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Prof. dr.Jeanne Adiwinata Pawitan, PhDDept. of Histology, FMUI

Onion - tearsSubstances in onion – tears (X)Lacrimal glandGlands in general• Endocrine glands• Exocrine glands

Mode of secretion Consistency of their secretion

Exocrine glands

CutUntil how deep? – skin – underlying tissuesSkin – (Q: related with cell & G?) Layers - epidermis – dermis, subcutis

Cells of the epidermis - (Q) – hyper/hypo pigmentation Keratinocytes Melanocytes Langerhans cells Merkel cells

What kind of tissue – epithelium Various kinds of epithelium

Bleeding

Blood – bloods cells • Appearance • Functions Platelets – what? Structure?• Non nucleated fragment of megakaryocyte• Small: 2-4 μm, disk shapedBlood vessel – endothelium

Platelets Central region – dark – granulomere

α granules Platelet aggregation: thrombospondin Blood coagulation: coagulation factors, platelet thromboplastin Vessel repair: PDGF

δ granules Ca, ADP, ATP - Platelet adhesion – aggregation Serotonin, histamin

λ granules: hydrolytic enzyme – clot resorption Periphery – clear – hyalomere

Plasmalemma: thromboxane A –platelet activator, vasoconstrictor Surface opening tubule system – increase surface area Dense tubular system (sequester Ca)

Endothelium Roles

Secretes substances Type II, IV, V collagen, fibronectin, laminin – extra cellular matrix Vasodilators + inhibitor of platelet aggregation: prostacyclin, NO Converting/inactivating serotonin, prostaglandin, bradykinin,

norepinephrin and thrombin Clotting factors: von Willebrand factor, tissue thromboplastin Vasoconstrictor: Endothelin I – vascular smooth muscle tone Plasminogen activator – lysis of thrombus

Luminal plasmalemma: thrombomodulin, heparin-like molecule – inactivate certain coagulation factor

Possess receptors for leucocytes adhesion molecules (L-selectin, β2 integrin) – leucocytes migrate into connective tissue

Red-swelling-pain

• Swelling – in what kind of tissue Connective tissue (loose) – cells Classification of connective tissue All kinds – microscopic appearance – function

–location - cells Pain – nerve tissue

Neurons

Loose connective tissue• Mast cells – histamines - vasodilatation

Content of granules Primary (preformed) mediators

Heparin, histamine Enzymes: neutral protease, peroxidase, superoxide

dismutase Eosinophil, neutrophil chemotactic factor

Secondary (newly synthesized) mediators Arachidonic acid precursor - cytokines:

leucotrienes, thromboxanes, prostaglandins Non A – cytokines: platelet activating factor,

bradykinins, IL, TNF.

Loose connective tissue

• Mast cells – activation and degranulation Have receptors for - Ig E – immediate

hypersensitivity – anaphylactic reaction Gartner 116-120

• Histiocytes (macrophages) phagocytosis – melanin – non exfoliating (Q:

remain for a long time?)

Finger movement• Tendons – what kind of tissue?

dense regular connective tissue Classification: collagenous, elastic Microscopic appearances: cells

• Muscles – microscopic appearances• Joints

Cartilage Classification: hyaline, elastic, fibro-cartilage Microscopic appearances: cells

Bones Bone structure – types: compact, cancellous (spongy) Microscopic appearance: cells

Joint - cartilage

Compact boneMicroscopic appearance: Periosteum Innercircumferential

lamellae outer circumferential

lamellae Haversian system – osteon

Haversian lamellae – osteocytes – lacunae - canaliculi

Haversian canals – blood vessels

Interstitial lamellae Volkman’s canal

Spongy bone• Bone trabeculae,

spicules – endosteum Osteogenic (progenitors) Osteoblasts Osteoclasts Osteocytes

Marrow cavity Bone marrow – reticular

connective tissue Blood vessels Precursors of blood cells Blood cells