Cell Biology, Tissues, and Integumentary System Vocabulary

Comprehensive vocabulary flashcards generated from lecture notes covering cell biology, transport processes, tissues, organelles, and the integumentary system.

Cell

The basic unit of biological organization composed of protoplasm/cytoplasm, cell membrane, and nucleus.

Prokaryotic Cell

The simplest and smallest type of cell, lacking a nuclear membrane.

Eukaryotic Cell

A multicellular cell type provided with a nuclear membrane.

Simple Diffusion

A passive transport process involving the movement of solute from an area of high solute concentration to an area of low solute concentration.

Facilitated Diffusion

A passive transport process involving the movement of solute from high solute concentration to low solute concentration with a carrier.

Osmosis

A passive transport process involving the movement of solvent (water) from an area of high solute concentration to an area of low solute concentration.

Filtration

The passive movement of water and solutes through a semipermeable membrane from an area with a higher hydrostatic pressure to an area of lower hydrostatic pressure along a pressure gradient.

Active Transport

The movement of solute through a membrane against a concentration gradient requiring a membrane carrier protein and energy (solute pumping).

Phagocytosis

An active transport process where insoluble substances are engulfed and enclosed in a vesicle known as a phagosome (cell eating).

Pinocytosis

An active transport process involving the engulfment of a small amount of fluid enclosed in a pinocytotic vesicle (cell drinking).

Exocytosis

An active transport process involving the ejection of a substance enclosed in a membranous vesicle that fuses with the plasma membrane and ruptures to release contents to the exterior.

Cytosol

The clear fluid part of cytoplasm in which particles and organelles are dispersed.

Mitochondria

Organelles known as chondriosomes or the powerhouse of the cell whose primary function is to synthesize Adenosine Triphosphate ($\text{ATP}$) as energy.

Cristae

The inner infoldings of mitochondrial membranes where cellular respiration occurs.

Ribosomes

Non-membrane covered organelles distributed in the cytoplasm or attached to rough ER that serve as sites of protein synthesis.

Rough Endoplasmic Reticulum

A granular system of membranes studded with attached ribosomes that functions in protein synthesis.

Smooth Endoplasmic Reticulum

A non-granular system of membranes involved in fat transport and sex hormone synthesis.

Golgi Apparatus

Also called Dictyosomes, a collection of flat saclike cisternae that acts as storage warehouses and packaging sites for cellular compounds, as well as carbohydrate synthesis.

Lysosomes

Membrane-bound digestive enzyme packages containing acid hydrolases that digest stored food, maintain organelles, and act as suicide agents for old or weak cells.

Peroxisomes

Microbodies containing catalase (which converts $H_2O_2$ into $H_2O$ and $O_2$) and oxidase, generating energy by oxidation dissipated as heat to contribute to body temperature.

Centrosome

A structure composed of two centrioles at right angles to each other that forms spindle fibers during cell division to guide duplicated chromosomes.

Nucleolus

A dense structure inside the nucleus that serves as the site of ribosome formation.

Membrane Epithelium

Form of epithelial tissue lining body surfaces, cavities, or coverings.

Glandular Epithelium

Form of epithelial tissue specialized to synthesize specific product secretions.

Simple Epithelium

Epithelial tissue made up of only one layer of cells.

Pseudostratified Epithelium

Epithelium made up of a single layer of cells that appears to have multiple layers because of the various locations of the nuclei.

Stratified Epithelium

Epithelium composed of several layers of cells with a distinct shape of cells on the most superficial layer.

Transitional Epithelium

Also called uroepithelium, a stratified epithelium whose layer thickness varies depending on the functional status and distension of the organ.

Endocrine Gland

A ductless gland that releases its secretions directly into the body (e.g., thyroid and pituitary glands).

Exocrine Gland

A gland provided with ducts to transport secretions (e.g., sweat and salivary glands).

Merocrine Gland

A gland whose mode of secretion involves no destruction of the secretory cells (e.g., eccrine sweat glands).

Apocrine Gland

A gland whose mode of secretion involves partial destruction of secretory cells (e.g., mammary glands, apocrine sweat glands of axillary/groin areas).

Holocrine Gland

A gland whose mode of secretion involves total destruction of secretory cells (e.g., sebaceous glands).

Fibroblasts

The most common cells found in loose or areolar connective tissue responsible for producing matrix fibers.

Ground Substance

The shapeless background matrix against which cells and collagen fibers are seen, containing proteoglycans made up of protein and polysaccharide.

Hyaline Cartilage

The most abundant cartilage in the body that covers bones, forms joints, and creates costal cartilages attaching ribs to the sternum.

Fibrocartilage

Cartilage that contains more collagen than hyaline cartilage, located in intervertebral disks and select joints.

Elastic Cartilage

Cartilage containing coiled elastic fibers among collagen bundles, found in the external ear, epiglottis, and auditory tube.

Osteocytes

Living bone cells located within matrix spaces called lacunae.

Melanin

A brown-black pigment produced by melanocytes in the stratum basale that protects the skin against UV rays.

Carotene

A yellowish pigment found in epidermal cells and fatty parts of the dermis that accounts for yellowish-tan skin color in Asians.

Hemoglobin

An oxygen-binding pigment found in RBCs that gives skin pinkish tones as oxygenated blood flows through dermal capillaries.

Albino

A skin disorder characterized by normal melanocyte counts but a lack of the enzyme tyrosinase.

Vitiligo

A skin disorder characterized by a lack or loss of melanocytes in localized areas.

Hirsute Skin

Thin, hairy skin covering the greater part of the body.

Glabrous Skin

Thick, hairless skin found on the palms, soles, and flexor surface of digits.

Stratum Malpighii

The grouped name for the inner three metabolically active layers of the epidermis (stratum basale, stratum spinosum, and stratum granulosum).

Stratum Basale

Also known as stratum germinativum, the deepest single layer of mitotically active cuboidal to low columnar cells supported by a basal lamina.

Keratinocytes

The principal cells of the epidermis that produce keratin and transform from living polygonal cells to non-viable squames cells.

Merkel Cells

Tactile cells situated in the stratum basale that aid in touch perception.

Langerhans Cells

Protective macrophagic cells present within the epidermis.

Stratum Spinosum

The thickest layer of the epidermis, composed of several stratified layers of spiny-appearing keratinocytes with limited mitosis.

Stratum Granulosum

An epidermal layer consisting of 3 to 4 flattened rows of cells containing distinct keratohyaline granules.

Stratum Lucidum

A clear translucent epidermal layer containing eleidin that exists only in thick skin regions such as the lips, soles, and palms.

Stratum Corneum

The outermost hornlike protective layer of the epidermis consisting of 25 to 30 layers of dead, flattened, anucleated scale-like cells.

Dermal Papillae

Projections from the papillary dermis into the epidermis that contain capillary loops, free nerve endings, and Meissner's corpuscles.

Meissner's Corpuscles

Touch receptors located within the dermal papillae of the papillary dermis.

Pacinian Corpuscles

Deep pressure receptors located within the reticular layer of the dermis.

Lanugo

Fine, silky fetal hair that appears during the last trimester of development.

Vellus Hair

Short, fine, narrow hair present on most parts of the body.

Terminal Hair

Thicker, heavily pigmented hair found on scalp, eyelashes, eyebrows, axilla, pubis, chest, and face.

Arrector Pili Muscle

Small fasciculi of smooth muscle whose contraction pulls hair vertically, dimpling skin to produce goosebumps.

Sebum

An oily substance mixed with fragmented cells secreted by sebaceous glands to keep skin moist and prevent hair brittleness.