Integumentary System (KT) Flashcards
What are the 2 components of the integumentary system?
- Cutaneous Membrane
2. Accessory Structures
What is included in the cutaneous membrane? (2)
- Epidermis
2. Dermis
What is included in the Accessory Structures? (3)
- Hair
- Nails
- Glands
Functions of the Integumentary System? (4)
- Protection
- Heat regulation
- Excretion of urea and uric acid
- Synthesizes Vitamin D
What does the integumentary system protect the body from? (6)
- Mechanical Damage
- Chemical Damage
- Bacterial Damage
- Thermal Damage
- UV radiation
- Desiccation
Characteristics of the epidermis (4)
- Stratified squamous epithelium
- Lacks blood vessels but can divide
- As new cells grow, the older cells get pushed to the surface
- Outer most layers are dead
The 4 cell types of the Epidermis
- Keratinocytes (90%)
- Melanocytes (8%)
- Langerhan Cells
- Merkel Cells
Characteristics of…
Keratinocytes
- produce keratin
- provide protection
Characteristics of…
Melanocytes
- produce melanin pigments which protects against UV radiation
- melanin transferred to other cells with long cell processes
Characteristics of…
Langerhan Cells
- from bone marrow
- part of an immune response
Stem cells divide to produce __________ at the basal lamina
Keratinocytes
As keratinocytes are pushed up towards the surface…
- They will fill with keratin and oils
- They slowly die
- Its a 4 week journey unless the outer layers are removed by abrasion
Layers of the Epidermis (5)
- Stratum Germinativum
- Stratum Spinosum
- Stratum Granulosum
- Stratum Lucidum
- Stratum Corneum
Characteristics of Stratum Germativum (2)
- Deepest single layer of cells
2. Combination of merkel cells, melanocytes, kerytinocytes and stem cells that divide repeatedly
How are cells attached in the Stratum Germativum layer?
Cells attached to each other and to the basal lamina by desmosomes & hemidesmosomes
Characteristics of the Stratum Spinosum (3)
- 8-10 cell layers held together by desmosomes
- Melanin taken in by the phagocytosis from near by melanocytes
- During slide preparation cells shrink and look spiny
Characteristics of Stratum Granulosum (3)
- 3 to 5 layers of flat dying cells
- Show nuclear degeneration
- Contain dark-staining keratohyalin granules
What are keratohyalin granules?
They release lipids that repel water
Characteristics of Stratum Lucidum (2)
- Seen in think skin on palms and soles of feet ONLY
2. 3 to 5 layers of clear, flat, dead cells
Characteristics of Stratum Corneum (4)
- 25 to 30 layers of flat dead cells filled with keratin and surrounded by lipids
- Continuously shed
- Barrier to light, heat, water, chemicals and bacteria
- Friction stimulates callus formation
2 types of Skin Thickness
- Thick Skin
2. Thin Skin
Think Skin
- Palmar and Planter surface
- About 30 layers of Stratum Corneum
- All 5 layers
Thin Skin
- Rest of body surfaces
- Fewer layers of Stratum Corneum
- No Stratum Lucidum
- Stratum germativum forms ridges that extend into the dermis
- Increases area of contact for better grip
Epidermal Ridges
-Produced in the epidermis by melanocytes
Melanin
Facts about Melanocytes
- Same number of melanocytes in everyone but different amounts of pigment produced
- UV in sunlight increases melanin production
Melanin production is in response to…
Melanocyte Stimulating Hormone
Melanocytes convert _________ to melanin?
Tyrosine
True/ False: There are several different types of melanin.
True
Typical brown or black melanin
Eumelanin
Red brown version of melanin
Pheomelanin
Freckles or liver spots…
Melanocytes in a patch
Benign localized overgrowth of melanocytes
Nevus or mole
Inherited lack of tyrosine; no pigment
Albinism
- Yellow orange pigment (precursor of Vitamin A)
- Found in stratum Corneum & Subcutaneous
Carotine
- Red, oxygen-carrying pigment in blood cells
- if other pigments are not present, epidermis is translucent and pinkness will be evident
Homoglobin
What are the 2 layers the dermis is composed of?
- Papillary Layer
- Reticular Layer
What does the Papilary Layer of the Dermis consist of?
- Areolar Connective Tissue
- Capillaries and Neurons
- Dermal Papillae
What does the Reticular Layer of the Dermis consist of?
- Anchoring layer
- Large vessels, nerves, adiposcytes, arrector pili muscle
- Dense irregular connective tissue
- Collagen-strength
- Elastic-strength, flexibility
These provide blood supply to the skin… (2)
- Cutaneous Plexus
- Papillary Plexus
- Network of arteries & veins supplying the skin
- In the subcutaneous layer
Cutaneous Plexus
- Follows the epidermal and dermal boundary
- Helps nourish the epidermal layer
Papillary Plexus
The stretching of fibers, loss of their elasticity, breaking of fibers
Stretch marks
Stretch marks form due to…
- Decrease in fiber elasticity
- Tearing of fibers
Also called the superficial fascia or the subcutaneous layer…
Hypodermis
What does the hypodermis consist of…?
- Areolar Connective Tissue
- Adipose connective tissue (insulator)
- Collagen and Elastic fibers
- No distinct boundary with dermis
- Major blood vessels & nerves
- Stabilizes skin
Hair (an accessory structure) is on most surfaces except… (4)
- Plantar and Palmer Surfaces
- Parts of digits
- Lips
- Eyelids (except eye lashes)
True/False: Hair number is fixed at birth?
True
What are the types of hair… (3)
- Vellus (peach fuzz)
- Terminal (thicker with darker pigment)
- Intermediate (arms)
* Hair is based on body location, age, and gender
The 3 basic parts of hair…
- Shaft- mostly projects above the surface of the skin
- Root- Penetrates into the dermis
- Bulb- is the base of the follicle
Each hair consists of… (3)
- Cuticle (outer most)
- Cortex (middle)
- Medulla (inner most)
What is hair composed of?
Dead keratinized epidermal cells
What does a hair follicle consist of?
(hair follicles surround the root)
-Has many sheaths and layers
Functions of hair… (3)
- Protection
- Reduction of heat loss
- Sensing light touch
Part of hair that…
- Sensory nerves surrounding follide
- Detect hair movement
Root hair Plexus
Part of hair that…
- is made up of smooth muscle
- Moves hair
- Causes “goose bumps”
Arrector Pili
Stages of hair growth… (3)
- Anagen Stage
- Catagen Stage
- Telogen Stage
- Lasts from 2 to 6 years depending on the boy part
- matrix cells at base of hair root producing length
Anagen Stage
- Lasts up to 2 weeks
- Matrix cells inactive and follide atrophies
Catagen Stage
- Hair follicle remains dormant
- Hair is eventually pushed out by new hair as cycle renews
Telogen Stage
This is the result of melanin produced in melanocytes in hair bulb
Hair color
Brown black/brown hair contains large amounts of…
Eumelanin
Blond hair results from…
Little eumelanin
Red hair has a high relative amount of…
Pheomelanin
Gray hair is the result of…
decline in all melanin production
Specialized exocrine glands found in the dermis… (4)
- Sebaceous Glands
- Sudoriferous Glands
- Ceruminous Glands
- Mammary Glands
- Secrete sebum (oil) by HOLOCRINE secretion
- Sebum decreases evaporation and decreases bacterial growth
Sebaceous Glands
2 Types of Sebaceous Glands
- With hair- sebum released into follicle
2. Not with hair- Sebum secreted onto epidermis
- Sweat glands
- Coiled tubular gland
- Sweat released by MEROCRINE secretion
- Under neutral control
Sudoriferous Glands
Types of Sudoriferous Glands (2)
- Apocrine
2. Eccrine
- On most body surfaces
- Greatest on palm
- Not associated with hair follicle
- Watery secretion called sensible perspiration
Eccrine Sweat Glands
Sensible perspiration is made up of… (3)
- water
- NaCl
- Urea
Function of Eccrine Glands… (3)
- Cooling
- Excretion
- Protection
- Associated with hair follicle
- Located in axillae & groin
- Produces viscous secretion starting at puberty
Apocrine Sweat
Functions of Apocrine Sweat Glands
- Reducing Friction
- Cooling
- Secrete pheromones
Modified Apocrine Sweat Glands… (2)
- Mammary (lactiferous) for milk production
- Ceruminous - in external ear, its secretion mixes with sebum to create ear wax
Parts of Nails… (4)
- Nail Body
- Nail Bed
- Nail root
- Lunula
Keratinized plate like structure
Nail body
Surface of the skin that covers the nail body
Nail bed
Source of nail production
Nail Root
Whitish, half-moon region at the base of the nail plate
Lunula
Tissue damage and cell death caused by heat, electricity, UV radiation or chemicals
Burns
Associated dangers of burns… (3)
- Dehydration
- Electrolyte imbalance
- Circulatory Shock
Characteristics of First Degree Burns
- skin red and swollen
- only epidermis damaged
Characteristics of Second Degree Burns
- skin red with blisters
- epidermis and upper dermis damaged
Characteristics of Third Degree Burns
- Gray, whitish, or black
- Destroys entire layer
Burns are critical when…
- Over 25% of body has second degree
- Over 10% of body has third degree
Effects of Aging… (5)
- Less hair
- Reduced blood supply
- Dermis tends to be thin
- Drying of epidermis
- Fewer melanocytes
