Integumentary System Flashcards
What does the integument include?
Body membranes
Skin
hair
Finernails
Sweat and Oil glands
Purpose of the skin
The first barrier to keep good things such as water in, and bad things such a as harmful bacteria out
How does the integumentary system work?
The skin has multiple layers that protect the body, help regulate body temp, and help excrete wastes via sweat
How does the integumentary system work?
The skin has multiple layers that protect the body, help regulate body temp, and help excrete wastes via sweat
Functions of Skin
Protection
Synthesises Vitamin D with UV
Homeostasis
Sensory reception
4 Basic types of tissue
Epithelium
Connective tissue
Muscle tissue
Nervous tissue
Cells in the dermis
Fibroblasts
Macrophages
Mast cells
WBCs
Fibres types in the dermis
Collagen
Elastin
Reticular
What does the dermis have a rich supply of?
Nerves and vessels
What does the dermis play a critical role in?
Temperature regulation
2 layers of the dermis
Papillary
Reticular
Papillary layer of the dermis
Areolar connective tissue
Includes dermal papillae
Reticular layer of the dermis
Network of collagen and reticular fibres
Role of collagen
Strength and resilience
Role of elastic fibres
Stretch-recoil
Role of tension lines
The direction the bundles of fibres are directed
Stratum corneum - cells
Cells are dead, flat membranous sacs with keratin
What makes skin water-resistant?
Glycolipids in extracellular space
Stratum granulosum - Cells
Cells are flattened, organelles are deteriorating
Cytoplasm full of granules
Stratum Spinosum - Cells
Cells contain thick bundles of intermediate filaments made of pre-keratin
Stratum Basale - Cells
Stem cells are actively dividing
Some newly formed cells become part of the more superficial layers
3 Skin pigments
Melanin
Carotene
Haemoglobin
Movement of melanin in granules
Passes from melanocytes to keratinocytes in stratum basale
Where are skin appendages derived from?
Epidermis but extend into dermis
What does skin appendages include?
Hair follicles
Oil and sweat glands
What are nails made of?
Hard keratin
Where does the nail grow from?
Nail Matrix
Where are hair and hair follicles derived from?
Epidermis and dermis
Functions of hair
Warmth
Sense light touch of skin
Protection
3 Types of Hair
Vellus
Intermediate
Terminal
What causes white hair?
Decreased Melanine and air bubbles in the medulla
How do oil glands produce sebum?
Holocrine Secretion
What is sweat produced in response to?
Heat and stress
Damaged by 1st degree burns
Epidermis
Damage by 2nd degree burns
Epidermis and upper dermis
Damage by 3rd degree burns
Full thickness: epidermis, dermis and often part of hypodermis
Immunity - Anatomical Barriers
Skin
Mucociliary escalator
Flushing action of saliva, tears, urine
Immunity - Chemical factors
Antimicrobial factors in sweat
HCl in stomach
lysozyme in tears/saliva
Role of Monocytes
Migrate into the tissues and become macrophages
Toll-like Receptors
Transmembrane protein, present on macrophages
Conserved across vertebrates
What do Toll-like receptors do?
Look out for and bind to microbes
Trigger a cascade of events to kill or protect against pathogens
Components of the innate response
Neutrophils
Monocytes / macrophages
NK cells
TLRs
Cytokines
Signalling molecules secreted by cells of the immune system and affect the behaviour of other cells
When do neutrophils release cytokines?
When they encounter a pathogen
When do macrophages release cytokines?
When they encounter a pathogen
When do Toll-like Receptors release cytokines?
Upon binding to a microbe or components of a microbe
When do NK cells release cytokines?
On encountering a microbe infected cell / tumor cell
When do lymphocytes release cytokines?
When they are activated
Interferons
Signalling proteins produced by virus infected Monocytes and lymphocytes
Role of interferons
Warn the neighbouring cells a virus is around
