Skin

Question 1

3 major layers of the skin and what’re they made of?

Answer 1

1) epidermis: stratified squamous epithelium 2) dermis: connective tissues 3). hypodermis of subcutaneous layer. composed of areolar and adipose CT.

Question 2

T/F: epidermis is avascular

Answer 2

true

Question 3

5 dif layers of epidermis from base to top

Answer 3

1) stratus basale 2) stratum spinosum 3) stratum granulosum 4) stratum lucidum 5) stratum corneum

Question 4

4 types of epidermal cells and locations

Answer 4

1) keratinocyte, found in all cll layers
2) melanocytes; found in stratum basale
3) tactile merkel cells; found on the stratum basale basically on basement membrane. raeches down into dermis by sensory nerve ending
4) epiderma dendritic cell/langerhaan cell: involved in immunity and found in stratum basale

Question 5

Where is the stratum lucidum present?

Answer 5

only found in the epidermis of THICK SKIN - palms of hands

Question 6

the stratum basale is a SINGLE LAYER of epidermis made of ___ ___ cells. How are these cells attached to the basement membrane? Function of stratum basale?

Answer 6

made of cuboidal/columnar cells. the keratinocytes are attached to each other and to the basement mebmrane by desmosomes and hemidesmosomes. Major function:

1) to attach the skin to the basement membrane
2) to reproduce by mitosis.

Question 7

thickest layer of the epidermis. function? How are these cells held together?

Answer 7

stratum spinosum is the thickest layer and provides strength and flexibility to the epidermis. 8-10 layesr are held together by demosomes. You can find langerhans and melanocytes in the spinosum layer.

Question 8

What layer of the epidermis is nuclear degeneration apparent in? What do these cells in this layer contain?

Answer 8

in the stratum granulosum, nuclear degeneration is apparant. the cells contain lamellar granules AND dark-staining keratohyaline granules. Both granule types promote dehydration of cells.

Question 9

in the stratum spinosum, keratin filamnets form bundles known as:

Answer 9

tonofibrils

Question 10

purpose of the stratum corneum. what is its purpose?

Answer 10

its 15ish layers of flat dead squamous cells. Its composed of keratin and surrounded by lipids. it acts as a barrier to light, heat, water, chemicals and bacteria

Question 11

keratinocytes produce ___ and ___ granules

Answer 11

lamellar and keratohyaline granules

Question 12

two major regions of the dermis

Answer 12

1) papillary region
2) reticular region

Question 13

the top 20% of the dermis is the ___ region. What is it made of? What is it’s function? What specialized cells/structures does it contain

Answer 13

PAPILLARY REGION. it is made of loose connective tissue and contains TYPE 7 COLLAGEN to anchor the epidermis to the dermis. It contains:

1) capillaries that feed the epidermis
2) meissner’s touch corpsucles and free nerve endings for senations of heat, cold, pain and tickle.

Question 14

the majority of the dermis is the ___ region. It contains ___ ___ ___ CT with collagen, elastic and reticular fibers. What specialized structures are located in this region? What is the purpose of this region?

Answer 14

RETICULAR REGION because it contains reticular fibers. made of DENSE IRREGULAR FIBROUS CONNECTIVE TISSUE. Purpose is to provide strength, extensibility and elasticity to skin. Contains:

1) oil glands
2) sweat gland
3) fat
4) hair follicles
5) cells and bloodvessels
6) pacinian corpuscles,
7) nerves.

Question 15

stretch marks are dermal tears to the ___ region

Answer 15

tears in the reticular region

Question 16

3 accessory structures of the ksin that are dervied from the epidermis

Answer 16

1) hair
2) oil and sweat glands
3) nails

Question 17

two portions of the hair. Also, what type of muscle surrounds the hair?

Answer 17

the hair consists of the shaft and root, and they are surrounded by arrector pili muscle, which is smooth muscle. the hair is also associated with sebaceous oil glands.

Question 18

label

Answer 18

Question 19

what is the arrow pointing to?

Answer 19

arrector pili muscle surrounding a hair follicle

Question 20

type of secretory system of sebaceous oil glands. What does it produce? Function?

Answer 20

HOLOCRINE. produces sebum that moistens hair and waterproofs and softens skin

Question 21

type of gland

Answer 21

sebaceous holocrine gland

Question 22

sweat glands can either be ___ or____

Answer 22

eccrine(merocine) or apocrine

Question 23

where can you find ceruminous glands?

Answer 23

produces a waxy substance, found in the external AUDITORY MEATUS

Question 24

epithelium of sweat glands

Answer 24

simple cuboidal. Eccrine or merocrine

Question 25

where can you find apocrine sweat glands? How can you differentiate between eccrine and apocrine sweat glands histologically?

Answer 25

aprocrine sweat glands are foudn in ubic and auxillary regions. they can be distinguished because they have a clean and large lumen, whereas eccrine sweat glands have messy lumens

Question 26

structure of apocrine sweat gland

Answer 26

simple coiled tubular

Question 27

___ skin covers all parts of the body, where as ___ skin covers palms and soles of feet.

Answer 27

thin skin, thick skin

Question 28

T/F: thick skin has hair follicles and sebaceous glands

Answer 28

false. thick skin lacks hair follicles, arrector pilli muscles, and sebaceous glands

Question 29

What type of skin has more sweat glands?

Answer 29

thick skin contains more sweat glands

Question 30

5 functions of the skin

Answer 30

1) thermoregulation
2) blood resvoir
3) protection
4) sensory functions: touch, pressure, vibration
5) synthesis of Vit D

Question 32

a first degree burn affects the ___

Answer 32

epidermis

Question 33

a second degree burn destroys:

Answer 33

entire epidermis and part of dermis. results in fluid filled blisters

Question 34

a full thickness burn destroys:

Answer 34

1) epidermis
2) dermis
3) hypodermis
- damaged area is numb because nerves are destroyed. causes scarring

Question 35

label

Answer 35

note the hypodermis is made of primarily adipocytes. just on top of the skeletal muscle

Question 36

meissner corpuscles are located ___ and pacinian corpuscels are located in the ____ and ____

Answer 36

meissner loctaed in dermal papillae just under the epidermis. but pacinian is located in deeper regions in the HYPODERMIS and DERMIS.

Question 37

two types of hairs

Answer 37

1) vellus: microscopic around the entire body
2) terminal hairs. larger and coarser hairs that everyone recognizes as hairs

Question 38

center of the shaft of the hair

Answer 38

medulla. typically cornified or completely absent in bleached hair

Question 39

the cortex of the hair is made of ___ cells, but in the shaft the cells are flattened and keratinized. What produces hair color?

Answer 39

made of cuboidal cells. pigment granules and air spaces between the cortical cells produce hair color.

Question 40

the ___ of the hair is made of hard keratin and surrounds the cortex

Answer 40

the CUTICLE

Question 41

what is the internal root sheath of hair? what three portions are there?

Answer 41

the internal root sheah is the part of the hair follicle and extends from its base to where the sebaceous gland enters.

3 layers:

1) curcile of the internal root sheath
2) huxley’s layer
3) henle’s layer.

Question 42

purpose of the external root sheath.

Answer 42

1) columnar region of sheath is in contact with connective tissue in the sheath.
2) polygonal cells are seaprated from the connective tissue of the sheath by a glassy membrane, which is an extension of the stratum basale and stratum spinosum of the epidermis.
3) external root sheath houses a population of epidermal stem cells capable of division. Serves as a source of sebaceous gland and follicle cells.

Question 43

label

Answer 43

external root sheath (A) is continuous with the stratum germinativum of the epidermis

internal root sheath (B) is continuous with the stratum corneum.

C & D are the cortex and medulla ( of the hair, respectfully

Question 44

the “hair” is loccated in

Answer 44

the cortex.

Question 45

T/F apocrine sweat secretion terminates at the skin surface

Answer 45

false. they terminate at the hair follicle and combine with bacteria to create a characteristic smell. merocrine/eccrine sweat secretions terminate at the sruface however, and they are present in regions that do not have hair at all, such as palms of hands.