Support and Movement Flashcards
How big is the integument system?
Largest system of the body.
16% of body weight.
1.5-2m^2 surface area.
Skin is the main part.
Others include: hair, nails, and glands.
What are the two components of the integument system?
Cutaneous membrane (skin)
Accessory structures: hair, nails, and glands.
What is the structure of the cutaneous membrane?
Other epidermis: epithelium
Inner dermis: cognitive tissue
Hypodermis- not part of the skin (basement membrane)
What are all the accessory structures?
Hair
Sebaceous gland
Apocrine sweat gland
Eccrine sweat gland
Mammary gland
Ceruminous glands (ears)
Nails
What are the accessory structures’s characteristics? (3)
Derived from embryonic epidermis.
Located in the dermis.
Project through the skin surface.
What is the blood and nerve supply?
Blood supply: blood vessels in the dermis, the epidermis is avascular and receives blood from the dermis though diffusion.
Nerve supply: sensory receptors for pain, temperature, touch, and pressure.
What are the seven functions of the integument system?
- Protects underlying tissues and organs
- Maintains body temperature (insulation and evaporation)
- Excretes water, salts, and organic wastes
- Synthesizes vitamin D3
- Stores lipids
- Sensation: pain – temperature – touch – pressure
- Gives shape
What is the epidermis?
Stratified squamous epithelium.
Avascular.
Keratinocytes:
most abundant cells in the epidermis
organized in layers
contain large amounts of keratin
What is keratinization (cornificatoin)?
Forming a protective layer of dead cells filled with keratin.
Occurs on all exposed skin surfaces except eyes.
Bear foot people are at higher risk due to overuse leading to thicker skin.
What is the dermal blood supply?
Arteries:
Cutaneous plexus; arterial network along the reticular layer.
Papillary plexus: capillary network in papillary layer.
Veins: venous plexus, receives blood from capillaries.
What is contusion (bruise)?
Skin blunt trauma- damage to blood vessles- blood leaks in dermis- black and blue colour.
What are bed sores (decubitus ulcers)?
Due to disturbances of dermal circulation.
Affect skin at pressure points.
Prevented by: frequent changing positions and air mattress with massaging features.
The dermis and never supply.
Never finer in the skin control blood flow, gland secretion, and sensations.
The dermis contains a number of receptors:
1. Pacinian corpuscles: pressure and vibration
2. Meissner’s corpuscles: light touch
3. Merkel discs: pressure, positions, and deep touch
4. Ruffni corpuscles: skin stretch
5. Free never endings: pain and temperature
What is the dermis?
Provides mechanical strength, flexibility and protection.
2 layers of CT.
Highly vascular.
Contains a variety of sensory receptors.
What is the hypodermis?
Subcutaneous tissue, superficial fascia.
Underneath the integument.
Quite elastic.
Stabilizes the skin and allows independent movement.
What is the structure of the hypodermis?
Areolar and adipose tissues.
Connected to the reticular layer of the dermis by connective tissue fibres.
Fats (lipid) storage.
What is the clinical importance of the hypodermis?
Has few capillaries and no vital organs.
Site of subcutaneous injections and liposuction.
What is the structure of the hair?
Structure: hair, hair follicle, and accessory structures.
What type of skin do you find hair?
Only in thin skin
What are the regions of the hair? (2 general)
Hair root:
lower part of the hair
attached to the integument
Hair shaft:
upper part of the hair
sticks out of the integument
What are the layers in hair?
Medulla: central core- keratin soft
Cortex: middle layer- kertain tough
Cuticle- outer layer- keratin tough
What is the hair follicle?
Located deep in dermis
Factory of hair
Wrapped in a dense connective tissue sheath
Base is surrounded by sensory nerves (root hair plexus)
Hair production by the follicle
Hair papilla:
contains capillaries and nerves
Hair bulb:
surrounds the papilla
produces:
hair layers
hair matrix
What are the accessory structures of the hair?
Arrector pili muscle:
involuntary smooth muscle
causes hair to stand up
produces “goose bumps”
Sebaceous glands:
secrete sebum (oil)
lubricate the hair
control bacteria
Where is hair not located?
Think skin.
Some parts of thin skin including lips, labia minora, and penis.
What are the two types of hair?
Vellus hairs:
soft, fine
cover body surface
Terminal hairs:
heavy, pigmented
head, eyebrows and other body areas after puberty (e.g., pubic – axillary)
What are the three functions of hair?
Protects and insulates
Guards openings against particles and insects
Sensitive to very light touch
What is the sebaceous gland?
Simple branched alveolar glands
Holocrine glands
Secrete sebum
Only in thin skin
What is the sebum gland?
Oily material
Contains lipids and other ingredients
Lubricates and protects the epidermis
Inhibits bacteria
Seborrheic dermatitis:
inflammation around hyperactive sebaceous gland (cradle cap, dandruff, and acne)
What are sweat glands?
Simple coiled tubular glands
Produce sweat
2 types:
merocrine (eccrine)
apocrine
What are merocrine sweat glands?
Widely distributed on body surface
especially on palms and soles
Discharge directly onto skin surface
Function:
excrete water, salts, and organic compounds
cool down the skin
flush microorganisms and harmful chemicals from skin
What are apocrine sweat glands?
Axilla, around nipples, and pubic region
Misnomer … merocrine gland
Discharge onto hair follicles
Produce sticky and cloudy secretions acted upon by bacteria intensify its odor
What are mammary glands?
compound alveolar glands
apocrine glands
produce milk
What are ceruminous glands?
simple coiled tubular glands
modified apocrine sweat glands
produce cerumen (earwax)
protect the eardrum
How are glands controlled?
Autonomic nervous system controls glands secretion:
global control:
works simultaneously over the entire body
regional control:
sweating occurs locally e.g., palms
How does skin control thermoregulation?
Main function of sensible perspiration:
regulates body temperature
works with cardiovascular system
Skin plays a major role in controlling body temperature:
acts as a radiator
removes heat from dermal circulation
works by evaporation of sensible perspiration
What are nails?
Produced in nail root: deep epidermal fold near the bone.
It is made of keratin.
What are three nail disease?
Clubbing
Psoriasis
Spoon nail
Step one of injury repair
Bleeding occurs at the site
Mast cells in the region trigger an inflammatory response
Step two of injury repair
After several hours:
A scab has formed
Cells of the stratum basale migrate along the edges of the wound
Phagocytes remove debris and more of these cells are arraying with the enhanced circulation in the area.
Clotting around the edges of the affected area partially isolates the region.
Step three of injury repair
About a week after the injury:
The scab has been undermined by epidermal cells migrating over the collagen giber meshwork produced by fibroblast proliferation and activity
Phagocytic activity around the site has almost ended and the fibrin clot is dissolving
Step four of injury repair
After several weeks:
The scab has been shed, and the epidermis is complete
A shallow depression marks the injury site, but fibroblasts in the dermis continue to create scar tissue that will gradually elevate the overlying epidermis.
What are four types of abnormal scars?
Hypertrophic scar (elevated)
Atrophic scar (healed ance)
Keloid
Stretch marks
What are burns and scalds?
Denaturation of cell proteins
Dehydration – protein loss – infection
Degrees:
first degree:
epidermis only
second degree:
epidermis and upper dermis
may include blisters
third degree:
full thickness ± underlying tissues
skin grafting is necessary
Dangers of facial burns and burns near joints
Effects of aging
Epidermal thinning
numbers of Langerhans cells
vitamin D3 production
glandular activity
blood supply
function of hair follicles
melanocyte activity
of elastic fibers
Slower repair rate
