Pathology of the Integumentary System - Part 2 Flashcards
(137 cards)
1
Q
List the components of skin
A
Epidermis
Basement membrane zone
Dermis
Adnexal structures
Subcutis (hypodermis)
2
Q
The basement membrane zone is located?
A
Between the epidermis and dermis.
3
Q
The subcutis is composed of _____ tissue
A
adipose
4
Q
Describe the adenxal structures
A
Hair follicles, apocrine glands
(epitrichial), eccrine glands
(atrichial), sebaceous glands,
arrector pili muscles
5
Q
Describe the subcutis
A
No subcutis in some areas (cheek,
eyelid, anus, and external ear)
6
Q
What can be seen in this image?
A
Hair follicle, sweat gland, etc.
7
Q
Label the image accordingly
A
8
Q
Components of the epidermis
* _______ ______ _______ epithelium
* Four cell types: ?
A
Keratinized, stratified, squamous,
* Keratinocytes (85%)
* Langerhans cells (3-8%)
* Melanocytes (5%)
* Merkel cells (2%)
9
Q
Label the image accordingly
A
10
Q
What are the functions of kertatinocytes?
A
- Permeability barrier
- Structural support
- Immunoregulation (secretes cytokines and inform Langerhaans cells).
11
Q
Label the image accordingly
A
12
Q
Structural support
* Contain _____
* _____ filaments that connects to _____
* Type varies in the layers of ______ and body _____
* Provide _______ integrity
* Intermediate filaments are used for _______ _____
* Abnormal keratins lead to
_______ ______.
A
keratin, Intermediate, desmosomes, epidermis, site, structural, diagnostic purposes, cornification defects
Tumor we suspect to be neoplastic, we stain for cytokeratin. If it is Positive = tumor that derives from epithelium so either an adenoma or carcinoma.
13
Q
Describe kertatinocyte differentiation and cornification.
A
Stratum basale have nucleus. When differentiate into stratum corneum they lose their nucleus. This is a normal process that takes 21 days to occur.
Secrete lipids into spaces in between keratinocytes.
14
Q
A
Keratinocytes are wedged in between lipids. This is why we like to put lotions on body —> keeps skin integrity intact.
15
Q
Hyperkeratosis is defined as excessive _______ or ________ of the stratum _____
A
thickening, hyperplasia, corneum
16
Q
What is the primary cause of Hyperkeratosis?
A
Primary - Mutation (lipid, enzyme, structural protein)
* Example: ichthyosis
17
Q
What is the secondary cause of Hyperkeratosis?
A
Secondary - Chronic irritation
* Example: Allergic skin disease, endocrine disorders, parasitic and bacterial
infections, etc
18
Q
Describe the image below
A
Orthokeratosis: the keratinocytes undergo complete
cornification and thus lose their nucleus. This is essentially programmed cell death.
19
Q
Describe the image below
A
Parakeratosis: keratinocytes undergo only partial
or incomplete cornification and thus retain their
nucleus. Increased and faster turn over, hence why we see retention of nuclei.
20
Q
What can be seen in this image?
A
Golden retriever ichthyosis
21
Q
Ichthyosis is defined as a _______ and/or ______
defect in the formation of the _______ ________.
A
congenital, hereditary, stratum corneum
22
Q
In cases of Ichthyosis, there is strong _____ predilection; genetic
testing for ______ (______) or _____
A
breed, ICH-1, PNPLA1, ICH-2
23
Q
Ichthyosis is characterized by ?
A
- Trunk
- Generalized scaling
- Lamellar orthokeratotic hyperkeratosis
24
Q
Label the image accordingly
A
25
Primary seborrhea is used to describe?
Excessive scaling.
26
What is the controversy surrounding primary seborrhea?
* NOT a diagnosis
* Need to rule out other causes of scaling (e.g. ectoparasitism,
metabolic diseases and endocrinopathies, allergic disease, etc.)
* Likely represents a variety of conditions such as pyoderma,
Malassezia dermatitis, sebaceous adenitis, allergic dermatitis,
Vitamin A-responsive dermatosis
27
Epidermal hyperplasia =
acanthosis
28
Epidermal hyperplasia is characterized by thickening due to ________ number of
cells within the _______, especially of
the _______ ______.
increased, epidermis, stratum spinosum
29
Epidermal hyperplasia is a common response to ______ irritation
such as ?
chronic, inflammation, trauma, metabolic
or nutritional disorders
30
What is an example of Epidermal hyperplasia?
acral lick dermatitis
31
What is this an image of?
Epidermal hyperplasia
32
Acral lick dermatitis = ?
Acral lick granuloma
33
Acral lick dermatitis is commonly seen in what species?
Dogs
34
Acral lick dermatitis is a _________ disorder often associated
with _______ diseases such as ?
multifactorial, underlying, atopy,
food allergy, trauma, endocrinopathy, bone
pain, neuropathy, or behavioral causes
35
Acral lick dermatitis is a consequence of ?
chronic focal trauma +/-
secondary deep pyoderma.
36
Lesions caused by acral lick dermatitis can be found on what part(s) of the body?
Dorsal carpus, or dorsolateral metatarsus
37
How would a lesion caused by acral lick dermatitis be described?
Focal alopecic, firm, raised plaque or
nodule
38
What can be seen in this image?
Acral lick dermatitis
39
Label the image accordingly. What disease is this?
Acral lick dermatitis
40
What is the response of the epidermis to injury?
Apoptosis, Necrosis, intercellular edema, intracellular edema, epidermal atrophy, acantholysis
41
Define apoptosis. What causes apoptosis? Provide an example.
* Programmed cell death
* Cause: physiologic process, immune-
mediated disease
* Example: erythema multiforme
42
Define necrosis. What is the cause of necrosis? Give an example.
* Death of cells and is characterized by
nuclear pyknosis, karyorrhexis, or karyolysis
* Cause: physical injury, chemical injury,
ischemia
* Example: Photosensitization
43
What can be seen in this image?
Apoptotic cell
44
Intercellular edema is also called?
Spongiosis
45
Intracellular edema is defined as? Give an example.
* Ballooning degeneration: superficial layer;
Example: viral infections such as pox virus
* Hydropic degeneration: basal layer;
Example: cutaneous lupus erythematosus
46
What can be seen in the image provided?
Intercellular edema = spongiosis
47
What can be seen in the image provided?
Intracellular edema, specifically? superficial layer
48
What can be seen in the image provided?
Intracellular edema, specifically? basal layer
49
What is the cause of epidermal atrophy?
Cause: hormonal imbalances (e.g. hyperadrenocorticism)
19
50
What can be seen in the image provided?
Epidermal atrophy
cushings, hyperadrenocortism
thinning of the skin, can see vessels
51
What can be seen in the image provided?
Epidermal atrophy
52
Acantholysis is a response of the epidermis to injury and can be defined as the disruption of
_________ junctions
(_______) between _________ of the epidermis
* Example: ?
intercellular, desmosomes, keratinocytes, pemphigus foliaceus,
pemphigus vulgaris
53
What can be seen in the image provided?
Acantholysis
54
Acantholysis
* Clinically – vesicle and bullae ?
55
What can be seen in the image provided?
Pemphigus foliaceus
56
What can be seen in the image provided?
Pemphigus vulgaris
57
List the Inflammatory Lesions of the Epidermis
Exocytosis, pustules, crusts
58
Exocytosis is defined as the aggregation of _______ _____ in the epidermis
migrating leukocytes
59
Pustules (________) are accumulations of ________ cells (___) within the epidermis
microabscesses, inflammatory, pus
60
Crusts: dried _____ and cellular ___ (i.e., dried _______) located on
the epidermal ____
fluid, debris, exudates, surface
61
Label these three images accordingly
A = exocytosis
B = pustules
C = crusts
62
Langerhans cells are important in the skin _______ _____. They are _______ cells.
immune system, dendritic
63
Where are Langerhans cells produced in the body? What is their function?
* Bone marrow derived
monocyte-histiocyte lineage
* Process and present antigens
to T cells (antigen-presenting
cells)
64
Label the image accordingly.
Langerhans cells
65
What can be seen in this image?
Contact hypersensitivity (allergic contact dermatitis)
66
Contact hypersensitivity (allergic contact dermatitis)
* Hapten-type delayed hypersensitivity
(type IV hypersensitivity)
* Name a dermatologic test using the
same principle
67
hapten-protein complexes
68
Melanocytes make up the _____ cell layer of epidermis,
anagen hair ______
* Transfer melanin to _______
* Epidermal _____ unit
* One melanocyte per __-___
keratinocytes
basal, follicles, keratinocytes, melanin, 10-20
69
Melanocytes
70
What are the functions of Melanocytes?
* Solar protection
* Protect and absorb UV light
* Scavenge free radicals
71
What are some examples of hyperpigmentation?
Lentigo simplex, post-inflammatory hyperpigmentation
72
What are some examples of hypopigmentation?
Vitiligo, copper deficiency
73
What are some examples of pigmentary incontinence?
cutaneous lupus erythematosus, uveodermatologic
syndrome
74
Define pigmentary incontinence.
The loss of melanin pigment
75
What is the pathogenesis of pigmentary incontinence?
damage to the cells of the basal layer or of the follicular
components → accumulation of the pigment in macrophages in the
upper dermis or perifollicular regions
76
What can be seen in this image?
Post-inflammatory hyperpigmentation
77
What can be seen in this image?
Lentigo simplex
Benign condition common in calico/tabby cats
78
What can be seen in these images?
Vitiligo
79
Uveodermatologic syndrome is also known as?
Vogt‐Koyanagi‐Harada‐like syndrome
80
What is Uveodermatologic syndrome?
What are the breed dispositions, if any?
What is it characterized by?
How would you diagnose it?
* Breed predispositions: Akita and arctic
breeds
* Acute uveitis, photophobia,
blepharospasm → blindness
* Depigmentation of nose, lips, eyelids,
and hair
* Diagnosis: Biopsy + ophthalmic workup
81
What can be seen here?
Uveodermatologic syndrome
This disease attacks the melanocytes and the eye (uveitis --> blindness).
82
What can be seen in this image?
Pigmentary incontinence
MQ phagocytizing melanin
83
What can be seen in this image?
Merkel Cells
* Mechanoreceptors in tylotrich pads and hair follicles
84
What is the function(s) of the basement membrane?
Provide an example of a basement membrane
* Anchors epidermis to dermis
* Protective barrier
* Wound healing (any wound that goes beyond basement membrane zone interferes with ability to heal; less likely).
* Site of many pathologic processes
* Example: Subepidermal blistering diseases like epidermolysis bullosa
85
What can be seen in this image?
Basement membrane
86
What can be seen in this image?
Subepidermal blistering disease
* Vesicles → ulcers
87
What can be seen in this image?
Subepidermal cleft
88
What is the dermis made up of? What is its function?
* Collagen, elastin, proteoglycans
* Perivascular dendritic cells,
lymphocytes, mast cells
* Tensile strength
* Supports blood vessels,
lymphatics, nerves
89
What can be seen in this image?
The dermis
90
What are the responses of the dermis to injury?
* Alterations in growth, development, or tissue maintenance
* Dermal Atrophy
* Fibrosis
* Collagen Dysplasia
* Solar Elastosis
* Abnormal deposits in the dermis
* Calcinosis cutis & calcinosis circumscripta
* Mucin
91
Ehlers-Danlos syndrome is also known as?
Collagen dysplasia, cutaneous asthenia, hyperelastosis cutis, dermatosparaxis
92
Ehlers-Danlos syndrome affects what species?
Dogs, cats, horses, cattle, sheep
93
Ehlers-Danlos syndrome is an ________ _____ defect in ______ collagen
* Specific enzyme defects affecting ______
synthesis or processing
inherited congenital, dermal, collagen
94
What is Ehlers-Danlos syndrome characterized by?
Cutaneous hyperextensibility and laxity,
tears, wounds, scars
95
In cases of Ehlers-Danlos syndrome, the histopathology may be? The diagnosis?
Histopathology may be inconclusive.
Diagnosis requires skin extensibility index
96
What can be seen in this image?
Ehlers-Danlos syndrome
97
Solar dermatitis is caused by?
Chronic exposure to sun light →
altered fibroblast function
98
What breeds are predisposed to solar dermatitis?
Lightly skinned, short‐coated breeds
99
What is solar dermatitis characterized by?
Erythema and scales → thick, firm
and wrinkled skin, with erosions,
ulcers, comedones
100
What parts of the body are affected by solar dermatitis?
Flank, groin, axilla
101
Solar dermatitis is associated with the development of?
squamous cell carcinoma,
hemangioma, and cutaneous
hemangiosarcoma
102
What can be seen in this image?
Solar dermatitis
103
What causes calcinosis cutis?
What parts of the body are affected?
What is it characterized by?
* Cause: hypercortisolemia
* Dorsal neck region or axilla
and groin
* Erythematous or white
plaques with ulcers
* Dermal mineralization with
granulomatous dermatitis
104
What can be seen in this image?
Calcinosis cutis
105
Label the image accordingly.
Calcinosis cutis
Red box = Multinucleated giant cells
Blue box = mineralized collagen fibers
106
Describe the inflammatory patterns of the dermis
107
What are the functions of hair follicles?
* Physical and photoprotective
barrier
* Thermoregulation
* Social communication
* Sensory perception
* Wound healing
108
Which species have simple hair follicles?
* Simple follicles
* Humans, cattle, horses, pigs
109
Label the image accordingly
110
What type of hair follicle is this?
Compound primary with secondary hair follicles
111
Describe the hair growth cycle
112
What can be seen in this image?
Anagen: growth phase
113
What can be seen in this image?
114
What are two examples of tactile hairs?
Sinus hairs, such as whiskers and vibrissae, and tylotrich hairs
115
Sinus hairs, such as whiskers and vibrissae, are ______-adapting mechanoreceptors
Slow
116
Tylotrich hairs
* ______ adapting mechanoreceptors
* ______ among normal hair
* _______ cells in tylotrich pads
Rapid, Scattered, Merkel
117
What type of tactile hair can be seen here?
Sinus hairs
118
What type of tactile hair can be seen here?
Tylotrich hairs
Carpal whiskers
119
What are the responses of the adnexa to injury?
* Atrophy
* Example: Endocrine dermatopathy
* Hair follicle dysplasia
* Example: color dilution alopecia
* Hair cycling disorders
* Inflammation – folliculitis/perifolliculitis/furunculosis
120
Which hormones stimulate anagen (influence hair cycle)?
* Hormones which stimulate anagen
* Thyroid hormone
* Androgens
121
Which hormones inhibit anagen?
* Hormones which inhibit anagen
* Glucocorticoids
* Estroge
122
What can be seen in each of these images?
123
What can be seen in this image?
Adenexal atrophy, e.g. endocrine dermatopathy
Mostly telogen
124
What can be seen here
?
Normal anagen
125
What are sebaceous glands?
What is their function?
Provide an example.
* Holocrine glands open into the hair follicle
* Sebocytes degenerate to form sebum
* Provides moisture for stratum corneum,
water repellant
* Antibacterial activity, pheromone
production
* Example: Sebaceous adenitis = very common
126
What can be seen in this image?
Sebaceous glands
127
Describe the breed predilection for sebaceous adenitis.
What age(s) are affected?
Describe its pathogenesis.
* Breed predilection! Standard
Poodle, Akita, Samoyed, Vizsla
* Young adult – middle-aged
* Pathogenesis unknown
* Dorsum, head, pinnae
* Scales, thinning of hair coat (long-
haired dogs) or annular alopecia
(short-haired dogs), follicular casts
* Diffuse loss of sebaceous glands or
granulomatous sebaceous adenitis
128
What can be seen in this image?
Sebaceous adenitis
Lots of scales/follicular cast = when you pluck the hair, see yellow greasy material adhered to the hair shaft.
129
What can be seen in this image?
Loss of sebaceous glands with periadenexal (adjacent to the adenexa) inflammation
130
Sweat glands are ______ glands (_______) that empty into ______ follicles.
apocrine, epitrichial, hair
131
What can be seen in this image?
Sweat glands
132
Apocrine glands are ______ glands (______) present in paw ______ and empty directly onto the ______ of the skin.
eccrine, atrichial, pads, surface
133
What can be seen in this image?
Apocrine glands
134
What can be seen in this image?
Apocrine glands
Sample from paw pad (no hair)
Glands deep in subcutis
Sweat through eccrine glands
135
Where is the subcutis is located?
What is the subcutis made up of?
What is its function?
* Between the dermis and skeletal muscle
* Adipose tissue (panniculus) and loose connective tissue.
* Metabolic storage pool
* Protects deeper structure
* Inflammation of panniculus = panniculitis (Ref: Lecture 5)
136
What are the functions of blood vessels?
* Blood vessels
* Skin metabolism
* Temperature regulation
* Defense against microorganisms
137
What are the functions of lymphatics?
* Lymphatics
* Supply, drainage of tissue fluid
* Defense against microorganisms
