Unit Test 1 - Anatomy and Physiology Flashcards

A set of 40 vocabulary flashcards reviewing essential concepts of tissue types, skin structure, homeostasis, and bone biology from lecture slides.

Hypothalamus

A control center in the brain that functions as a thermostat with a set point of $37^{\circ}\text{C}$, sending commands to effectors to regulate body temperature.

Thermoregulatory Set Point

The normal temperature target around which body temperature fluctuates, usually kept between $36.7^{\circ}\text{C}$ and $37.2^{\circ}\text{C}$.

Positive Feedback Loop

An escalating process, such as blood clotting, where an initial stimulus produces a reaction that accelerates the process until a blood clot patches the vessel wall.

Epithelial Tissue

A tissue type that covers exposed body surfaces, lines internal passageways and chambers, and produces specialized glandular secretions.

Connective Tissue

A tissue type that fills internal spaces, provides structural support, and stores energy.

Muscle Tissue

A tissue type composed of specialized cells that contract to produce body movement.

Nervous Tissue

A tissue type that propagates electrical impulses and carries information throughout the body.

Avascularity

A defining characteristic of epithelial tissues indicating that they completely lack blood vessels.

Polarity (Epithelia)

The presence of structural and functional differences between the exposed apical surface and attached basal surface of epithelial tissue.

Simple Squamous Epithelium

A single layer of flat cells found in mesothelia, endothelia, kidney tubules, cornea lining, and alveoli that reduces friction and controls permeability.

Stratified Squamous Epithelium

Multiple layers of flat epithelial cells located on the surface of the skin and lining the mouth, throat, esophagus, rectum, anus, and vagina to protect against abrasion.

Transitional Epithelium

A specialized stratified epithelium lining the urinary bladder, renal pelvis, and ureters that permits repeated cycles of stretching without damage.

Merocrine Secretion

A mode of exocrine secretion in which products are released from secretory vesicles via exocytosis, such as in merocrine sweat glands.

Apocrine Secretion

A mode of exocrine secretion where the product is released by shedding apical cytoplasm, as seen in mammary glands.

Holocrine Secretion

A mode of exocrine secretion where the entire cell bursts and dies to release its product, requiring replacement by stem cells (e.g., sebaceous glands).

Fibroblasts

The most abundant cells in connective tissue proper that secrete protein fibers and hyaluronan (cellular cement).

Mast Cells

Connective tissue cells that release histamine and heparin to trigger an inflammatory response.

Mesenchymal Cells

Stem cells present in connective tissue proper that divide and differentiate to regenerate connective tissue cells.

Collagen Fibers

Long, straight, unbranched fibers in connective tissue proper that are strong and flexible, resisting force in a single direction.

Reticular Fibers

Interwoven networks of thin fibers (stroma) that resist forces in many directions and stabilize functional cells (parenchyma).

Elastic Fibers

Branched and wavy fibers containing elastin that return to their original length after being stretched.

Interstitial Growth (Cartilage)

A mechanism of cartilage growth from within, occurring when chondrocytes divide inside lacunae and secrete new matrix.

Appositional Growth (Cartilage)

A mechanism of cartilage growth at the outer surface, where inner perichondrium cells differentiate into chondroblasts and secrete matrix.

Skeletal Muscle Tissue

Muscle tissue composed of long, cylindrical, striated, multinucleate cells that moves or stabilizes the position of the skeleton.

Cardiac Muscle Tissue

Muscle tissue located in the heart composed of short, branched, striated cells with a single nucleus, interconnected by intercalated discs.

Smooth Muscle Tissue

Nonstriated muscle tissue composed of short, spindle-shaped cells with a single central nucleus, found in the walls of visceral organs and blood vessels.

Stratum Corneum

The most superficial layer of the epidermis, consisting of multiple layers of flattened, dead, interlocking keratinocytes that are water resistant.

Stratum Lucidum

A glassy, clear layer of the epidermis present exclusively in thick skin, located above the stratum granulosum.

Stratum Basale

The deepest layer of the epidermis attached to the basement membrane, containing basal cells (stem cells), melanocytes, and tactile (Merkel) cells.

Keratinocytes

The body's most abundant epithelial cells, found in the epidermis, which synthesize and store large amounts of keratin.

Melanosomes

Intracellular vesicles produced by melanocytes that package melanin pigment and transfer it into nearby keratinocytes.

Carotene

An orange-yellow pigment present in epidermal cells that contributes to overall skin coloration.

Diaphysis

The extended tubular shaft of a long bone, composed of a wall of compact bone surrounding a medullary cavity.

Epiphysis

The expanded wide region at each end of a long bone, mostly composed of spongy (trabecular) bone.

Metaphysis

The narrow cartilaginous junction region where the diaphysis and epiphysis meet in a long bone.

Osteocytes

Mature bone cells located in lacunae that maintain the protein and mineral matrix of bone tissue.

Osteoblasts

Immature bone cells that synthesize and secrete organic components of the matrix, a process called osteogenesis.

Osteoclasts

Large multinucleate bone cells that secrete acids and enzymes to dissolve bone matrix during osteolysis.

Osteogenic Cells

Stem cells located in the endosteum and inner periosteum whose cell divisions produce osteoblasts.

Osteon

The basic functional unit of compact bone, featuring concentric lamellae arranged around a central canal containing blood vessels.