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.
[5.1] Describe the dermis.
Deeper part of the skin composed of dense irregular connective tissue containing collagen and elastic fibers.
[5.1] What is the papillary region?
Superficial region containing collagen and fine elastic fibers.
[5.1] What are dermal papillae?
Dome-shaped structures of papillary region projecting to underside of epidermis, increasing surface area.
[5.1] What are free nerve endings?
Dendrites that lack structural specialization, found in dermal papillae.
[5.1] Describe the reticular region.
Layer of dermis attaching to subcutaneous layer, contains thick collagen fibers, fibroblasts, and wandering cells. Provides strength, extensibility, and elasticity.
[5.1] What are epidermal ridges?
A series of ridges and grooves present on the tips of digits, creating strong bonds between epidermis and dermis as well as increasing surface area for grip.
[5.1] Which pigments impart shades to skin?
Melanin, hemoglobin, and carotene.
[5.2] Describe hair.
Columns of dead keratinized epidermal cells bonded by extracellular proteins.
[5.2] What is the hair shaft?
Superficial portion of the hair projecting above the surface of the skin.
[5.2] What is the hair root?
Portion of the hair deep to the skin, projecting from either the dermis or the subcutaneous layer.
[5.2] What is the hair follicle?
A structure made of the epithelial root sheath, and the dermal root sheath
[5.2] What two compnents make up the epithelial root sheath?
The external root sheath and the internal root sheath.
[5.2] What is the external root sheath?
Part of the hair follicle formed by the downward extension of the epidermis.
[5.2] What is the internal root sheath?
A sheath formed by epithelium between external root sheath and the hair.
[5.2] What is the dermal root sheath?
Dense dermis surrounding the epithelial root sheath.
[5.2] What is the hair bulb?
The base of a hair follicle and it’s surrounding dermal root sheath.
[5.2] What is the papilla of the hair?
A dome-shaped indentation containing areolar connective tissue and blood vessels, nourishing the hair follicle.
[5.2] What is arrector pili?
Smooth muscles within the dermis attached to hairs, controlling movement of hair via contractions.
[5.2] Describe a sebaceous gland.
Simple branched acinar glands secretion secreting sebum.
[5.2] What is sebum?
A mixture of triglycerides, cholesterol, proteins, and inorganic salts.
[5.2] Describe a sudoriferous gland.
Glands secreting sweat, classified into eccrine and apocrine.
[5.2] What is an eccrine sweat gland?
Simple coiled tubular glands deep in dermis that open to the surface of epidermis.
[5.2] What is an apocrine gland?
Simple coiled tubular glands with larger ducts and lumens that open to hair follicles.
[5.2] Describe ceruminous gland.
Glands present in subcutaneous layer in the external auditory canal and secrete cerumen.
[5.2] Describe a nail.
Plates of tightly packed, hard, dead keratinized epidermal cells.
[5.2] List the components of a nail.
- Nail body.
- Free edge.
- Nail root.
- Lunula
- Hyponychium
- Nail bed
- Eponychium
- Nail matrix.
[5.3] What are the types of skin?
Thin (hairy) skin and thick (hairless) skin.
[5.4] What are the functions of skin?
Thermoregulation, blood reservoir, protection, excretion and absorption, cutaneous sensation, synthesis of vitamin D.
