The Integumentary System

The Integumentary System

Integument is__________ Skin and its __________make up the

integumentary system A fatty layer (_________) lies deep to it Two distinct regions

____________________

Functions of skin

____________ Cushions and insulates and is waterproof Protects from chemicals, heat, cold, bacteria Screens UV

Synthesizes __________ with UV Regulates _______ _________ Prevents unnecessary ________ loss __________ reception (nerve endings)

Epidermis

Keratinized stratified squamous epithelium Four types of cells

__________ – deepest, produce keratin (tough fibrous protein) __________ - make dark skin pigment melanin ___________– associated with sensory nerve endings ____________ cells – macrophage-like dendritic cells

Layers (from deep to superficial) Stratum _______ or germinativum – single row of cells attached to

dermis; youngest cells Stratum _________ – spinyness is artifactual; tonofilaments

(bundles of protein) resist tension Stratum __________ – layers of flattened keratinocytes producing

keratin (hair and nails made of it also) Stratum ___________ (only on _______ and _______) Stratum ____________ – horny layer (cells dead, many layers

thick)

(see figure on next slide)

Epithelium: layers (on left) and cell types (on right)

Remember…

Four basic types of tissue

___________ – epidermis just discussed____________ tissue - dermis__________ tissue__________ tissue

Dermis Strong, _________ connective tissue: your

“hide” _______: fibroblasts, macrophages, mast cells,

WBCs Fiber types: ________, _______, reticular Rich supply of ________ and ________ Critical role in _________ regulation (the

vessels) Two layers (see next slides)

___________ – areolar connective tissue; includes dermal papillae

____________ – “reticulum” (network) of collagen and reticular fibers

*Dermis layers

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*

*Dermal papillae

Epidermis and dermis of (a) thick skin and (b) thin skin(which one makes the difference?)

Fingerprints, palmprints, footprints Dermal __________ lie atop dermal ridges _________ the overlying epidermis into epidermal __________ Are “_______ _________” because of sweat pores _____________ determined

_____________ creases Deep dermis, from _____________ folding

Fibers __________: strength and resilience Elastic fibers: stretch-recoil

______________: stretch marks ____________ lines (or lines of cleavage)

The direction the bundlesof fibers are directed

The dermis is the receptive site for the pigment of tattoos

Hypodermis

“Hypodermis” (Gk) = _________ the skin “Subcutaneous” (Latin) = ________ the skin Also called “_________ _________”

“fascia” (Latin) =band; in anatomy: sheet of connective tissue

______ tissue which stores fat and anchors skin (_______ tissue and _________ cells)

Different patterns of accumulation

(male/female)

Skin color Three skin pigments

________: the most __________________: from ________ and _____ ______________: the ______ of light skin

_______ in granules passes from ________ (_____ number in all races) to keratinocytes in stratum basale_________ by lysosomes_________ in colorProtection from UV light vs vitamin D?

Skin appendages

Derived from epidermis but ______ into dermis

IncludeHair and _____ follicles__________ (oil) glands_________ (sudoiferous) glandsNails

Nails

Of hard __________ Corresponds to ________ and _______ Grows from nail _______

Hair and hair follicles: complexDerived from epidermis and dermisEverywhere but ______, ______, ______, parts of _______

*“arrector pili” is smooth muscle

*

Hair papilla is connective tissue________________

Hair bulb: epithelial cells surrounding papilla

Functions of hair_______ – less in man than other mammalsSense _______ touch of the skin_______ - scalp

Parts________ imbedded in skin________ projecting above skin surface

Make up of hair – ______ _______ Three concentric layers

_________ (core)__________ (surrounds medulla)__________ (single layers, overlapping)

Types of hair _______: fine, short hairs __________ hairs __________: longer, courser hair

Hair growth: averages 2 mm/week _______: growing Resting phase then shed

Hair loss Thinning – age related Male pattern baldness

Hair color _______ of melanin for black or brown; ________

form of melanin for red _________: _______ melanin and ____ ______ in

the medulla ____________ determined though influenced by

hormones and environment

Sebaceous (oil) glands Entire body except ______ and ________ Produce _________ by holocrine secretion Oils and lubricates

Sweat glands Entire skin surface

except ______s and part of ______ genitalia

Prevent overheating _____ cc to _____

(is mostly water) Humans most

efficient (only ______ have)

Produced in response to _____ as well as ______

Types of sweat glands Eccrine or merocrine

Most numerous True sweat: 99% water, some salts, traces of waste Open through pores

Apocrine Axillary, anal and genital areas only Ducts open into hair follices The organic molecules in it decompose with time - odor

Modified apocrine glands Ceruminous – secrete earwax Mammary – secrete milk

Disorders of the integumentary system Burns

Threat to life ________ loss of body fluids ___________ and fatal _________ shock Infection

Types First degree – _______: redness (e.g. _______) Second degree – _______ and upper _____: ______ Third degree - full thickness

Infections Skin cancer

BurnsFirst-degree(epidermis only; redness)

Second-degree(epidermis and dermis,with blistering)

Third-degree(full thickness, destroying epidermis, dermis, often part of hypodermis)

Critical burns

Over ____ of the body has ________ burns

______ of the body has second-degree burns

Third-degree burns on _____, _____, or _____

Estimate by “rule of 9’s”

Tumors of the skin Benign, e.g. warts Cancer – associated with UV exposure

(also skin aging)_______ keratosis - premalignant______ cell - cells of stratum basale_______ cell - keratinocytes_______ – melanocytes: most dangerous;

recognition: A - Asymmetry B - Border irregularity C - Colors D - Diameter larger than 6 mm

Basal cell carcinoma

Sqaumous cell carcinoma

Melanoma

Skin Cancer