The integumentary system Flashcards
Week 2
What is an alternative name given to the subcutaneous layer?
Hypodermis
Name the pigment secreted by specialised cells in the skin that is capable of absorbing ultraviolet light
Melanin
What is keratin?
Keratin is a structural protein produced by keratinocytes, the primary cell type in the epidermis, it is essential for the skin’s strength, waterproofing, and protective barrier against stressors
What is the role of melatonin in relation to skin?
It protects the skin from oxidative stress, UV radiation, and inflammation, regulates pigmentation, and supports wound healing processes
What is the role of Carotene in relation to skin?
It supports skin health by contributing to coloration, antioxidant defence, UV protection, and Vitamin A synthesis
What is the role of collagen in relation to skin?
It is a structural protein that forms a key component of the extracellular matrix in the skin, and is essential for skin structure, elasticity, hydration, and repair
What are langerhans cells?
A specialised immune cell found in the epidermis, the outermost layer of the skin, they are crucial for detecting and responding to external threats e.g. pathogens / harmful substances
What are merkel cells?
Specialised sensory cells found in the epidermis, they are involved in sensation of light touch and are particularly important for detecting textures, shapes, and edges
What cells male up the stratum basale
This layer of epidermis is composed of a single row of cuboidal or columnar keratinocytes
Where is stratum lucidum found?
In thick skin
Which layer of the epidermis thickens as a result of constant exposure to friction, leading to the formation of a callus?
Stratum corneum
What kind of tissue is the dermis mostly made up of?
Dense irregular connective tissue containing collagen and elastic fibres
What is the role of sweat glands in skin?
They are essential for thermoregulation, waste excretion, and skin protection
What are the features of a keloid scar?
Overgrowth of fibrous tissue that forms at the site of a skin injury, extending beyond the original wound boundaries, it is caused by an excessive production of collagen during the healing process
Describe the process of wound healing, more specifically haemostasis
- Surrounding blood vessels constrict to reduce blood flow
- Platelets aggregate to form a temporary plug
- Coagulation cascade activates, producing fibrin, strengthening the clot
- Platelets release growth factors that stimulate following stages of wound healing
What is hirsutism?
A condition characterised by excessive body hair caused by tumours in adrenal glands, testes or ovaries
What is the outermost layer of the epidermis called?
Stratum corneum
What is Bilirubin?
A yellowish pigment produced during the breakdown of RBCs, more specifically the breakdown of haem, elevated levels of bilirubin lead to jaundice
What is the name given to redness of the skin such as seen in patients with inflammation, infection or heat exposure?
Erythema
Define the term pallor
Abnormal paleness or lightness of the skin caused by reduced blood flow, decreased oxygen levels, or decrease in RBC content
Describe the appearance of eczema
Of the skin - patches of redness, blistering, and extreme itching
Name, in order, the layers / strata of the epidermis from most superficial to deepest
Corneum, lucidum, granulosum, spinosum, basale
What do sebaceous glands do?
They are found in the skin and produce sebum (an oily substance that lubricates and protects the skin and hair)
What causes acne?
Inflammation of sebaceous glands caused by bacteria which thrive in the lipid-rich sebum
Name the main functions of skin
- Thermoregulation
- Blood reservoir
- Protection
- Detection and response to cutaneous sensations
- Excretion and absorption
- Vitamin D synthesis
