Lab Exam 1

Vocabulary practice flashcards covering microscope components, magnification calculations, cell structures and organelles, and the stages and mechanisms of mitosis.

Compound Light Microscope

An optical instrument containing more than one lens that uses visible light rays transmitted through a specimen to magnify and produce an image.

Oil Immersion Lens

A high-magnification ($100\times$) objective lens that requires the application of a specialized immersion oil between the lens and slide for proper viewing.

Parfocal

A design characteristic of microscope lenses where a specimen in focus under one objective remains in focus, or nearly so, when switching to other objectives.

Iris Diaphragm

An adjustable shutter on a microscope that regulates the diameter of the cone of light passing upward through the specimen, affecting illumination and image sharpness.

Condenser

A lens located beneath the stage that focuses the cone of light from the light source onto the specimen slide.

Wet Mount

A temporary microscope slide preparation in which a specimen is suspended in a transparent liquid droplet, such as water or saline, covered with a coverslip.

Microscope Magnification

A measurement of how much larger a microscope makes an object appear, calculated as the product of the ocular lens power and the objective lens power.

Drawing Magnification (Scale)

The ratio describing the size of a specimen drawing relative to its actual physical size, calculated using the formula $\text{Magnification} = \frac{\text{Size of drawing}}{\text{Actual size}}$.

Depth of Field

The vertical thickness or depth of a specimen plane that remains sharply in focus under a given objective lens at any one time.

Eukaryotic Cell

A cell that possesses a true membrane-bound nucleus containing genetic material and specialized membrane-bound organelles.

Organelles

Highly complex subcellular structures that carry out specialized, essential physiological functions within eukaryotic cells.

Vital Stains

Non-toxic chemical stains that can be applied to living cells to enhance cellular contrast without killing or disrupting them.

Nucleolus

A darkly staining, dense spherical body found inside the nucleus that consists of nucleoprotein.

Nucleoplasm

The gel-like nuclear fluid inside the nuclear membrane in which chromosomes and nucleoli are suspended.

Endomembrane System

A coordinated system of membrane-bound organelles near the nucleus—including the plasma membrane, rough ER, smooth ER, Golgi apparatus, lysosomes, and vesicles—that sort, process, package, and deliver molecules.

Flagella

Long, slender cellular projections extending from the cell surface that primarily perform locomotor functions.

Cilia

Short, hair-like cellular projections that allow movement and propel substances along the surface of the cell or away from it.

Microvilli

Tiny, finger-like projections of the plasma membrane that significantly increase the overall surface area of the cell.

Cell Cycle

The complete sequence of growth, replication of nuclear and cytoplasmic contents, and division undergone by a cell, consisting of interphase followed by mitosis and cytokinesis.

Mitosis

The process of eukaryotic cell division that precisely divides the replicated nuclear contents and chromosomes between two identical daughter nuclei.

Cytokinesis

The division of the cytoplasmic contents of a parent cell into two separate daughter cells, typically occurring concurrently with telophase.

Histones

Protein complexes around which long chromosomal DNA molecules wrap tightly to package and organize chromatin.

Diploid

Having two complete sets or copies of each chromosome within each somatic cell ($2n$; in humans, $2n = 46$).

Haploid

Having only one copy of each chromosome ($n$; in humans, $n = 23$), typical of gametes such as ova and sperm.

Ploidy Number ($n$)

The fundamental number of distinct chromosomes present in an organism's gametic or haploid complement (for humans, $n = 23$).

Blastula

An early embryonic developmental stage characterized by rapidly dividing cells, commonly utilized to observe mitotic figures under a microscope.

Interphase

The metabolic phase between cell divisions during which the cell grows, performs normal functions, and replicates its chromosomes into pairs of sister chromatids.

Centromere

The constricted attachment region on a replicated chromosome that joins sister chromatid pairs and binds to spindle microtubules.

Prophase

The first phase of mitosis, during which chromatin coils into visible chromosomes, the nuclear membrane dissolves, and centriole pairs migrate apart to establish spindle poles.

Aster

A star-like radial array of polymerized microtubules that forms around each centriole pair during early mitosis.

Metaphase

The mitotic phase where chromosomes, attached by spindle fibers at their centromeres, align completely along the equatorial metaphase plate.

Metaphase Plate

The plane bisecting the mitotic spindle axis at right angles upon which all chromosomes align during metaphase.

Anaphase

The mitotic stage initiated by the splitting of centromeres, during which separated sister chromatids (daughter chromosomes) migrate toward opposite spindle poles.

Telophase

The final stage of mitosis during which spindle microtubules depolymerize, new nuclear envelopes assemble around each daughter chromosome set, and chromatin uncoils.

Cleavage Furrow

A constricting groove that forms in the middle of a dividing animal cell along the plane of the metaphase plate, pinching the parent cell into two daughter cells during cytokinesis.

Epithelial Tissue Characteristics

Tightly packed cells with minimal extracellular matrix, apical and basal polarity, basement membrane attachment, avascularity, and high regenerative capacity.

Simple Squamous Epithelium

A single layer of flat cells specialized as a thin diffusion barrier; lines lung alveoli and blood/lymph vessels as endothelium.

Simple Cuboidal Epithelium

A single layer of cube-like cells specialized for absorption and secretion; lines kidney tubules and pancreatic ducts.

Simple Columnar Epithelium

A single layer of tall, cylindrical cells lining the stomach, intestines, and gallbladder; often possesses microvilli and mucus-secreting goblet cells.

Keratinized Stratified Squamous Epithelium

Multiple cell layers where apical cells accumulate tough, waterproof keratin protein; forms the epidermis of mammalian skin.

Non-Keratinized Stratified Squamous Epithelium

Multiple cell layers that lack keratin and line moist surfaces subjected to mechanical abrasion, such as the esophagus.

Transitional Epithelium

A stratified epithelium lining the urinary bladder capable of distension, transitioning from dome-shaped to flattened squamous-like cells.

Pseudostratified Ciliated Columnar Epithelium

A single layer of cells with nuclei at varying heights that appears stratified; features apical cilia that propel mucus and lines the trachea.

Extracellular Matrix

The non-cellular component of connective tissue consisting of clear ground substance and protein fibers (collagen, elastic, or reticular).

Areolar Connective Tissue

A loose connective tissue containing fibroblasts, macrophages, and mast cells within an unorganized mesh of collagen and elastic fibers; cushions organs and binds epithelia.

Adipose Tissue

A loose connective tissue dominated by adipocytes with large lipid droplets and minimal matrix; provides energy storage, thermal insulation, and organ cushioning.

Reticular Tissue

A loose connective tissue composed of a branching network of reticular fibers that forms the internal supporting stroma of lymphoid organs like the spleen and lymph nodes.

Dense Regular Connective Tissue

Connective tissue with densely packed, parallel bundles of collagen fibers and sparse fibroblasts; provides tensile strength in tendons and ligaments.

Dense Irregular Connective Tissue

Connective tissue with randomly interwoven networks of tough collagen fibers; resists multi-directional tension in the dermis of the skin.

Dense Elastic Tissue

Connective tissue featuring abundant coiled, branching elastic fibers allowing stretch and recoil; found in the walls of large arteries, the trachea, and lungs.

Hyaline Cartilage

Supporting tissue featuring chondrocytes within lacunae in a firm ground substance with collagen fibers; provides smooth joint surfaces and structural support in the trachea.

Fibrocartilage

Supporting connective tissue characterized by dense collagen fiber bundles and chondrocytes; absorbs compressive shock in intervertebral discs, knees, and the pubic symphysis.

Compact Bone

Supporting connective tissue with a mineralized hydroxyapatite matrix organized into concentric lamellae around central canals, with osteocytes residing in lacunae.

Chemical Level of Organization

The simplest structural level where atoms combine to form molecules.

Cellular Level of Organization

The level where molecules assemble into organelles and cells, the fundamental structural and functional units of life.

Tissue Level of Organization

Groups of similar cells and surrounding material working together to perform a specialized function (epithelial, connective, muscular, nervous).

Organ Level of Organization

Structures composed of two or more distinct tissue types working together to carry out specialized, complex functions.

Organ System Level of Organization

A group of related organs that work together to accomplish a common physiological purpose, comprising 11 body systems.

Anatomical Position

Standard reference posture where the subject stands erect, facing forward, with arms at the sides and palms facing anteriorly.

Superior (Cranial) vs. Inferior (Caudal)

Superior indicates above or toward the head; inferior indicates below or toward the feet.

Anterior (Ventral) vs. Posterior (Dorsal)

Anterior indicates toward the front of the body; posterior indicates toward the back of the body.

Medial vs. Lateral

Medial refers to being closer to the anatomical midline; lateral refers to being further away from the midline.

Proximal vs. Distal

Proximal indicates nearer to a limb's point of attachment; distal indicates farther from the point of attachment.

Superficial vs. Deep

Superficial indicates toward the outer surface of the body; deep indicates inward and farther away from the surface.

Parietal vs. Visceral

Parietal refers to the outer wall lining of a cavity; visceral refers to the layer directly covering an internal organ.

Sagittal Plane

A vertical plane that divides the body or an organ into unequal right and left parts.

Midsagittal (Median) Plane

A vertical plane that passes directly down the midline, dividing the body into equal right and left halves.

Frontal (Coronal) Plane

A vertical plane that divides the body or an organ into anterior (front) and posterior (back) portions.

Transverse (Cross) Plane

A horizontal plane that divides the body or an organ into superior (upper) and inferior (lower) portions.

Thoracic Cavity

The chest cavity containing the pleural cavities surrounding each lung, the pericardial cavity surrounding the heart, and the central mediastinum.

Abdominopelvic Cavity

The large cavity subdivided into the superior abdominal cavity (digestive organs) and inferior pelvic cavity (urinary bladder, internal reproductive organs, rectum).

Axillary Region

The anatomical landmark referring to the armpit.

Popliteal Region

The anatomical landmark referring to the hollow area at the back of the knee.