Ch. 5 Integumentary

Question 1

3 layers of skin

Answer 1

epidermis, dermis, subcutaneous (hypodermis)

Question 2

Epidermis

Answer 2

• most superficial layer
• consists of epithelial tissue
• prevents water loss
• protects against abrasion and UV light

Question 3

Cells of epidermis

Answer 3

keratinocytes and melanocytes

Question 4

keratinocytes

Answer 4

• produce a protein mixture called keratin (makes cells more durable)
• all cells in all layers are these

Question 5

melanocytes

Answer 5

contribute to skin color

Question 6

keratinization

Answer 6

cells moving from the deeper epidermal layers to the surface and change shape and chemical composition

Question 7

Epidermal strata

Answer 7

the many layers of cells in the epidermis (different regions)

Question 8

Stratum basale (germinativum)

Answer 8

• single layer of cuboidal or columnar cells
• layer of epidermis that all cells arise from (basement membrane)
• attach to dermis by desmosomes
• mitosis happens, daughter cells get pushed upwards

Question 9

Stratum spinosum

Answer 9

• consist of daughter cells from basale
• cells are still alive
• keratin fibers accumulate and are stockpiled
• lamellar bodies accumulate

Question 10

Lamellar body (SS)

Answer 10

vesicles filled with triglycerides and other lipids

Question 11

Stratum granulosum

Answer 11

• cells begin to flatten out and die

- lamellar bodies release lipids or fats and oils (cause the water proofing of skin)

Question 12

Stratum lucidum

Answer 12

• not much difference between here and granulosum
• not present in all areas of the body
• cells are dead and appear transparent

Question 13

Stratum corneum

Answer 13

• most superficial stratum of epidermis
• 2 to 3 dozens dead cells thick
• cells begin to shed due to non-working desmosomes

Question 14

Keratohylin granules

Answer 14

• cross linking protein

- more of this, the tougher the cell

Question 15

Thick skin

Answer 15

• has all 5 epithelial strata

- ie. palms of hands and soles of feet

Question 16

Thin skin

Answer 16

• stratum lucidum is usually absent

- covers the rest of the body

Question 17

Skin color

Answer 17

melanin, melanocytes, and melanosomes

Question 18

Melanin

Answer 18

• the group of pigments primarily responsible for skin, hair, and eye color
• absorbs UV radiation (ie. tanning)

Question 19

Melanocytes

Answer 19

• irregularly shaped cells that produce melanin
• does not produce new epidermal cells
• extend into the stratum spinosum

Question 20

Melanosomes

Answer 20

• transport vesicles that are filled with melanin

- cells in stratum spinosum phagocytize a portion of the melanocyte that contains melanin which contains color

Question 21

Production on melanin

Answer 21

-enzyme tyrosinase convert the aa tyrosine to dopaquinone (which can convert to a variety of active pigments, melanin being most common)

Question 22

Dermis

Answer 22

-connective tissue containing fibroblasts, a few adipocytes and macrophage

Question 23

Macrophage

Answer 23

first line of defense against foreign substances

Question 24

Reticular layer of dermis

Answer 24

• deep
• dense irregular connective tissue that contain collagen elastic fibers
• main layer of dermis

Question 25

Paillary layer of dermis

Answer 25

-contain dermal papillae that interdigitates with epidermis

Question 26

Dermal papillae

Answer 26

- dermal extensions into epidermis - finger prints are derived from this - blood vessels extend into the living portions of the epidermis though this

Question 27

Cleavage lines in dermis

Answer 27

tension lines | -elastic and collagen fibers that are oriented more in some directions than in others

Question 28

Accessory structures

Answer 28

hair, glands, nails

Question 29

Hair

Answer 29

is dense and covers most of the body

Question 30

lanugo

Answer 30

delicate, unpigmented hair that is in place by the 5th or 6th month of fetal development

Question 31

Terminal hairs

Answer 31

- long, coarse and pigmented hairs - replace lanugo of scalp, eyelids and brows - are in place at time of birth

Question 32

Vellus hairs

Answer 32

- short, fine unpigmented hair | - replace lanugo on the rest of the body

Question 33

Anatomy of hair

Answer 33

- root: below skin surface - bulb: base of hair root - shaft: above skin surface

Question 34

Medulla

Answer 34

- central axis of the hair | - consists of 2 or 3 layers of cells containing soft keratin

Question 35

Cortex

Answer 35

- forms the bulk of the hair | - consists of cells containing hard keratin

Question 36

Cuticle

Answer 36

- -a single layer of cells that contain hard keratin | - covers the cortex

Question 37

Hair follicle

Answer 37

housed in the dermis, but it is epidermal tissue | -consists of dermal root sheath, epithelial root sheath, matrix, hair papilla

Question 38

Dermal root sheath

Answer 38

covering of hair follicle

Question 39

Epithelial root sheath

Answer 39

divided into internal and external parts - internal: next to the cuticle external: inbetween internal and root sheath

Question 40

Matrix

Answer 40

- growth zone (produces hair) | - undifferentiated epithelial cells

Question 41

Hair papilla

Answer 41

- where dermis of skin project into hair bulb | - contains blood vessels that provide nourshiment

Question 42

Glands

Answer 42

sebaceous, sweat, ceruminous, mammary

Question 43

Sebaceous glands

Answer 43

- located in the dermis - simple or compound aveolar glands - produce sebum

Question 44

Sebum

Answer 44

hair lubercation; oily white substance rich in lipids

Question 45

Sweat glands

Answer 45

eccrine or apocrine

Question 46

Eccrine sweat

Answer 46

- liqid sweat - collects tissue fluid from the dermis - active transport to collect Na+ and Cl+ ions and put them back into dermal tissue, solution reaches surface and is considered hypoosmotic sweat

Question 47

Apocrine sweat

Answer 47

- housed in the sub q | - scent glands

Question 48

Ceruminous gland

Answer 48

- modified eccrine sweat glands that are located in the ear canal - produce cerumen

Question 49

Cerumen

Answer 49

- earwax | - composed of the combined secretions of ceruminous glands and sebaceous glands