Histology III: Integument and Barriers to Infection

Question 1

what is the integument?

Answer 1

largest organ of the body

Question 2

what components does the integument possess?

Answer 2

1) skin
2) epidermal derivatives
i. nails
ii. hair
iii. sweat and sebaceous glands
iv. mammary glands

Question 3

how thick in mm is thin and thick skin

Answer 3

thin skin 1-2 mm

thick upwards to 5 mm

Question 4

what layers does the integument have?

Answer 4

3:
1. epidermis (ectoderm)
2. dermis (mesoderm)
3) hypodermis (mesoderm) or subcutaneous fascia

Question 5

How does the integument factor into differential diagnosis?

Answer 5

colors = illnesses possibly

yellow = jaundice 
blue/purple = cyanosis 
pale = anemia

Question 6

tension lines

Answer 6

also called cleavage lines/lines of danger

Question 7

what causes tension lines

Answer 7

arrangement of collagen fibers in the dermis

Question 8

Epithelium: germ later derivative and composition

Answer 8

ectoderm, stratified squamous cell keratinocytes

Question 9

Dermis: germ later derivative and role

Answer 9

mesoderm, mechanical strength

reservoir of defensive elements

Question 10

Hypodermis: other name, significance

Answer 10

subcutaneous or deep fascia

has a thin layer between itself and the muscle called the epimysium or periosteum

Question 11

Structure of the skin : name the five layers

Answer 11

1) stratum basale
2) stratum spinosum
3) stratum granulosum
4) stratum lucidum
5) stratum corneum

Question 12

Layer of malphigi

Answer 12

stratum basale and spinosum

Question 13

epidermal/dermal interface:

primary epidermal ridge and primary dermal ridge

Answer 13

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

Question 14

interpapillary peg

Answer 14

from the primary epidermal ridge, projects/locks with the dermis

primarily found in thick skin!!!

Question 15

dermis of the thick skin: dermal papillae

Answer 15

papillary layer:

pegs/papillae, connect with dermal layer
basal keratinocytes stay attached to basement membrane using hemidesmosomes

Question 16

what is significant about the papillae?

Answer 16

they are highly vascularized

Question 17

reticular layer

Answer 17

collagen bundles/coarse reticular fibers for support