Histology: Skin Histology

Front 1

Skin essentially comprises Epidermis, Dermis. And subcutis/ Hypodermis. T/f

Back 1

True

Front 2

Hypodermis not part of skin. T/f

Back 2

True

Front 3

Epidermis is outermost layer – primarily functional and protective. T/f

Back 3

True

Front 4

Skin is subdivided into five layers which migrate upwards and whose purpose is ultimately to form the end layer, or stratum corneum – the outer layer of dead cells that protects us from our environment in the process called keratinization. T/f

Back 4

True

Front 5

The integument is the largest system of the body: It constitutes 15% of body weight It is 1.5 to 2 m2 in area. T/f

Back 5

True

Front 6

A fatty layer (hypodermis) lies deep to the skin. The skin is made up of two distinct regions

Epidermis

Dermis.

T/f

Back 6

True

Front 7

First line of defense is the stratum corneum, which is primarily composed of laminated keratin. T/f

Back 7

True

Front 8

Mention the Layers of the Epidermis: From Inside to Outside

Back 8

Basal layer (stratum germinativum) : A single layer of cells arranged like columns – which divide and turn into the next layer

Spinous layer (stratum spinosum) whose cells, keratinocytes, begin to form keratin.

Granular layer (str. Granulosum) is where cells flatten out and stretch into the

Stratum lucidum and eventually die to form the

Stratum corneum.“horny layer” Composed of laminated keratin.

Front 9

Epidermis is consist of Keratinized stratified squamous epithelium. T/f

Back 9

True

Front 10

Epidermis consist of Four types of cells. Mention them

Back 10

Keratinocytes – deepest, produce keratin (tough fibrous protein) “A family of durable protein polymers that are found only in epithelial cells. They provide structural strength to skin, hair and nails. The fibrous protein is produced by keratinocytes.

” Melanocytes - make dark skin pigment melanin

Merkel cells – associated with sensory nerve endings

Langerhans cells – macrophage-like dendritic cells.

Mnemonics

Kola makes me laugh

Front 11

Mention Epidermis Layers (from deep to superficial).

Back 11

Stratum basale or germinativum – single row of cells attached to dermis; youngest cells

Stratum spinosum – spinyness is artifactual; tonofilaments (bundles of protein) resist tension

Stratum granulosum – layers of flattened keratinocytes producing keratin (hair and nails made of it also)

Stratum lucidum (only on palms and soles)

Stratum corneum horny layer (cells dead, many layers thick)

Front 12

• Dermis

Strong, flexible connective tissue: your “hide”

Cells found in the Dermis are:

Back 12

fibroblasts, macrophages, mast cells, WBc

Front 13

Dermis:

Fiber types: collagen, elastic, reticular Rich supply of nerves and vessels Critical role in thermoregulation (the vessel. T/f

Back 13

True

Front 14

Dermis consists Two layers

Back 14

Papillary – areolar connective tissue; includes dermal Papillae

Reticular – “reticulum” (network) of collagen and reticular fibers

Front 15

Superficial layer is the papillary dermis, a thin layer primarily of collagen f ibers. T/f

Back 15

True

Front 16

Deep layer is Reticular dermis – composed of thickly layered collagen fibers. T/f

Back 16

True

Front 17

_________ are Arranged in dome-shaped inclusions jutting into base of, and feeding small blood vessels into, the epidermis above.

Back 17

Papillary Dermis

Front 18

Reticular dermis Contains numerous small vessels, cutaneous nerves and apocrine glands. T/f

Back 18

True

Front 19

Dermal papillae lie on top of dermal ridges. T/f

Back 19

True

Front 20

The Dermis is the receptive site for pigment of tattoos. T/f

Back 20

True

Front 21

Fingerprints, palmprints, footprints are genetically determined. T/f

Back 21

True

Front 22

Finger print, footprint and palm print contains “sweat films” because of sweat pores. T/f

Back 22

True

Front 23

Flexion creases

Deep dermis, from continual folding. T/f

Back 23

True

Front 24

Tension lines (or lines of cleavage) are The direction the bundles of fibers are directed. T/f

Back 24

True

Front 25

Hypodermis are Also called “superficial fascia”. T/f

Back 25

True

Front 26

Hypodermis consists Fatty tissue which stores fat and anchors skin (areolar tissue and adipose cells) with different patterns of accumulation in (male/female). T/f

Back 26

True

Front 27

Hypodermis is A layer of fat loosely marbled with connective tissue and the deeper parts of apocrine glands. T/f

Back 27

True

Front 28

Hypodermis has important route for small to medium-sized blood vessels, sensory and autonomic nerves, lymphatics. • Deep to this is the deep fascia then skeletal muscle. T/f

Back 28

True

Front 29

Skin color.

Three skin pigments.

Back 29

Melanin: the most important

Carotene: from carrots and yellow vegies

Hemoglobin: the pink of light skin

Front 30

Melanin in granules passes from melanocytes (same number in all races) to keratinocytes in stratum basal. T/f

Back 30

True

Digested by lysosomes

Variations in color

Protection from UV light through Vitamin D synthesis

Front 31

Skin appendages are Derived from dermis but extend into epidermis. T/f

Back 31

False.

It extends from epidermis to dermis.

Include

Hair and hair follicles

Sebaceous (oil) glands

Sweat (sudoiferous) glands

Nails

Front 32

Make up of hair – soft keratin. T/f

Back 32

False

Hard keratin

Front 33

Hair is made up of Three concentric layers

Back 33

Medulla (core)

Cortex (surrounds medulla)

Medulla (core) Cortex (surrounds medulla) Cuticle (single layers, overlapping)

Medulla (core) Cortex (surrounds medulla) Cuticle (single layers, overlapping)

Cuticle (single layers, overlapping)

Front 34

Types of hair are:

Back 34

Vellus: fine, short hairs

Intermediate hairs

Terminal: longer, courser hair

Front 35

Hair growth: averages 4 mm/week. T/f

Back 35

False

2mm per week

Active: growing

Resting phase then shed

Front 36

Hair loss (Alopecia)

Thinning – age related

Male pattern baldness. T/f

Back 36

True

Front 37

Sebaceous (oil) glands

•Entire body. T/f

•Produce sebum by holocrine secretion. T/f

•Oils and lubricates. T/f

Back 37

False- except palm and soles

True

True

Front 38

Sweat glands

•Entire skin surface except nipples and part of external genitalia. T/f

•Prevent overheating Humans most efficient(only mammals have). T/f

•Produced in response tostress as well as heat. T/f

Back 38

True

True

True

Front 39

Type of sweat gland

Back 39

Eccrine or merocrine:

•Most numerous

•True sweat: 99% water, some salts, traces of waste

•Open through pores

Apocrine:

•Axillary, anal and genital areas only. •Ducts open into hair follices.

•The organic molecules in it decompose with time - odor.

Modified apocrine glands: •Ceruminous – secrete ear wax.

•Mammary – secrete milk.

Front 40

Types of Burn:

Back 40

First degree – epidermis: redness (e.g. sunburn)

Second degree – epidermis and upper dermis: blister

Third degree - full thickness

Front 41

Over 10% of thebody has third-degree burns. T/f

Back 41

True

Front 42

35 % of the body has second-degree burns. T/f

Back 42

False.

25%

Front 43

Study for 15sec

Back 43

Done