Integument 5a Flashcards Preview

A&P 1 > Integument 5a > Flashcards

Flashcards in Integument 5a Deck (22)
Loading flashcards...
1

Skin (Integument) Consists of three major regions

Epidermis – outermost superficial region
Dermis – middle region
Hypodermis (superficial fascia) – deepest region

2

Epidermis 4 distinct cell types are

Keratinocytes, Melanocytes, Merkel cells, and Langerhans’ cells

3

Keratinocytes

produce the fibrous protein keratin

4

Langerhans’ cells

epidermal macrophages that help activate the immune system

5

Merkel cells

function as touch receptors in association with sensory nerve endings

6

Layers of the Epidermis: Stratum Basale (Basal Layer)

Deepest epidermal layer firmly attached to the dermis, Consists of a single row of the youngest keratinocytes,
Cells undergo RAPID DIVISION, hence its alternate name, stratum germinativum

7

Layers of the Epidermis: Stratum Spinosum (Prickly Layer)

Cells contain a weblike system of intermediate filaments attached to desmosomes, Melanin granules and Langerhans’ cells are abundant in this layer

8

Layers of the Epidermis: Stratum Granulosum (Granular Layer)

Thin; three to five cell layers in which drastic changes in keratinocyte appearance occurs, Keratohyaline and lamellated granules accumulate in the cells of this layer

9

Layers of the Epidermis: Stratum Lucidum (Clear Layer)

Thin, transparent band superficial to the stratum granulosum, Consists of a few rows of flat, dead keratinocytes, Present only in thick skin

10

Layers of the Epidermis: Stratum Corneum (Horny Layer)

Outermost layer of keratinized cells, Accounts for three quarters of the epidermal
thickness

11

Stratum Corneum (Horny Layer) functions

Waterproofing, Protection from abrasion and penetration, Rendering the body relatively insensitive to
biological, chemical, and physical assaults

12

Dermis

Second major skin region containing strong, flexible connective tissue, Cell types include fibroblasts, macrophages, and occasionally mast cells and white blood cells

13

Dermis two layers are

papillary (top) and reticular (bottom)

14

Papillary layer

Areolar connective tissue with collagen and elastic
fibers, Its superior surface contains peglike projections called dermal papillae

15

Dermal papillae contain

capillary loops, Meissner’s corpuscles, and free nerve endings

16

Capillary loops

temperature

17

Reticular layer

Accounts for approximately 80% of the thickness
of the skin, Collagen fibers in this layer add strength and resiliency to the skin, Elastin fibers provide stretch-recoil properties

18

Hypodermis

Subcutaneous layer deep to the skin, Composed of adipose and areolar connective tissue

19

Three pigments contribute to skin color

Melanin, Carotene, Hemoglobin

20

Melanin

yellow to reddish-brown to black
pigment, responsible for dark skin colors

21

Carotene

yellow to orange pigment, most obvious in the palms and soles of the feet

22

Hemoglobin

reddish pigment responsible for the pinkish hue of the skin