Chr. 5 - Integumentary System Flashcards
[5.1] What are the two components of the cutaneous membrane?
Epidermis and dermis.
[5.1] What are lamellated corpuscles?
Nerve endings sensitive to pressure.
[5.1] What is deep to the dermis?
The subcutaneous layer.
[5.1] Describe the epidermis.
A layer of keratinized stratified squamous epithelium, composed of four types of cells: keratinocytes, melanocytes, intraepidermal macrophages, and tactile epithelial cells.
[5.1] What are keratinocytes?
Cells that produce the keratin, a tough fibrous protein protecting the skin and layers deep to it, and lamellar granules.
[5.1] What are lamellar granules?
Secretory organelles secreted by keratinocytes, forming a water-repellant membrane.
[5.1] What are melanocytes?
Cells in the epidermis that produce melanin.
[5.1] What is melanin?
A yellow-red or brown-black pigment able to absorb UV light, responsible for shade of skin.
[5.1] What are intraepidermal macrophages?
Cells participating in immune responses by recognizing foreign microbes.
[5.1] What are tactile epithelial cells?
Cells containing a tactile disc, aiding in detecting of touch sensation.
[5.1] What is thin skin?
Regions of the epidermis where only four strata are present: stratum basale, spinosum, granulosum, and corneum.
[5.1] What is thick skin?
Regions of the epidermis where five strata are present: stratum basale, spinosum, granulosum, and corneum, and lucidum.
[5.1] What is the stratum basale?
The deepest layer of the epidermis composed of a single row of cuboidal or columnar keratinocytes.
[5.1] What is the stratum spinosum?
Layer of keratinocytes about 8-10 layers thick, containing coarser bundles of keratin that extend into the desmosomes, providing increased strength and flexibility.
[5.1] What is the stratum granulosum?
Layer of epidermis superficial to spinosum, where keratinocytes are undergoing apoptosis. Presence of keratohyalin defines this layer, which is responsible for forming lamellar granules.
[5.1] What is the stratum lucidum?
Layer of epidermis superficial to granulosum, consisting of 4-6 layers of clear dead keratinocytes, providing additional toughness.
[5.1] What is the stratum corneum?
Layer of epidermis most superficial, consisting of 25-30 layers of dead keratinocytes.
[5.1] Describe the process of keratinization.
Cells moving from the stratum basale to the stratum corneum, accumulating more keratin as they progress.