Hsf: Skin

Front 1

Skin makes up _____ of the body weight.

Back 1

-16%

Front 2

Functions of Skin (7)

Back 2

-Maintains the integrity of body fluids; it prevents desiccation and injury to the body
-Keeps out most foreign material and microorganisms
-Protects the body from effects of ultraviolet rays of the sun
-Has mechanisms to cool the body when it is hot and to reduce loss of heat when the body is cold
-Helps regulate blood pressure by directing the blood flow
-Contains sensory nerve endings
-Synthesizes vitamin D

Front 3

2 Layers of Skin

Back 3

-Epidermis
-Dermis

Front 4

______ _____ underlies skin.

Back 4

-Subcutaneous Connective Tissue

Front 5

What is epidermis derived from?

Back 5

-Ectoderm

Front 6

What epidermis classified as?

Back 6

-Stratified squamous epithelium

Front 7

What is dermis derived from?

Back 7

-Mesoderm

Front 8

What does dermis form?

Back 8

-A thick, dense, layer consisting of collagen fibers (Type I), fibroblasts, blood vessels, nervous elements

Front 9

The primary cell of the epidermis is the _______.

Back 9

-kerationocyte

Front 10

Stratum Basale (def)

Back 10

-basal cell layer
-main site of keratinocyte proliferation

Front 11

Stratum Spinosum (def)

Back 11

-Cells migrate through this spinous cell layer
-Its where the intracellular bridges formed by desmosomes are particular apparent, into the granular cell layer

Front 12

Stratum Granulosum (def)

Back 12

-Granular cell layer
-Where accumulation of keratohyalin granules and lipid filled lamellar bodies fill the cells

Front 13

Stratum Corneum (def)

Back 13

-Consists of dead cells filled with keratin filaments

Front 14

The contents of the lamellar bodies is secreted into the extracellular spaces between the _______ _____ and the _____ _____.

Back 14

-Stratum Granulosum
-Stratum Corneum

Front 15

What represents a large component of the barrier function of the epidermis even though its the thinnest layer?

Back 15

-Stratum corneum

Front 16

Stratum Corneum Barrier: Cause

Back 16

-Due to insoluble proteins on the inner surface of the dead corneal cells
-Envelope of lipids attached to the cell by ester bonds

Front 17

Keratinocytes throughout the epidermis are tightly attached to each other by many, many _____.

Back 17

-desmosomes

Front 18

Hemidesmosomes in Skin

Back 18

-Enable firm attachment to the basement membrane zone

Front 19

How are the cells of the epidermis nourished?

Back 19

-Diffusion only

Front 20

Where is the melanocyte located?

Back 20

-Above the basement membrane zone in the basal layer

Front 21

Where do the melanocytes originate embryologically?

Back 21

-in the neural crest and migrate to the skin

Front 22

What do melanocytes produce?

Back 22

-Melanosome

Front 23

What takes up melanosome?

Back 23

-Keratinocyte

Front 24

The type of ______ determines the pigment of skin.

Back 24

-Melanosome

Front 25

Langerhans Cells (def)

Back 25

-bone marrow-derived macrophage-like cells which migrate into the epidermis
-make up 3% of epidermis

Front 26

Function of Langerhans Cells in Epidermis

Back 26

-Antigen recognizing cells

Front 27

The Langerhans cells migrate out of the ______ into the _____ ______ to induce an _____ ______

Back 27

-Epidermis
-Lymph nodes
-Immune Response

Front 28

Where is the basement membrane zone? What does it consist of?

Back 28

-Junction between the dermis and the epidermis
-Consists of typical basal lamina with underlying reticular fibers

Front 29

What does the basement membrane zone serve as?

Back 29

-To anchor epidermis to the dermis

Front 30

Skin Diseases that Damege Basement Membrane Zone

Back 30

-Result in loss of the epidermis and its barrier function over the affected area

Front 31

Papillary dermis (def)

Back 31

-upper part of dermis
-consists of relatively loose connective tissue, collagen and dense networks of elastic fibers
-Blood vessels and tactile elements (sensory receptors) of nervous tissue are present

Front 32

Reticular Dermis (def)

Back 32

-Below the papillary dermis
-Composed of thick collagen bundles running in all directions
-Blood vessels and lymphatics course through the reticular dermis
-No distinct boundary between the dermal layers

Front 33

______ ______ within the dermis help regulate body heat loss and blood pressure.

Back 33

-Blood vessels

Front 34

How do blood vessels accomplish its aid to the dermis?

Back 34

-Accomplished through arteriovenous shunts (control the flow of blood through the skin)--->large volumes of blood can be channeled through the skin=bringing it close to the surface for cooling, and increasing the vascular volume to decrease pressure

Front 35

What is the origin of hair?

Back 35

-Epidermal

Front 36

Hair Shaft (def)

Back 36

-Equivalent to the cornified layer, and consists of dead cells
-Arises form the hair root of living cells

Front 37

The hair and its root are contained in a ______ ______.

Back 37

-Hair follicle

Front 38

The hair acts as a duct for the _____ ______.

Back 38

-Sebaceous Gland

Front 39

What causes hair to lift?

Back 39

-contraction of the arrector pili muscle attached to the hair follicle

Front 40

What is the origin of nails?

Back 40

-Epidermal

Front 41

The nail is essentially a plate of ____ ______ that contain _____ ____.

Back 41

-Keratinized cells
-Hard keratin

Front 42

Sebaceous Sweat Glands (def)

Back 42

-Holocrine glands which produce sebum

Front 43

Sebum (def)

Back 43

-semi-liquid mixture of "fatty" product containing cholesterol, triglycerides and glandular-cell debris

Front 44

_____ ____ are generally attached to hair follicles, which act as ducts to convey the secretion to the surface.

Back 44

-Sebaceous glands

Front 45

Function of Sabeaceous Glands in Man

Back 45

-To lubricate the scalp and face
-Associated with acne in man

Front 46

The meibomian gland of the eyelid is a _____ ____.

Back 46

-Sabaceous gland

Front 47

Where do the apocrine sweat glands occur? (5)

Back 47

-Axilla
-Mons pubis
-Areola of the breast
-Circumanal area
(located deep in the subcutaneous tissue and usually open into a hair follicle)
-Scalp

Front 48

What do apocrine sweat glands secrete?

Back 48

-Apical portion of their cytoplasm
-After Puberty: yellowish, sticky fluid

Front 49

Why is yellowish, sticky fluid produced from the apocrine sweat glands?

Back 49

-In response to stress or sexual stimulation

Front 50

In other mammals, aprocrine sweat glands serve as ___________ and ______ ____.

Back 50

-Sex attractors
-Territorial Markers

Front 51

Name some modified Apocrine Glands (2)

Back 51

-External Auditory Meatus
-Moll's Gland

Front 52

Where are the arteries that supply blood to the skin?

Back 52

-In the Subcutaneous layer

Front 53

Arteriovenous Shunts (def)

Back 53

-Direct connections between arterial and venous circulation in skin
-Play important role in thermoregulation

Front 54

Innervation of Skin

Back 54

-Rich Nerve Supply=free nerve endings on almost all skin surfaces, and Meissner's corpuscles, and Pacinian corpuscles

Front 55

Meissner's corpuscles (def)

Back 55

-Discriminate sensation of touch

Front 56

Pacinian corpuscles (Def)

Back 56

-Discriminate the sensation of pressure

Front 57

Merkel Cells (def)

Back 57

-Specialized cells of the epidermis
-Form close associations with nerve endings

Front 58

The combination of epithelial cell and nerve ending form a type of ________.

Back 58

-Mechanoreceptor

Front 59

How is regeneration of skin accomplished?

Back 59

-By proliferation and migration of the keratinocytes over the injured space

Front 60

Skin Color: Components of a Healthy Person

Back 60

-Melanin: give shades of brown or black
-Hemoglobin
-Carotene

Front 61

Carotene (skin color indicates...)

Back 61

(from the diet)
-Gives the skin a yellowish color

Front 62

Hemoglobin (skin color indicates....)

Back 62

-reddish color when oxygenated or bluish color when de-oxygenated
-Dilated blood vessels increase redness, vasocontriction causes the skin to look pale