Pt 1. Integument and Barriers to Infection

Question 1

2 components of Integumentary System:

Answer 1

► 1) skin
► 2) epidermal derivatives ( nails, hair, sweat &
sebaceous glands and mammary glands)

Question 2

3 layers of Integumentary System (skin)

Answer 2

Consists of 3 layers: epidermis (ectoderm),
dermis (mesoderm) & hypodermis
(subcutaneous layer=superficial fascia)

Question 3

Skin categorized as thick and thin (what are the widths in mm?

Answer 3

(>5mm). (1-2mm).

Question 4

5 General functions of Integumentary system:

Answer 4

◦ Protection – UV light, mechanical, chemical &
thermal insult
◦ Water barrier
◦ Thermoregulation – insulation via hair & SQ fat; heat
loss facilitated by sweating & dermal capillary
network
◦ Metabolic functions- synthesis of the precursors of
Vitamin D; energy stored as fat
◦ Sensation – largest sense organ in the body,
contains receptors for touch, pressure, pain &
temperature

Question 5

Fingerprints are
produced by
____
and underlying
dermal papillae
and are
permanent

Answer 5

epidermal ridges

Question 6

What is dermatoglyphics?

Answer 6

the study of ridge patterns of the skin

Question 7

Tension lines, cleavage lines or Lines of Langer are due
to the arrangement of ____in the dermis

Answer 7

collagen fibers

Question 8

An incision made ____ to the cleavage lines will result in less gaping, faster healing, and less scar tissue

Answer 8

parallel

Question 9

Epidermis derived from

Answer 9

ectoderm

Question 10

Epithelial barrier with the ability to regenerate

Answer 10

Epidermis

Question 11

Epidermis is what kind of epithelium

Answer 11

stratified squamous keratinized epithelium

Question 12

Dermis derived from

Answer 12

mesoderm

Question 13

–mechanical strength
–reservoir of defensive elements
(skin layer)

Answer 13

dermis

Question 14

connective tissue between superficial fascia and muscle

Answer 14

epimysium or periosteum

Question 15

____ of the dermis is the subcutaneous layer

Answer 15

hypodermis (superficial fascia)

Question 16

pertaining to skin

Answer 16

cutaneous

Question 17

List the 5 layers of the epidermis of thick skin

Answer 17

Stratum Basale (germantivum)
Stratum Spinosum
Stratum Granulosum
Stratum Lucidum (thick only)
Stratum Corneum

Question 18

Primary epidermal ridge of epidermis interlocks with _____
ridge

Answer 18

subjacent dermal

Question 19

Epidermal ____ and rete ridges interlock with the dermal ridge

Answer 19

interpapillary peg

Question 20

Dermal papillae project upward into the _____

Answer 20

epidermal layer

Question 21

cells of epidermis

Answer 21

keratinocytes

Question 22

Variable thickness of epidermis

Answer 22

<1 mm to >5

Question 23

–thick, highly keratinized layer
–restricted to valor (soles) and palmar surfaces
–lack hair (glabrous)

Answer 23

Thick Skin of epidermis

Question 24

Epidermis supplied and nourished by _____

Answer 24

blood vessels in underlying (subjacent) dermis

Question 25

Progressive damage to ____ fibers leads to loss of skin tone

Answer 25

elastic (aging--not good with repair)

Question 26

______ connect the dermal layers with the epidermal layer and fit into pits of epidermal layer

Answer 26

Pegs or Papillae

Question 27

Basal Keratinocytes of epidermis are anchored to ____ by ____

Answer 27

Basal Lamina. Hemidesmosomes.

Question 28

Dermis of thick skin has 2 layers:

Answer 28

Papillary and Reticular Layer

Question 29

Tissue types of Papillary Layer in Dermis

Answer 29

Dense Irregular CT. Type I collagen/elastic fibers

Question 30

Tissue types in Reticular Layer of Dermis

Answer 30

Collagen bundles and coarse reticular fibers for support

Question 31

____ layer of dermis is thicker and contains less cells

Answer 31

Deep reticular layer

Question 32

Layer of skin containing hair follicles, sweat, and sebaceous glands

Answer 32

Dermis

Question 33

Dermis interdigitates with underlying ____

Answer 33

hypodermis

Question 34

Thick collagen bundles and elastic fibers in reticular layer form _____

Answer 34

lines of tension, Langer's Lines

Question 35

Acute or chronic autoimmune skin disease, involving formation of blisters (bullae) at space between epidermis and dermis

Answer 35

Bullous Pemphigoid Antigens

Question 36

Bullae are formed by immune reaction intiated by formation of ______

Answer 36

IgG autoantibodies

Question 37

The bullae are formed by an immune reaction, initiated by the formation of IgG autoantibodies targeting cytoskeleton linker protein dystonin (Bullous Pemphigoid Antigen1) and/or type XVII collagen, (also called (Bullous Pemphigoid Antigen 2),which is a component of ______

Answer 37

hemidesmosomes

Question 38

Blood and lymphatic vessels course through the ___

Answer 38

dermis

Question 39

Blood and lymphatic vessels course through the dermis and function in

Answer 39

thermoregulation and nutrition of the skin

Question 40

located at junction of papillary & reticular layers

Answer 40

Subpapillary plexus

Question 41

located at junction of reticular layer & hypodermis

Answer 41

Cutaneous plexus

Question 42

located deep within hypodermis; largest of the three vascular plexi

Answer 42

Subcutaneous plexus

Question 43

Vascular Plexi used in thermoregulation—in fingertips & ears, associated with AV shunts containing ____

Answer 43

glomus bodies

Question 44

glomus bodies reroute blood from ___ to ____ circulation

Answer 44

Bypass capillary bed, re-route blood from arterial to venous circulation --Thickened regions of smooth Mm in wall of arterioles, surrounded by connective tissue capsule.

Question 45

Components of Stratum Basale

Answer 45

Keratinocytes (cuboidal or columnar), rest on basement membrane --hemidesmosome --mitotic figures

Question 46

Components of Stratum Spinosum

Answer 46

Keratinocytes (flatterned polygons) with oval nucleis. --Desmosomes --spine-like cell processes (prickle cells)

Question 47

Components of Stratum Granulosum

Answer 47

Keratinocytes (flatterned cells, flat nuclei) --Basophilic Keratohyaline Granules (containing Involucin) --inc tight junctions

Question 48

Basophilic keratohyaline granules contain a protein _____ that interact with cytokeratin tonofibrils to produce that protein keratin

Answer 48

(involucin)

Question 49

Keratinization initiated by release of _____ => rupture of keratohyaline granules & polymerization of their contents

Answer 49

lysosomal enzymes

Question 50

What happens as keratinocytes mature?

Answer 50

Die and lose nuclei

Question 51

Cells of granular layer contain membrane-bound, lamellar structures called ____—contain glycolipids, provide waterproofing coat for skin cells

Answer 51

keratinosomes

Question 52

Cells of _______ layer mature to form waterproof layer of keratinized cells, with glycolipid coating on surface of epidermis

Answer 52

granular

Question 53

Components of Stratum Lucidum

Answer 53

--Keratinocytes with no nuclei --intermediate layer between granulocytes and startum corneum --forms barrier to water --found in thick skin

Question 54

Components of Stratum Corneum

Answer 54

Keratinocytes are flatterned, no nucleus (called squames) --contain keratin filaments --aids in a permeability barrier, prevents desication --continuously exfoliated (dequamation)

Question 55

dequamation

Answer 55

continuously exfoliated

Question 56

Neuroectodermal (i.e., of neural crest origin) dendritic cells present in epidermis

Answer 56

Melanocytes

Question 57

Melanocytes quantity and where present

Answer 57

Small # cells, restricted to basal layer

Question 58

Responsible for production of melanin

Answer 58

melanocytes

Question 59

Melanin released from melanocytes in organelles called _____

Answer 59

melanosomes

Question 60

Melanin released from melanocytes in melanosomes and taken up by ____ cells

Answer 60

surrounding epidermal cells

Question 61

_____occurs when skin cannot produce melanin quickly enough to prev UV injury to blood vessels

Answer 61

sun burn

Question 62

Two types of melanin—

Answer 62

◦ eumelanin ◦ pheomelanin

Question 63

eumelanin

Answer 63

dk brown, black pigment)— present in dark haired individuals

Question 64

pheomelanin

Answer 64

(red to yellow pigment)— present in individuals with red or blond hair

Question 65

lighter skinned individuals produce ____ pigment or digest pigment ____

Answer 65

less or faster

Question 66

Autoimmune disease => destruction of melanocytes => depigmentation

Answer 66

Vitiligo

Question 67

Melanin synthesis under control of pituitary hormone _____

Answer 67

melanocyte stimulating hormone (MSH)

Question 68

To produce melanin, tyrosine precursor first oxidized to DOPA (3,4- dihydroxyphenalalanine) by tyrosinase located in organelles called ____

Answer 68

premelanosomes

Question 69

To produce melanin,_____ precursor first oxidized to DOPA (3,4- dihydroxyphenalalanine) by ____ located in organelles called premelanosomes

Answer 69

tyrosine. tyrosinase.

Question 70

conversion of _____ to melanin occurs in melanosomes

Answer 70

DOPA

Question 71

Albinos lack ___, so DOPA & melanin not formed;

Answer 71

tyrosinase

Question 72

Albinos lack tyrosinase, so ____ & melanin not formed;

Answer 72

DOPA

Question 73

___ can be used as a marker, to differentiate melanocytes from keratinocytes containing phagocytosed melanin

Answer 73

Tyrosinase

Question 74

Useful in distinguishing tumor types, e.g., melanoma vs. squamous cell carcinoma

Answer 74

Melanin

Question 75

Functions of Melanin: DNA subject to damage by UV; melanin functions as UV shield to protect nucleus; inhibits _____

Answer 75

mutagenesis

Question 76

___ necessary for normal neural development

Answer 76

Melanin

Question 77

MITF (microphthalemia- associated transcription factor)

Answer 77

* regulates the differentiation of melanocytes

Question 78

excess MITF associated with

Answer 78

melanoma

Question 79

Lack of MITF associated with

Answer 79

albinism type 1

Question 80

Name the cell: phagocytic, involved in immune responses ◦ antigen-presenting cells ◦ monitor foreign antigens that contact epidermis

Answer 80

Langerhans cells (fixed tissue M)

Question 81

Langerhans cells contain distinctive _____

Answer 81

Birbeck Granules (look like tennis rackets)

Question 82

Langerhans Cells located within

Answer 82

Stratum Spinosum

Question 83

►Involved in contact allergic dermatitis ►Contain abundant cytoplasmic extentions

Answer 83

Langerhans Cells

Question 84

Langerhan cells interact with T cells in the ____

Answer 84

lymphatic System

Question 85

activated T cells then travel back to the epidermis through the blood stream and release pro-inflammatory ___ to neutralize the antigen

Answer 85

cytokines (cytokines amplify the immune response)

Question 86

inflammatory skin disorder ◦ initiated by Langerhans cells

Answer 86

Psoriasis

Question 87

What happens to the stratum corneum in psoriasis?

Answer 87

it thickens and forms plaques

Question 88

What happens to the epidermal papillae in psoriasis?

Answer 88

they elongate

Question 89

Inflam disorder resulting in excess proliferation of epidermal keratinocytes from stratum basale to stratum corneum

Answer 89

Psoriasis