Lect 2 Integumentary System

Question 1

Integument basic structures

Answer 1

skin
sweat glands
sebaceous glands
hair
nails

Question 2

skin functions

Answer 2

reception
protection
regulation of body temp
excretion
absorption

Question 3

Specialized peripheral receptors

Answer 3

mechanoreceptors
thermoreceptors
nociceptors

Question 4

mechanoreceptors

Answer 4

respond to touch and pressure

• merkel disc
• meissner’s corpuscle
• pacinian corpuscle
• ruffini organ

Question 5

thermo receptors

Answer 5

respond to cold and warmth

-free nerve ending

Question 6

nociceptor

Answer 6

respond to pain

-free nerve ending

Question 7

Epidermis

Answer 7

4-5 layers constantly shed and replaced

• produces keratin, pigment and immune cells
• derived from the ectoderm

Question 8

dermis

Answer 8

• CT containing collagen and elastic fibers
• contains blood vessels, nerve endings, hair follicles & glands
• derived from mesoderm

Question 9

hypodermis

Answer 9

superficial fascia

-loose CT w/ adipose cells

Question 10

rete apparatus

Answer 10

• the dermal ridge and the epidermal ridge interface
• the interface between the epidermis and dermis is formed by raised ridges of the dermis (dermal ridges, or papillae) which interdigitates with invaginations of the epidermis called epidermal ridges

Question 11

dermal ridges

Answer 11

part of the rete apparatus

raised edges of the dermis

Question 12

epidermal ridge

Answer 12

part of the rete apparatus

invaginations of the epidermis

Question 13

epidermis cell types

Answer 13

stratified squamous keratinized epithelium
-four cell populations
1 keratinocytes
-melanocytes
-langerhans cells
-merkel cells
contain free nerve endings

Question 14

Keratinocytes

Answer 14

largest population of cells in the skin
produces keratin, lipids, lipoproteins
cytomorphosis- at night
Five identifiable zones:
1 stratum basale (germinativum)
2. stratum spinosum
3. stratum granulosum
4. stratum lucidum
5. stratum corneum

Question 15

Layers of keratinocytes

Answer 15

many desmosomes are located on the lateral cell membrane of keratinocytes attaching stratum basale cells to each other and to cells of the stratum spinosum

Question 16

hemidesmosomes

Answer 16

basally located
attach cells to the basal lamina
-attach basal cell membrane to underlying basal lamina

Question 17

stratum corneum

Answer 17

cytoplasm of cells has been replaced by keratin

Question 18

stratum granulosum

Answer 18

substance from the keratohyalin granules combines with tonofibrils converting them to keratin

Question 19

upper stratum spinosum

Answer 19

cells begin to produce keratohyalin granules

Question 20

lower stratum spinosum

Answer 20

tonofilaments merge into bundles called tonofibrils

Question 21

stratum basale

Answer 21

cells begin synthesizing intermediate filaments call tonofilaments

Question 22

lamellar bodies

Answer 22

aka membrane coating granules
produced by keratinocytes
membrane bound
contain glycophospholipid 
serve to waterproof the skin

Question 23

waterproofing skin

Answer 23

lipids make hydrophobic barrier

• in stratum granulosum, the lipid contents of the lamellar bodies are extruded into the intercellular spaces
• keratinocytes also produce membrane coating granules called ‘lamellar bodies’ which contain glycophospholipid

Question 24

Granule formation in epidermis

Answer 24

keratinocytes produce 2 types
Keratohyalin granules
Lamellar bodies

Question 25

Keratohylalin granules

Answer 25

not membrane bound
contain keratin filaments
serve to toughen the skin

Question 26

melanocytes

Answer 26

location: stratum basale
-contain tyrosinase–> converts tyrosine that is transported into cell to melanin
melanin transffered to keratinocytes via melanosomes

Question 27

Langerhans cells

Answer 27

dendritic cells
Contain birbeck granules-unknown funciton
-phagocytosis and APC

Question 28

Merkel cells

Answer 28

associated with sensory nerves which tranverse basal lamina of the epidermis
mechanoreceptors (light tough)

Question 29

Dermis composition

Answer 29

papillary layer

• type III collagen
• elastic fibers
• anchoring fibrils (VII)
• capillary loops
• CT cells

Question 30

skin Sensory receptors

Answer 30

Dermis: meissner, pacinian, Ruffini organ

Epidermis; merkel disks, free nerve endings

Question 31

Glands in reticular layer

Answer 31

sweat glands - eccrine, apocrine

sebaceous glands

Question 32

Eccrine sweat gland

Answer 32

holocrine - disintegrates cell and its content
merocrine- cell stays intact
apocrine - pinched off portion of cell (secretion)

Question 33

myoepithelial cells of eccrine sweat glands

Answer 33

• share basal lamina of the acinar cells
• acini of many multicellular exocrine glands (sweat glands & majory salivary glands) possess myoepithelial cells
• have some smooth muscle cell characteristics (contractility)
• cells wrap around secretory units (acini) and some of the small ducts
• contractions assist in expressing secretions from the acini and from some small ducts

Question 34

Apocrine Sweat gland

Answer 34

found only in axilla (arm pit), the areola of the nipple, and the anal region
Ducts of apocrine glands open into canals of hair follicles

Question 35

Sebaceous glands

Answer 35

found throughout the body embedded in the dermis (except palms, soles & sides of the feet)

• secretory product of the sebaceous glands, sebum, is a wax like, oily mixture of cholesterol, triglycerides, etc.
• like apocrine sweat glands, sebaceous glands are associated with hair follicles

Question 36

Reticular layer of dermis

Answer 36

hair follicles & arrector pili muscles

Question 37

meissner’s corpuscle

Answer 37

light touch, eoisinophilic

Question 38

pacinian corpuscle

Answer 38

deep pressure/vibration