Skin Strata ( Identification, Structure, and Function)

Question 1

Answer 1

Epidermis; five layers (Stratum Basale, Stratum Spinosum, Stratum granulosum, Stratum Lucidum (thick skin), and Stratum Corneum.

Question 2

Answer 2

Dermis deep to the Epidermis. Contains two layers (superficial papillary layer and the deep reticular layer)

Question 3

Answer 3

Papillary layer of the dermis ( Superficial to the reticular layer) Represents the upper 1/5th of the dermis, contain collagen, elastic fibers, and areolar connective tissue, dermal papillae, capillary loops, and Meissner’s Corpuscle; immediate to the stratum basale and provides nutrition and oxygen.

Question 4

What is the purpose for dermal papillae?

Answer 4

Increase SA which helps with contact with the epidermis (strength and sites for nutrition)

Question 5

Answer 5

Reticular layer, deep to the papillary layer, bottom 4/5th layer, DIRCT, Pacinian Corpuscles,

Question 6

Answer 6

Merocrine sweat gland (Momo small); Eccrine (simple coiled tubular), contain myoepithelial cells, function: temperature regulation and excretion

(urea, uric acid, ammonia); location (forehead, palms, soles,)

Question 7

Answer 7

Hair Follicles ( three layers: Cuticle (outer layer keratinized), Cortex ( thick, elongated portion, contains pigment, Medulla (Inner layer, pigment and air).

Question 8

Answer 8

Sebacceous Glands, produce Sebum, (simple, branched, and acinar), holocrine secretion

Question 9

Sebum

Answer 9

Fat, cholesterol, and protein mixture produced by the sebacceous glands. Keeps hair from drying (brittle) out and skin, inhibits certain bacteria

Question 11

Answer 11

Merkel Cells - detect very fine and light touch. Located in the stratum basale of the epidermis.

Question 13

Answer 13

Arrector Pili Muscle - responsible for contracting and standing hair up, found in papillary layer of the dermis, contract in response to physiological or emotional stress i.e cold or fear, ANS, which traps air for insulation or shows greater/ scarier appearance.

Question 14

Answer 14

Meissner’s Corpuscle- located in the papillary layer of the dermis, sensitive nerve endings that detect fine touch, pressure, and slow vibrations

Question 15

Answer 15

Ruffini Corpuscle - located in the dermis, ligaments, and tendons, responsible for crude touch and stretching

Question 16

Answer 16

Apocrine Sweat gland (Simple, coiled, tubular, exocytosis) ( Appa “bigger sweat glands); need to say apocrine sudoiferous gland, location: axilla, pubic, and anal areas. Activated at puberty responsible for smell, not active during thermoregulatory sweating, secrete pheromones, sweat, in response to emotional stress and sexual excitement, have myoepithelial cells,

Question 17

Answer 17

Merocrine Sweat glands (Eccrine) - thermoregulation and excretion

Question 18

Polymastia

Answer 18

mammary glands are specialized apocrine glands

Question 19

Answer 19

Apocrine Sweat Glands

Question 20

Answer 20

Pacinian Corpuscle - deep pressure and fast vibrations located deep in the dermis or hypodermis

Question 21

Answer 21

Hair Follicles.

Question 22

Answer 22

Stratum Corneum - top layer, dead, keratinization complete, lack nuclei,

Question 23

How long does Keratinization take place and what enzyme is necessary for Stratum Basale to Stratum Corneum stratification?

Answer 23

4-6 weeks, Epidermal growth factor

Question 24

Answer 24

Stratum Lucidum; Only Present in thick skin (palms and soles); nothing inside of cells except for keratin fibrils and eleidin (Keratin precursor)

Question 25

Answer 25

Stratum Granulosum apoptosis begins here, presence of keratohyalin and keratin granules, lamellar granules also present

Question 26

Keratohyalin

Answer 26

enzyme released by the stratum granulosum responsible for assembeling keratin intermediate filaments into keratin

Question 27

Lamellar granules

Answer 27

secreted from the stratum granulosum, fuse with plasma membrane and release lipid-rich secretion between SG, SL, and SC. Acts as a water repellant and denies the entry of microbes.

Question 28

Answer 28

Meissner’s Corpuscle, located in the papillary layer of the dermis, responsible for fine touch, pressure, and slow vibrations.

Question 29

Answer 29

Stratum spinosum

Question 30

F

Answer 30

F - Dermis.

Question 31

Answer 31

Merkel Cells (located in the epidermis) - responsible for fine and very light touch

Question 32

Carotene vs Melanin

Answer 32

1) Melanin - brown/black or red-yellow pigment, DNA protection from UV light and neutralizing free radicals vs 2) Carotene yellow-orange, vision as a precursor to vitamin A, stored in the stratum corneum in over consumption

Question 33

Thick Skin vs Thin Skin

Answer 33

1) Thin Skin hairy, sebacceous glands, lack stratum lucidum, Dermal papillae few and irregular 2) Thick skin, lack hair, no sebacceous glands, greater number of sensory receptors and sudoiferous glands; dermal papillae more ordered, numerous, and taller

Question 34

Vellus Hair

Answer 34

Peach fuzz, fine, location faces

Question 35

Terminal hair

Answer 35

head, eyebrows, eye lashes (develop at puberty); males 95% terminal 5% vellus. Females 35% terminal and 65% vellus

Question 36

Intermediate hair

Answer 36

Hair on arms and legs