The Integumentary System Flashcards
What is the integument?
-The outer layer covering the body including the skin, glands, hair and nails
What are the functions of the integument?
-Protection, sensation, vitamin D, production, temperature regulation and excretion
What are the layers of the skin?
-Epidermis, dermis, hypodermis
What is the function of the epidermis?
-Prevents water loss and abrasion damage
What is the function of dermis?
-Structural strength from connective tissues
What are the layers of the dermis?
-Papillary layer and reticular layer
What does the dermis contain?
-Hair follicles, oil and sweat glands, sensory receptors, and blood and lymphatic vessels
What are the features of the papillary layer in the dermis?
-made up of fine collagenous and elastic fibres, contain blood vessels, have dermal papillae to increase the strength of the bond to the dermis
What are the features of the reticular layer?
-Denser, has more collagenous and elastic fibres
How does the dermal layer heal?
-Fibroblasts proliferate
What are the features of collagen fibres?
-Generally have some predominant direction and if it is made parallel to this, the scar will be less prominent
What are the layers of epidermis ?
-Stratum basale, stratum spinous, stratum granulosum, stratum lucidum, stratum corner
What is keratinisation?
-Epithelial cells have more and more keratin to help with waterproofing as they migrate upwards towards the surface
What are basol cells?
-Precursors of keratinocytes
What are keratinocytes ?
-Epidermal cells composed of keratin, lipids, and other proteins. Make up 90% of cells in skin
What are melanocytes ?
-Produce pigment (melanin) and filter ultraviolet light
What are Langerhans cells?
-Specialised dendritic cells found in the skin-part of the immune system
What are Merkel cells?
-Touch receptors in the epidermis
What is the stratum germinativum?
-The growth layer at the bottom of the spidermis that is made up of the stratum basal and stratum spinosum
What are the features of the stratum basal?
-Contain basal cells that undergo mitosis
What are the features of the stratum spinosum?
-Contain keratinocytes to hold cells together, begins to generate keratin and lipids, contains langerhans cells
What types of layers make up the strata?
-Stratum granulosum, stratum lucidity, stratum corneum
What are the features of the stratum granulosum?
-Hold lots of deposits of keratin-granules so grainy
What are the features of the stratum lucidium?
-Clear layer where cells die as they are so full of keratin
What are the features of the stratum corneum?
-Top layer on the skin of dead skin cells filled with keratin that are constantly shed
How does the stratum corneum relate to drug delivery?
-Lipid soluble substances will diffuse through lipid layers
What types of sweat glands are found in the epidermis?
-Ecrine sweat glands and apocrine sweat glands?
What are the features of eccrine sweat glands?
-most common, found all over the body, secrete perspiration, eliminates waste and cools body
What are the features of apocrine sweat glands?
-Open into hair follicles and have limited distribution-mainly found in arm pits and genitalia
What are sebaceous glands?
-oil glands that open to a hair follicle to secrete sebum and give an anti fungal property
Why is gland secretion and shed skin important?
-Creates a surface film protective layer that has antibacterial, lubrication and hyperactive properties. Also a buffer of irritants and blocks toxins
What does skin colour depend on?
-Pigments (melanin and beta carotene), blood (Hg) and thickness of stratum, corneum
What is melanin?
-Group of pigments that protect from UV
How can skin pigmentation be used in diagnosis?
-Skin reactions can be determined by pigmentation response
