Integument Flashcards
(27 cards)
Seven functions of the Integument System
1 Physical protection from environmental hazards 2 Thermoregulation 3 Excretion 4 Synthesis/storage of lipid reserves 5 Synthesis of vitamin D3 6 Provides sensory information 7 Coordinates immune response to pathogens and malignancies of the skin
The Skin’s 3 layers and their respective tissues
Epidermis–Epithelium, variable thickness Dermis–Connective tissue, variable thickness Hypodermis (Subcutaneous)–Loose Connective Tissue, superficial fascia.
Describe the Epidermis (4 facts)
Stratified squamous epithelium Keratinized Number of layers varies Distinct layers better recognized in thick skin
Layers of the epidermis
Basal lamina Stratum basale Stratum spinosum Stratum granulosum Stratum lucidum (thick skin only) Stratum corneum Surface
The two names for the lowest layer of the epidermis
Stratum basale Stratum germinativum
Stratum germinativum: How many layers of cells? What is the shape of the cells?
Single cell layer on the basement membrane. Cells are Cuboidal/columnar in shape.
Stratum germinativum: Different cell types
Keratinocyte–most common, produce keratin Melanocyte–few, produce melanin (pigment) granules to distribute to adjacent cells Langerhans cell–associated with immune system (contact dermatitus) Merkel cell–part of nervous system, has sensory neuron attached. (nutritional and environmental info)
Stratum spinosum: How many layers of cells? Cell type? Type of attachments? What do those attachments do for the skin?
Few to several layers thick Primarily karatinocytes (prickle cells) Distinct intercellular attachments present (Desmosomes) Responsible for mechanical strength (skin isn’t very permeable)
Stratum granulosum: How many layers? Cell shape? Type of granules present? Status of the cells?
3-5 layers thick Cells become flattened Granules have Keratohyalin (immature keratin) Cells are starting to die.
Stratum lucidum: Found where? Status of keratin? Status of cell apoptosis?
Only found in thick skin. High concentration of immature keratin Most cellular organelles are disrupted.
Stratum corneum: Status of cell apoptosis? Composition of substances? Purpose of corneum?
Cells are “bags of keratin” Keratin and glycolipids add water resistance (soft keratin) Corneum layers are sloughed off continuously.
Dermis: Location? Nickname? Why is it nicknamed that way? Junction structure? What human feature is a direct result of the dermis structure?
Deep to the epidermis Nicknamed, Anchor–anchored by numerous filaments. The junction is irregular–epidermal ridges, dermal papillae and dermal ridges. Fingerprint.
Name the Dermal layers and their features
Papillary layer–Dermal papillae, Capilleries, Nerve axons Reticular Layer–Hair follicles, sweat/sebaceous glands
Dermal cells
Fibroblasts Macrophages–Other immune system cells, Neutrophils Smooth muscle–Associated with hair follicle (makes hair stand on end), Erector pili muscles.
Hypodermis (Subcutaneous layer): Type of tissue? Is the boundary distinct? What is a third name for this layer?
Loose connective tissue–Immune system, blood cells, adipocytes. Indistinct boundary. Superficial fascia.
Hair: Where is it found? Describe the root.
Epithelial pockets (Follicles)–associated with glands. Hair root.Portion in the follicle. Forms hair bulb.(Deepest portion of follicle. Center of mitotic activity.)
Hair structure: Layers? Describe each layer, at least two characteristics.
Medulla–Innermost layer. Cuboidal cells/keratohyalin (hard keratin) granules. absent in vellus hair Cortex–Thickest portion, flate cells w/ hard keratin, location of melanocytes. Cuticle–forms keratinized scales–absorb melanin.
What are the three types of hair?
Terminal–Typical hair of scalp. Vellus–“Peach fuzz” present in infants. Intermediate–Growth associated with sex hormones.
Growth patterns: Describe the cyclical pattern.
Active-mitosis occurring, hair is growing. Usually longest portion of cycle. 30% of cycle. Phase is 3 years. Resting–mitosis stopped, club hair occupies follicle. 1 year. Short except in baldness–go into rest.
Sebaceous Glands
Associated with hair follicles. Outrgrowth of external root sheath. Exceptions, lubrication: Lip margin, nipple, glans and prepuce, genitals. Holocrine type secretion. (explosion)
Sweat Glands: Types of secretion? Modified types?
Merocrine and Apocrine Modified types, Ceruminous–wax production in ear, no hair, merocrine. Mammary–Hormonal regulation–estrogen in development. Prolactin–milk production. Apocrine type secretion.
Merocrine Sweat Glands Distribution? Cell type? tricky Function
Wide distribution Simple tubular with myoepithelial cells Merocrine secretion Temperature regulation
Apocrine Sweat Glands Size and location compared to merocrine glands? Distribution? What instigates their function? Secretion type?
Misnamed, not apocrine secretion type. Larger than Merocrine and deeper. Distribution confined–axilla, groin, and genital regions. Stimulated by steroid hormones (puberty). Merocrine type secretion.
Nails What are they? Functions?
Plates of hard keratin. Protects skin. Prevents distortion of finger and toe tips. Improves manual dexterity.
