Integumentary System

Question 1

Integumentary System

Answer 1

• Outer covering of the body
• e.g. Skin, glands, hair, nails

Question 2

Funtion of the integument

Answer 2

• For production against abrasion, UV light, Microoranisms and water loss
• Sensation
• Vitamin D production
• Temperature regulation
• Excretion

Question 3

Epidermis

Answer 3

• The surface epithelial
  layer
• Prevents water loss and abrasion
  damage

Question 4

Dermis

Answer 4

• An underlying dense
  connective tissue layer
• Structural strength

Question 5

The subcutaneous layer

(Hypodermis)

Answer 5

• Not part of skin but allows structural integrity contains adipose (insulate)

Question 6

Dermis

Connective tissue fibres

Answer 6

• Collagen / elastic fibres
• Fibroblast cells

Question 7

Layers of the dermis

Answer 7

Papillary layer (superficial)
Reticular layer (deep)

Question 8

Structure of Dermis

Answer 8

• Hair follicles / associated muscles
• Sensory receptors
• Sweat and sebaceous glands
• Blood vessels
• Lymphatic vessels

Question 9

Papillary layer

Answer 9

• Fine collagenous and elastic fibers
• Blood vessels: supply epidermis Oxygen/nutrients
• Dermal papillae→ increase strength of bond to epidermis
• finger prints

Question 10

Reticular layer

Answer 10

• Denser, collagenous fibers and elastic fibers
• Collagen & Elastic Fibres = strength / stretchability
• Some key functions: Strength, temperature
  regulation, nutrients to epidermis

Question 11

Dermal growth and repair

Answer 11

• Dermis does NOT continually shed and
  regenerate itself
• The wounds heal by fibroblasts proliferation
• Collogen fibres are predominately in one direction (cleavage lines) during surgical inscision parrel to lines to reduce scaring
• over streached skin (damaged dermis)

Question 12

Epidermis structure

Answer 12

• Ava vascular there are 4/5 layers
• Toughest part of of skin Stratum Lucidium
• Mitosis only occours in the stratum basale
• Keritinisation in the stratum corneum (dead cells) waterproof

Question 13

Melanocytes

Answer 13

• pigment-producing cells (5%
  of the total)
• filter ultraviolet light

Question 14

Langerhans cells

Answer 14

• dendritic (branched)
• immune cells
• In the Stratum spinosum layer

Question 15

Merkel Cell

Answer 15

• Sensory
  receptor cells
• In basal layer

Question 16

Epidermis cell layers

Stratum germinativum

Answer 16

• Stratum basale and stratum spinosum
• The growth layer

Question 17

Base layer

Stratum basale

Answer 17

• Basal cells; only these cells undergo mitosis
• migrate up - become Keratinocytes
• Merkel cell (information); Melanocyte for protection

Question 18

Spiny layer

Stratum spinosum

Answer 18

• Keratinocytes: held together (desmosomes)
• Strength /flexibility
• Begin to generate keratin and lipid
• Some basal cells limited cell division
• Langerhans cells (engulf bacteria)

Question 19

granular layer

Stratum granulosum

Answer 19

• Cells deposits keratin granules - grainy
• Superficial cells: begin to degenerate

Question 20

Clear layer

Stratum lucidum

Answer 20

• Dead cells
• Cell walls filled with keratin / keratohyalin

Question 21

Stratum corneum

Answer 21

• Dead cells filled with keratin (barrier area)
• 15-30 layers
• Constantly shed
• Cells surrounded by lipids

Question 22

Function of Stratum corneum

Answer 22

• Keratin/keratohyalin
• protect against water loss
• prevents penetration of microbes
• The dehydration of underlying tissues
• Mechanical protection against abrasion for the
  more delicate, underlying layer

Question 23

Drug delivery through skin

Answer 23

• lipid-soluble substances will diffuse through lipid layers

Question 24

Encrine Sweat Glands

Answer 24

• Most Common,
• Open directly through sweat pores
• Function throughout life
• Secretion: mostly water with a few salts
• Secrete perspiration or sweat;
• eliminate wastes; and cools body

Question 25

Apocrine Sweat Glands

Answer 25

• Open into hair follicles
• Limited distribution—arm pits/ genitalia
• Limited function in humans
• Begin to function at puberty
• Body odour

Question 26

Sebaceous glands

Answer 26

• Hair folicle
• Secrete seburm which is a oily substance that is a lubricant for hair and skin
• prevents excessive water loss from the skin
• Lipid - antifungal activity

Question 27

Gland secretion and shed skin (surface flim)

Answer 27

Protective barrier formed by mixing of secretions of
sweat and sebaceous glands with sloughed epithelial
cells from skin surface

Question 28

Function of skin shedding

Answer 28

• Antibacterial, antifungal activity
• Lubrication
• Hydration of skin surface
• Buffer of caustic irritants
• Blockade of toxic agents

Question 29

Skin Colour

Answer 29

• Melanin produced by Melanocytes:
• Melanin into vesicles called
  melanosomes
• Phagocytosed by Epithelial cells
  (Keratinocytes)
• To form a Nuclear Cap
• All Keratinocytes can contain melanin,
  only the melanocytes produce it.

Question 30

Annular erythema

Answer 30

• Skin reaction that can be triggered by an infection or some medicines

Question 31

Vitamin D production

Answer 31

• UV light converts a form of cholesterol to chlecalciferol D3
• Blood transports precursor/Cholecalciferol to liver and kidneys wher vitamin D is produced
• Vitamin D is essential for normal absorption of calcium and phosphorous