Histology III: Integument and Barriers to Infection Flashcards
what is the integument?
largest organ of the body
what components does the integument possess?
1) skin
2) epidermal derivatives
i. nails
ii. hair
iii. sweat and sebaceous glands
iv. mammary glands
how thick in mm is thin and thick skin
thin skin 1-2 mm
thick upwards to 5 mm
what layers does the integument have?
3:
1. epidermis (ectoderm)
2. dermis (mesoderm)
3) hypodermis (mesoderm) or subcutaneous fascia
How does the integument factor into differential diagnosis?
colors = illnesses possibly
yellow = jaundice blue/purple = cyanosis pale = anemia
tension lines
also called cleavage lines/lines of danger
what causes tension lines
arrangement of collagen fibers in the dermis
Epithelium: germ later derivative and composition
ectoderm, stratified squamous cell keratinocytes
Dermis: germ later derivative and role
mesoderm, mechanical strength
reservoir of defensive elements
Hypodermis: other name, significance
subcutaneous or deep fascia
has a thin layer between itself and the muscle called the epimysium or periosteum
Structure of the skin : name the five layers
1) stratum basale
2) stratum spinosum
3) stratum granulosum
4) stratum lucidum
5) stratum corneum
Layer of malphigi
stratum basale and spinosum
epidermal/dermal interface:
primary epidermal ridge and primary dermal ridge
Primary epidermal ridge: interlocks with dermal projections to create a barrier. has a major interpapillary peg (a big peg) that projects into the dermal ridge
Primary dermal ridge interlocks with the primary epidermal ridge: it has secondary papillary ridges near where the interpapillary peg inserts into the dermis
interpapillary peg
from the primary epidermal ridge, projects/locks with the dermis
primarily found in thick skin!!!
dermis of the thick skin: dermal papillae
papillary layer:
pegs/papillae, connect with dermal layer
basal keratinocytes stay attached to basement membrane using hemidesmosomes
