SKIN

Question 1

Acts as a barrier protecting the body against injury and dehydration.

Answer 1

SKIN

Question 2

Its tactile sense organs receive stimuli from the environment.
Thermoregulation and water balance.

Answer 2

SKIN

Question 3

Free edge of nail plate, body, root which is the proximal end of nail plate covered by skin fold

Answer 3

NAILS parts

Question 4

Plates of closely compacted hard keratin
Formed by keratinization of epithelial cells in a nail matrix

Answer 4

NAILS

Question 5

Found in axilla, mons pubis, circumanal
region
Larger than eccrine gland
Located in the dermis and duct opens into
the canal of hair follicle

Answer 5

Apoccrine Sweat Glands

Question 6

Coiled tubular glands located deep in the
dermis
Slender duct ascends to the epidermis and
opens as a sweat pore on surface of skin
Widely distributed throughout the integument

Answer 6

ECCRINE SWEAT GLANDS

Question 7

muscle inserts into the CT
sheath of hair follicle slightly above its
midpoint

Answer 7

Arrector pili

Question 8

 Absent in the palms and soles
 Lateral surfaces of feet
 Glans penis, inner surface of prepuce
 Clitoris
 Labia minora and inner surfaces of labia
majora

Answer 8

HAIRS

Question 9

 Embedded in the dermis
 Appendages of the hair follicle located above
the insertion of the arrector pili muscle
 Ducts open into the upper 3rd of the
follicular canal
 Lobular structures consisting of elongated
acini that open into a short duct
 Holocrine gland
 Secretion is called sebum

Answer 9

SEBACEOUS GLANDS

Question 10

 Subcutaneous layer
 Loose CT which anchors the skin to the
underlying fascia or bone
 Contains fat cells

Answer 10

HYPODERMIS

Question 11

Tough leathery layer of connective tissue
that supports the epidermis and binds it to
the subcutaneous tissue

Answer 11

DERMIS
(Corium)

Question 12

2 layers are identified for dermis

Answer 12

 Superficial papillary layer (collagen type
III)
 Deeper reticular layer (collagen type I)

Question 13

 Cells resemble keratinocytes but have a
small dense granules in the cytoplasm
 Few cells in the basal layer
 Present in areas like the fingertips
 Special role for sensory perception

Answer 13

MERKEL CELLS

Question 14

Specialized cells in the basal layer or in the
underlying dermis
 Produce the pigment melanin, responsible
for the pigmentation of the skin and hair

Answer 14

MELANOCYTES

Question 15

synthesized in the melanocytes by
the action of tyrosinase enzyme acting on
tyrosine

Answer 15

Melanin

Question 16

Consists of 15-20 layers of flattened nonnucleated heavily keratinized cells (horny
cells)
 Cytoplasm is filled with keratin filaments
embedded in a matrix
 Surface cells are continuously shed
(desquamated), referred to as stratum
disjunctum

Answer 16

STRATUM CORNEUM

Question 17

 A layer of thin, translucent, lightly stained,
refractile cells
 Layer is apparent in thick skin like the skin of
palms and soles

Answer 17

STRATUM LUCIDUM

Question 18

 Not identifiable in the thinner skin
 Consists of 4-6 rows of very flat cells
 Nuclei begin to degenerate in the outer row
of the stratum granulosum; nuclei are rarely
seen in the stratum lucidum

Answer 18

STRATUM LUCIDUM

Question 19

 Consists of 3-5 layers of flattened polygonal
cells
 Distinguishing features
 Cytoplasm contain large granules with
irregular shape called keratohyaline
granules

Answer 19

STRATUM GRANULOSUM

Question 20

 Cuboidal or slightly flattened cells
 Prominent feature is the presence in the
cytoplasm of numerous bundles of keratin

Answer 20

STRATUM SPINOSUSM
(Malpighian Layer)

Question 21

Seen on light microscope and are called
tonofilaments
 End and insert at desmosomes
 Therefore play an important role in
maintaining cell cohesion

Answer 21

STRATUM SPINOSUSM
(Malpighian Layer)

Question 22

Single layer of cells supported by a basal lamina
 Cells are cuboidal or low columnar, nucleus is
large and cytoplasm basophilic
 Intermediate keratin filaments

Answer 22

Stratum Basale
(Stratum Germinativum)

Question 23

Contain stem cells, its proliferation is responsible
for the continuous renewal of the epithelium
 Mitotic figures are seen
 Human epidermis renewed every 15-30 days

Answer 23

Stratum Basale
(Stratum Germinativum)

Question 24

Stratified squamous epithelium
 Multiple layers of keratinocytes
 5 zones
 Stratum basale (Stratum germinativum)
 Stratum spinosum (Malpighian layer)
 Stratum granulosum
 Stratum lucidum
 Stratum corneum

Answer 24

Epidermis

Question 25

Surface epithelium

Answer 25

Epidermis

Question 26

Underlying connective tissue layer

Answer 26

Dermis or corium

Question 27

Its most reliable identifying feature
histologically is the presence of
cytoplasmic granules called Birbeck
granules
 Function
 Antigen trapping and antigen presentation

Answer 27

LANGERHANS CELLS

Question 28

 Hair bulb
 Hair papilla
 Hair matrix (epithelial cells)
 Glassy layer
 External root sheath
 Internal root sheath

Answer 28

HAIR FOLLICLE
Structure