What are the components of the integumentary system?
Cutaneous and Accessory
Fxns of the Integumentary System
Barrier, thermoregulation, sensations, Waste removal, immune, blood reserve, vit D synthesis
Major layers to the skin and they teype of tissue found in each.
- Epidermis - stratified squamous epithelium
- Dermis - areolar CT and dense CT
- Subcutaneous layer or hypodermis - adipose and areolar CT
What is another name for skin?
What are some of the sensations the skin can detect?
Pain, pressure, temp and touch
How is the skin involved in homeostasis?
Provides info to the central nervous system about the state of the body plus its other fxns the skin participates in homeostasis.
What are the 5 layers of the epidermis from deep out
- Stratum Basal
- Stratum spinosum
- Stratum Granulosum
- Stratum Lucidum
- Stratum Corneum
What is the fxn of stratum basal and what cells can be found there?
- basal cells, merkel cells and melanocytes.
- fxn: Layer interlocks with dermis and new cell production
What is the fxn of the stratum spinosum and what cells can be found there?
- 8-10 layers of keratinocytes that migrated from stratum basal as well as dendritic cells which stimulate immune response
- fxn: Immunity stimulation and cell division to increase thickness
What is the fxn of the stratum granulosum and what cells can be found there?
- 3 - 5 layers of karatinocytes that migrated from stratum spinosum.
- fxn: produce keratin making cells thinner and flater and membranes to thicken and become less permeable.
- produce keratohyalin which causes cells to dehydrate, die and form tight layer with keratin fibers.
What is the fxn of stratum lucidum and what cells can be found there?
- Found only in thick skin areas like soles and palms. Extra layers of dead cells.
- fxn: increase thickness and protection against pressure and wear and tear.
What is the fxn of stratum corneum and what cells can be found there?
- Outermost layer of skin. 15-20 layers of dead keratincytes - full of keratin
- fxn: barrier layer. waterproof due to keratin. protect from loss and microbe entry
What are epidermal ridges?
The design of the stratum basal which has finger like extension down into the dermis. Provides more surface area to attach to the dermis.
What are keratinocytes?
cells that produce keratin
What is keratin?
tough fibrous protein component of nails, hair and calluses as well as the general integumentary surface.
What are melanocytes?
cells that produce melanin
What is melanin?
yellow-brownish pigment that is transferred to neighboring keratinocytes. This pigment gives the skin its color. All people have the same number and distribution of malanocytes. It is the activity level of the cells that vary between individuals.
What causes freckles?
localization of overactivity of melanocytes
What is Vitilago and what causes it?
a condition where one's melanocytes have been destroyed resulting in patches of lighter skin. Patches will typically spread.
Other than melanin, what pigment contributes to skin color?
Where is the papillary region located and what kind of tissue is it made of?
in the dermis and it is made of areolar tissue.
What structures can be located in the papillary region?
capillaries, lymphatics and sensory neurons that supply the surface of the skin.
Where is the reticular region located and what kind of tissue is it made of?
in the dermis deep to the papillary region and is made of dense irregular CT with collagen and elastic fibers and Adipose
What structures can be located in the reticular region?
hair follicles, sebaceous glands, nerves and sweat ducts.
What part of the skin are reticular and papillary regions part of?
What is the difference between elastic and extensible?
Because of elastin, elastic can be stretched and will recoil. Because of collagen, skin is extensible which means it can extend but doesnt mean it will recoil. Sometimes results in stretch marks
Where are hair follicles located and what are their fxn?
- Reticular layer of the dermis
- fxn: location/tube for hair growth
Where are hair roots located and what are their fxn?
- portion of hair located in hair follicle that goes from bulb and goes 1/2 way to surface.
- fxn: It anchors hair into skin
Where are the arrector pili muscles located and what are their fxn?
- in the papillary layer of the dermis where it connects to the sheath surrounding the hair follicle.
- fxn: makes hair stand on end due to emotional or temperature stimuli. In animals it is a method to keep warm/insulated.
what are 2 sweat glands Where are they and what are their fxn?
- Merocrin sweat glands and apocrine sweat glands are found in the Reticular layer of the dermis
- fxn: merocrin sweat glands help control body temp, flush toxins and provide traction.
Where is a hair root plexus and what is its fxn?
- Reticular layer of the dermis wrapped around the base of each hair.
- fxn: sensory neuron that is sensitive to movement of the hair.
What is the hypodermis, where is it and what are some of the fxn?
- layer deep to the dermis comprised of loose fibrouse CT and adipose tissue.
- fxn: stabilize the skin position or anchor it. it is thick, vascular and innervated. It also cushions large vessels, muscles and bones as well as insulate.
What are 4 major types of glands in the Integumentary system?
Sebaceous glands, merocrine and apocrine sweat glands and ceruminous glands.
Where are tactile discs located and what is their fxn?
- located in the epidermis
- fxn: sense fine touch and or pressure in very precise location
Where are tactile corpuscles located and what is their fxn?
- in the dermal papillary layer
- fxn: sensitive to pressure, low frequency vibration and change in shape and touch.
Where are lamellated corpuscles and what are their fxn?
- deep in the dermis
- fxn: sense deep pressure and vibration
Where are Ruffini corpuscles located and what are their fxn?
- deep reticular layer
- fxn: sense changes in tension or shape of skin because changes tug on collagen fibers. Does not adapt meaning response will continue until you make change
Where are free nerve endings located and what are their fxn?
- found in the epidermis
- fxn: sense temp and pain along with some light touch to avoid more serious tissue damage.
What type of secretion does the merocrine gland produce?
What type of secretion does the apocrine gland produce?
sticky, smelly, and thick sweat
What type of secretion does the Sebaceous gland produce?
sebum - mix of lipids, lysozyme (anit-microbe enzyme), and proteins
What type of secretion does the ceruminous gland produce?
cerumen - earwax
Where does the merocrine gland secrete?
directly on the skin
Where does the apocrine gland secrete?
into the hair follicle
What are the 5 types of injuries?
abrasion, incision, laceration, puncture, contusion
What is a laceration?
cut with jagged edges
What is a contusion?
bruise - bleeding but blood trapped in dermis.
What are the 4 stages of healing?
- Inflammatory phase
- Migratory phase
- proliferative phase
- maturation phase
What happens in the inflammatory phase?
- increased blood flow, swelling, pain, redness, chem release attracts phagocytes
- blood fills wound and forms scab and fibroblasts appear at edges of injured area
What happens in the migratory phase?
phagocytes move in and continue to move in to remove debris and epithelial cells and fibroblasts migrate under scab to start forming new epidermis
What happens in the proliferative phase?
- Rapid epidermal cell division and growth
- Collagen fibers from fibroblasts form scar tissue
- blood vessels are reestablished
What happens in the maturation phase?
- scab sloughs off
- Collagen is organized and fibroblasts decrease in numbers but as the dermis continues to heal, the tissue gets thicker - raising a scar.
Name some of the major fxns of the hair
Protect for UV rays, conserve heat, sensory input and protection of areas such as the eyes
5 parts of the nail
nail bed, free edge, cuticle, nail root, nail body
Effects of aging on the integumentary system
decreased cell replacement, thinner skin, slower healing, less hair, less collagen (more delicate), less elastin (more wrinkles), less pigment (less UV protection) and less oil (dry skin)
How many recognized degrees of burns are there?
What are 2 factors considered when determining severity of burn?
- extent - amount of surface area covered
- depth - what layers are affected.
What are some characteristics of a 1st degree burn?
epidermis only - red, mild pain, low risk of scaring
What are some characteristics of a 2nd degree burn?
mostly epidermis but may reach dermis in center of burn, red, pain, blisters, minimal scaring, increase risk of infection when blisters break open.
What are some characteristics of a 3rd degree burn?
destroys epidermis, damage may reach the hypodermis, high risk for infection, may be no pain initially, dehydration, grafting may be necessary.
What are some characteristics of a 4th degree burn?
burn thru all skin and hypodermis! Damage to muscle, bone and deep fascia. Affects circulation. Great risk of death.
Name risk factors of skin cancer
Age, amount of sun exposure over the years, genetics and pale skin
What are the 3 skin cancers we discussed in class?
- Basal cell carcinoma
- Squamous cell carcinoma
- Malignant melanoma
Describe basal cell carcinoma
- located in stratum basal
- most common form of skin cancer
- often caused by UV radiation and virtually never spreads
Describe squamous cell carcinoma
common, rarely spreads, restricted to sun exposed areas, rarely spreads.
Describe malignant melanoma
cancerous melanocytes grow quickly and matastasize through the lymphoid system. outlook is grim.
What is a keloid?
scar that has spread past original injury. it is dark and shiny in appearance and people who burn earier are at greater risk
What is a hypertropic scar?
lacks pigmentation and typically along original lines/borders of injury . Lacks pigmentation.
What are the ABCD's of skin cancer?
- A - Asymmetry
- B - Border
- C - Color
- D - Diameter