ME03 - Integumentary System

Question 1

What is the Dual Origins of the Skin

Answer 1

Epidermis (superficial layer) _ develops from surface ectoderm Dermis (deep layer) _ develops from the underlying mesenchyme

Question 2

What are the different GERM LAYERS

Answer 2

Ectoderm | Mesoderm | Endoderm

Question 3

On the Development of Epidermis

Answer 3

Initially, 5 weeks - ectodermal cells (cuboidal cells) 2 months: Periderm or epitrichium (Flat cells); Basal Layer (cuboidal in shape) Intermediate (3rd) zone End of 4th month - ***Horny layer is the outermost layer in the epidermis. - ***Granular layer_ - ***Spinous layer_ - ***Germinative Layer _ simple cuboidal epithelium. - ***Corium 2nd trimester (4-6 weeks) Cells of periderm are cast off; Found in the amniotic fluid.

Question 4

When are melanocytes seen

Answer 4

1st 3 months Epidermis is invaded by the cells arising from the neural crest.

Question 5

Function of melanocyte

Answer 5

This is the cell that produces melanin pigmentation, this is the one that gives color to the skin

Question 6

On the Development of Dermis

Answer 6

From mesenchyme__ Lateral plate mesoderm (limbs and body wall) Paraxial mesoderm__ Back_ Neural crest cells__ Face and Neck_ 3rd and 4th month Corium forms irregular papillary structures, dermal papillae. Dermal Papilla contains a capillary or sensory nerve end organ Subcorium (deeper layer) _ contains large amounts of fatty tissue.

Question 7

Whitish paste that covers the baby’s skin at birth

Answer 7

Vernixcaseosa

Question 8

Function of Vernixcaseosa

Answer 8

Protects the skin against macerating action of amnioting fluid

Question 9

On the DEVELOPMENT of the HAIR and SEBACEOUS GLAND

Answer 9

Solid epidermal proliferations(from ectoderm germ layer of the hair) penetrate underlying dermis Hair buds Hair buds invaginate >> Hair papilla _ Rapidly filled with mesoderm(smoothmuscle) = develop vessels/nerve endings ***Sebaceous _ ectoderm, epithelial

Question 10

Cells in center of hair buds become spindle-shaped and keratinized:

Answer 10

Hair shaft

Question 11

Peripheral cells become cuboidal:

Answer 11

Epithelial hair sheath

Question 12

Dermal root sheath and arrectorpili muscle are formed from?

Answer 12

Mesenchyme

Question 13

Smooth muscle attached to dermal root sheath

Answer 13

Arrector Pili

Question 14

Classification of Hair

Answer 14

Origin: Ectodermal Fundamental type: Epithelium Subtype: Glandular

Question 15

What pushes the hair upward?

Answer 15

Continuous proliferation of epithelial cells at base of shaft

Question 16

First hairs appear at eyebrow &upper lip develop in what month

Answer 16

End of 3rd month

Question 17

What do you call the first hairs?

Answer 17

Lanugo hair, shed at time of birth

Question 18

Small bud at epithelial wall of hair follicle form what gland

Answer 18

Sebaceous glands

Question 19

When cells from the gland degenerate. It produces what substance

Answer 19

Sebum - fatlike substance

Question 20

Sweat glands and mammary glands develop from _______

Answer 20

Epidermal proliferations

Question 21

Classification of Sebaceous Gland

Answer 21

MUCOUS: Oily secretion (Serous - water secretion)

Question 22

On the DEVELOPMENT of SWEAT GLANDS

Answer 22

Eccrine - Buds from germinative layer of the epidermis _ Apocrine - From same epidermal buds that produce hair follicles

Question 23

On the DEVELOPMENT of NAILS

Answer 23

_ Ectodermal thickening in the dorsum of digits _ Nail fields, surrounded by nail folds

Question 24

Largest organ, 15-20%; Integument, Cutaneous covering. Basically the organ of Integumentary System

Answer 24

Skin

Question 25

Function of SKIN

Answer 25

Protection _ UV light Excretion - perspiration Sensory - touch Thermoregulation _ adipose tissues Metabolic _ Vitamin D Sexual signaling _ for animals

Question 26

What are the main layers of SKIN

Answer 26

\_ Epidermis - self generating stratified squamous epithelium |Produces surface layer of the CHON KERATIN Dermis _ layer of fibrocollagenous and elastic tissue - contains blood vessels, nerves, and sensory receptors \*\*\*Papillary layer is lighter in staining. \*\*\*Reticular Layer

Question 27

Surface epithelium | Germinal basal layer mitosis

Answer 27

EPIDERMIS

Question 28

ACTIVITIES/Function in the Epidermis

Answer 28

Production of keratin - "keratinocytes" _ Rate of mitosis = Rate of desquamation| 15-30 days, 25 to 50 days

Question 29

What are the sublayers of EPIDERMIS

Answer 29

Stratum CL GraSba (Corneum, Lucidum, Granulosum, Spinosum, Basale)

Question 30

[Sublayers of Epidermis] Germinal layer _ Constant supply of new keratinocytes _ Mitotic figures

Answer 30

Stratum basale

Question 31

Describe the cells, Nucleus and Cytoplasm of Stratum Basale

Answer 31

Cells: simple cuboidal or low columnar in a single layer separated from Dermis\_basement membrane bound by \_hemidesmosomes \*\*\*Hemidesmosomes _ attachment of cell to the basement membrane _ Nucleus: large, round or oblong _ Cytoplasm: basophilic

Question 32

[Sublayers of Epidermis] Layer that has cuboidal to polygonal cells Presence of Cytokeratin (synthetic fibrillar protein) aggregates to form tonofibrils (intracellular fibrils) Tonofibrils converge upon desmosomes

Answer 32

Stratum spinosum

Question 33

Describe the cells, Nucleus and Cytoplasm of Stratum Spinosum

Answer 33

Large, cuboidal to polygonal, some flattened cells _ with large pale staining nuclei and prominent nucleoli (indicator of their active CHON synthetic function) _ bound by desmosomes to adjacent cells Central nucleus _ Cytoplasmic basophilia

Question 34

Sublayers of Epidermis that at the surface, granular layer cells lose their nuclei and cytoplasm, leaving the masses of formed keratin

Answer 34

Stratum Granulosum

Question 35

Describe the cells, Nucleus and Cytoplasm of Stratum Granulosum

Answer 35

2-3 rows of flattened cells(more flattened when near the surface) _ Nucleus: central _ Cytoplasm filled with numerous \_keratohyaline\_, coarse basophilic granules(contain Sulphur containing amino acids such as Cysteine)

Question 36

What makes up the KERATIN

Answer 36

Tonofibrils + K eratohyaline = KERATIN

Question 37

Sublayers of Epidermis Layer where there are few layers of compacted highly refractileeosinophilic cells It has a Wavy clear strip

Answer 37

Stratum Lucidum

Question 38

Describe the cells, Nucleus and Cytoplasm of Stratum Lucidum

Answer 38

Non-evident organelles & nuclei _ Cytoplasm contain dense packed filaments in a matrix called \_Eleidin\_ | Desmosomes are still seen

Question 39

Sublayers of Epidermis Layer of skin where there the most superficial layer slough off or \_desquamates\_ _ Desquamation: preceded by disruption of desmososmes and internal structure of cells | Filled with mature keratin _ Squamous plates or scales fused together o Plates are remnants of cells that contain keratin

Answer 39

Stratum Corneum

Question 40

Describe the cells, Nucleus and Cytoplasm of Stratum Corneum

Answer 40

Dead and dying cells _ Flat and cornified cells; anucleated _ Filled with mature keratin

Question 41

Structural changes in keratinization involve the following:

Answer 41

Aggregation and arrangement of filaments _ Formation of keratohyaline granules _ Loss of organelles as a result of accumulation of granule

Question 42

Attachment of cell to the basement membrane

Answer 42

Hemidesmosomes

Question 43

Attachment of cell to another cell

Answer 43

Desmosomes

Question 44

What are the Differences between thin and thick Skin

Answer 44

THICK SKIN (Palms and Soles) 5 layers of Epidermis including Stratum lucidum Presence of Sweat Glands Hair follicle, Arrector Pili Muscle and Sebaceous glands are absent THIN SKIN (Rest of the Body) 4 layers of Epidermis Presence of Sweat Glands, Hair follicle, Arrector Pili Muscle, Sebacous glands and Sweat glands

Question 45

What are the different cells of Epidermis

Answer 45

Keratinocytes Melanocytes Langerhans Cells Merkel Cells

Question 46

\_ Principal cells/ parenchyma _ Synthesize keratin: a family of polypeptides with 40,000 to 70,000 m.w. _ Contain hydrophobic glycolipid _ Responsible for water repellant characteristic

Answer 46

Keratinocytes

Question 47

Lamellated pale staining ovoid bodies

Answer 47

Keratinosomes/Odland Bodies

Question 48

Cell responsible for the Synthesis and release of the brown pigment \_melanin\_ _ Located scattered infrequently in the basal layer & junction of dermis _ Round cells with pale-staining cytoplasm _ From cell body _ long cytoplasmic processes, run in spaces between keratinocytes of stratum spinosum

Answer 48

Melanocytes

Question 49

Enzyme synthesized from Tyrosine by melanocyte within specific cytoplasmic organelles called melanosomes FOR MELANIN SYNTHESIS

Answer 49

Tyrosinase

Question 50

Areas in the Body where melanocytes are numerous

Answer 50

More numerous in areas more exposed to sunlight (such as face) More active in dark skinned people.

Question 51

Dendritic cells _ Present in all layers of epidermis especially stratum spinosum _ Also around blood vessels in papillary dermis _ Pale-staining cytoplasm, extends as cytoplasmic processes between keratinocytes

Answer 51

Langerhans Cells

Question 52

Rod-like granules with regular cross- striations, one end distends in a vesicle (tennis racket) found in Langerhans Cells

Answer 52

Birbeck granules

Question 53

Function of Birbeck granules

Answer 53

Antigen-presenting cells, for contact allergic and other cell -mediated response Also play an important role in Rejection Mechanisms in skin allograft.

Question 54

Specialized touch receptors _ Scattered sparsely among basal cell layer _ Difficult to distinguish from melanocytes _ Presence of dense cored vesicles in the cytoplasm

Answer 54

Merkel Cells

Question 55

Function of Merkel Cells

Answer 55

paraneurons involved in sensory reception

Question 56

Provides a flexible but strong base for the epidermis Binds to the hypodermis Function : Thermoregulation

Answer 56

DERMIS

Question 57

Two zones of DERMIS

Answer 57

Two zones _ Papillary _ Reticular - Composed of bundles of collagen fibers and strands of elastic fibers - Responsible for tone and texture of the skin

Question 58

An important constituent of both Papillary and Reticular zones Long and thick in reticular, and follow course of collagen fibers Very fine, scanty, scarcely stained in papillary

Answer 58

Elastin | Black against red stained collagen

Question 59

Cellular components found in the DERMIS

Answer 59

Fibroblasts Lymphocytes Mast cells Tissue macrophages

Question 60

Loose connective tissue of DERMIS Consists of small, highly sensitive, vascular papillae Each papilla, made of very fine interlacing collagen fibers with few elastic fibers

Answer 60

Papillary Dermis

Question 61

Contents of Papillary Dermis

Answer 61

Venules Arterioles Capillary loops Lymphatics Fine nerve twigs from Meissner\_s corpuscles

Question 62

Dense irregular connective tissue Coarse, irregular bundles of collagen Fibroelastic Blood vessels are larger and deeper Cells are mainly fibroblasts and histiocytes

Answer 62

Reticular Dermis

Question 63

\_ Subcutaneous layer of loose connective tissue beneath the dermis _ Aka subcutaneous tissue, subcutis, or superficial fascia _ Binds skin loosely to subjacent organs _ Not a part of the skin proper _ Mainly adipose tissue

Answer 63

Hypodermis | _ Panniculusadiposus

Question 64

What are the different skin appendages

Answer 64

\_ Hairs _ Sebaceous glands _ Sweat glands _ Nails

Question 65

Highly modified keratinized structures Produced by hair follicles

Answer 65

Hair

Question 66

A terminal expansion of the follicle where hair growth takes place

Answer 66

Hair bulb

Question 67

Vascular Tissue in Hair

Answer 67

Dermal Papilla

Question 68

Secrete an oily substance called sebum _ Embedded in the dermis except in areas lacking hairs

Answer 68

Sebaceous glands

Question 69

Classify Sebaceous glands

Answer 69

Holocrine, Mucous secretion, Simple branched alveolar glands

Question 70

Function of Sebaceous glands

Answer 70

Lubricates the epidermis and hair

Question 71

Relationship between hair follicle, sebaceous gland, and arrector pili:

Answer 71

Smooth muscle form arrector pilimuscle; obliquely placed in relation to epidermis _ Contraction of muscle = erection of hair shaft (and follicle), producing depressions in the skin (orange peel appearance) known as gooseflesh

Question 72

Compression of sebaceous glands aids in emptying glands into hair follicle, oiling the hair shaft. True or False?

Answer 72

True.

Question 73

A mixture of triglycerides, waxes, squalene, and cholesterol & its esters and remnants of degenerating/dead cells

Answer 73

Sebum

Question 74

Sudoriferous glands Important in thermoregulation React by secreting in stressful situations

Answer 74

Sweat Glands

Question 75

Classify Sweat Glands

Answer 75

Simple, coiled tubular glands

Question 76

Function of Sweat Glands

Answer 76

Act as an excretory organ by eliminating metabolic waste products. Secrete watery fluid, ammonia, sodium, chloride, urea, and uric acid by merocrine process Discharge directly into the skin surface

Question 77

What are the secretory and excretory portions of an Eccrine sweat gland

Answer 77

Secretory portions:Single layer of large cuboidal or columnar cells Excretory ducts: Two layers of smaller cuboidal cells; Narrower lumen

Question 78

What are the cells seen in Eccrine sweat glands

Answer 78

Myoepithelial cells: Between secretory cells and basement membrane ; Contraction expels sweat into ducts

Question 79

Found in the axillae, areola, inguinal, and genital regions Viscid, milky secretion which, when acted upon by bacteria, produces an objectionable odor. Discharge into hair follicles Begin functional activity at puberty

Answer 79

Apocrine Sweat Glands

Question 80

What activates Apocrine Sweat Glands

Answer 80

Activated by adrenergic nerves; secretion increased by emotional stress.

Question 81

What is the secretory part of Apocrine Sweat Gland

Answer 81

Secretory portion _ Coiled tubular type _ Widely dilated lumen _ Low cuboidal cells _ Eosinophilic cytoplasm

Question 82

A highly specialized appendage

Answer 82

Nail

Question 83

Consists of dense keratinized plate

Answer 83

Nail plate

Question 84

Rests on a stratified squamous epithelium

Answer 84

Nail bed

Question 85

Proximal end of the nail

Answer 85

Nail root

Question 86

Underlying nail root; where nail growth occurs

Answer 86

Nail matrix

Question 87

White crescent shape at base of nail

Answer 87

Lunula

Question 88

Skin overlying root of nail

Answer 88

Nail fold

Question 89

Highly keratinized free edge

Answer 89

Eponychium

Question 90

Skin beneath free end of nail

Answer 90

Hyponychium

Question 91

What are the different clinical correlations with the Integumentary System

Answer 91

Eczema | Urticaria | Contact dermatitis | Acne vulgaris | Psoriasis | Vitiligo | Nexus | Freckles | Melanoma | Carcinoma

Question 92

What clinical presentation is this?

Answer 92

Acne vulgaris

Question 93

What clinical presentation is this?

Answer 93

Carcinoma

Question 94

What clinical presentation is this?

Answer 94

Contact Dermatitis

Question 95

What Clinical Presentation is this