Derm Flashcards
What is the function of skin
-Acts as a barrier, protects the individual, provides shape of the body, produces sweat hair and other extras, thermoregulation, plays a part in immunoregulation
What are the layers and cells within the epidermis
-Layers
*Basal layer - epidermal proliferation
*Spinous layer - structural strength, communication through desmosomes, contains immune cells, epidermal differentiation
*Granular layer - lamellar bodies and keratohyalin granules
*Horny layer - thickness varies, process of desquamation (exfoliation) in an important part of epidermal barrier
-Cell types
~Keratinocytes major cell type
~Langerhans cell - Antigen presenting and immunoservailance
~Melanocytes - pigment producing
~Merkel cells - sensory - changes in pressure
What are the components of the dermis
-Cells
*fibroblasts, dermal dendrocytes, cells of immune system
-Fibers
*collagen, elastic
-Ground substance
-vascular and nervous supplies
What is the function of hair
It’s similar to skin
Protection (physical, chemical, microbial, camouflage, UV), thermoreg, sensory
What is the hair cycle
- Anagen
-growth phase - hair follicle forms a new hair shaft - Catagen
-transitional phase - hair reaches max growth and follicle loses its blood supply - Telogen
-resting phase - natural hair shed
What are the cells involved in skin immunity
-resident cells
*Keratinocytes
*Langerhans cells - Ag presenting cells
*endothelial cell
*mast cells
*macrophages
-Recruited cells
~Neutrophils and eosinophils
~T -lymphocytes
What type of hair follicles that cat and dogs have
Compound follicles - multiple hairs in a single follicle
What are some things that influence the hair cycle
Extrinsic factors - season, daylight hours
Intrinsic factors - genetics, cytokines, hormones
What is a macule
Is a primary lesion that is a Change in color that’s <1cm
What is a patch
It’s a primary lesion that is a change in color >1cm
(Macules join together)
What is Petechia
Primary lesion of pinpoint bleeding in the skin
What is Ecchymoses
It’s a primary lesion of patches of bleeding in the skin
What is a papule and a plaque and when would you see them
They are a primary lesion
-papule - solid raised mass <1cm
-plaque - solid raised mass >1 cm
Seen in insect bites and allergies
What is a pustule
Pjs filled raised lesion <1cm
What is a follicular papule and when you would see it
Commonly known as folliculitis, it’s raised swelling with hair shaft coming through
It’s seen with BacT skin infections
What is a vehicle and a bulla
-Vesicle - serum filled papule <1cm
-Bulla - serum filled papule >1cm
What are primary lesions seen with allergies
-Wheal
-Angioedema
What is a nodule
A very solid palpable mass >1cm
