Derm- PP slides Flashcards
what is the most frequent reason for malpractice in derm?
failure to diagnose
notice characteristics of skin such as
color, moisture, temp, texture, mobility & turgor, lesions
Red color of oxyhemoglobin best assessed at ?
fingertips, lips, and mucous membranes but in dark skinned people, palms and soles
For central cyanosis, look in
lips, oral mucosa, and tongue
For jaundice look in
sclera
skin layers from the inside towards the outer most layer are ?
subcutaneous tissue, the dermis, the epidermis
epidermal appendages
Hair Sebaceous glands Sweat glands (eccrine and apocrine) Nails
epidermis characteristics
Thin but tough- has no blood cells Tightly bound cells – replaced every 4 weeks Stratified zones starting with the stratum germinativum - “basal cells” Blend of keratin and melanin
dermis characteristics
inner supportive layer made of connective tissue AKA collagen Tough – helps to resist tearing Elastic / resilient capacity Placement of the nerves, sensory receptors, blood vessels, and lymphatics.
characteristics of subcutaneous layer
Adipose tissue - AKA “fat” Stores fat for energy Provides insulation Soft cushioning effect
hair
HAIR – is vestigial: no longer needed for protection from cold or trauma It is threads of keratin Held in place by the “arrector pili” that contract and elevate the hair – cause “goose bumps”
2 types of hair
fine/faint = vellus course/thick = terminal
sebaceous glands
Produce protective “lipid” substance – sebum – which is secreted through the hair follicle The sebum lubricates skin & hair Abundant in the scalp, face, forehead & chin
2 types of sweat glands
eccrine and apocrine
eccrine sweat gland
Coiled and open directly onto the skin surface Produce dilute saline – “sweat” As sweat evaporates, body temperature controlled Floods the skin surface with sweat for cooling Abundant on the body, and mature at 2 months age Everywhere on the skin – greatest concentration on the palms, soles, and forehead Controlled by the hypothalamic thermostat
apocrine sweat gland
Thick & milky secretion that opens into the hair follicle Mainly in axillae, anogenital nipple & navel area Vestigial in humans Become active during puberty – increased by emotional stress and sexual stimulation Normal skin flora react with apocrine sweat to create body odor Represent scent glands Found chiefly in the axillae, eyelid, breast, and anogenital areas – but do not develop until puberty In humans – little purpose except the production of odor Any stress in emotion causes adrenergic sympathetic discharge from the apocrine glands The functioning of the gland decreases with the aging adult.
nails
Hard plate of keratin Longitudinal ridges become prominent in aging Appear pink from the underlying highly vascular epithelial cells New keratinized cells start in the lunula
(more) characteristics of subcutaneous tissue
Serves as a receptor for the formation and storage of fat Is a locus of highly dynamic lipid metabolism Insulates the body from extremes in temperature Supports the blood vessels and nerves The site of origin for sweat glands and hair follicles Cushions the body against injury The scaffolding for underlying body parts Provides boundaries for body fluid Protects underlying tissues from microorganisms, harmful substances, and radiation Modulates body temperature Synthesizes vitamin D Heaviest single organ in body (16% of body weight)
Major function of skin is to keep the body in homeostasis so it.. (specifically functions of subq tissue)
Provides boundaries for body fluid Protects underlying tissues from microorganisms, harmful substances, and radiation Modulates body temperature Synthesizes vitamin D Heaviest single organ in body (16% of body weight)
The mechanical properties of the skin depend mainly on
the dermis (the middle/ the “true” skin). This is achieved by the collagen and elastic fibers. -Initially, skin stretches easily, primarily as a result of reorientation of collagen fibers toward the load axis and a reduction in their convolution. -Elastic fibers maintain the tone of the skin and are responsible for restoring the extensibility of slack skin. -After the initial slack has been taken up, skin becomes much harder to extend. However, under continued stretch, further irreversible extension does occur through the process of viscous slip/extension. -This is mainly dependent on collagen fibrils and holds the epidermis in place
the dermis contains
Contains blood, lymph, & peripheral nerves
the layer of the epidermis
outer horny layer- the stratum corneum Underlying horny layer (stratum mucosum)
what are the functions of the outer horny layer of the epidermis?
(aka stratum corneum) -Effective barrier against water and electrolyte loss -Effective barrier against the penetration of toxic agents and ultraviolet radiation -Intact it prevents invasion of normal bacterial to the bloodstream -Low water content, with a high electrical resistance and thus is the main component of the skin to offer some protection against damage from low-voltage electric current.
what are the functions of the inner horny layer of the epidermis?
(aka stratum mucosum) -Contains Langerhan cells -Function as antigen-presenting cells that migrate to the lymph -Play an important role in allergic response












































































