Thymus One of the few glands to shrink with age 70 grams to 3 grams Contained

Thymus one of the few glands to shrink with age 70

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Thymus One of the few glands to shrink with age, 70 grams to 3 grams Contained within a capsule Invaginations of the capsule are called trabeculae and form thymic lobules just like the RLN The dark outside layer is the cortex and where the initial T cell programming occurs The lighter center called the medulla is the final program area for maturing pre-T cells occurs
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Thymus continued Other cells in the thymus include dendritic cells derived from monocytes and act as antigen presenting cells Also epithelial cells function to secrete thymic hormones to assist in T cell programming, and form the framework of the thymus Thymic corpuscles are located in the medulla and manufacture keratohyaline and keratin of unknown function
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Spleen Largest lymphatic organ Also contains a capsule with trabeculae In this case the outside layer is the stroma containing reticular and fibroblast cells The parenchyma contains the splenic artery of white pulp that houses a high number of lymphocytes (B and T cells) The splenic vein forms the red pulp containing RBCs, macrophages for phagocytosis of old RBCs, and 1/3 rd of all the bodies platelets Look up the word splenunculi
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Non-specific disease defense mechanisms AKA innate First line of defense that is both physical and chemical Does not need programming centers
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Normal microbiota Takes up: Space Nutrients Gases like oxygen Vitamins Release bacteriocins The vast majority are toxic to other organisms such as other microbes and of course humans The few that are not toxic to humans can possibly be used as antibiotics
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Skin Skin is a pressure vessel Shedding completely every two weeks Oil and sweat is bacteriostatic The skin is waterproof The skin is dead Clotting stops bleeding but also entraps microbes
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Interesting facts Microbes vary on area and person Some are coccoid others are bacilli Hand washing with antibacterial is a risk for infection 8 hour to recolonize Triclosan is a trichlorinated bi-phenolic
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Eyes We always cry Drains into the acid pit Tears flush Tears also contain lysozyme Lysozyme disrupts the formation of bacterial cell walls undergoing division Lysozyme is also found in saliva and mucous in general
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Ear wax Cerumen is long chain fatty acids Also an as yet unknown agent that is bacteriostatic Interesting note is that genetically people are either hard of soft wax secretions
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Gastrointestinal Acid and alkaline environment Many digestive enzymes also kill microbes Initial microbiota is important Oral antibiotics have made a mess of the microbiota of a lot of people
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Respiratory system At a high risk: because the lungs are: living, thin, high surface area, and exposed Conchae AKA nasal turbinates Mucous lined Smart cilia Vibrissae Epiglottis High number of RLNs and macrophages
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  • Fall '16
  • Lambrini Nicopoulos
  • Physiology, Anatomy, cells, dendritic cells, Cytotoxic Cells, RLN

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