Integument System

Question 1

What are the layers of the integument system?

Answer 1

Epidermis

Dermis

Hypodermis

Question 2

What are the accessory structures of the skin?

Answer 2

• hair

- nail

Question 3

Summarize the epidermis of the skin

Answer 3

Epidermis- epithelial tissue

5 layers

4 cells typed

Question 4

Summarize the dermis

Answer 4

Dermis- connective tissue

2 regions

-nerve corpuscles

Question 5

What is the hypodermis?

Answer 5

A subcutaneous layer

• NOT part of the skin
• adipose tissue
• connective tissue
• highly vascularized
• nerve endings

Question 6

Describe the epidermis in detailed

Answer 6

5 layer

-stratified squamous keratinized epithelium

4 cell types:
-Kerwtinicytes, approx. 90%, produce protective protein keratin, water-repellant sealant

Melanocytes- 8% produce melanin determine skin color and absorbs uv light
-malignant melanoma

• Langherhans- macrophages
• Merkel- touch sensor

Question 7

Give the layers of the epidermis from top to bottom

Answer 7

• Corneum
• Luciderm
• granulosum
• spinosum
• Basale(germinativum)

Question 8

Describe the Corneum

Answer 8

25-30 layers flag dead cells- corneocytes/shames
Desquamation or shredding is continuous: 4-6 weeks

Keratin- protect underlying layers

Question 9

Describe the luciderm

Answer 9

4-6 layers of dead cells

Contain large amounts of keratin

Question 10

Describe the granulosum

Answer 10

3-5 layers of cells
Organelles begin to die- apoptosis

Keratohyalin protein assembles filaments into keratin

Lamellar granules-releases water repellent material between cells

Question 11

Describe the spinosum

Answer 11

8-10 Layers of rounded cells
Keratinocytes contain coarser filament

Upper layer flatter in shape

Deepest layer highly active

“Spines” are appearent

Question 12

Describe the basale

Answer 12

Actively dividing cuboidal- columnar cells

Stem cells produce new keratinocytes

Contain filaments which attach to desmosomes

Desmosomes anchor cells to each other.

Hemidesmosomes anchor cell to basement membrane

Question 13

What is the papillary dermis?

Answer 13

• interdigitates with epidermis - anchor, increased surface area - dermal papillae
• thin collagen and elastic fibers - strength and elasticity
• capillaries
• nerves - free endings, Meissner’s corpuscles (touch receptors)

Question 14

What is Resticular Dermis?

Answer 14

• Bundles of collagen fibers, thick elastic fibers- strength, elasticity
• cells- fibroblasts, macrophages
• glands, hair follicles
• nerves, blood vessels

Question 15

What is the function of hair?

Answer 15

-protects from sunlight , frictions, heat loss, foreign particles

Question 16

What is hair?

Answer 16

Extension of keratinized epithelium of Skin

Shaft- extends above the skin

Root- below the skin penetrating into the dermis
-Surrounded by hair follicle - two epithelial sheaths

Question 17

Explain the structure of the root and shaft

Answer 17

1. Inner concentric layer: medulla-irregular cells and pigment granules, air spaces
2. Middle concentric layers: cortex-elongated cells with pigment granules and air spaces
3. Outer concentric layers: cuticle-single layer of thin flat keratinized cells
4. Inner sheath- produced by hair matrix (germinal layer of cells)
5. Outer sheath- downward continuation of the epidermis-at the base contains only the stratum basale layer
6. Dermal root sheath- surrounds the hair follicle

Question 18

Describe hair papilla

Answer 18

• loose connective tissue with capillary loop

- located in the bulb

Question 19

What are the functions of the stratum basale of the hair?

Answer 19

Gives rise to the hair matrix

• responsible for the growth
• replacement of hair after shredding
• produced the internal root sheath

Question 20

What are nails?

Answer 20

Tightly packed keratinized epidermal cells

Question 21

Explain the parts of the nail

Answer 21

Stratum corneum
-Body (plate) - hardened keratin

• Hyponychium (nail bed) -anchors nail to the fingertip
• Eponychium(cuticle)
• Lunula -white crescent shaped

Stratum basale
- Matrix-deep to nail root, highly mitotic

Root-proximal part of the nail
Free edge

Question 22

Describe sebaceous glands

Answer 22

Sebaceous gland- simple, branched acinar

Absent on soles and palms

Sac like base

Lumen filled with cells

Mostly empties at neck of hair follicle

Question 23

Describe the sudoriferous sweat gland

Answer 23

Sudoriferous -sweat gland

Eccrine/Merocrine

-simple coiled tubular

Abundant on forehead, palms, soles

Excretory

Question 24

Describe the apocrine sweat gland

Answer 24

Simple coiled tubular

Axilla, aerola

Adolescents

Question 25

What is a burn?

Answer 25

Damage to tissue Graded according to severity

Question 26

What are the degrees of burns?

Answer 26

First degree- epidermal injury Second degree- epidermis and upper dermis injury Third degree- full thickness, epidermis and dermis