Lecture 3 Tissue COVID (5) PDF

Categories of Connective Tissues CT Fluid Supportive proper CT CT Loos Dense Bloo Lymp e d h...

Categories of Connective Tissues CT Fluid Supportive proper CT CT Loos Dense Bloo Lymp e d h Bone Cartilag Irregula Regular e r Elastic Hyaline Elastic Fibrocartilag Areola Adipose Reticula e r r Fascia Body’s connective tissue framework Layers & wrappings that support and surround organs Provides routes for blood vessels, lymphatics & nerves 3 Layers Superficial Fascia Deep Fascia Subserous Fascia Marfan Syndrome Connective tissue disorder Inherited condition (autosomal dominant) Abnormal fibrillin-1 protein Manifestations: skeletal:  tall – long limbs & fingers – loose joints – … ocular:  lens dislocation cardiovascular:  heart valve abnormality – aortic dissecting aneurysm Muscle Tissue Muscle Tissue Specialized for contraction 3 types: skeletal muscles:  body muscles responsible for movement cardiac muscles:  only in the heart smooth muscles:  walls of hollow, contracting organs (e.g., blood vessels - urinary and digestive tracts) Classification of Muscle Cells Striated (banded) or Nonstriated (not banded = smooth) Voluntary (consciously) or Involuntary (automatically) Mononucleated or Multinucleated Skeletal Muscle Cells Striated – voluntary – multinucleated Long and thin Do not divide Produced by stem (satellite) cells No centriole WHY? Cardiac Muscle Cells (Cardiomyocytes) Striated – involuntary – mononucleated Branching – connected at intercalated discs Do not divide Regulated by pacemaker cells Smooth Muscle Cells Nonstriated – involuntary – mononucleated Small and tapered (spindle-shaped) Can divide and regenerate Neural Tissue Neural (Nervous) Tissue Specialized for conducting electrical impulses Rapidly senses internal or external environment Processes information and controls responses 98% in the brain & spinal cord Types of Neural Cells Types of Neural Cells Neurons: functional nerve cells perform electrical communication do not divide (no centrioles) Neuroglia: support cells repair and supply nutrients to neurons Body Membranes Membranes Physical barriers Line or cover portions of the body Consist of: epithelium areolar connective tissues (lamina propria) 4 Types of Membranes 1. Mucous 2. Serous 3. Cutaneous 4. Synovial Mucous Membrane (Mucosa) Lines passageways with external connections Digestive, respiratory, urinary, and reproductive tracts Mucous secretion Structure: epithelial surfaces: Epithelium  moist to reduce friction and  facilitate absorption and excretion connective tissue (lamina propria): Lamina propria (areolar tissue)  areolar tissue Serous Membranes Line cavities not open to the outside Thin but strong 2 layers: parietal layer:lines the cavity visceral layer: covers organs fluid in between to reduce friction Structure: Transudate Mesothelium Areolar tissue Cavities & Serous Membranes Pleura: covers lungs Pericardium: covers heart Peritoneum: covers abdominal organs Cutaneous Membrane (Skin) Outer surface of the body Thick, waterproof and dry SEtp d riatht sq m iefileiu Structure: us ua ? m ep o m i th el iu Epithelium Areolar tissue Dense irregular connective tissue Synovial Membranes Line articulating (moving) joint cavities Produce synovial fluid (lubricant) Articular (hyaline) tissue Protect bone ends Synovial fluid Lack true epithelium Capsule Capillary Adipocytes Areolar tissue Synovial Epithelium membrane Bone Tissue Injuries & Repair Tissues respond to injuries to maintain homeostasis Cells restore homeostasis with 2 processes: inflammation regeneration (healing) Inflammation Tissue’s first response to injury Triggered by: trauma infection Manifestations of inflammatory response: pain tenderness swelling redness hotness Inflammatory Process (1) Damaged cells release chemicals (e.g., PGs – K+) in the interstitial fluid Cells break down: lysosomes release enzymes tissue destruction = necrosis necrotic tissue & cellular debris = pus abscess = pus trapped in an enclosed area Mast cells release chemicals mediators (e.g., histamine – heparin) Dilation of blood vessels (vasodilation) Inflammatory Process (2) Vasodilation: increases blood circulation in the area warmth and redness brings more nutrients and O 2 removes wastes Plasma diffuses into the area: swelling and pain Phagocytic white blood cells: clean up the area Regeneration (Healing) Starts when injury or infection is cleaned up Depends on cell type: epithelial & connective tissue:  regenerate well cardiac cells & neurons:  do not regenerate  wounds heal by connective tissue scar Process of Regeneration New cells: produced by stem cells migrate into area Fibroblasts move into necrotic area: lay down collagen fibers (scar tissue) Summary: Inflammation & Regeneration Effects of Aging on Tissues Thinning of epithelial and connective tissues Increased bruising and impaired healing Increased bone brittleness and fractures Joint pain and degeneration Muscle wasting and weakness Cardiovascular disease Mental deterioration … Summary: Four Types of Tissue  Classification of Tissues Epitheliu Connectiv Muscle Neural m e Epitheli Glands Skeleta Smooth a l Cardia Endocri Exocrin Neuron Neurogli ne e Fluid CT c CT proper a Supportive Dense Blood Lymph CT Loose Bone Cartilage IrregularRegular Areolar Adipose Reticular Elastic Hyaline ElasticFibrocartilage