Test 2- Integumentary System Flashcards
What are the structures within the integumentary system?
Skin
Hair
Nails
Glands
What are the functions of the integumentary system?
Protection Sensation Temperature regulation Vitamin D production Excretion Immunity
List 3 layers of the skin and describe
Epidermis: superficial epithelial tissue
Dermis: connective tissue
Subcutaneous tissue: not part of the skin
- loose connective tissue that connects skin to underlying structure
Types of epidermal cells
Keratinocytes
Melanocytes
Langerhans cells
Merkels cells
Explain Keratinocytes
Most cells produce keratin for strength
Explain melanocytes
Contribute to the skins colour
Explain Langerhans cells
Part of the immune system
Define Merkels cells
Detect light, touch and superficial pressure
Define desquamate
Cells of deeper layers undergo mitosis; as they move towards the surface the old ones slough off
Define keratinization
As cells nice outward through the layers, they fill with keratin, die, and serve as a layer that resists abrasions
Explain epidermal strata
Stratum basale ( germinitivum) - deepest portion of epidermis & single layer
Stratum spinosum- limited cell division
Stratum granulosum- contains keratohyolin
Stratum lucidum- thin, clear zone found on palms and soles
Stratum corneum - most superficial and consists of cornified cells
Describe thick skin:
- has all 5 epithelial strata
- found in places subject to pressure ( palms, fingertips, soles)
Describe thin skin:
- more flexible than thick skin
- covers rest of body
- hair grows here
Skin colour is determined by what 3 things?
- pigment
- blood circulation
- thickness of stratum corneum
What does the dermis contain?
Papillary: superficial ( outer)
Reticular: deep ( inner)
Explain the hair cycle and resting stages:
Growth: cells added at base and hair elongates. Average rate 0.3 mm/ day
Rest: follicle shortens and holds hair in place.
- Rest, then hair falls out of follicle.
- New hair begins
Name and describe the glands :
Sebaceous glands:
- oily secretion
- prevents drying and may inhibit bacteria
- empties into hair follicle
Sweat glands:
- has two types
1. Merocrine ( eccrine) - most common
- opens directly into surface of the skin
- has own pores
- coiled part in dermis, duct exits through epidermis
- can be found in palms and soles
- Apocrine
- active at puberty
- usually open into hair follicles superficial to opening of sebaceous glands
- secretion is odourless but when acted upon by bacteria, may become odiferous
Ceremonious gland :
- modified merocrine sweat glands
- Example ear wax
- in combination with hairs it prevents dirt and insects from entering
Mammary glands:
-modified apocrine sweat glands
Physiology of the integumentary system
Protection:
- against abrasions
- against microorganisms
- melanin against UV radiation
- nails self defence
Sensation :
- pressure
- temperature
- pain
- touch
Temperature regulation:
- sweat causes evaporative cooling
- arteriolar in dermis change diameter, more or less blood flows through the dermis
Vitamin D production:
- begins at the skin
Stimulates uptake of Calcium and Phosphate from intestines
- promotes calcium and phosphate release from bones
- reduced calcium loss from kidneys
- increases blood calcium levels
Excretion:
- removal of waste products from the body
- sweat: water, salt, ammonia and uric acid
What are the effects of aging on the integumentary system?
- skin is more easily damaged because epidermis tissue and amount of collagen decreases
- skin infections are more likely
- wrinkling occurs due to decrease in elastic fibres
- skin becomes drier
- sunlight ages skin more rapidly
What are the classification of burns?
- first degree
- second degree
- third degree
List the skin grafts:
- split skin
- Artificial skin
- cadavers or pigs
Explain the rule of nines :
- used to estimate the amount of body that is burned
What is the purpose of the epidermis?
- Resists abrasion
- Reduces water loss through the skin
What is the purpose of the dermis ?
- responsible for most of the structural strength of the skin
