Integumentary System Flashcards
Name the cell types of the epidermis
Keratinocytes
Melanocytes
Dendritic (Langerhans) cells
Tactile (Merkel) cells
Name the 2 distinct regions of the skin
Epidermis
Dermis
Which layer of skin do keratinocytes arise from?
Stratum basale
What are melanocytes and what do they do?
They are spider-shaped epithelial cells that synthesise melanin.
What does melanin do?
Protects the keratinocyte nucleus from UV light.
Where are Langerhans cells made?
Bone marrow (then they migrate to the epidermis)
What do Langerhans cells do?
Ingest foreign substances
Where are tactile cells found?
Epidermal-dermal junction
What is a tactile cell associated with and what does the combination do?
Each tactile cell is intimately associated with a disc-like sensory nerve ending. The combination is called a tactile disc and it is the sensory receptor for touch.
Name the layers of the epidermis in order from deep to superficial
Stratum basale Stratum spinosum Stratum granulosum Stratum lucidum Stratum corneum
Name the layers of the dermis
Papillary layer
Reticular layer
What 3 pigments contribute to skin colour?
Melanin
Carotene
Heamoglobin
Name the appendages of the skin
Hair Hair follicles Nails Sweat glands Sebaceous glands
What are hairs made of?
Dead, keratinised cells
What are the chief regions of a hair
Shaft
Root
What are the 3 layers of keratinised cells in a hair called?
Medulla
Cortex
Cuticle
What’s the name of the muscle associated with a hair follicle?
Arrector pilli
What is the role of the arrector pilli muscles in humans?
It’s contractions force sebum out of hair follicles to the skin surface where it acts as a skin lubricant.
What’s the name of the pale, fine hair?
Vellus hair
What’s the name of the coarser, longer hair?
Terminal hair
What are nails?
Scale like modifications of the dermis
Which layer of the skin extends beneath the nail as the nail bed?
Stratum basale
Where on the body are there no sweat glands?
Nipples
Parts of the external genitalia
What are the 2 types of sweat glands?
eccrine (merocrine)
Apocrine
Where are eccrine sweat glands particularly abundant?
Palms
Soles of the feet
Forehead
What is an eccrine sweat gland?
A simple, coiled, tubular gland.
The secretory part lies coiled in the dermis and the duct extends to open in the funnel-shaped pore at the skin surface.
What is sweat?
Hypotonic filtrate of the blood
How do apocrine glands secrete sweat?
Into hair follicles
Which parts of the body lack sebaceous glands?
Palms
Soles
What do sebaceous glands secrete?
Sebum
Functionally, what are sebaceous glands?
Holocene glands (they accumulate oily lipids until they become so engorged that they burst)
What does sebum do?
softens and lubricates the hair and skin
What stimulates the secretion of sebum?
Hormones
