Introduction to the Integumentary System Flashcards
(95 cards)
What is the function of the skin?
- Secretion e.g. sweat and smell
- Absorption
- Protection
- Sensory
- Appearance
- Body temperature control
- Blood reservoir
What are the 3 layers of the skin?
Epidermis
Dermis
Hypodermis
What are the characteristics of the epidermis?
- Epithelial
- Non-vascular
- Protective
- Outermost layer
What are the characteristics of the dermis?
- Vascular
- Fibrous connective tissue
- Epithelial gland structures e.g. sebaceous glands and sweat glands
- Smooth muscle
- Sensory
Describe the vasculature of the dermis
It is capillaries which have extended upwards from large blood vessels within the hypodermis
Provides skin pigmentation
Function of connective tissue in the dermis
holds the skin together
Function of smooth muscle in the dermis
attached to smooth muscle which when it contracts causes goose bumps
Provides the pungent smell of animals as a defence mechanism
What is the sensory purpose in the dermis?
Allows the detection of pressure, temperature etc.
What are the characteristics of the hypodermis?
- Not skin
- Protective
- Adipose and loose
- Connective tissue
- Vascular
What is the function of connective tissue in the hypodermis?
Strength
A base structure for the dermal attachment
What is the 5 layers of the epidermis?
- Stratum basale
- Stratum spinosum
- Stratum granulosum
- Stratum lucidum
- Stratum corneum
Describe the stratum basale
- Bottom layer of the epidermis
- Contacts the dermis
- made mainly of keratinocytes
- Has specialised epithelium and immune cells
Describe the stratum spinosum
Has weakly differentiated keratinocytes which express the karatin fibres and lamellar bodies
What are keratohyalin?
Keratinocytes which have gone to their next stage of differentiation
Describe the stratum granulosum
Keratohyalin and a hard protein envelope form
Lamellar bodies release lipids and cells die
Describe the stratum lucidum
Dead cells containing dispersed keratohyalin’s
Describe the stratum corneum
Dead cells with a hard protein envelope
The cells contain keratin and are surrounded by lipids
What is a keratinocyte?
A cell which is involved in wound healing due to its stem cell properties
Primary cell of the epidermis
It produces keratin
Where are keratinocytes formed?
Stratum basale
How do keratinocytes move to the surface
mitosis
How are keratinocytes connected to one another?
desmosomes
When is keratin produced?
as cells migrate
what is the function of filaggrin?
causes keratin to dimerise (keratinisation)
If a wound bleeds what does this mean and what is the function of keratinocytes?
You have cut the dermis
Keratinocytes heal the wound and they recruit immune cells to remove pathogens