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Histology > Skin > Flashcards

Skin Flashcards

1
Q

What basis of study would crime scene investigators use to capture the large and unique dermal ridges of the suspect?

A

dermatoglyphics

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2
Q

What three processes occur during the acute to subacute phase change in first intention healing?

A

neovascularization
fibroplasia
re-epithelialization

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3
Q

How are antlers different than horns?

A

antlers have a bony core; horns come from keratin from a horn bud

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4
Q

What are the 3 layers of the skin, superficial to deep?

A

epidermis
papillary layer of dermis
reticular layer of dermis
hypodermis

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5
Q

Thick skin has a thick ___ layer.

A

cornified

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6
Q

In inflammation more intense in first intention wound or second intention wound healing? Why?

A

second intention; because there is more necrotic debris, exudate, and fibrin to be removed

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7
Q

Which layer of the dermis is thicker and less cellular?

A

deep reticular layer

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8
Q

What type of melanin is present in individuals with dark or brown hair?

A

eumelanin

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9
Q

Which glands are alveolar, holocrine glands consisting of branches acini?

A

sebaceous glands

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10
Q

Which glands develop at puberty?

A

apocrine glands

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11
Q

As epithelial cells mature, they fill with ___ and die.

A

keratin

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12
Q

What are the sphincters called in arterioles?

A

glomus bodies

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13
Q

Birds and reptiles produce ___ keratins and are found in things like feathers, claws, scales, and beaks.

A

beta

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14
Q

What determines the overall length of hair on the body?

A

the ratio of growth between the active growth and resting phases

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15
Q

Where would you find the most Meissner’s corpuscles?

A

in the hands, feet, lips, and genitalia

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16
Q

What coating on the surface of skin cells forms a mature waterproof layer?

A

glycolipid coating exocytosed from keratinized cells

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17
Q

What is the dermis composed of?

A

dense irregular collagenous connective tissue (Type I collagen) with elastic fibers

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18
Q

What represents the interaction between keratohyaline granules and tonofibrils?

A

process of keratinization

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19
Q

What is the most common form of hair loss?

A

androgenic alopecia

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20
Q

What happens if the neonate does not ingest the colostrum?

A

increased chance of death due to infection due to decreased maternal antibodies

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21
Q

The ____ is lined by actively dividing epithelial cells (like the stratum basale).

A

root bulb

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22
Q

Which types of skin cancers are derived from epithelial cells?

A

squamous cell carcinoma

basal cell carcinoma

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23
Q

In the animal kingdom, what are apocrine glands used for?

A

sexual attractant pheromones

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24
Q

Which type of laceration would heal with less scarring?

A

skin incisions or lacerations parallel to Langer’s lines

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25
Q

Where would you find the subcutaneous plexus?

A

deep within the hypodermis

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26
Q

Under what hormone control is melanin synthesis under?

A

pituitary hormone (melanocyte stimulating hormone)

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27
Q

What does the deep reticular layer of the dermis interdigitate with?

A

the subcutis (underlying hypodermis)

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28
Q

Besides pigmentation, where else is melanin important?

A

it is necessary for normal neural development

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29
Q

What is the deepest layer of the epidermis?

A

stratum basale (stratum germinativum)

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30
Q

Where do melanocytes originate from?

A

neuroectoderm (neural crest origin) dendritic cells present in epidermis

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31
Q

Mammary glands are highly modified ____.

A

apocrine glands

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32
Q

Straight hair is more ____ in cross-section; wavy hair is more ____ in cross-section; curly hair is more ____ in cross-section.

A

round; oval; flattened

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33
Q

Where does adrenergic sweating begin on the body?

A

palms and soles of feet

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34
Q

What sensory receptor is the most numerous in the skin?

A

free nerve endings

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35
Q

Where would you find Langer’s lines?

A

in the reticular layer of the epidermis

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36
Q

What is it called when cells mature from the stratum basale to the stratum corneum in wound repair?

A

keratinization

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37
Q

____ healing occurs when wound edges are not able to be approximated and may contain extensive loss of tissue.

A

Second intention

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38
Q

What is the superficial portion of a hair follicle called?

A

infundibulum

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39
Q

What is the developing hair surrounded by?

A

internal and external root sheath

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40
Q

In people with albinism, ____ form but do not mature.

A

premelanosomes

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41
Q

What are the phases of hair growth?

A

anagen
catagen
telogen
exogen

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42
Q

____-skinned individuals produce less pigment or digest pigment faster.

A

Lighter

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43
Q

What type of nerve fibers do Meissner’s and Pacinian corpuscles possess?

A

afferent nerve fibers (surrounded by modified Schwann cells - more modified in PC)

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44
Q

Under what influence do mammary glands in females develop?

A

pituitary and ovarian hormones

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45
Q

What is an example of modified apocrine glands in the ear?

A

ceruminous wax glands (secrete cerumen)

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46
Q

Where would you find vellus hair?

A

fine body hair of women and children

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47
Q

Why do we make melanin?

A

because DNA is subject to damage by UV and melanin functions as a shield to prevent mutagenesis

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48
Q

What are the layers of the epidermis, from superficial to deep?

A 
stratum corneum
stratum lucidum (thick skin)
stratum granulosum
stratum spinosum
stratum basale
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49
Q

Where does melanin go?

A

it is taken up by surrounding epidermal cells

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50
Q

Why are Demodex mites helpful?

A

they keep hair follicles clear which prevents sebum buildup and potential acne

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51
Q

What layer of the epidermis is continuously exfoliated or desquamated?

A

stratum corneum

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52
Q

What initiates keratinization?

A

the rupture of lysosomes and release of lysosomal enzymes; rupture of keratohyaline granules + polymerization of contents

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53
Q

Are the collagen bundles in he dermis randomly oriented?

A

NO - follow lines of tension

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54
Q

__ are used in thermoregulation, especially in the periphery of the body.

A

Vascular plexi

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55
Q

Hair, nails, sebaceous glands, sweat glands, and horns are all considered ___.

A

skin appendages

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56
Q

____-skinned individuals produce more pigment and retain more pigment longer.

A

Darker

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57
Q

Where do mammary ridges or milk lines extend from?

A

from axillae to groin

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58
Q

Why do tattoos “blur” and fade?

A

because macrophages come along to digest the ink but cannot, so they die and another macrophage comes along. These macrophages do not remain in the same position so the lines of tattoo ink become slightly blurred as macrophages get replaced.

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59
Q

The ___ is the darkly pigmented, ridged region around the nipple and contains numerous glands (merocrine, sebaceous).

A

areola

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60
Q

How many sebaceous glands are associated with a hair follicle?

A

one or more (develop as outgrowths of external root sheath)

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61
Q

Where is hair absent from?

A

thick skin of palms and soles of feet

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62
Q

What is the nail lunula covered by?

A

the cuticle or eponychium

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63
Q

What exfoliated layer of the skin makes up the bulk of house dust and dandruff?

A

stratum corneum dead cells

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64
Q

What type of sensory receptors look like melanocytes and are located in stratum basale?

A

Merkel cells

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65
Q

What is first intention healing from?

A

a clean, surgical incision

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66
Q

What enzyme do people affected with albinism possess?

A

tyrosinase

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67
Q

After birth, what is the secretory product of the mammary glands for the first few days?

A

colostrum

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68
Q

Which cell layer is characterized by keratohyaline granules?

A

stratum granulosum

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69
Q

What is gray hair the result of?

A

decreased melanin production or even air bubbles

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70
Q

These glands contain proteins, carbohydrates, ammonia, lipids and organic products.

A

apocrine glands

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71
Q

What is the nail bed called?

A

hyponichium

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72
Q

These unbranched, tubular glands have 1-2 layers of cuboidal or columnar epithelium with excretory ducts.

A

merocrine/eccrine glands

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73
Q

What burn involves only the epidermis?

A

1st degree burn

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74
Q

How can you distinguish an amelanotic melanoma from a squamous cell carcinoma or basal cell carcinoma?

A

by using a stain for tyrosinase
(+) = melanocytes
(-) = not melanocytes

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75
Q

How is tyrosinase useful in tumor identification?

A

tyrosinase can be used as a marker in tumor cells to differentiate between melanocytes and keratinocytes containing phagocytosed melanin

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76
Q

Which keratins are more delicate?

A

alpha

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77
Q

These glands have coiled, tubular glands with large dilated lumina.

A

apocrine glands

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78
Q

Demodex mites feed on ___ secretions.

A

sebaceous gland

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79
Q

What is one of the most common causes of acne?

A

hypertrophy

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80
Q

Where would you find free nerve endings in the skin?

A

in the epidermis and papillary dermis

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81
Q

Which layer of the epidermis has spiny, prickly-looking cells?

A

stratum spinosum

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82
Q

What does a pilosebaceous unit consist of?

A

a hair follicle, associated arrector pili muscle, and sebaceous gland

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83
Q

Wound repair if often referred to as what?

A

re-epithelialization

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84
Q

What is hair made of?

A

dead keratin

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85
Q

What are mammary glands drained by?

A

drained into the terminal ducts&raquo_space; lactiferous ducts&raquo_space; lactiferous sinus (in nipple)

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86
Q

In first intention healing, when do neutrophils infiltrate the clot?

A

within 3-24 hours (acute phase)

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87
Q

What layer of the dermis contains hair follicles, sweat glands and sebaceous glands?

A

deep reticular layer

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88
Q

Where is the nail matrix?

A

underneath the lunula (white crescent) at the base of the nail

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89
Q

What prevents shear and mechanical abrasion of the skin?

A

the corrugations in the attachment area between the epidermis and papillary layer

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90
Q

How does the sebaceous gland release its contents?

A

by secreting the entire cells in its duct

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91
Q

The two layers of the dermis are ___ and ___.

A

superficial papillary layer; deep reticular layer

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92
Q

What is the inactive resting phase of hair growth called?

A

telogen

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93
Q

What are “goosebumps” caused by sympathetic stimulation due to cold, fear, or aggression?

A

piloerection

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94
Q

The internal root sheath corresponds to the ___ of the skin.

A

stratum corneum

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95
Q

During ___, fibroblasts produce collagen that migrate into the wound.

A

fibroplasia

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96
Q

What are the flattened, enucleate, dead cell remnants of skin cells?

A

squames

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97
Q

At the base of the bulb is a ____, which is an invagination of dermis containing blood vessels.

A

vascular core (dermal papilla)

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98
Q

___ are derived from the neural crest and are pressure-sensitive mechanoreceptors.

A

Merkel cells

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99
Q

What causes thick “caterpillar” eyebrows in older men?

A

the missed telogen (rest) phase of the hair growth cycle

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100
Q

What does the proximal end of the nail, the “nail root,” attach to?

A

the periosteum of distal phalanx

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101
Q

How does your body retain heat in cold temperatures?

A

by bypassing heat-releasing capillary beds with AV shunts

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102
Q

Where does hair growth occus?

A

deep within the terminal expansion of the follicle “root bulb”

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103
Q

What is indicative of a change in phagocytic cells?

A

the transition from acute to subacute phase

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104
Q

____ is an alkaline, yellowish secretion with high protein and salt content, low lipid and carbohydrate content and many antibodies.

A

Colostrum

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105
Q

Where and how is sweat secreted?

A

onto the skin surface; via a sweat pore

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106
Q

Which sensory receptor lacks connective tissue capsule and associated Schwann cells?

A

free nerve endings

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107
Q

Where do new keratinocytes come from?

A

from the deep germinal layer (matured in 25-50 days)

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108
Q

What hair is certain vellus hair replaced with at puberty?

A

terminal hair

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109
Q

Why do we suture wounds?

A

to attempt to turn a second intention wound healing process into a first intention wound healing process

110
Q

These glands only secrete product.

A

merocrine/eccrine

111
Q

What forces the shunting of blood around the capillaries?

A

thickened regions of smooth muscle (sphincters) in the walls of arterioles called glomus bodies - when they contract they force blood into AV shunts

112
Q

How long does it take to replace a fingernail? A toenail?

A

3 months; 9 months

113
Q

Where does the oxidation of a tyrosine precursor to DOPA occur?

A

premelanosomes

114
Q

____ forms tonofilaments which aggregate into larger tonofibrils and anchor to desmosomes.

A

Cytokeratin

115
Q

Why would a surgeon choose to make an incision along a tension line?

A

so it will heal with less scarring

116
Q

What happens to collagen in an individual with a vitamin C deficiency?

A

collagen breaks down; old scars can re-open and bleed

117
Q

Is sweating a form of excretion? Why or why not?

A

YES - because sweat contains urea and uric acid

118
Q

What sensory receptors does the skin contain?

A

touch, pressure, pain and temperature

119
Q

Why is waxing not permanent?

A

it removes the hair follicle but does not remove the germinal layer that exhibits growth

120
Q

What are the 4 main functions of skin?

A

protection
sensation
thermoregulation
metabolic functions

121
Q

A raised, thickened scar from excess fibroplasia during healing is called a what?

A

keloid

122
Q

An infarct, ulcer or abscess would heal through ____ healing.

A

second intention

123
Q

What layers of skin do hair follicles originate in?

A

dermis (and sometimes hypodermis)

124
Q

During first intention healing when is the incision filled with granulation tissue?

A

day 5

125
Q

What phase of hair growth signals the end of active growth?

A

catagen

126
Q

In individuals with androgenic alopecia, what enzyme do they have high levels of?

A

5-a-reductase (causes follicular atrophy)

127
Q

What do Pacinian corpuscles detect?

A

mechanical and vibratory pressure

128
Q

What contributes to the itching experienced during wound healing?

A

presence of inflammatory cells and their products

129
Q

What raises the hair follicles by attaching to the sheath and epidermal ridges?

A

arrector pili muscles

130
Q

What kind of lamellar structures contain glycolipids and provide waterproofing coat for skin cells?

A

keratinosomes (Odland bodies)

131
Q

Is the dermis vascular?

A

highly (many sensory receptors)

132
Q

Why do we “tan?”

A

because exposure to UV light stimulates melanin synthesis (via MSH)

133
Q

Where is the hair growth phase long but the resting phase short?

A

scalp

134
Q

These glands have a secretory, cuboidal epithelium that is 2-3 cell layers thick and surrounds a large lumen.

A

apocrine glands

135
Q

What is the purpose of sebum?

A

waterproofing and moisturizing skin and hair

136
Q

Where would you not find merocrine glands?

A

the lips and genitalia

137
Q

When does epithelial reapproximation by new stratum basale cells begin during first intention healing?

A

within 24-48 hours

138
Q

____ sense heat and cold, touch, pain, an movement.

A

Free nerve endings

139
Q

Does the epidermis have blood vessels?

A

NO

140
Q

What are the organelles melanin is released from?

A

melanosomes

141
Q

What are the two kinds of sweating?

A

thermoregulatory - cholinergic

emotional - adrenergic

142
Q

Can you find sebum in non-haired skin?

A

YES - sebum secreted directly onto skin

143
Q

What are the metabolic functions of the skin?

A

energy stored in subcutaneous fat as triglycerides; Vitamin D synthesized in skin; maintains homeostasis; sweating; immune defense

144
Q

What accounts for our fingerprints (dermatoglyphs)?

A

large dermal ridges in thick skin

145
Q

Where would you find the subpapillary plexus?

A

at the junction of papillary and reticular layers

146
Q

What augments re-epithelialization in haired skin in second intention wound healing?

A

the migration of cells from the external root sheath of hair follicles

147
Q

What slowly restores the multi-layered stratified epidermis during second intention wound healing?

A

the simultaneous proliferation and maturation of keratinocytes behind the migrating front

148
Q

How is the epidermis supplies and nourished?

A

by blood vessels in underlying or subjacent dermis

149
Q

Can the epidermis be thick or thin?

A

yes (1 mm to more than 5 mm)

150
Q

What is the thickest layer of epidermis in thick skin?

A

stratum corneum

151
Q

What is the largest organ in the body?

A

skin

152
Q

How does skin protect the body?

A

blocks UV, mechanical, chemical and thermal damage; prevents dehydration; provides physical barrier to keep microorganisms out

153
Q

What is the involuting phase of hair growth called?

A

catagen

154
Q

What does 5-a-reductase convert its product to?

A

testosterone to dihydroxytestosterone

155
Q

What layer of the epidermis is only present in thick skin?

A

stratum lucidum

156
Q

What happens when keratinocytes mature?

A

they die and lose nuclei and other organelles

157
Q

What does the nail rest on?

A

the nail plate rests on a bed of stratified squamous epithelium

158
Q

What are the two types of melanin?

A

eumelanin and pheomelanin

159
Q

___ is an autoimmune disease characterized by the destruction of melanocytes, leading to depigmentation.

A

Vitiligo

160
Q

What do sebaceous glands secrete? How?

A

oily sebum via a pilosebaceous canal

161
Q

This layer is located below the dermis and is composed of loose irregular connective tissue and adipose tissue.

A

hypodermis

162
Q

The protein fraction is secreted by ____ glands; the lipid fraction is secreted by ____ glands.

A

merocrine; apocrine

163
Q

What forms the nail plate?

A

keratin filaments embedded in amorphous matrix

164
Q

Where is the hair growth phase short and resting phase long?

A

arm hair, eyebrows, body hair

165
Q

Melanocytes are a type of ____ cell.

A

neuroectodermal

166
Q

How is the stratum basale secured to the basal layer?

A

by numerous hemidesmosomes, via anchoring filaments and microfibrils

167
Q

What cells contain distinctive Birbeck granules?

A

Langerhans cells

168
Q

What forms the matrix for tonofibrils of cytokeratin and leads to a mass of mature keratin?

A

the release and polymerization of lysosomal enzymes

169
Q

What is the thickest layer of epidermis in the skin?

A

stratum spinosum

170
Q

Where would you find the most Pacinian corpuscles?

A

in the fingertips and around joints

171
Q

Fingernails grow at ___ the rate of toenails.

A

3X

172
Q

In first intention healing, when are neutrophils replaced by macrophages?

A

day 3-7 (transition from acute to subacute phase)

173
Q

What compounds are not formed in those who have albinism?

A

DOPA; melanin

174
Q

What are structural pigments?

A

cells are lined up and layered in sheets which cause the reflection and refraction of light (iridescence)

175
Q

What kind of sweating is adrenergic (sympathetic)?

A

emotional sweating

176
Q

The ___ layer is composed of soft keratin and acts as a hydrophobic barrier.

A

stratum corneum (squames)

177
Q

The ___ plexus is located at the junction of the reticular layer and hypodermis.

A

cutaneous

178
Q

In the fingers, toes, and ears, vascular plexi are associated with AV shunts called ___.

A

glomus bodies

179
Q

____ is genetic and androgen-dependent hair loss.

A

Androgenic alopecia

180
Q

Which glands secrete their product along with some of the cytoplasm?

A

apocrine sweat glands

181
Q

During what time period of first intention healing is connective scar tissue covered in intact epithelium?

A

month 2

182
Q

What happens when the epithelial cells lining hair bulbs mature?

A

they fill with hard keratin filaments arranged in parallel bundles (which meld together to form hair)

183
Q

The cells of the epidermis are called ___.

A

keratinocytes

184
Q

How are mammary glands arranged inside the body?

A

as tubulo-acinar glands organized into secretory lobules

185
Q

Which layer of the epidermis consists of keratinized, stratified squamous epithelium?

A

epidermis

186
Q

What causes the acrid odor of sweat?

A

bacterial breakdown

187
Q

How much melanin do melanocytes contain?

A

not much actually because they release melanin to get taken up by surrounding epithelial cells

188
Q

Thick skin that lacks hair is ___ skin.

A

glabrous

189
Q

Why do our fingers and toes get cold in freezing tempertures?

A

because the capillary beds are bypassed and blood is rerouted from arterial to venous circulation to maintain body temperature

190
Q

Where are Langerhans cells generally located?

A

deep within the stratum spinosum

191
Q

What attributes to psoriasis plaques?

A

expedited keratinocyte maturation (leads to absence of a granular layer and abnormal keratohyaline and tonofibrils)

192
Q

What are the 3 main layers of the skin?

A

epidermis
dermis
hypodermis

193
Q

Is hair growth continuous?

A

NO - happens in phases

194
Q

What burn involves both the epidermis and the dermis?

A

2nd degree burn

195
Q

Where does nail proliferation and differentiation occur?

A

in the germinal zone in the nail matrix

196
Q

What is the most superficial layer of the epidermis?

A

stratum corneum

197
Q

What are inactive mammary glands composed of?

A

dense irregular collagenous connective tissue, interspersed with adipose tissue and smooth muscle

198
Q

What kind of sweating is cholinergic (parasympathetic)?

A

thermoregulatory sweating

199
Q

Humans produce 54 different types of keratin, which are all ___ keratins.

A

alpha

200
Q

Which parts of the body have a thick keratinized layer?

A

palms and soles of feet

201
Q

How long is the process from keratinization to desquamation and lifting of the scab to reveal new cells?

A

3 weeks

202
Q

Does hard keratin or soft keratin contain more disulfide bonds to allow cross-linking?

A

hard keratin

203
Q

What happens due to progressive damage to elastic fibers?

A

loss of skin tone

204
Q

What constituents is the sebum high in?

A

lipids and cell debris

205
Q

Coarse hair on scalp, axillae and pubis are known as ___ hair.

A

terminal

206
Q

What is the growth phase of hair growth called?

A

anagen

207
Q

The ____ sheath actually lines the hair follicle.

A

external root

208
Q

Milk production is both ___ and ___.

A

merocrine; apocrine

209
Q

What are the mechanoreceptors or touch receptors in the dermal ridges of the papillary layer?

A

Meissner’s corpuscles

210
Q

Mammary glands are ___ in males and females until ___.

A

identical; puberty

211
Q

To produce ____, a tyrosine precursor is oxidized to DOPA by tyrosinase and then eventually to its final product.

A

melanin

212
Q

Release of lysosomes can also lead to the ___ of the cell.

A

death

213
Q

What does the high number of antibodies in colostrum equate to?

A

passive immunity for offspring

214
Q

What is the prominent cellular product of the stratum spinosum?

A

cytokeratin

215
Q

What are Ruffini corpuscles?

A

small dermal mechanoreceptors, common in the soles of the feet

216
Q

____ glands are simple, coiled, tubular glands surrounded by myoepithelial cells and assist in secretion.

A

Sweat

217
Q

What varies in melanin for different indivduals?

A

variable rates of melanin production and degradation by lysosomal enzymes

218
Q

Which type of sweat gland discharges thick and viscous secretions into the hair follicle?

A

apocrine glands

219
Q

Which vascular plexus in the skin is the largest of the 3?

A

subcutaneous plexus

220
Q

Where does thermoregulatory sweating first occur on the body? What about the last place to occur?

A

axillae, forehead and scalp; last on hands and feet

221
Q

When would skin grafting be necessary?

A

in full-thickness abrasion or 3rd degree burns or if the wound is very large

222
Q

The ____ is a modified basement membrane that separates hair bulb from surrounding dermis.

A

glassy membrane

223
Q

What is the shedding of the old hair shaft called?

A

exogen

224
Q

What burn involves all three layers of the skin?

A

3rd degree burn

225
Q

Why does the phenomena of raised hair in puffed up cats or raised hackles in dogs not translate to humans?

A

we have such a reduced hair code the changes can’t be seen

226
Q

What are the epidermal projections into the dermis called?

A

epidermal ridges (rete ridges)

227
Q

Is adrenergic sweating from sympathetic or parasympathetic stimulation?

A

sympathetic

228
Q

What type of melanin is present in individuals with blonde or red hair?

A

pheomelanin

229
Q

What forms the lines of tension, Langer’s lines?

A

thick collagen bundles and elastin fibers

230
Q

Where is melanin released from?

A

melanocytes in organelles called melanosomes

231
Q

How does the skin facilitate thermoregulation?

A

insulation via hair and subcutaneous fat; heat loss by sweat glands and dermal capillary network

232
Q

These are mechanoreceptors located in the dermis and hypodermis and are large ovoid structures.

A

Pacinian corpuscles

233
Q

____ contain abundant cytoplasmic extensions and do not stain well on HE.

A

Langerhans cells

234
Q

What are the three anastomosing vascular plexi of the skin?

A

superficial subpapillary plexus
deep cutaneous plexus
deeper subcutaneous plexus

235
Q

What is the layer of the epidermis superficial to the stratum basale?

A

stratum spinosum

236
Q

These granules are non-membrane bound, electron dense granules.

A

keratohyaline granules

237
Q

Why are white cats with light eyes usually deaf? Why do those with albinism often have neurologic deficits? Why do Dalmatians need to be bred to have a certain number of spots?

A

because normal pigmentation is important for normal neural development

238
Q

Which types of skin cancer are derived from melanocytes?

A

melanoma

239
Q

What exfoliated cells in females are collected for a Pap smear?

A

cervical cells

240
Q

What is the hair shaft produced by?

A

hair follicles (cylindrical downgrowths of epithelium covered by collagen sheaths)

241
Q

Melanosomes containing eumelanin are ___; those containing pheomelanin are ___.

A

elongate; ovoid

242
Q

What 3 processes together lead to the production of granulation tissue?

A

neovascularization
fibroplasia
re-epithelialization

243
Q

Is cholinergic sweating sympathetic or parasympathetic?

A

parasympathetic

244
Q

What type of cells does the stratum basale consist of?

A

cuboidal germinal cells that rest on the basement membrane

245
Q

What are unique to primates?

A

flattened nails

246
Q

During what time period of first intention healing is granulation tissue matured, inflammation is decreasing, and inflammatory cell products cause itching?

A

week 2

247
Q

The ___ can also be referred to as the subcutis, superficial fascia or panniculus adiposus.

A

hypodermis

248
Q

What are Langerhans cells associated with regarding allergies?

A

involved in contact allergic dermatitis

249
Q

What skin layer cells migrate to the edges of the wound in second intention healing?

A

stratum basale

250
Q

What cells facilitate wound contraction?

A

myofibroblasts

251
Q

What is the homogenous epidermal layer of enucleate cells between the stratum granulosum and stratum corneum?

A

stratum lucidum

252
Q

What is sweat composed of?

A

hypertonic solution of salts and ammonia, urea, and uric acid

253
Q

Sweat is important for ___ cooling.

A

evaporative

254
Q

What stimulation causes goosebumps?

A

sympathetic

255
Q

____ are fixed tissue macrophages and antigen presenting cells.

A

Langerhans cells

256
Q

What is the excessive secretion of sebum called?

A

seborrhea

257
Q

Do skin cell cancers have the tendency to metastasize?

A

yes - all are aggressive with tendency to metastasize

258
Q

Where do mammary glands develop along?

A

paired epidermal ridges (mammary ridges/milk lines)

259
Q

What does hair aid in?

A

protection and thermoregulation

260
Q

What are the dermal projections into the epidermis called?

A

dermal ridges (dermal papillae)

261
Q

What is the purpose of keratin plates?

A

to prevent matting

262
Q

What is the structure of a hair shaft?

A

outer cortex and inner medulla covered by a thin cuticle of keratin plates

263
Q

____ are in the stratum spinosum and ____ are in the stratum basale, but they look the same!

A

Langerhans cells; melanocytes

264
Q

What produces hair color?

A

the incorporation of the absorbed melanin from neighboring melanocytes into the cortex of hair

265
Q

In apocrine glands, what stimulates secretion?

A

sympathetics (adrenergic)

266
Q

In the dermis, the ___ layer is thin and interdigitates with the epidermis.

A

papillary layer

267
Q

This cell layer has polyhedral cells with prominent intercellular bridges (desmosomes), numerous cytoplasmic processes, and folding of the cell membrane.

A

stratum spinosum

268
Q

Are apocrine gland secretions odorless when secreted?

A

YES

269
Q

What are melanocytes responsible for?

A

production of melanin, or skin pigment

270
Q

Do all individuals have the same number of melanocytes?

A

YES

271
Q

What are the two types of sweat glands?

A

merocrine/eccrine and apocrine

272
Q

Where are melanocytes largely restricted to? Where can they extend into?

A

basal cell layer (processes may extend into stratum spinosum)

Histology (6 decks)

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