Tissues and Integumentary System Review

Vocabulary flashcards covering muscle tissues, nervous tissue, layers of the integument, and epidermal strata from lecture notes.

Muscle Fibers

Cells that comprise muscle tissue, which cause movement by shortening when active.

Skeletal Muscle Tissue

Tissue composed of long, cylindrical, striated fibers with multiple nuclei in the periphery under voluntary control that attach to bone and/or skin.

Cardiac Muscle Tissue

Striated, branched/Y-shaped muscle tissue found in the wall of the heart (myocardium) that initiates its own contraction autorhythmically and may be binucleated.

Intercalated Discs

Structures containing strong gap junctions that attach cardiac muscle cells end-to-end, allowing rapid passage of electrical current from one cell to the next during each heartbeat.

Smooth Muscle Tissue

Involuntary, non-striated tissue composed of short, fusiform cells with a single nucleus, found in the walls of most internal organs such as the stomach, intestines, and urinary bladder.

Neurons

Nerve cells capable of initiating and conducting electrical activity throughout the body for communication and control of body functions, located in the brain, spinal cord, and nerves.

Glial Cells

Nervous tissue cells that support and protect neurons, consisting of 4 types in the central nervous system (including microglial cells) and 2 types in the peripheral nervous system.

Integument

The skin covering the body, also known as the cutaneous membrane, which includes derivatives such as nails, hair, sweat glands, and sebaceous (oil) glands.

Epidermis

The superficial layer of the integumentary system composed of keratinized stratified squamous epithelium.

Dermis

The deep layer of the integument consisting of an upper papillary layer made of areolar CT and a lower reticular layer made of dense irregular CT.

Subcutaneous Layer

A layer lying under the dermis (not part of the skin) composed of areolar CT and adipose CT, also known as the hypodermis.

Calcitriol

The active form converted by the kidneys from Vitamin D3 produced by the skin.

Stratum Basale

The deepest epidermal layer consisting of a single layer of cells attached to the basement membrane and adjacent to the dermis.

Keratinocytes

The most abundant epidermal cells that divide to replace shed cells and produce tough keratin protein that protects and makes skin water resistant.

Melanocytes

Cells in the stratum basale that produce melanin to absorb UV light and prevent DNA damage, transferring melanin granules to keratinocytes via cytoplasmic processes.

Tactile Cells

Specialized cells located in the stratum basale that are sensitive to touch.

Stratum Spinosum

An epidermal layer composed of several layers of specialized, non-dividing keratinocytes attached to each other via desmosomes.

Epidermal Dendritic Cells

Immune cells located in the stratum spinosum that act as phagocytes to fight infection and initiate immune responses.

Stratum Granulosum

An epidermal layer consisting of 3 to 5 layers of keratinocytes undergoing keratinization, where cytoplasm fills with keratin filaments and organelles begin to degrade.

Keratohyalin Granules

A type of keratin granule found in keratinocytes of the stratum granulosum involved in the keratinization process.

Lamellar Granules

Granules in the stratum granulosum that release lipids into the extracellular space to help form a water barrier.

Stratum Lucidum

A thin, translucent region two to three cell layers thick found exclusively in thick skin such as the palms of hands and soles of feet.