The Integumentary System

Front 1

Functions of skin

Back 1

Protection-barrier to bacteria;cushioning
Thermoregulation- sweating to loose heat, hair to retain heat, blood supply to capillaries
Sensation-heat, cold, itch, touch, pain
Excretion and absorption-urea and ammonia
Vitamin D production

Front 2

cutaneous membrane

Back 2

aka skin, 2 layers. Superficial, thinner portion composed of pithelial tissue=epidermis. Deeper thicker connective tissue part=dermis

Front 3

subcutaneous layer

Back 3

aka hypodermis, deep to the dermis not part of skin composed of areolar and adipose tissues. storage for fat and large blood vessels that supply the skin.

Front 4

Keratin

Back 4

tough, fibrous protein that helps protect the skin and underlying tissues from heat, microbes, and chemicals.

Front 5

Keratinocytes

Back 5

90% of epidermal cells, form the protective layer. produce the protein keratin and lamellar granules which release a water-repellent sealant.

Front 6

Melanocytes

Back 6

8% of epidermal cells, deep in epidermis. produce the pigment melanin which provides protection from ultraviolet light

Front 7

Langerhans cells

Back 7

arise from red bone marrow and migrate to the epidermis, special type of white blood cell, release hystamines. participate in immune responses against microbes

Front 8

Merkel cells

Back 8

least numerous epidermal cells, located in the deepest layer where they contact the flattened process of a sensory neuron called a tactile (merkel) disc.

Front 9

Layering of the epidermis

Back 9

superficial to deep.
Stratum corneum
Stratum lucidum -thick skin only
Stratum granulosum
Stratum spinosum
Stratum basale

Front 10

Thick skin

Back 10

palms, fingers, soles of feet
thick stratum spinosum and corneum, stratum lucidum is present, more dermal papillae (palm, finger,foot prints)

Front 11

Stratum basale

Back 11

Deepest layer, stem cells are undergoing mitosis, replace lost skin cells. one row of cuboidal or columnar keratinocytes.

Front 12

Stratum spinosum

Back 12

cells bound by desmosomes support for the epidermis, some mitosis is occuring.

Front 13

Stratum granulosum

Back 13

cells become squamous, fill with keratin, produce lipids waterproofing (lamellar granules), apoptosis programmed cell death, cells are specialized for their function and no longer going through mitosis

Front 14

Stratum lucidum

Back 14

only in thick skin,, clear layer of dead cells

Front 15

Stratum corneum

Back 15

dead cells containing keratin, multiple layers of overlapping cells for protection, gradually lost off surface

Front 16

Dermis

Back 16

2nd deeper part of the skin composed mainly of connective tissue, blood vessels, nerves, glands, and hair follicles.

Front 17

Papillary layer

Back 17

1/5 of total dermal layer. areolar connective tissue.

Front 18

Dermal Papillae

Back 18

fingerlike projection of the papillary region of the dermis that may contain capillary loops (blood capillaries) some contain touch receptors called corpuscles of touch and free nerve endings. blood vessels in the dp reduce the distance to each cell...nutrients can reach the cells and waste doesn't accumulate

Front 19

Reticular layer

Back 19

deep layer of the dermis that is attached to the subcutaneous layer. dense irregular connective tissue, a few adipose cells, hair follicles, nerves, sebaceous glands and sudoriferous (sweat)glands.

Front 20

Capillary loops

Back 20

smooth muscle sphincters regulate blood flow. Normal conserve heat, blushing lose heat.

Front 21

Color of skin

Back 21

Melanin, hemoglobin, and carotene 3 pigments that create wide variety of skin colors.

Front 22

Hair

Back 22

aka pili, offers some protectin from injury and sun (head) decreases heat loss, protects eyes, ears, nose from foreign particles, sensing light touch

Front 23

hair shaft

Back 23

superficial portion of the hair which projects above the surface of skin

Front 24

hair root

Back 24

portion of hair deep to the shaft that penetrates into the dermis and sometimes into the subcutaneous layer.

Front 25

3 concentric layers of hair

Back 25

shaft and root have inner medulla layer, middle cortex, and the cuticle.

Front 26

hair follicle

Back 26

surrounds the root of the hair made up of an external root sheath and and internal root sheath together reffered to as an epithelial root sheath.

Front 27

bulb

Back 27

base of each hair follicle. houss the papilla of the hair (contains areolar tissue and blood vessels that nourish the growing hair. also contains a germinal layer of cells called the matrix.

Front 28

hair growth

Back 28

eash follicle goes through a growth stage and a resting stage. during growth cells of the matrix differentiate, keratinize and die as new cells are added at the base of the hair root it grows longer. after resting hair falls out and new hair begins to grow in its place.

Front 29

Sebaceous glands

Back 29

usually connected to hair follicles, secrete oil onto cuticle of hair. strengthen hair

Front 30

eccrine sweat glands

Back 30

sweat on to surface of skin, more common. located in the deep dermis sometimes the upper subcutaneous layer

Front 31

apocrine sweat glands

Back 31

sweat onto hair, armpits and groin, begin to function at puberty.

Front 32

Nails

Back 32

plates of tightly packed, hard, dead, keratinized epidermal cells.

Front 33

nail matrix

Back 33

deep to the nail root were cells divide by mitosis to produce growth

Front 34

nail root

Back 34

portion that is buried in a fold of skin

Front 35

epinychium

Back 35

aka cuticle a narrow band of epidermis that extends from and adheres to the margin of the nail wall

Front 36

hyponychium

Back 36

secures nail to fingertip

Front 37

nail growth

Back 37

cells divide by mitosis in the matrix, specialize into nail cells.

Front 38

superficial wounds

Back 38

only damage to the epidermis, doesn't bleed. cells in the stratum basale divide and migrate to cover the wound and the other layers are replaced from the stratum basale, a little pain b/c nerve projections in epidermis.

Front 39

deep wound healing

Back 39

when a wound extends to the dermis and subcutantious layer. 4 stages.

Front 40

Inflammatory phase

Back 40

blood clot forms, inflammation helps eliminate microbes, foreign material and dead cells. WBC, phagocytes migrate into area, blood vessels open up to get more blood flow to area.

Front 41

Migratory phase

Back 41

scab forms, migration of stratum basale, fibroblasts migrate, blood vessels grow. begins process of healing.

Front 42

Proliferative phase

Back 42

epithelial growth, random collagen, blood vessels grow.

Front 43

Maturation phase

Back 43

scab sloughs off. organized collagen, normal circulation.

Front 44

neutrophils

Back 44

phagocytic white blood cells. come during inflammatory phase

Front 45

monocyte

Back 45

develop into macrophages that phagocytize microbes. come during inflammatory phase

Front 46

first degree burn

Back 46

damage to epidermis

Front 47

second degree burn

Back 47

damage to dermis

Front 48

third degree burn

Back 48

damage to hypodermis and deeper tissues