6 Covering and Lining Epithelium Outer covering of external body surfaces and some organsLines body cavities, interiors of respiratory and gastrointestinal tract, and forms ductsMakes up portions of sense organsTissue from which gametes develop
7 Strategies for Identifying Epithelial Tissues Layers of Cells- simple- stratified- pseudostratified• Shapes of Cells- squamous- cuboidal- columnar
8 Simple Epithelium Single layer of cells Absorption, diffusion, filtrationMinimal wear and tearFound in capillaries and alveoli
12 Pseudostratified Epithelium Only one layer of cells and looks like multiple layers.All cells attached to a basement membrane.Not all cells reach the free surface.Many have cilia on the free surface.Many have goblet cells to secrete mucous.
14 Epithelial Cell Shapes Squamous – flat, scale-like shaped cellsCuboidal – box or cube-shaped cellsColumnar – column or rectangular-shaped cells
15 Connective Tissue Most abundant tissue in the body. Binding and supporting tissue.Primarily composed of collagen fibers.Contain the protein collagen.Extremely vascular(Except cartilage which is avascular)
17 Adipose TissueLoose connective tissue in which special cells, adipocytes, store fatDerived from fibroblastsNucleus and cytoplasm pushed to the side of the cell by large fat dropletFat droplet - triglyceride moleculesMajor energy reserveProtects and insulates internal organsReduces heat loss through the skin
19 Cartilage Avascular - no blood vessels or nerves so very slow healing can withstand tremendous forcesChondrocytes - mature cartilage cellsLacunae - spaces where chondrocytes are locatedPerichondrium - dense connective tissue covering that surrounds the surface of cartilage
20 Types of Cartilage Hyaline Cartilage (Articular Cartilage) FibrocartilageElastic Cartilage
21 Hyaline Cartilage Most abundant type of cartilage Bluish-white in appearanceCovers ends of long bonesReduces friction at joints (can absorb some shock)Forms costal cartilage at ends of ribsMakes up most of the embryonic skeleton
30 Osseous Tissue (Bone) Maintained by specialized cells osteoblasts -osteocytes -osteoclastsIntercellular substances consists of mineral saltscalcium carbonatecalcium phosphatecollagen fibersTwo types of bone tissue:Compact Bone -Spongy Bone
31 Compact (Dense) Bone Structure called osteons (Haversian System) Concentric rings of bone called lamellaeVertical canals within lamellae house blood vessels and nerves (Central Haversian Canals)Perforating (Volkman’s Canals)Lacunae lake of fluid containing osteocytesCanaliculi - canals to nourish and support osteocytes
33 Spongy (Trabecular) Bone Calcium salts and collagen fibers not as densely packedMatrix is made up of thin plates of mineral salts and collagen fibers called spicules or trabeculaeSpaces between the matrix contain red bone marrowHematopoietic Tissue
34 Muscle Tissue Composed of muscle cells (muscle fibers) Highly specialized (produces tension)Can convert chemical energy to mechanical energyPlays a major role in thermoregulationThree Types of Muscle Tissue:Skeletal Cardiac Smooth
35 Skeletal Muscle Attached to bones Striated appearance under a microscopeVoluntary muscle (conscious control)MultinucleatedContractile elements - MyofilamentsSarcolemma - muscle cells membraneSarcoplasm - muscle cells cytoplasm
37 Cardiac Muscle Forms bulk of heart wall (myocardium) Striated muscle Involuntary muscle (generally)Typically has a centrally located nucleusSarcolemma has specialized structures called intercalated discstransmits action potential from cell to cellstrengthens the myocardium
41 Nervous TissueHighly specialized tissue sensitive to various stimuli. Basic unit is the neuron.Capable of converting stimulus to nervous impulses (electrical event)Transmits impulses to:other neuronsglandsmuscle fibers
42 Nerve Cells (Neurons) Cell Body Axons Dendrites contains nucleus and other cell organellesAxonssingle, long processes that transmit nerve impulses away from the cell bodyDendriteshighly branched processes that transmit nerve impulses toward the cell body
44 Gland(s)A cell or group of highly specialized epithelial cells that secrete substances into ducts, onto a surface, or into the blood.
45 Exocrine Glands Secrete their products into ducts (tubes) May enter at the surface or lining of the covering epithelium.goblet cell secret mucussweat glands secrete perspirationcells lining the outer ear secreted oil and waxsalivary glands secret saliva and digestive enzymes
47 Endocrine Glands Ductless glands Secrete products into extracellular spaces where it diffuses into the blood.Secreted products are hormones, chemicals that regulate body functions.Examples of endocrine glands include the pituitary gland, thyroid gland, pancreas, ovaries, and adrenal glands.
49 Membranes Mucous Membranes Serous Membranes Cutaneous Membrane - Skin lines structures that have opening to the external environmentSerous Membranessurrounds organs and lines body cavities without access to the external environmentCutaneous Membrane - SkinSynovial Membranelines cavities of freely movable joints
50 Mucous MembranesLines structures with opening to the external environmentEpithelial layer secretes mucusPrevents cavities from drying outTraps foreign particlesLubricates particles as it moves throughLines respiratory, gastrointestinal, urinary, reproductive tracts
51 Serous MembranesLines body cavities that do not open to the external environmentConsists of two layers:Visceral Layer - covers organs or structuresParietal Layer - attached to cavity wallSecretes a fluid between the layers (Serous Fluid) that provides lubricationPleura - Pericardium - Peritoneum
52 Cutaneous MembraneSkinto be discussed in great detail next chapter
53 Synovial Membrane Not really an epithelial membrane Contains no epithelial tissueLines cavities of freely movable jointsSecretes synovial fluid which lubricates hyaline (articular) cartilageAlso nourishes the hyaline (articular) cartilage
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