CH 5 Histology.pptx

Chapter 05 Lecture Outline Copyright © McGraw-Hill Education. Permission required for reproduction or display. 1  Introduction Tissue categories – Epithelial – Connective – Nervous – Muscular Tissue—similar cells perform a specific role Histology = mi...

Chapter 05 Lecture Outline Copyright © McGraw-Hill Education. Permission required for reproduction or display. 1  Introduction Tissue categories – Epithelial – Connective – Nervous – Muscular Tissue—similar cells perform a specific role Histology = microscopic tissue anatomy 5-2  Tissues Tissues differ in: – Types and functions of their cells – Characteristics of the matrix (extracellular material) fibrous proteins ground substance – fluid or gel 5-3  Epithelial Tissue sheets of cells, one or more cells thick covers surfaces and lines cavities constitutes most glands avascular high rate of mitosis 5-4  Epithelial Tissue Functions: – Protect from injury and infection – Produce secretions – Excrete wastes – Absorption – Filter substances – Sense stimuli 5-5  Epithelial Tissue Basal surface—facing the blood supply Apical surface—faces body surface or lumen (internal cavity) lumen blood 5-6  Epithelial Tissue Simple epithelia Stratified epithelia – one layer of cells – more than one layer – Named by shape – Named by shape of apical cells Copyright © The McGraw-Hill Companies, Inc. 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(a) Classes of epithelium Pseudostratified Simple Stratified columnar (b) Cell shapes Squamous Cuboidal Columnar 5-7 Figure 5.3  Simple Epithelia one layer of cells – Simple squamous (thin, scaly cells) – Simple cuboidal (square or round cells) – Simple columnar (tall, narrow cells) 5-8  Simple Squamous epithelium Figure 5.4a,b rapid diffusion Locations: alveoli, glomeruli, endothelium, and serosa 5-9  Simple Cuboidal Epithelia Figure 5.5a, b – Absorption and secretion – Locations: liver, thyroid, mammary and salivary glands, bronchioles, and kidney tubules 5-10  Simple Cuboidal Epithelium Simple cuboidal Cuboidal cell epithelium Lumen of Nucleus of cuboidal tubule cell Photos © McGraw-Hill Education  Simple Columnar Epithelium Figure 5.6a,b – Single row of tall, narrow cells with microvilli – Absorption and secretion – Locations: lining of GI tract, uterus, kidney, and uterine tubes 5-12  Stratified Epithelia Range from 2 to 20 or more layers of cells named for apical surface cells – Stratified squamous – Stratified cuboidal – Stratified columnar (rare) 5-13  Stratified Squamous Epithelia most widespread epithelium Deepest layers undergo mitosis Two kinds – Keratinized – Nonkeratinized 5-14  Stratified Squamous Epithelia Figure 5.8a,b Keratinized – Resists abrasion; retards water loss – Locations: epidermis; palms and soles especially 5-15  Stratified Squamous Epithelia Figure 5.9a, b Nonkeratinized – without surface layer of dead cells – Locations: tongue, oral mucosa, esophagus, and vagina 5-16  Stratified Cuboidal Epithelia Figure 5.10a,b – Secretes sweat; produces sperm, produces ovarian hormones 5-17  Connective Tissue: Overview Connective tissue—living cells sitting in a non- living matrix they secrete – fibers – ground substance Supports, connects and protects organs variable vascularity 5-18  Connective Tissue: Overview Functions of connective tissues: – Binding of organs—tendons and ligaments – Support—bones and cartilage – Physical protection - fat, bones – Immune protection—white blood cells – Movement—bones – Storage—fat, calcium, phosphorus – Heat production—brown fat in infants – Transport—blood 5-19  Fibrous Connective Tissue Cells – fibroblasts produce fibers and ground substance of matrix – immune cells – adipocytes store fat 5-20  Fibrous Connective Tissue Matrix 1. Fibers Collagen fibers – tough, flexible, abundant body proteins—25% – Tendons, ligaments, deep skin, some bone Reticular fibers – Thin collagen – framework of spleen Elastic fibers – protein called elastin – stretchy 2. Ground substance proteins and carbohydrates – gelatinous – Responsible for stiffness of cartilage 5-21  Types of Fibrous Connective Tissue Loose connective tissue – Much gel-like ground substance Dense connective tissue – many fibers in matrix – vary in fiber orientation Figure 5.13 5-22  Types of Fibrous Connective Tissue Figure 5.14a, b Areolar tissue – Loosely organized – Underlies epithelia, between muscles, passageways for vessels 5-23  Types of Fibrous Connective Tissue Reticular tissue Figure 5.15a, b – supportive framework – in lymph nodes, spleen, thymus, and bone marrow 5-24  Types of Fibrous Connective Tissue Figure 5.16a, b Dense regular connective tissue – parallel fibers – Tendons and ligaments 5-25  Types of Fibrous Connective Tissue Figure 5.17a,b Dense irregular connective tissue – Locations: dermis of skin; capsules around organs 5-26  Adipose Tissue Adipocytes - cells White fat is main type – cell outline resembles chicken wire – energy store – thermal insulation – Cushions organs – Contributes to body contours – subcutaneous - under skin Brown fat—only in fetuses, children – Color from blood vessels and mitochondria – heat-generating 5-27  Adipose Tissue Figure 5.18a,b 5-28  Cartilage connective tissue with flexible matrix chondrocytes (cells) in lacunae (spaces) No blood vessels – Diffusion – Heals slowly Types vary by fiber composition – Hyaline cartilage, fibrocartilage, and elastic cartilage 5-29  Hyaline Cartilage Figure 5.19a,b – Clear, glassy appearance joints, trachea, larynx, growth of juvenile long bones 5-30  Elastic Cartilage Figure 5.20a,b elastic fibers flexible support – Locations: external ear and epiglottis 5-31  Fibrocartilage Figure 5.21a,b – large, coarse bundles of fibers absorbs shock – Locations: pubic symphysis, menisci, and intervertebral discs 5-32  Bone Bone (osseous) tissue is a calcified connective tissue Two forms – Spongy bone: porous Delicate struts of bone: trabeculae Found in heads of long bones and in middle of flat bones – Compact bone: dense, calcified tissue 5-33  Bone Figure 5.22a,b Compact bone is arranged in cylinders that run longitudinally through shafts of long bones – Blood vessels and nerves travel through central canal 5-34  Bone Osteon—central canal and its surrounding concentric lamellae (onion-like layers) Osteocytes—mature bone cells within lacunae Canaliculi—tiny canals radiating from each lacuna for diffusion 5-35  Blood Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fluid connective tissue Platelets Neutrophil Lymphocyte Erythrocyte Monocyte s s Transport function Plasma—blood’s ground substance Formed elements – Erythrocytes— RBCs – Leukocytes—WBCs – Platelets—cell fragments involved in clotting (b ) Figure 5.23b 5-36  Nervous Tissue Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nervous tissue— Nuclei of glial cells Axon Neurosom a Dendrite s communication by electrical and chemical signals neurons (nerve cells) Neuroglia (glial) – Protect and assist neurons – numerous (b ) Figure 5.24b 5-37  Nervous Tissue Neuron parts Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nuclei of glial Axon Neurosom Dendrite cells a s – Neurosoma (cell body) Houses nucleus – Dendrites Receive signals; short – Axon (nerve fiber) Sends outgoing signals very long (b ) Figure 5.24b 5-38  Muscular Tissue Muscular tissue—elongated cells specialized to contract movements – body and limbs – digestion – waste elimination – breathing and speech – blood circulation source of body heat Three types 5-39  Skeletal Muscle – muscle fibers—long thin cells – attach to bone – multiple nuclei – Striations – Voluntary 5-40 Figure 5.25a,b  Cardiac Muscle only in heart – cardiomyocytes are branched cells – one nucleus – Intercalated discs electrical and mechanical connection – Striated and involuntary Figure 5.26a,b 5-41  Smooth Muscle Figure 5.27a,b fusiform cells one central nucleus; no striations – Involuntary – Most is visceral muscle—walls of hollow organs 5-42  Glands Gland—cell or organ that secretes or excretes – Usually epithelial tissue in a capsule – Secretion—product useful to the body – Excretion—waste product 5-43  Endocrine and Exocrine Glands Exocrine glands—contact with surface using a duct Endocrine glands— no ducts; secrete hormones directly into blood Some organs have both – Examples: liver, gonads, pancreas 5-44 Endocrine and Exocrine Glands Figure 5.30a, b 5-45  Exocrine Gland Structure Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Simple coiled Compound Compound tubular acinar tubuloacinar Example: Sweat gland Example: Key Pancreas Duc Example: Mammary t gland Secretory Figure 5.31 portion Duct shape: simple vs. compound Gland shape 5-46  Types of Secretions Serous – thin, watery Perspiration, milk, tears, digestive juices Mucous – glycoprotein, mucin, + water = mucus – Goblet cells: mucous glands 5-47  Membranes Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Mucous coat Cilia Mucin in Epithelium goblet cell Ciliated cells of pseudostratified epithelium Basement Mucous membrane membrane (mucosa) Blood vessel Lamina Collagen fibers propria Figure Fibroblast Elastic fibers (a) Muscularis mucosae 5.33a Mucous membrane (mucosa) – lines passages that open to the external environment – 3 Sublayers: epithelium, areolar tissue, smooth muscle 5-48  Membranes Serous membrane (serosa)—internal lining membrane – Simple squamous epithelium Figure 5.33b 5-49  Tissue Growth Hyperplasia—growth through cell multiplication Hypertrophy—enlargement of preexisting cells Neoplasia— tumor – Benign or malignant – abnormal, nonfunctional tissue 5-50  Tissue Development Differentiation—tissue becomes specialized Stem cells—undifferentiated cells – Have potential to differentiate into mature functional cells 5-51  Tissue Repair – Regeneration: replacement of dead or damaged cells – Fibrosis: replacement of damaged cells with scar tissue 5-52 Tissue Degeneration and Death 1 Atrophy— loss in cell size or number Necrosis—pathological tissue death – Infarction—sudden death of tissue when blood supply is cut off – Gangrene—tissue necrosis Decubitus ulcer (bed sore) Dry gangrene: complication of diabetes Wet gangrene: liquefaction of organs with infection Gas gangrene: infection of soil bacterium, hydrogen bubbles in tissues Tissue Degeneration and Death 2 Apoptosis—programmed cell death – Normal death of cells – Phagocytized by macrophages – Billions of cells die by apoptosis