int

Question 1

Components of the Integumentary System

Answer 1

Question 2

Functions of the Int System

Answer 2

• physical and immunological protection
• thermoregulation (sweat glands and insulation)
• sensation
• metabolic functions (Vit D synthesis and stores energy as subcutaneous fat)

Question 3

Composition

Answer 3

Composed of all four tissue types:

1. Epithelium
2. Connective Tissue
3. Muscle
4. Nerve

Question 4

Epithelium in Skin (2)

Answer 4

covers surface and forms boundary

Question 5

Connective Tissue in Skin (2)

Answer 5

supports epithelium, provides strength and resiliency

Question 6

Muscle in IS (2)

Answer 6

controls diameter of blood vessels, adjusts position of hairs

Question 7

Nerve Tissue in IS (3)

Answer 7

controls smooth muscles, generates sensation, stimulates glands

Question 8

Skin - size/weight

Answer 8

largest organ system of body:

• ~2 sq meters or 22 sq feet
• 15% body weight
• thickness from 0.5 mm to 4.0 mm
• average thickness 1 - 2 mm

Question 9

Answer 9

Question 10

Answer 10

Question 11

Answer 11

Question 12

Stratum Germinativum - aka? composed of? attached to?

Answer 12

• aka stratum basal (b/c it’s the basal layer, job is to continuously divide)
• large basal cells
• firmly attached to basal lamina (which is attached to CT)

Question 13

basal cells

Answer 13

stem cells that divide to give rise to new keratinocytes (found in stratum germinativum/basal)

Question 14

Stratum Spinosum - composed of?

Answer 14

• “spiny” layer
• composed of keratinocytes
• where cells are first called keratinocytes

Question 15

Keratinocytes

Answer 15

• first called in stratum spinosum
• contain bundles of tonofilaments (intermediate filaments, attach to desmosomes)
• desmosomes attach keratinocytes together
• keratinocytes still capable of division

Question 16

Stratum Granulosum - develop? synthesize? secrete? death?

Answer 16

• “granular” layer
• develop large numbers of keratin filaments
• synthesize keratohyalin granules
• secrete lipids that fill spaces between cells = forms a water repellent sealant
• cells alive here, but keratinocytes die once ready to leave

Question 17

Stratum Lucidum - found where? large amounts of?

Answer 17

• “clear” layer (because there is so much keratin, once they become dehydrated they become less clear)
• found only in thick skin of finger tips, palms and soles of feet
• large amounts of keratin and thickened plasma membranes

Question 18

Stratum Corneum - composition? properties?

Answer 18

• corne = hard or hoof like
• multiple layers of dead cells
• cells continuously shed and replaced
• water repellent barrier
• protects against abrasion and microbe invasion (more abrasive forces = more layers)

Question 19

Thin vs. Thick Skin (layers - 3)

Answer 19

• stratum corneum much thinner (in thin)
• other layers less clear in thin
• papillae less well developed in thiin

Question 20

Thin vs. Thick Skin (location and creation)

Answer 20

• thick: can be turned thin if no abrasive forces
• thin: found in axilla becasue less abrasive forces
• thin can be turned thick after being subjected to abrasive forces (blisters, callouses)

Question 21

Answer 21

Question 22

Melanocytes (constitute %, produce, contain, transfer)

Answer 22

• constitute 8% epithelial cells
• produce melanin pigment
• contain long, slender processes which insert between keratinocytes
• transfer melanin granules to keratinocytes

Question 23

Langerhans Cell (arise in? migrate to? what kind of cell? funciton in?)

Answer 23

• arise in bone marrow
• migrate to epidermis
• phagocytic cells
• function in immune response

Question 24

Merkel Cells (number? location? function?)

Answer 24

• least numerous cell type
• located only in basal layer
• function in touch sensation (delicate touch)

Question 25

skin color due to a combination of?

Answer 25

* dermal blood supply * variable quantities of three pigments - melanin (brown/black), pheomelanin( red/yellow), and carotene (yellow/orange)

Question 26

Pale Skin (pink colour due to? dilation of blood vessels? lowered oxygenation..?)

Answer 26

* pink: hemoglobin in dermal blood vessels * dilation of BV during inflammation increases red color * lowered oxygenation of blood: hemoglobin darkens, skin appears blue (cyanosis)

Question 27

DARk Skin (due to? # melanocytes? melanin synthesis?)

Answer 27

* increased amount of pigment * # constant whether in dark light skin (depends on how active they are) * rate of melanin synthesis and transfer is increased (which absorbs UV light, prevents DNA damage)

Question 28

Functions of Melanin? (3)

Answer 28

* absorbs UV, prevents UV induced DNA damage * pigment accumulates around cell nucleus * melanocytes increase rate of synthesis in response to UV exposure - results in tanning

Question 29

UV - induced Skin Damage to Epidermis?

Answer 29

* chromosomal damage * causes skin cancer

Question 30

UV induced skin damage to dermis?

Answer 30

* damage to fibroblasts * alters composition of extracellular matrix * premature wrinkling

Question 31

dermis - what? components (2)?

Answer 31

* connective tissue layer beneath epidermis 1. superficial papillary layer 2. deep reticular layer

Question 32

Papillary Layer - properties? type of tissue? purpose? nerve endings?

Answer 32

* thin * consists of areolar CT * papillae increase area of contact with epidermis * nerve endings for: touch, temp sensation, pain, tickle/itch

Question 33

Reticular Layer - properties? tissue type? composed of? function?

Answer 33

* thick * consists of dense irregular CT * many elastic fibres * provides extensibility and elasticity to skin