integumentary Flashcards
what is the outermost layer of skin know as
skin epidermis
name the 4 major cells found in the epidermis
keratinocytes, melanocytes, Merkel cells and dendritic cells
what is the role of keratinocytes
produce keratin, born deep is epidermis and flatten as they move up to surface of skin, the main cell type in the epidermis
the role of melanocytes
secrete melanin and found in the deepest layer of the epidermis
the role of Merkel cells
specialised in sensory aids like - light touch and texture
the role of dendritic cells
activate immune defence and injest invaders/ foreign materials
name the other major layer of the skin
skin dermis
what are the 2 sublayers of the dermis
papillary layer and the reticular layer
name structure of the papillary layer
loose areolar connective tissue (elastic fibres loose and stretchy)
name the structure of the reticular layer
dense irregular connective tissue (made of collagen so very tough and strong)
name the 6 features found overall in the dermis
collagen, elastic fibres, blood vessels, nerve endings, sweat glands, hair follicles
name the 4 main functions of the skin
protection, temperature regulation, secretion, cutaneous sensation
name 3 things the skin must provide protection against
infection, physical damage(UV), chemical damage/ dehydration
name 2 ways in which the skin monitors temp
hair follicles- trap layer of air to insulate and sweat glands- evaporations help cooling
name 2 glands found in the skin that secrete
sebaceous gland- secreting oil and apocrine gland- secretes milky/oil producing sexual scent
name two features in the skin allowing for cuteness sensation
free nerve ends- touch/pain/temp and pacinlan corpuscle- vibration and pressure
name the 4 stages of soft tissue repair
- haematoma, 2.scab formation, 3.granulation phase, 4. regeneration and remodelling
name 3 things that occur in the haematoma phase of STR
- inflammatory chemicals released, 2. local blood vessels become leaky, 3. WBC, fluid and clotting proteins seep into damaged area
name 2 tings that occur in scab formation in STR
- clot seals injured area from infection, 2. clot dries and forms scab
name 4 things that occur in granulation phase in STR
- ingrowth of fragile capillaries replace scab, 2. fibroblasts multiply and produce collagen fibres and growth factors, 3. macrophages phagocytise dead cells and debris, 4. surface epithelial begins to multiply over granulation tissue
name 3 things that occur in regeneration and remodelling phase of STR
- fibroses area contracts pulling wound together, 2. epithelium thickens under scab that then detaches, 3. fully generated epidermis with scar-tissue underneath.
name the 4 stages of bone repair
haematoma, soft callus, hard callus and remodelling
name e the 2 things that happen in haematoma phase of BR
blood vellsel in bone and periosteum are torn, 2. bone cells become starved and die, causing cell death and swelling and haematoma forms
name the 3 stages in soft callus formation in BR
1.fibroblasts and chondroblasts invade site, 2. fibroblasts produce collagen connecting ends of bone, 3. chondroblasts produce cartilaginous matrix that then calcifies forming soft callus (fibro-cartillaginous callus)
