Week 3 Flashcards
Function of Integumentary System
- Protect- bacteria, sun, temperature
- Sensory- Touch (Merkel Cells); Vibration (Pacinian Receptor)
- Thermoregulation- Sweat; Arrector Pili Muscle
- Vitamin D Synthesis- melanin
Connective Tissue
-Loosely packed
-Connects/Protects
Types of Connective Tissue
-Bone
-Cartilage
-Loose Connective
-Dense Connective
-Blood
Parts of the integumentary System
-Skin
-Hair
-Nails
-Glands
Layers of the Skin
-Epidermis
-Dermis
-Hypodermis Technically NOT part of the skin
Epidermis
-Outside layer of skin
-Karatinized
-Avascular
-Protects
Avascular
no blood vessels
Tissue of the Epidermis
Stratified Squamous Epithelium
How many layers of tissue are in the Epidermis?
4-5 layers
- 4 Layers = most of the body
- 5 Layers = palms of hands/soles of feet
Layers of the Epidermis
-Stratum Basale
-Stratum Lucidum
Stratum Lucidum
extra (5th) layer in thick skin
Stratum Basale
-Where mitosis occurs (skin is made)
-BASE layer
-Contains Keratinocytes
Keratinocytes
cells that produce keratin
Keratin
Protein that provides toughness & waterproofing
Two types of cells of the Epidermis
- Merkel Cells
- Melanocyte
Merkel Cell
Sense of touch
Melanocyte
Produces melanin
Dermis
-2nd layer
-contains sweat glands, hair, arrector pili muscle
-vascularized
-has nerve endings
Tissue of the Dermis
Connective Tissues
Layers of Dermis
-Papillary Layer
-Reticular Layer
made of connective tissue
Vascularized
Contains blood vessels
Two proteins in connective tissue of the Dermis
- Elastin
- Collagen
Elastin
Provides stretch to skin
Collagen
-tensile strength
-resists deformation
Hypodermis
NOT part of skin
-Keeps skin to body
-has adipose tissue
-connects, insulates, cushions
Function of Melanin
-Gives pigmentation
-protects skin DNA
Melanocytes
Cells that make melanin
everyone has the same number
How is melanin produced?
- Sun stimulates the production
- Keratinocytes signal to melanocytes to being production
- Melanin that is produced is carried by melanosomes
- Melanosomes go to keratinocytes
- Melanin to skin = protection
Melanosome
vesicles carrying melanin
2 Forms of Melanin
- Eumelanin
- Pheomelanin
What layer of skin does HAIR begin?
Dermis
Hair Matrix
-High amount of keratin
Hair Papilla
connective tissue
Function of Hair
-Protection
-Sensation
-Thermoregulation
-Communication
Arrector Pili Muscle
-Contracts when cold
-Hair stands up = traps warm air close to skin
What turns over faster; hair or skin?
Skin
Why does hair turn white?
-As you age, melanocytes stop making melanin
- Melanosomes still go to the hair but contains no pigment
Function of Nails
-Protects
-Supports
-Fine motor tasks
2 Types of Sweat Glands
- Eccrine Sweat Glands
- Apocrine Sweat Glands
Eccrine Sweat Glands
-Most of the body
-Palms, Soles, Forehead
-Used to keep cool
-water
Apocrine Sweat Glands
-Armpits/Genitals
-Thick organic compound
-more susceptible to bacteria breakdown
Sebaceous Glands
-Closely attached to hair
-produces oil (sebum)
Function of Sebaceous Glands
-Waterproofing
-Lubricates
