Integumentary System-General

Natural Science 151 153 with Shoepe at Loyola Marymount University

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By: Washington Nieshe
Created: 2011-03-04
Size: 70 flashcards
Views: 25

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Bodies largest and heaviest organ

A. Epidermis

B. Dermis

C. Hypodermis, subcutaneus layer associated with skin.

Thick Skin

Covers the palms, soles, and corresponding surfaces of the fingers and toes.

Epidermis about 0.5 mm thick

Has sweat glands but no hair follicles or sebaceous (oil) glands.

Thin Skin

Covers the body, exceptions: palms, soles, and surfaces of fingers and toes.

Epidermis about 0.1 mm thick

Possesses hair follicles, sebaceous glands, and sweat glands.

6 Functions of Skin

1) Resistance to trauma and infection
2) Barrier functions
3) Vitamin D Synthesis
4) Sensation
5) Thermoregulation
6) Nonverbal Communication

Epidermis

Keritanized stratified squamos epithelium

Consists of dead cells packed with the tough protein keratin

Lacks blood vessels and depends upon diffusion of nutrients from underlying connective touch

Sparse nerve endings for touch and pain

5 Cells of the Epidermis

1) Stem cells
2) Keratinocytes
3) Melanocytes
4) Tactile (Merkel) cells
5) Dendritic (Langerhans) cells

Stem Cells

Undifferentiated cells that divide and give rise to keratinocytes.

Found only in the deepest layer of the epidermis, the stratum basale

Keratinocytes

Predominant cell type in the epidermis

Produce keratin, a protein that provides strength to skin, hair, and nails.

Melanocytes

Occur only in the stratum basale

Synthesize the brown to black pigment melanin

Tactile (Merkel) Cells

Found in the basal layer of the epidermis and are associated with an underlying dermal nerve fiber

Dendritic (Langerhans) Cells

Found in stratum spinosum and stratum granulosum

They are macrophages that stand guard against toxins, microbes, and other pathogens that penetrate into the skin and alert the immune system so the body can defend itself.

A. Stratum Corneum
B. Stratum Lucidum
C. Stratum Ganulosum
D.Stratum Spinosum
E. Stratum Basale

Stratum Basale

Deepest stratum layer.

Consists mainly of a single layer of cuboidal to low columnar stem cells and keratinocytes resting on the basement membrane.

Melanocytes are primarily found in this layer.

Cell mitosis occurs in this layer

Stratum Spinosum

Consists of several layers of keratinocytes

Dendritic cells are found in this layer

Stratum Granulosum

Consists of three to five layers of flat keratinocytes

The keratinocytes of this layer contain dark-staining kerathyalin granules

Stratum Lucidum

Clear, thin zone superficial to the stratum granulosum, seen only in thick skin

Keratinocytes in this layer are densely packed with a clear protein called eleidin.

The cells in this layer have no nuclei or other organelles

Stratum Corneum

Consists of up to 30 layers of dead, scaly, keritanized cells that form a durable surface layer.

This layer is especially resistant to abrasion, penetration, and water loss.

Dermis

Connective tissue layer beneath the epidermis.

Composed mainly of collagen

Well supplied with blood vessels, sweat glands, sebaceous glands, and nerve endings

Piloerector Muscles

Smooth Muscles associated with hair follicles that contract in response to stimuli such as cold, fear, and touch

Dermal Papillae

Upward waves, fingerlike extensions of the dermis.

Epidermal Ridges

Downward waves, extensions of the epidermis.

Papillary Layer of Dermis

A thin zone of areolar tissue in and near the dermal papillae.

Allows for mobility of leukocytes and other defenses against organisms introduced through breaks in the epidermis.

Rich in small blood vessels.

Reticular Layer of Dermis

Consists of dense irregular connective tissue.

Hypodermis

Layer of connective tissue deep to the skin

Pads the body and binds the skin to underlying tissues.

Subcutaneous Fat

Hypodermis composes primarily of adipose tissue

Serves as an energy reservoir and thermal insulation

Virtually absent from the scalp but relatively abundance in the breasts, abdomen, hips, and thighs

Melanin

Skin pigment roduced by melanocytes

Eumelanin

Brownish black pigment

Pheomelanin

Reddish yellow sulfur-containing pigment

Cyanosis

Blueness of the skin resulting from a deficiency of oxygen in the circulating blood.

Erythema

Abnormal redness of the skin caused by increased blood flow in dilated cutaneous blood vessels or by dermal pooling of red blood cells

Occurs in such situations as exercise, hot weather, sunburn, anger, and embarrassment.

Pallor

Pale or ashen color that occurs when there is so little blood flow through the skin that the white color of the dermal collagen shows through .

Can result from emotional stress, low blood pressure, circulatory shock, cold temperatures, or severe anemia

Albinism

Genetic lack of melanin that usually results in milky white hair and skin and blue-gray eyes

Jaundice

Yellowing of the skin and whites of the eyes resulting from high levels of bilirubin in the blood

Hematoma

Bruise

A mass of clotted blood showing through the skin

Usually due to accidental trauma, but may indicative hemophilia, or other metabolic or nutritional disorders, or physical abuse

A. Hair
B. Sweat Pores
C. Merocrine Sweat Gland
D. Cutaneous Blood Vessels
E. Motor Nerve Fibers

A. Dermal Papilla
B. Tactile Corpuscle (touch receptor)
C. Blood Capillaries
D. Hair Follicle
E. Sebaceous Gland
F. Hair Receptor

A. Hair Receptor
B. Apocrine Sweat Gland
C. Hair Bulb
D. Sensory Nerve Fibers
E. Piloerector Muscle
F. Lamellar (pacinian) Corpuscle (pressure receptor)

Accessory Organs

Hair, nails, and cutaneous glands

Hair

slender filament of keratinized cells that grows from a hair follicle

Hair Follicle

An oblique epidermal pit that contains a hair and extends into the dermis or hypodermis.

Three Kinds of Hair

1) Lanugo - fine, downy, unpigmented hairs
2) Vellus - fine, pale hair
3) Terminal hair- longer, coarser, and usually more heavily pigmented

3 Zones of Hair

1) Bulb, a swelling at the base where the hair originates in the dermis or hypodermis
2) Root, remainder of the hair within the follicle
3) Shaft, portion above the skin surface

Three Developmental Stages of Hair Growth

Anagen
Catagen
Telogen

Anagen Stage of Hair Growth

(Growing phase, 6-8 yrs)
Stem cells multiply and follicle grows deeper into the dermis; hair matrix cells multiply and keratinize, causing hair to grow upward; old club hair may persist temporarily alongside newly growing hair.

Catagen Stage of Hair Growth

(Degenerative Phase, 2-3 weeks)
Hair growth ceases; hair bulb keratinizes and forms club hair; lower follicle degenerates.

Telogen Stage of Hair Growth

(Resting Phase, 1-3 months)
Dermal papilla has ascended to level of bulge; club hair falls out, usually in telogen or next anagen.

Alopecia

Thinning of the hair, or baldness

Pattern Baldness

Condition in which hair is lost from specific regions of the scalp rather than thinning uniformly across the entire scalp.

Hirutism

Excessive or undesirable hairiness in areas that are not usually hairy, especially in women and children.

Functions of hair

Hair receptors can alert us to parasites
Source of recognition
Aids in transmission of sexual scent
Guard hairs guard the nostril and ear canals
Eyelashes serve as a quick debris shield
Eyebrows enhance facial expression

A. Free Edge
B. Nail Body
C. Nail Groove
D. Nail Fold
E. Lunule
F. Eponychium (cuticle)

A. Nail Plate
B. Nail Root
C. Nail Fold
D. Free Edge
E. Nail Body
F. Eponychium (cuticle)
G. Nail Bed
H. Nail Matrix

Sudiferous Glands

Sweat glands

Two Types: Merocrine and Apocrine

Merocrine Sweat Glands

Sweat glands that function in evaporative cooling

Widely distributed over the body surface

Open by ducts onto the skin surface

Apocrine Sweat Glands

Sweat glands that function as scent glands

Found in the regions covered by the pubic, axillary, and male facial hair

Open by ducts into hair follicles

Sebaceous Glands

Produce an oily secretion called sebum.

Ceruminous Glands

Found only in the external ear canal, where their secretion combines with sebum and dead epidermal cells to form earwax, or cerumen.

Mammary Glands

Milk-producing glands located in the breasts

Acne

Inflammation of the sebaceous glands
Caused by follicle becoming blocked with keratinocytes, sebum, and bacteria

Dermatitis

Any inflammation of the skin
Typically marked by itching and redness
Often contact dermatitis is caused by exposure to toxic foliage such as poison ivy.

Eczema

Itchy, red, skin lesions caused by an allergy, usually beginning before age 5
May progress to thickened, leathery, darkly pigmented patches of skin.

Psoriasis

Recurring, reddened plaques covered with silvery scale
Sometimes disfiguring; possibly caused by an autoimmune response

Rosacea

Red rashlike area, often in the area of the nose and cheeks
Marked by fine networks of dilated blood vessels

Basal Cell Carcinoma

Most common type of skin cancer
Least dangerous as it seldom metastisizes

Squamos Cell Carcinoma

Skin cancer that arises from keratinocytes of the stratum spinosum

Chance of recovery is good with early detection and surgical removal, but if it goes unnoticed or is neglected the cancer can metastasize to the lymph nodes and become lethal

Malignant Melanoma

Skin cancer that arises from melanocytes
Accounts for no more than 5% of skin cancers
Most deadly form, can be treated surgically, but if it metastasizes it is unresponsive to chemotherapy and is usually fatal

ABCD Rule for Skin Cancer

A = Asymmetry (two sides of pigmented mole do not match)
B = Border Irregularity (borders of mole are not smooth)
C = Color (different color in pigmented areas)
D = Diameter (spot is larger than 6m in diameter)

First Degree Burn

Involves only epidermis marked by redness and slight edema and pain

Heals in a few days and seldom leaves scars

Ex. Sunburns

Second Degree Burn

Involve epidermis and a part of the dermis but leave at least some of the dermis intact

May be red, or white and blistered and very painful

May take from 2 weeks to several months to heal and may leave scars

Third Degree Burn

Epidermis, all of dermis, and often some deep tissues (muscle and bone) are destroyed

Skin can regenerate only from the edges of dermis

Often requires skin grafts

About this deck

By: Washington Nieshe
Created: 2011-03-04
Size: 70 flashcards
Views: 25

About StudyBlue

“Simply amazing. The flash cards are smooth, there are many different types of studying tools, and there is a great search engine. I praise you on the awesomeness.”
Dennis