Integumentary System

Epidermis

superficial layer contains stratified epithelium tissue arranged in layers

Epidermis layers

stratum corneum, stratum luciderm, stratum granulosum, stratum spinosum, stratum basal

Stratum CLGSB

cunty lunch girls so back (corneum, luciderm, granulosum, spinosum, basale)

Epidermis does not contain

blood vessels

Epidermis function

protects body from outside, hydrates skin, produces new skin cells, and determines skin color

Strata

epithelium tissue arranged in layers

Langerhan cells are found

In epidermis (stratum basale)

Flattened polygonal cells

Keratinocytes in stratum granules

Polyhedral

Keratinocytes in stratum spinous

Dermis

middle layer

Dermis contains

collagen, blood vessels, glands, hair follicles, and nerve endings

Dermis function

support and protect skin and deeper layers, thermoregulation, aid in sensation

Deep reticular area

Strengthens skin and provides elasticity

Superficial papillary layer

Fingerlike projections that contain blood capillaries

Deepest layers of epidermis receives nutrients from

Superficial papillary layer

Dermis consists of

loose connective tissues

Hypodermis (subcutaneous)

innermost layer, stores energy, connects dermis to muscles and bones, insulates body, protects body from harm

Hypodermis made of mostly

Fat

Subcutaneous layer consists of

loose connective tissue, adipose tissue, blood vessels, nerve endings

Dermal papillae

protrusions of dermal connective tissue into epidermal layer

Dermal papillae function

regulate hair growth

Melanocytes

produce and distribute melanin

Melanocytes located

deepest portion of epidermis and superficial dermis (stratum basale)

Stratum Corneum

cells hardened with keratin

Keratin

secreted by keritoncytes located in deep layers of epidermis

Stratum Corneum function

first line of defense against environment

Stratum Luciderm

thin somewhat translucent layer of cells

Stratum Luciderm found especially in

thickened parts of epidermis, palms of hands or soles of feet

Stratum Granulosum

Accumulate dense basophilic keratohyalin granules to prevent fluid loss from body

Stratum Granulosum contains

cells that have lost nuclei; contain granules that harbor keratin

Keratohyalin granules contain

lipids that help form waterproof barrier

Stratum Granulosum function

prevent fluid loss from body

Stratum Spinosum

keratinocytes held together by sticky proteins (desmosomes)

Stratum Spinosum contains

prickle cells

Stratum Spinosum function

helps make skin flexible and strong; keratin is synthesized

Stratum Basale

deepest of five layers

Stratum Basale function

cells can divide and move to top

Sebaceous glands

microscopic exocrine gland in skin that opens into a hair follicle to secrete sebum

Sudiferous

sweat duct that transports secretion to surface of epidermis

Vellus hairs

fine hairs located on body’s surface

Terminal hairs

thicker more pigmented found on head and genitals

Arrector pili muscle

band of smooth muscle connects to each hair follicle

Sebum

secreted in response to contraction of arrector pili muscle

Sebum contains

triglyceride, protein, cholesterol, and some electrolytes

Sebum makes hair

flexible and hydrated

Apocrine sweat glands

secrete substance into hair follicle; starts at puberty and can develop odor

Apocrine sweat glands are located

in axilla and genital regions

Eccrine sweat glands secrete substances

directly onto surface of skin

Eccrine sweat gland function

regulate body temp and excretes water and electrolytes

Cuticle

stratum corneum extends over proximal portion of nail

Heat moves

via molcules from warmer to cooler temperatues

Hypothalamus

controls body temp by opening and closing sweat glands and contracting muscles

Basement membrane

connects epidermis to dermis

Skin contains

2 layers + subcutaneous layer

Psoriasis

keratinocytes abnormally divide rapidly and migrate from stratum basale to stratum corneum

Skin synthesizes

vitamin D when a precursor molecule absorbs ultraviolet radiation (inactive)

Vitamin D is activated by

liver and kidneys

Why is vitamin D important?

helps body absorb calcium and helps in calcium transport

Lamellar granules

specialized organelles found in stratum granulosum

Lamellar granules contain

lipids that are essential for formation and maintenance of stratum corneum

Lamellar granules function

production and storage of lipids

Merkel cell found

right below epidermis very close to nerve endings

Merkel cell function

receive sensation of touch

Where do hairs begin to grow?

base of hair follicle called bulb

Hair papilla contains

blood vessels and nerves that surround hair bulb

Cutaneous plexus

network of blood vessels located in dermis

Lamellated corpuscle

type of sensory receptor that detects deep pressure and high frequency vibrations

Tactile corpuscle

specialized nerve endings that detect light touch and low-freqeuncy vibrations

Stratum Basale AKA

Stratum Germinativum

Layers of Dermis

Papillary layer and reticular layer

Langerhan cells

Macrophages

Langerhan cell function

Protect body from pathogens by ingesting and destroying bacteria/harmful organisms

Melanin

Dark pigment that protects us from UV rays

Ceruminous gland found

External auditory canal

Ceruminous gland function

Protect outer ear

Sebaceous glands are absent in

Palms

Melanoma checks for

Asymmetry, border, color, diameter, and evolution (ABCDE)

Albinism occurs because

People lack melanin

Ceruminous gland

Modified apocrine sweat gland