Question 1

The epidermis is composed of a {{c1::keratinized stratified squamous epithelium}}, derived from {{c1::ectoderm}}.

Accepted Answer

(picture)

Question 2

Skin is categorized as thick or thin, depending on the thickness of the {{c1::epidermis}}.

Accepted Answer

(picture)

Question 3

Describe various layers and cells of {{c1::epidermis}} and {{c1::dermis}}.

Accepted Answer

(picture)

Question 4

Thin skin has {{c1::4}} layers, while thick skin has {{c1::5}} layers.

Accepted Answer

(picture)

Question 5

The epidermis is composed of {{c1::stratified squamous epithelium}}.

Accepted Answer

(picture)

Question 6

Describe the structure and functions of {{c1::skin}}.

Accepted Answer

(picture)

Question 7

The skin provides {{c1::immunologic information}} obtained during antigen processing to the appropriate effector cells in the lymphatic tissue.

Accepted Answer

(picture)

Question 8

7-dehydrocholesterol is synthesized from {{c1::cholesterol}}.

Accepted Answer

(picture)

Question 9

7-dehydrocholesterol is converted to vitamin D3 ({{c1::Cholecalciferol}}) by sunlight.

Accepted Answer

(picture)

Question 10

In the light microscope, stratum lucidum often has a {{c1::refractile appearance}} and may stain poorly.

Accepted Answer

(picture)

Question 11

Finger-like connective tissue protrusions, {{c1::dermal papillae}}, project into epidermis.

Accepted Answer

(picture)

Question 12

Sebaceous glands are a {{c1::Holocrine}} type of gland.

Accepted Answer

(picture)

Question 13

The secretory segment of eccrine sweat glands is located deep in the {{c1::dermis}} or in the upper part of the {{c1::hypodermis}}.

Accepted Answer

(picture)

Question 14

The melanocyte has long dendritic processes that contain accumulated {{c1::melanosomes}} and extend between the cells of the epidermis.

Accepted Answer

(picture)

Question 15

Malignant melanoma is the most serious form of skin cancer. Individual melanoma cells, which originate from melanocytes, contain large nuclei with {{c1::irregular contours}} and prominent {{c2::eosinophilic nucleoli}}.

Accepted Answer

(picture)

Question 16

The skin acts as a {{c1::barrier}} that protects against physical, chemical, and biologic agents in the external environment.

Accepted Answer

(picture)

Question 17

The thickness of the skin varies from less than {{c1::1}} mm to more than {{c1::5}} mm.

Accepted Answer

(picture)

Question 18

Langerhans’ cells are {{c1::dendritic}}-appearing, {{c1::antigen-presenting}} cells in {{c1::stratum spinosum}}.

Accepted Answer

(picture)

Question 19

The {{c1::infundibulum}} extends from the surface opening to the level of the opening of its sebaceous gland.

Accepted Answer

(picture)

Question 20

Under the nail is a layer of epithelium, the proximal portion of which is referred to as the {{c1::nail matrix (NM)}}.

Accepted Answer

(picture)

Question 21

Stratum corneum consists of anucleate squamous cells filled with {{c1::keratin filaments}}.

Accepted Answer

(picture)

Question 22

Keratinocytes in the stratum spinosum begin to produce {{c1::keratohyalin granules}} and membrane bounded {{c2::lamellar bodies}}.

Accepted Answer

(picture)

Question 23

The organization of intercellular lipid lamellae is responsible for the formation of the {{c1::epidermal water barrier}}.

Accepted Answer

(picture)

Question 24

Stratum lucidum is only seen in {{c1::thick skin}}.

Accepted Answer

(picture)

Question 25

Stratum granulosum is the most superficial layer of the {{c1::nonkeratinized}} portion of epidermis.

Accepted Answer

(picture)

Question 26

The internal root sheath consists of {{c1::Henle’s layer}}, {{c2::Huxley’s layer}}, and {{c3::cuticle of internal root sheath}}.

Accepted Answer

(picture)

Question 27

Basal cells are connected to each other and to the supra-basal keratinocytes by {{c1::desmosomes}}.

Accepted Answer

(picture)

Question 28

Melanin is produced by the oxidation of tyrosine to {{c1::3,4-dihydroxyphenylalanine (DOPA)}} by tyrosinase and the subsequent transformation of DOPA into melanin.

Accepted Answer

(picture)

Question 29

The skin is the {{c1::largest}} organ, constituting {{c1::15-20}} percent of its total body mass.

Accepted Answer

(picture)

Question 30

Stratum spinosum is several cells thick, made of {{c1::Keratinocytes}}.

Accepted Answer

(picture)

Question 31

Because of their appearance, the cells in this layer are known as {{c1::prickle cells}}.

Accepted Answer

(picture)

Question 32

Melanocyte is a dendritic cell that is scattered among the basal cells of the stratum {{c1::basale}}.

Accepted Answer

(picture)

Question 33

Keratinocytes in this layer contain numerous {{c1::keratohyalin granules}}.

Accepted Answer

(picture)

Question 34

Junction between the epidermis and dermis (epidermal–dermal junction) is seen in the light microscope as an {{c1::uneven}} boundary.

Accepted Answer

(picture)

Question 35

Merkel’s cells are dendritic cells located in the {{c1::stratum basale}}.

Accepted Answer

(picture)

Question 36

Apocrine gland has a duct that opens into {{c1::follicle canal}}.

Accepted Answer

(picture)

Question 37

The hair shaft consists of the {{c1::medulla}}, {{c2::cortex}}, and {{c3::cuticle of hair shaft}}.

Accepted Answer

(picture)

Question 38

Keratinocytes phagocytose the tips of the melanocyte processes containing the melanosomes, the process is {{c1::pigment donation}}.

Accepted Answer

(picture)

Question 39

One keratinocyte exhibits a {{c1::keratohyalin granule (KG)}}.

Accepted Answer

(picture)

Question 40

Dermis is composed of two layers: the {{c1::papillary layer}} (PL) and the {{c1::reticular layer}} (RL).

Accepted Answer

(picture)

Question 41

Sebaceous glands secrete {{c1::sebum}} that coats the hair and skin surface.

Accepted Answer

(picture)

Question 42

Eccrine sweat glands are independent structures, not associated with the {{c1::hair follicle}}.

Accepted Answer

(picture)

Question 43

The concentric cellular lamellae of the Pacinian corpuscle are visible because of {{c1::flat, fibroblast-like supportive cells}}.

Accepted Answer

(picture)

Question 44

Much of the keratinocyte cytoplasm is filled with {{c1::tonofilaments}}.

Accepted Answer

(picture)

Question 45

{{c1::Merkel’s}} corpuscles

Accepted Answer

(picture)

Question 46

Vitiligo is frequently associated with disorders of {{c1::autoimmune origin}}, with thyroid abnormalities being the most common.

Accepted Answer

(picture)

Question 47

Epidermis consists mainly of a stratified squamous keratinized epithelium composed of cells called {{c1::keratinocytes}}.

Accepted Answer

(picture)

Question 48

Langerhans’ cells are part of the {{c1::mononuclear phagocyte system}} and do not form {{c1::desmosomes}} with keratinocytes.

Accepted Answer

(picture)

Question 49

Apocrine glands become {{c1::functional}} at {{c1::puberty}}.

Accepted Answer

(picture)

Question 50

Stratum basale (aka stratum germinativum) is a single layer of {{c1::columnar or cuboidal}} cells.

Accepted Answer

(picture)

Question 51

ABCDE rule for Melanoma: Asymmetrical shape of skin lesion, Border of the lesion is {{c1::irregular}}, Color variations; melanomas usually have {{c2::multiple}} colors, Diameter of skin lesion; moles greater than {{c3::6}} mm are more likely to be suspicious, Evolving: change in mole appearance.

Accepted Answer

(picture)

Question 52

Epidermal {{c1::free endings}}

Accepted Answer

(picture)

Question 53

Vitiligo is an acquired pigmentary disorder of the skin that is characterized by circumscribed, {{c1::depigmented}} macules and patches.

Accepted Answer

(picture)

Question 54

Merkel cell carcinoma (MCC) is a rare but highly {{c1::aggressive}} type of skin cancer.

Accepted Answer

(picture)

Question 55

Hair follicle is divided into {{c1::three}} regions.

Accepted Answer

(picture)

Question 56

Nails are plates of {{c1::keratinized}} cells containing hard keratin.

Accepted Answer

(picture)

Question 57

Lack of pigmentation occurs in {{c1::albinism}}. In this hereditary condition, premelanosomes are produced by melanocytes, but because of the absence of {{c1::tyrosinase}}, the transformation of tyrosine into 3,4-dihydroxyphenylalanine (DOPA) and the subsequent transformation of DOPA into melanin fail to occur.

Accepted Answer

(picture)

Question 58

Melanocytes are derived from {{c1::Neural crest cells}}.

Accepted Answer

(picture)

Question 59

Papillary layer consists of {{c1::loose connective tissue}} and is located immediately underneath the {{c1::epidermis}}.

Accepted Answer

(picture)

Question 60

Eccrine sweat gland has a duct that opens on the {{c1::surface}}.

Accepted Answer

(picture)

Question 61

Three less abundant epidermal cell types: pigment-producing {{c1::melanocytes}}, antigen-presenting {{c1::Langerhans cells}}, tactile epithelial cells or {{c1::Merkel cells}}.

Accepted Answer

(picture)

Question 62

Apocrine glands are large-lumen tubular glands associated with {{c1::hair follicles}}.

Accepted Answer

(picture)

Question 63

Three Meissner’s corpuscles are shown residing within the {{c1::dermal papillae}}.

Accepted Answer

(picture)

Question 64

Usually, an abrupt transition occurs between the nucleated cells of the stratum granulosum and flattened, desiccated, anucleate cells of the {{c1::stratum corneum}}.

Accepted Answer

(picture)