revise!!!

• STRATUMS basale, spinosum, granulosum, lucidum, corneum
• merkel cells are mechanoreceptors
• melanocytes produce melanin to protect nuclei from UV damage
• keratinocytes synthesise keratin which form a waterproof barrier using keratin filaments
• langherhan cells are resident dendritic immune cells
• vasodilation leading to increased blood flow (erythema) leading to inc. vascular permeability from contraction of endothelium from histamine, bradykinin, leukotrine, substance P mediators and direct vessel injury. This leads to oedema. Simultaneously rolling, adhesion and emigration of neutrophils that phagocytose.
• Serous


  Exudation of cell-poor fluid. Some protein, small number of inflammatory cells. Usually occurs in the peritoneum, pleura, or pericardium. Can also be caused by non-inflammatory conditions.
• Fibrinous


  Due to large vascular leaks or a local procoagulant stimulus. Fibrinogen (from leak) causes fibrin which later organises to fibrous. Occurs in body cavities e.g. meninges and serosal surfaces.
• Suppurative


  Living and dead neutrophils are abundant but mixed with products of tissue digestion to form "pus." An abscess is a localised collection of pus (creates own space vs empyema in potential space).
• Ulcerative


  Local defect, or excavation, of the surface of an organ or tissue. Produced by the sloughing (shedding) of inflamed necrotic tissue.
• Papillary (superfcial) dermis – dermal papillae, separated from

  epidermis by basement membrane, collagen and elastc fbres,

  anchoring fbres from BL of epidermis, capillary loops, Meissner

  corpuscle

  Reticular (deep) layer – bundles of collagen fbres, elastc fbres,

  sweat glands, sebaceous glands, hair follicles, smooth muscle

  fbres (arrector pili), Pacinian and Ruffini corpuscles in deeper

  dermis
• Cell mediated immunity:

  • components - T lymphocytes (actvated by APCs – professional

  (MHC2) and non-professional (MHC1))

  • defence against: bacteria and viruses within phagocytc or infected

  host cells, fungi, protozoa and helminths

  Antbody mediated (humoral) immunity:

  • Components: B lymphocytes (actvated by T-dependent antgens or T-

  independent antgens) & antbodies

  • Defence against bacteria, bacterial toxins, and viruses in bodily fuids
• eccrine sweat glands are abundant and odourless
• apocrine more viscous and thick, bacteria break down to form odour, controlled by nervous system and hormones
• Exotoxins: secreted by some bacteria

  (mainly gram +ve) into surrounding

  medium, rapidly dispersed (soluble in

  body fuids). Heat labile, destroy host

  cells or disrupt certain cellular

  functons. 3 types – AB toxins,

  Membrane disruptng toxins,

  Superantgens. botulism, diptheria, tetanus
• Endotoxins: component of outer-

  membrane of Gram-negatve bacteria.

  Death of bacterial cell liberates

  endotoxin, hence antbiotcs lyse

  bacterial cells temporarily releasing

  endotoxin. Endotoxin exposure does

  not promote formaton of efectve ant-

  toxin. typhoid and meningococcal meningitis
• stimulus, cytokine (kinin, histamine), dilation, flow, permeability, oedema, migration of neutrophils