week 7-skin Flashcards

Question

what is seborrhoeic dermatitis and treat,ment?

Answer 1

``` • Infants aged 3-8 months • Yellow, waxy scales on the scalp, thick and difficult to remove • Pink flaky patches on forehead, eyebrows, behind ears, nappy area • Due to developing sebum glands ``` • Infants – Emollients or mineral oils (for scalp) – Topical steroids with antifungal (for body) • Adults – Shampoos with ketoconazole, Zn pyrithione, Se sulfide (anti-yeast) – Steroid scalp lotions/mousses – Topical mild corticosteroids with salicylic acid (for scalp) – Topical mild corticosteroids with anti-yeast – creams/ ointments (clotrimazole, miconazole and nystatin) – Oral antifungals (severe cases)

Answer 2

break in the epithelial integrity of the skin – may affect deeper layers even to bone

Answer 3

``` • Superficial – Damage to epithelium – Heals rapidly through regeneration of epithelial cells • Partial thickness – Involves dermal layer – Vascular damage • Full thickness – Involves subcutaneous fat and deeper – Longest time to heal – new connective tissue required – Contraction during healing ```

Answer 4

- bleeding - inflammation - proliferative - remodeling

Answer 5

- injury to the skin leading to bleeding where a blot clot from to stop the bleeding - inflammation occurs to stop infection occurring so lots of immune cells come into the area and encourage new vessels - proliferation= making more connective tissue and pull the wound closed formed a new epidermal - remodelling to bring it back to normal decrease immune cells there

Answer 6

- durining inflammation= neutrophils and macrophage they ll produce MMP ROS,IL,PDGF - GRANULATION=fibroblasts, macrophages, endotheial cels TNF,IL - Re-epithelialisation= keratinocytes, MMP, KGF, EGF - Tissue remodelling= fibroblasts, collagen , MMPs, TGf3

Answer 7

• Microvascular injury – blood seeps into wound • Injured vessels contract • Coagulation cascade activated by tissue factor • Clot formation and platelet aggregation • Platelets trapped in clot release PDGF, IGF, EGF, TGF-β which attract and activate fibroblasts, macrophages and endothelial cells • Also release serotonin, which increases vascular permeability

Answer 8

• Activation of complement • Infiltration of neutrophils within 24-48h • Diapedesis into wound and phagocytosis of bacteria and foreign particles, with ROS and degrading enzymes – prevent infection • Dying cells cleared by macrophages or extrusion to wound surface

Answer 9

• Blood monocytes arrive and become macrophages (48-72 hr) – key cell type for repair – cytokines and growth factors to recruit fibroblasts, keratinocytes and endothelial cells to repair damage – Collagenases to degrade tissue – Poor wound healing when inadequate monocytes/ macrophages • Lymphocytes enter wound (>72hr) and are involved in remodelling

Answer 10

Fibroblast migration – produce fibronectin, hyaluronan, collagen, proteoglycans – Proliferate and construct new ECM • Collagen synthesis – strength and integrity • Angiogenesis – TGF beta and PDGF from platelets, TNF and bFGF from macrophages – Capillary sprouts invade fibrin/fibronectin-rich wound clot and organise microvascular network • Granulation tissue formation – Mainly proliferating fibroblasts, capillaries ,macrophages in matrix of collagen GAGs and fibronectin and tenascin • Epithelialisation – single layer of epidermal cells migrate from wound edges to form delicate covering, basal cells increase proliferation, new basement membrane – EGF stimulates epithelial mitogenesis and chemotaxis, bFGF and KGF stimulate proliferation

Answer 11

• Matrix matures and remodels – Fibronectin and HA broken down – Collagen bundles increase in diameter and strength (80% of strength of original) – Ongoing collagen synthesis and breakdown by TGFbeta and MMPs – Collagen becomes more organised and shrink to bring wound margins closer together – Fibroblasts and macrophages apoptose – Capillary outgrowth halted and blood flow reduced – Acellular, avascular scar results

Answer 12

* Pressure * Mechanical injury/Trauma * Infection/Foreign substances * Oedema * Necrosis * Topical agents * Lack of oxygen delivery (Ischemia) * Desiccation and dehydration

Answer 13

``` Old age • Obesity • Chronic diseases eg diabetes, anemia • Connective tissue disorders • Immunosuppression • Smoking • Malnutrition • Vascular insufficiency • Stress • Radiation or chemotherapy ```

Answer 14

• Neuropathy – Diabetes mellitus, Spinal injuries • Ischemia – Atherosclerosis, PVD, Microangiopathy (DM) • Peripheral oedema – DVT, Varicose veins, renal or cardiac failure • Pressure – Poor mobility, spinal cord injuries, dementia, diabetes mellitus, old age, terminal illness • Other – Connective tissue disorders leading to vasculitis, Systemic diseases, malignancy, smoking, drugs such as corticosteroids and hydroxyurea

Answer 15

* Presence of necrotic and unhealthy tissue * Excess exudate and slough * Lack of adequate blood supply * Absence of healthy granulation tissue * Failure of re-epithelialisation * Cyclical or persistent pain * Recurrent wound breakdown * Clinical or sub-clinical infection

Answer 16

* Protective barrier – physical and chemical * Involved in mechanical support * Prevents loss of moisture * Reduces harmful effects of uv radiation * Sensory organ – touch, temperature, pressure etc * Helps regulate body temperature * Immune organ to detect infections * Involved in production of vitamin D * Excretion of waste products

Answer 17

epidermis>dermis>hypodermis

Answer 18

``` Keratinocytes – Main cell type – Numerous layers – Stem cells • Merkel cells – Pressure, attached to nerves – Different locations in skin • Melanocytes – Melanin, protect from uv – Basal region • Langerhans cells – Immune - Dendritic cells – All layers of epidermis • T cells – CD8 positive ```

Answer 19

``` -theres stem cells in the stratum basale that Stem cells – self renew Rapidly proliferate – Responsible for replenishing tissue Differentiate into different cells -10-20µm 15-25 flattened, stacked hexagonal cornified cells (corneocytes) -Cells have died and lost nuclei Enriched lipids and keratin ```

Answer 20

- tyosinne is metabolised to dopa and then todopaquinone through tyrosinase - in the presense of cystein dopaquinen becomes pheomelanins that are the red pigment that people with freckles and red hair have more of - but dopaquinine can be metabolised to eventually for eumelanins that are the blackand brown pigemnt shown in darker skin

Answer 21

``` Middle skin layer, 1-6mm fibrous and elastic tissue. Made of connective tissue Supportive and cushioning tissue composed mainly of collagen (70%), elastin and fibrillin • Immune cells – several types • Number of structures found – Nerve endings – Blood vessels – Lymph vessels – Piloerector muscles – Hair follicles – Sweat glands – Sebaceous glands ```

Answer 22

Subcutaneous fat layer acts as a: – Mechanical protector – Thermal insulator – Energy store Heat regulation uses subcutaneous fat pad (hypodermis) and skin blood supply Thickness depends on whole body adiposity but need a minimal amount for skeletal and organ protection

Answer 23

where • Sweat glands • Oil glands • Hairs and follicles • Nails

Answer 24

• Signal-mediated response to cellular insult by: – Infectious agents • Bacteria, Fungi, Viruses, Parasites etc – Toxins • Chemical, Radiation, UV, Biological etc – Physical stresses • Mechanical, Burns, Trauma, etc • Protective response – ultimate goal to remove initial cause of injury and consequences of injury – the necrotic cells and tissues

Answer 25

``` • 1cm2 human skin contains up to 1b microorganisms – bacteria, fungi, viruses, mites • Beneficial – Protect against disease • Detrimental – Exacerbate skin lesions – Promote disease – Delay wound healing • Interact with host immune system – Bi-directional • Affected by lifestyles ```

Answer 26

- chnage in amount due to n the skin due to infection of long term antibiotic use or over growth - leads to inflammation in the skin producing proinflammatory cytokines which can damage the barrier to the skin allowing the immune system to infiltrate, disrupt physical barrier and microbes can infilitrate

Answer 27

-if they have a chronic illness like diabtete or wounds -chnages the microbl community that can be taken over by pathogens and they penearte to sterile tissues leading to inflammation leading to breakdown of barrier, impaired wound healing