Integumentary System

Question 1

components of integumentary system

Answer 1

1. skin

2. epidermal derivatives

Question 2

major functions of integumentary system

Answer 2

1. protective
2. immunologic
3. homeostasis
4. sensory
5. endocrine
6. exocrine

Question 3

two principle layers of skin

Answer 3

1. epidermis

2. dermis

Question 4

what tissue type is present in the epidermis?

Answer 4

keratinized stratified squamous epithelium

Question 5

what germ later is the epidermis derived from?

Answer 5

ectoderm

Question 6

what tissue type is found in the dermis?

Answer 6

connective tissue

Question 7

what germ layer is the dermis derived from?

Answer 7

mesoderm

Question 8

what is deep to the skin, and what is it composed of?

Answer 8

Hypodermis/subcutaneous layer/ subcutaneous fascia

vascularized adipose tissue

Question 9

thick vs thin skin

Answer 9

thick: on palms of hands and soles of feet, hairless, thicker epidermis
thin: everywhere thick isn’t, hair follicles present, thinner epidermis

Question 10

Epidermal layers

Answer 10

1. stratum basale
2. stratum spinosum
3. stratum granulosum
4. stratum lucidum (only in THICK skin)
5. stratum corneum

Question 11

cells found in the epidermis

Answer 11

keratinocytes (85%)
melanocytes (5%)
langerhan’ cells (2-5%)
merkel’s cells (6-10%)

Question 12

keratinocytes

Answer 12

principles cell type of epidermis, produce keratins (structural protein of epidermis), produce lamellar bodies,

Question 13

lamellar bodies

Answer 13

tubular/ovoid shaped membrane bound organelles, contain lipid,form water barrier

Question 14

stratum basale

Answer 14

single layer of basophilic cells, simple cuboidal/simple low columnar, mititically active, contain stem cells, production of intermediate filaments (tonofilaments) begins

Question 15

stratum spinosum

Answer 15

keratinocytes exhibit spines, cell processes attaches to adjacent cells via desmosomes, tonofilments –> tonofibrials (via keratohyalin) begins, lamellar bodies form

Question 16

stratum granulosum

Answer 16

intensely basophilic, tonofibrils complete, keratinization occurs, lamellar bodies released

Question 17

keratinization

Answer 17

conversion of granular cells into cornified cells

Question 18

stratum lucidum

Answer 18

only in thick skin, thin translucent layeer of eosinophilic cells, nucleus and cytoplasmic organelles disappear

Question 19

stratum corneum

Answer 19

nuclei and cytoplasmic organelles absent, 85% filled w/ keratin, cells at surface sloughed off, glycolipids in EC space

Question 20

function of melanocytes

Answer 20

productionand secretion of melanin (synthesized and stored in melanosomes)

Question 21

Melanocytes

Answer 21

dendritic cells (round cell bodies in s. basale, processes in s. spinosum), melanosomes are transferred into keratinocytes

elongated nuclei surrounded by clear cytoplasm

Question 22

why does melanin accumulate over the nuclei?

Answer 22

to protect the DNA from UV radiation

Question 23

Langerhan’s cells

Answer 23

antigen presenting cells in s. spinosum, encounter and process antigens entering thru skin, present processed antigen to T lymphocytes

Question 24

what are langerhan’s cells derived from?

Answer 24

Bone marrow

Question 25

Merkel's cells

Answer 25

mechanoreceptor associated w/ sensory nerve endings, in s. basale, contains neurosecretory granules, base is Merkel's corpuscle

Question 26

Merkel's corpuscle

Answer 26

expanded plate like terminal of afferent nerve fibers at base of cells

Question 27

Basal Cell Carcinoma

Answer 27

most common, resembles cells of s. basale, slow growing tumor

Question 28

Squamous cell carcinoma

Answer 28

second most common, highly atipical cells at all levels of epidermis

Question 29

Malignant melanoma

Answer 29

most serious form, originates from melanocytes, irregular pigmented, multicolor lesion

Question 30

two layers of dermis

Answer 30

1. papillary layer | 2. reticular layer

Question 31

Papillary layer

Answer 31

superficial layer of dermis, loose CT, have dermal papillae that project into epidermis

Question 32

reticular layer

Answer 32

deep layer of dermis, consist of DCT, thicker than papillary layer but with fewer cells

Question 33

Pacinian corpuscles

Answer 33

large oval structures found in dermis/hypodermis, detect pressure and vibration, myelinated nerve endings surrounded by capsule of concentric lamellae

Question 34

Meissner;s corpuscles

Answer 34

tapered cylindrical structures, located in dermal papillae of hairless skin, flattened schwann cells form lamellae, detect light touch, unmyelinated nerve ending following spiral paths

Question 35

types of epidermal skin appendages, and derivative

Answer 35

1. hair and follicles 2. eccrine sweat glands 3. apocrine sweat glands' 4. sebaceous glands derived from down growths of epidermal epithelium during development

Question 36

hair

Answer 36

elongated filamentous, keratinized structures hat project from follicles

Question 37

hair follicle

Answer 37

responsible for production and growth of a hair

Question 38

arrector pili muscle

Answer 38

SM extending from CT sheath surrounding hair follicle to pap. layer of dermis, contraction acsues hair to stand on end, role in insulation and symp innervation

Question 39

eccrine sweat glands

Answer 39

widely distributed, simple coiled tubular gland, merocrine secretion, thermoregulatory, excretes wastes and excess salts

Question 40

Secretory portion of eccrine sweat glands

Answer 40

double layer of epithelial cells, larger and lighter than duct cells, in deep dermis or upper hypodermis

Question 41

Duct portion of eccrine sweat glands

Answer 41

narrower outside diameter and lumen than secretory portion, double layer of cuboidal cells, smaller and darker than secretory portion, lead to epidermal surface

Question 42

apocrine sweat glands

Answer 42

in axillary and perineal areas, viscous, protein rich sweat secreted into hair follicles, merocrine secretion, coiled tubular glands with wide lumen, begin functioning at puberty, bacterial breakdown of sweat leads to BO

Question 43

Secretory portion of apocrine sweat glands

Answer 43

very wide lumen, simple cuboidal epi, eosinophilic cytoplasm, in upper hypodermis/deep dermis

Question 44

Duct portion of apocrine sweat glands

Answer 44

stratified cuboidal epi, narrow lumen, empties into follicle canal

Question 45

sebaceous glands

Answer 45

everywhere except thick skin, branched acinar gland, secete sebum into hair follicle, holocrine secretion, involved w/ acne