $\rightarrow$ Tongue $\rightarrow$ Vertebrae.
  • Proximal to Distal: Thigh $\rightarrow$ Knee $\rightarrow$ Calf $\rightarrow$ Ankle $\rightarrow$ Foot $\rightarrow$ Hallux.
  • Superior to Inferior: Buccal region $\rightarrow$ Cervical region $\rightarrow$ Pectoral region $\rightarrow$ Umbilicus $\rightarrow$ Inguinal region.
  • Medial to Lateral: Nose $\rightarrow$ Eye $\rightarrow$ Ear.
  • Superficial to Deep: Skin $\rightarrow$ Superficial fascia $\rightarrow$ Muscle.

4. Body Cavities, Subcavities, and Serous Membranes

• Posterior (Dorsal) Body Cavity: Encloses central nervous system, contains cerebrospinal fluid (CSF).
  • Cranial Cavity: Formed by skull; houses the brain.
  • Vertebral (Spinal) Cavity: Formed by vertebral column; houses the spinal cord.
• Anterior (Ventral) Body Cavity: Partitioned by the diaphragm into thoracic and abdominopelvic cavities.
  • Thoracic Cavity: Superior cavity housing:
  • Pleural Cavities: Envelop lungs; lined by parietal and visceral pleural membranes.
  • Mediastinum: Central space containing esophagus, trachea, major blood vessels, and pericardial cavity.
  • Pericardial Cavity: Encloses heart; lined by parietal and visceral pericardial membranes.
  • Abdominopelvic Cavity: Inferior cavity housing:
  • Abdominal Cavity: Superior area housing stomach, liver, gallbladder, spleen, pancreas, kidneys, adrenal glands, and intestines.
  • Pelvic Cavity: Inferior area within bony pelvis housing bladder, internal reproductive organs, and rectum.
  • Peritoneal Cavity: Potential space lined by peritoneal membrane.
    • Intraperitoneal Organs: Enclosed within peritoneal cavity (stomach, liver, spleen, small intestine, tail of pancreas).
    • Retroperitoneal Organs: Located posterior to peritoneal cavity (kidneys, adrenal glands, ureters, bladder, pancreas head/body).
• Serous Membranes: Double-layered sheets secreting lubricating serous fluid.
  • Parietal Layer: Lines cavity walls.
  • Visceral Layer: Covers organ surfaces directly.

5. Abdominopelvic Quadrants

• Right Upper Quadrant (RUQ): Liver (right lobe), gallbladder, duodenum, head of pancreas, right kidney, right adrenal gland, hepatic flexure, sections of transverse colon and small intestine.
• Left Upper Quadrant (LUQ): Stomach, spleen, liver (left lobe), body/tail of pancreas, left kidney, left adrenal gland, splenic flexure, sections of transverse colon and small intestine.
• Right Lower Quadrant (RLQ): Cecum, appendix, ascending colon, small intestine, lower right kidney, right ureter, right ovary/uterine tube or right spermatic cord.
• Left Lower Quadrant (LLQ): Descending colon, sigmoid colon, small intestine, lower left kidney, left ureter, left ovary/uterine tube or left spermatic cord, urinary bladder.

6. Rat Dissection and Comparative Anatomy

• Dissection Tools:
  • Surgical Scissors: Used with blunt tip facing downward during body wall cuts to protect internal organs.
  • Teasing Needles / Probes: Used to separate tissues along natural fascial planes.
• Key Anatomical Structures:
  • Incisors & Molars: Teeth adapted for gnawing/cutting (incisors) and grinding (molars).
  • Trachea & Esophagus: Trachea is anterior and cartilage-ringed; esophagus is collapsible and directly posterior to trachea.
  • Liver Anatomical Difference: Rats lack a gallbladder; bile flows directly from liver to duodenum.
  • Bifurcate Uterus: Uterus has two large horns (cornua) to accommodate large litter sizes.
• Structure-Function Relationships:
  • Color: Dark red organs (liver, spleen, kidneys) indicate rich vascularization for filtration/metabolism; pale organs (esophagus, bladder) indicate storage/conduit roles.
  • Texture: Dense/muscular walls (heart, stomach) churn/pump; soft/spongy tissue (lungs) allows compliance for gas exchange.

7. Microscopy: Components, Physics, and Calculations

• Microscope Components:
  • Ocular Lens: Magnifies image $10\times$.
  • Objective Lenses: Mounted on revolving nosepiece:
  • Scanning ($4\times$): Lowest power, largest working distance and field of view.
  • Low Power ($10\times$): Medium magnification.
  • High Power ($40\times$): High detail.
  • Oil Immersion ($100\times$): Highest magnification, requires immersion oil and maximum light intensity.
  • Focusing Knobs: Coarse adjustment (moves stage in large increments; low power only) and Fine adjustment (fine-tunes focus; required for high power).
  • Substage Optics: Condenser focuses light; Iris diaphragm controls aperture/brightness.
• Optical Formulas & Limits:
  • Total Magnification:
    $\text{Total Magnification} = \text{Ocular Lens Magnification} \times \text{Objective Lens Magnification}$
  • Resolving Power Limits: Unassisted eye = $100\,\mu\text{m}$; Light microscope = $0.2\,\mu\text{m}$; TEM = $2\,\text{nm}$.
• Field Dynamics:
  • Increasing magnification reduces working distance, depth of field, and field of view, while increasing light requirements.
  • Compound optics invert and reverse images vertically and horizontally.

8. The Cell Cycle and Mitosis

• Interphase ($\sim 90\%$ of cell cycle):
  • $G<em>1$ Phase: Metabolic growth; non-dividing cells enter non-replicating $G</em>0$ phase.
  • S Phase: DNA replication occurs; identical sister chromatids form, joined at centromeres.
  • $G_2$ Phase: Final protein synthesis and organelle/centrosome duplication.
• Mitosis (M Phase):
  1. Prophase: Chromatin condenses into chromosomes; nuclear envelope degrades; mitotic spindle forms.
  2. Metaphase: Chromosomes align along equatorial metaphase plate.
  3. Anaphase: Centromeres split; sister chromatids separate into individual daughter chromosomes moving to opposite poles.
  4. Telophase: Chromosomes uncoil into chromatin; nuclear envelopes reassemble; spindle dissolves.
• Cytokinesis: Cleavage furrow forms via actin microfilament contraction, splitting cell into two identical daughter cells.

9. Experimental Analysis of Transport Dynamics

• Diffusion Matrix (Agar Gel):
  • Solute size inversely affects rate: Orange G ($\text{MW} = 452\,\text{g/mol}$, $17\,\text{mm}$ distance) diffuses faster than Eosin Y ($\text{MW} = 692\,\text{g/mol}$, $15\,\text{mm}$ distance).
  • Warm temperatures ($37^\circ\text{C}$) accelerate diffusion; cold temperatures ($4^\circ\text{C}$) retard diffusion.
• Dialysis Permeability & Indicator Assays:
  • Membrane cutoff: $12,000\text{--}14,000\,\text{MW}$.
  • Solute size order: $\text{Starch} > \text{Glucose} > \text{NaCl} > \text{Water}$.
  • Starch Assay: Lugol's Iodine reagent (Positive = Blue/Black; Negative = Yellow/Clear).
  • Glucose Assay: Benedict's Solution + $2\,\text{min}$ boil (Positive = Green/Yellow/Red precipitate; Negative = Clear Blue).
  • NaCl Assay: Silver Nitrate ($\text{AgNO}_3$) reagent (Positive = White precipitate; Negative = Clear).
• Osmosis & Tonicity:
  • Osmometer Rate Formula:
    $\text{Rate} = \frac{\text{Distance Moved (mm)}}{ ext{Time (min)}}$
  • Steeper solute gradients produce greater osmotic pressure and faster fluid movement rates.
  • De-shelled Egg Mass Calculations:
    $\text{Change in Mass (g)} = \text{Final Mass} - \text{Initial Mass}$
    $\text{Percent Change in Mass (\%)} = \left( \frac{\text{Change in Mass}}{\text{Initial Mass}} \right) \times 100\%$
  • Tonicity Definitions: Hypotonic (water enters cell/gains mass), Hypertonic (water leaves cell/loses mass), Isotonic (no net mass change; egg internal isotonic point $\approx 6.5\%\text{--}7.5\%$ corn syrup).

10. Hydrostatic Pressure and Filtration Dynamics

• Filtration: Movement of water and small solutes across semipermeable membranes driven by hydrostatic pressure gradients.
• Flow Rate Relationship: Higher fluid column height creates higher hydrostatic pressure, yielding faster filtration rates ($30\,\text{drops/10\,s}$ full funnel vs $16\,\text{drops/10\,s}$ half-full funnel).
• Pore Selectivity: Soluble particles smaller than membrane pores (Copper Sulfate) pass into filtrate; particles or molecules larger than pores (Charcoal, Starch) are retained on filter media.