Chap 5 Flashcards
Integumentary System consists of
- cutaneous membrane
- accessory membrane
Cutaneous membrane =
skin
Accesory membrane =
hair, nails
EPIDERMIS
- stratified squamous epithelium
- main cell type = keratinocytes
- hemidesmosomes to basal lamina
Thin skin =
4 layers of keratinocytes
Thick skin =
5 layes of keratinocytes
Epidermal layers - superficial to deep
- Stratum Corneum
- Stratum Lucidium
- Stratum Granulosum
- Stratum Spinosum
- Stratum Basale (germinativum)
Stratum Corneum
- “horn”
- dead cells tightly interconnected by desomosomes
- water resistant
- 15-30 layers of keratinocytes
Stratum Lucidium
- “clear”
- thick skin only
- acked with keratin and devoid of organelles
Stratum Granulosum
- “grainy”
- large amounts of protein keratin and keratohylain
- 3-5 layers of keratinocytes
Stratum Spinosum
- “spiny”
- 8-10 layers of keratinocytes
- includes Langerhans (dendritic) cells
Stratum Basale (Germinativum)
- anchored to basal lamina
- epidermal ridges which interlock with dermal papillae
Melanin packages into vesicles =
melanosomes
Breakdown of melanosomes =
light skinned
Breakdown in stratum granulosum
dark skinned
niggers
Orange/ yellow pigament
carotene
Yellow/ brown pigament
Melanin
Melanocytes in stratum basale =
skin colour
Function of Melanin
protection from effects of UV radiation
What produces hair colour?
Melanin
Cyanosis
-low blood flow
DERMIS – 2 layers
- Papillary layer
- recticular layer
Papillary layer
- areolar tissue
- dermal papillae = folds on surface
Reticular layer
- dense irregular tissue
- collagen and elastic fibres
collagen =
very strong, resists stretching
elastic fibres =
stretchy
Nerve cells regulate to:
- blood flow
- secretion rates
- moniter sensory receptors
Sensory Receptors respond to:
- light touch
- deep pressure
- vibration
- chemicals
- temp
HYPODERMIS - tissue types
-areolar and adipose tissue
Functions
- elasticity
- reduce heat loss
- energy reserve
- blood reservoir
HAIR
- insulates
- protects
- detects movement
- arrector pili
Sebaceous Glands
secrete oil through holocrine secretion
-2 types:
_ simple branched alveolar glands
_ sebaceous follicles
simple branched alveolar glands
share duct with hair follicle
sebaceous follicles
not associated with hair follicles
Sebaceous glands functions
- inhibits bacterial growth
- lubs and protects keratinized cells (hair and skin)
Sweat glands =
sudiriferous glands
Merocrine sweat glands
-controlled by theromoreglutatory and emotional center
-Function:
_cooling
_excrete water
_flushes
Apocrine sweat glands
- includes cermuninous and mammary glands
- odour
_____ cells are contractile cells that squeeze the gland
Myoepithelial
Ceruminous glands (modified apocrine sweat gland)
- secretion: cerumen = ear wax
- protects ear drum by trapping foreign particles
Skin Cancer types
- basal carcinoma
- Squamous cell carinoma
- Melanoma
Basal Carcinoma
- least dangerous, most common
- stratum basale
Squamous cell carinoma
-stratum spinosum
Melanoma
-least common, most dangerous
-Characteristics:
_Asymmetry
_Border
_Colour
_Diameter
