Histology Lecture 23 PDF

Histology Lecture 23 terms how to study blood draw blood with anti coagulant smear it on slide stain it with Wright stain/Geemstar granulocyte vs agranulocyte granulocyte have...

Histology Lecture 23 terms how to study blood draw blood with anti coagulant smear it on slide stain it with Wright stain/Geemstar granulocyte vs agranulocyte granulocyte have specific granules What is the lifespan of erythrocytes? The lifespan of erythrocytes is approximately 120 days. What is the primary function of erythrocytes? The primary function of erythrocytes is gas exchange, transporting oxygen and carbon dioxide. What is a key protein found in erythrocytes? Erythrocytes contain hemoglobin, which is essential for oxygen transport. Histology Lecture 23 1  How is the erythrocyte membrane structured? The erythrocyte membrane is supported by a 'membrane skeleton linkage', which provides structural integrity and flexibility. What are the ABO antigens, and what determines them? ABO antigens on erythrocytes are determined by the presence of N- acetylgalactosamine (A antigen) or galactose (B antigen). What is the Rh factor? The Rh factor is a protein found on erythrocytes that determines whether blood type is Rh-positive or Rh-negative. where are aged or damaged erythrocytes cleared from the body? Erythrocytes are cleared by the spleen, liver, and bone marrow. central pallor center of RBC alpha spectrin part of RBC cytoskeleton. allows RBC to deform and squeeze through narrow capillaries molecule that determines blood type Histology Lecture 23 2  platelet mechanism platelet binds, activate, and aggregates to plug primary hemostasis vWF binding: von Willebrand factor (vWF) binds to exposed collagen at the injury site. Platelet adhesion: Platelets adhere to vWF, undergoing a conformational change. Activation: Platelets activate and release granules (e.g., ADP, thromboxane A2). Aggregation: Platelets recruit additional platelets and aggregate to form a platelet plug. GPIb adhesion recptor for vWF GPIIB-IIIa aggregation receptor Histology Lecture 23 3  bernard soulier syndrome defect in GP1b glanzmann thrombasthenia defective GPIIB-IIIa ADP and TxA2 activators of platelets Aspirin blocks thrombxane Histology Lecture 23 4  platelet dense and alpha granules Dense granules: Contain ADP, Ca²⁺, and serotonin. Facilitate platelet activation, aggregation, and vasoconstriction. Alpha granules: Contain vWF (von Willebrand factor) and growth factors (e.g., PDGF, VEGF). Promote platelet adhesion and tissue repair. What is the lifespan of platelets? The lifespan of platelets is 7-10 days. What is the primary function of platelets? The primary function of platelets is hemostasis, which involves stopping bleeding by forming clots. What is the precursor cell for platelets? Platelets are derived from megakaryocytes, which release them into the bloodstream. What types of granules are found in platelets? Platelets contain alpha granules and dense granules, which store and release factors crucial for clotting and hemostasis. What membrane proteins are essential for platelet function? Key membrane proteins include: GP Ib, important for adhesion. GPIIb-IIIa, critical for aggregation. What are the three basic reactions involved in platelet function? Adhesion – platelets stick to damaged vessel walls. Aggregation – platelets bind to each other to form a plug. Secretion – granules release their contents to amplify clotting. What are some diseases associated with platelet membrane proteins? Histology Lecture 23 5  Glanzmann's thrombasthenia is associated with defects in GPIIb-IIIa. Bernard-Soulier syndrome is caused by issues with GP Ib What are the targets of common antiplatelet drugs? Clopidogrel targets the ADP receptor, inhibiting platelet aggregation. Aspirin inhibits thromboxane formation, reducing platelet activation. feature of granulocytes segmented nucleus What role do neutrophils play Neutrophils are key players in acute inflammation, responding quickly to infection or injury. attacks bacterium infections What types of granules are found in neutrophils, and what are their functions? Primary (Azurophilic) Granules – Contain bactericidal proteins to kill pathogens. Secondary (Specific) Granules – Contain lactoferrin, which binds Fe³⁺ to limit bacterial growth. Margination, Diapedesis, Chemotaxis, Opsonization, Phagocytosis Histology Lecture 23 6  Margination: Neutrophils align along the blood vessel wall near the site of injury. Diapedesis: Neutrophils migrate through the vessel wall into the tissue. Chemotaxis: Neutrophils move toward chemical signals (e.g., cytokines) released at the injury site. Opsonization: Pathogens are marked with opsonins (e.g., antibodies, complement) to enhance recognition. Phagocytosis: Neutrophils engulf and digest pathogens or debris. eosinophils attack parasites eosinophil structure and cytoplasmic granule Structure: Eosinophils have a bilobed nucleus (2 lobes). Cytoplasmic granules: Contain uniform, red-staining specific granules. Histology Lecture 23 7  eosinophil specific crystalloid granule Major Basic Protein basophil nuclear structure and cytoplasmic granules Nuclear structure: The nucleus is bilobed (2 lobes). The nuclear-to-cytoplasm ratio is approximately 1:1. Cytoplasmic granules: Contain coarse, dark purple, and non-uniform granules. Granules store histamine and other mediators involved in allergic and inflammatory responses. Histology Lecture 23 8  basophils vascular permeability allergic response basophil specific granules histamine hepearin anticoaggulant Monocyte lifespan The lifespan of monocytes is a few days in the bloodstream. What is the nucleus-to-cytoplasm ratio in monocytes? 1:1 What is the structure of the monocyte nucleus? The monocyte nucleus is indented in shape. What type of cytoplasmic granules do monocytes contain? Monocytes contain azurophilic granules, which are lysosome-like and aid in their immune functions. What are the main functions of monocytes? Histology Lecture 23 9  Phagocytosis – Engulfing and digesting pathogens and debris. Antigen presentation – Presenting antigens to T cells via MHC II molecules. Cytokine release – Producing cytokines to regulate immune responses. Differentiation into macrophages – Transforming into macrophages for tissue- specific immune functions. Lymphocyte lifespan and function varied (long live) adaptive immunity humoral response B cells CD20+ cellular immune response T cells CD8+ and CD4+ lymphocyte nucleus to cytoplasm ratio high 4:1 Histology Lecture 23 10