Integumentary System

Question 1

Components of Integumentary system

Answer 1

Skin & Epidermal Derivatives (hair, follicles, glands, nails)

Question 2

Major Functions of Integumentary

Answer 2

protective, immunologic, homeostasis, sensory, endocrine, exocrine

Question 3

Skin consists of two principle layers:

Answer 3

epidermis & dermis

Question 4

Epidermis

Answer 4

superficial layer of skin - keratinized stratified squamous - ectoderm derivative - avascular

Question 5

dermis

Answer 5

connective tissue - derived from mesoderm - highly vascularized

Question 6

Thick Skin

Answer 6

found on palms and soles only - skin is hairless - much thicker epidermal layer than any other location

Question 7

Thin Skin

Answer 7

found everywhere except palms and soles - much thinner layer - hair present in most places

Question 8

Thin Skin Layers

Answer 8

4 layers - bottom to top (basale, spinosum, granulosum, corneum)

Question 9

Thick Skin Layers

Answer 9

5 layers - bottom to top (basale, spinosum, granulosum, lucidum, corneum)

Question 10

Cells of epidermis:

Answer 10

Keratinocytes (85%), Melanocytes (5%), Langerhan’s Cells (2-5%), Merkels cells (6-10%)

Question 11

kertatinocytes

Answer 11

principle cell type of epidermis - produce keratins (structural protein of epidermis) - form tonofilaments - participate in formation of water barrier by production of lamellar bodies (lipids)

Question 12

Stratum Basale Layer

Answer 12

single layer of basophilic cells - cuboidal shaped - mitotically active layer with stem cells that produce the keratinocytes & tonofilaments

Question 13

stratum spinosum

Answer 13

keratinocytes with spinous cytoplasmic processes - attached to adjacent cells via desmosomes - tonofilaments are bundled to form tonofibrils - begin productio of keratohyalin granules & lamellar bodies

Question 14

stratum granulosum

Answer 14

keratinocytes contain the formed keratohyaline granules - conversion of granular cells into cornified cells (keartinization)

Question 15

stratum lucidum

Answer 15

only found in thick skin - thin, translucent (white) layer of eosinophilic cells - nucleus & cytoplasm organelles become disrupted & disappear

Question 16

stratum corneum

Answer 16

cells lose nuclei & cytoplasmic organelles - mostly keratin (85%) - sloughed at the surface

Question 17

melanocytes

Answer 17

produce & secrete the pigment melanin - dendritic cells found in stratum basale - long processes extend upward between keratinocytes in the stratum spinosum - protects DNA from UV -

Question 18

Langerhan cells

Answer 18

antigen presenting cells found within stratum spinosum - present antigen to T lymphocytes within the lymph node -

Question 19

Merkel cells

Answer 19

mechanoreceptor cells associated with sensory nerve endings - usually within stratum basale - Merkel’s corpuscle (base of cells with terminal of aferent nerve fibers)

Question 20

3 major types of skin cancer

Answer 20

Basal cell carcinoma, squamous cell carcinoma, malignant melanoma

Question 21

Basal cell carcinoma

Answer 21

slow growing - resembles cells of stratum basale

Question 22

Squamous cell carcinoma

Answer 22

highly atypical cells at all levels of epidermis

Question 23

malignant melanoma

Answer 23

most serious - presents irregularly pigmented and multicolored lesions

Question 24

Dermis consists of 2 layers

Answer 24

papillary layer - reticular layer

Question 25

Papillary Layer

Answer 25

loose (areolar) connective tissue - have dermal papillae - projects into epidermis at the junction

Question 26

Reticular Layer

Answer 26

dense irregular connective tissue - thicker than papillary but fewer cells -

Question 27

Pacinian Corpuscles

Answer 27

large ovoid structures found in dermis & hypodermis - myelinated nerve ending within a concentric lamellae - detects pressure & vibration

Question 28

Meissner Corpuscle

Answer 28

tapered cylindrical structures - located within dermal papillae of hairless - flattened schwann cells form lamellae - UNMYELINATED - detect light touch

Question 29

Epidermal Skin Appendages

Answer 29

hair & follicles, eccrine, apocrine, sebaceous glands

Question 30

Arrector Pili Muscle

Answer 30

smooth muscle extending from connective tissue of hair follicle to papillary layer of dermis - causes hair to stand on end upon contraction - insulation & sympathetic innervation

Question 31

eccrine sweat gland

Answer 31

widely distributed, simple coiled tubular - thermoregulatory - excretes wastes and salts

Question 32

eccrine sweat gland secretory portion

Answer 32

double layer of epithelial cells - lighter and larger than duct cells - located in the dermis or hypodermis

Question 33

eccrine sweat gland duct portion

Answer 33

double layer of cuboidal - smaller and darker than secretory - leads to epidermal surface

Question 34

Apocrine sweat glands

Answer 34

protein rich - secreted into hair follicles - merocrine secretion - coiled tubular - functional at puberty - bacterial breakdown of sweat leads to body odor -

Question 35

apocrine secretory portion

Answer 35

very wide - simple cuboidal - eosiniophilic - found in hypodermis or dermis

Question 36

apocrine duct portion

Answer 36

stratiied cuboidal - narrow lumen - empties into follicle canal

Question 37

sebaceous oil glands

Answer 37

found everywhere besides thick skin (no hair follicles) - branched acinar - sebum lipid - secretes into hair follicle - holocrine secretion - acne causing