Flashcards in Integumental system Deck (78):
What germ layer is the epidermis derived from
Role of the integumental system
Vit. D synthesis
What are the three layers of skin
What is the top layer of the epidermis called
What is the bottom layer of of the epidermis called
What cells compose the stratum corneum
What are keratinocytes
Dead cells found in the stratum corneum
What are melanocytes
Have pigment and protect DNA of keratinocytes
What cells compose the stratum basalis
What is the purpose of basal cells
Describe the epidermis
Composed of two layers
4-5 Layers of cells
Describe the dermis
Thicker than the other two layers
Rich nerve and blood supply
What does the dermis contain
Sensory nerve endings
What are the two zones of the dermis
Describe the papillary zone
Zone of the dermis
Loose connective tissue
Describe the reticular zone of the dermis
dense irregular connective tissue
dense concentration of collagenous, elastic, and reticular fibers that weave throughout it
Inner surface --> sensitive
Outer -> exposed to elements --> thicker
Describe the Hyperdermis
Loose connective tissue
Size = variable
What are the two types of skin
What is the difference b/w thick and thin skin
Thick skin = hairless, thick epidermis, oil glands
Thin skin = hairy
What is the rule of 9's
Fluid is proportional to surface area affected
What are the different types of sweat glands
Throughout the body
secrete their substances by exocytosis.
Genital and armpits
secrete an oily/waxy matter, called sebum
Junction between skin and mucous membrane
Describe Pilosebaceous units
hair follicle, sebaceous gland, and an arrector pili muscle
Arrector Pili muscle
Muscle that pushes hair through skin -> gives us goose bumps
What are the two main types of nerve fibres
Sensory and motor
What are the three types of senesory nerve fibres
Touch and pressure
What are the different types of motor nerves
Sudomotor nerve fibres
Nerve fibres that go to the sweat glands
Pilomotor nerve fibres
Go to the arrector pili muscle
Vasomotor nerve fibres
Go to the blood vessels
The motor nerve fibres are part of which nervous system?
Sympathetic Nervous system
Area of skin supplied by a specfic spinal cord segment
From what do dermatomes develop
How many segements of dermatome are there
Experience pain at a different site than it actually originates from
Due to visceral organs lacking a good nerve supply
What are blood vessels derived from
Where is blood found in skin
Dermis and hyperdermis
What is an angiosome
Block of tissue supplied by a source artery and vein
What is the role of the lymphatic system
Take away pathogens
Areas of skin drained by a particular node
Lymphs from different areas that are mixed up
Where is the cervical lymph area
Where is the axillary lymph centres
Where is the inguinal lymp centres
What layers of skin is the lymphatic system found
Superficial dermal lymphatic plexus
Deep dermal plexus
Where is the superficial dermal lymphatic plexus found
Adjacent to the epidermis
Where is the deep dermal plexus found
What germ layer is the dermis derived from?
What germ layer are Cutaneous nerves derived from
neural crest (ectoderm).
In the human embryo, limb buds for the upper limb appear during which week?
As the embryo grows, the upper limb bud takes with it fibres from which spinal nerves
C5 (pre-axial) to T1 (post-axial)
The growing lower limb takes as its nerve fibres those connected to which spinal cord segments
L1 (pre-axial) to S2 (post-axial).
In the early embryo, the longitudinal axis of the body is marked by the ?
What do somites give rise to
What are derma-myotomes?
precursor of dermis and muscles
What do derma-myotomes give rise to?
Nerves and arteries tend to enter a muscle together
The point where the nerve enters a muscle hilum
muscles causing movement at a proximal joint (e.g. shoulder) tend to be supplied by more superior/inferior spinal segment?
distal movements (e.g. fingers) are supplied by more superior/inferior spinal segments?
The cardiovascular system develops from which germ layer
What is vasculogenisis
Blood vessel formation within developing foetus
vessel-forming cells that differentiate from other mesoderm.
What oganic matter does the dermis contain?
collagen (for support) and elastic fibres (for flexibility)
What is collagen and elastic fibres made of
Being fair, tanned, brown or black is determined by
amount and distribution of melanin
nail plate is the harder external surface
nail bed lies under the nail plate
The lunule is the whiter crescent extending out from the cuticle
clumps of angioblasts that have flattened into endothelial cells.
tube-like arrangements formed by organising angiocysts.