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Tissues of the Body. From Cells to Organ Systems. Cells combine to form tissues, and tissues combine to form organs. Tissues are groups of cells closely associated that have a similar structure & perform a related function. Cells combine to form 4 primary tissues
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FromCellstoOrganSystems Cells combine to form tissues, and tissues combine to form organs Tissues are groups of cells closely associated that have a similar structure & perform a related function • Cells combine to form 4 primary tissues • *Epithelial *Nervous • *Connective *Muscle
Epithelial Tissue Locations: Covers the body Lines the cavities, tubes, ducts and blood vessels inside the body Covers the organs inside body cavities Epithelial Tissue Functions: Protection from physical & chemical injury, Protection against microbial invasion, Contains receptors which respond to stimuli, Filters, secretes & reabsorbs materials and Secretes serous fluids to lubricate structures. Epithelial Tissue
Epithelial Tissue • Two types: • membranous epithelia form the coverings or linings of organs • glandular epithelia form exocrine and endocrine glands • Sheets of cells with specialized contacts & cell junctions • Basal lamina: protein scaffolding secreted by epithelial cells • Basement membrane: reticular fibers (crossed collagen network) that supports epithelium--really associated connective tissue
Connective tissue support Nutrients from capillaries in underlying connective tissue Nerves pass through Easily regenerates Different cell shapes & arrangements Epithelial Tissue
Simple: just one layer or cell shape Stratified: multiple layers and cell shapes Classes of Epithelia
Simple Epithelia TYPE CELL SHAPE EXAMPLE SquamousSquashed CuboidalCubed ColumnarColumns Pseudo-stratified Flat cells give rise to columns Endothelium (lines blood vessels), mesothelium (serous lining of celom) Walls of glands Lining of gut tube; sometimes with cilia like lining of uterine tube With cilia in respiratory tubes to move mucous & particles out of the lungs
SimpleSquamous One cell thick Forms solid layer of cells which line blood vessels, body cavities & cover organs in body cavities Lubrication Squamous Epithelia • StratifiedSquamous • Multiple layers • Forms epidermis (Skin) lining of the mouth • Lubrication & protection
SimpleCuboidal One cell thick, roughly cube shaped Lines ovaries, kidneys, thyroid glands, where secretion & absorption take place Cuboidal Epithelia • Stratified Cuboidal • In multiple layers w/one layer attached to basement membrane & one w/free edge • Mammary & sweat glands • Secretion, absorption & protection
Simple Columnar One cell thick column shaped (long & narrow) Line digestive tract where re-absorption & secretion occurs. Columnar Epithelia • Stratified Columnar • Stacked nucleus on top of nucleus • Lines vas deferans, male urethra • Gives support and some movement.
Columnar Epithelia • Pseudostratified • gives the appearance of more than one layer of columnar epithelial cells • Every cell is attached to the basement membrane • Lines the trachea, fallopian tubes • movement
Transitional Epithelia • Transitional • Several layers of epithelial cells • Forms tissue that must stretch like the bladder • Stretches, protects against seepage
Glandular Epithelia • Glandular • A gland consists of one or more cells that make and secrete a particular product. • Endocrine: secretions diffuse directly into the blood vessels. Ex.– thyroid, adrenals, pituitary • Exocrine: secretions empty through the ducts to the epithelial surface. Ex.- sweat, oil
Types of Epithelium 7 1 2 3 4 5 6
Muscle Tissue: Associated with the bones of the skeleton, the heart and in the walls of the hollow organs of the body. Muscle Tissue Functions: Movement & Locomotion Maintains posture Produces heat Facial expressions Pumps blood Peristalsis Muscle Tissue
Muscle Tissue • Consists of specialized cells that contract when stimulated • The body has three types of muscle tissue: • Skeletal • Cardiac • Smooth muscle
Muscle Tissue • Cardiac (involuntary) HEART • Smooth (involuntary) ORGANS • Skeletal (voluntary) BONES Cardiac Muscle Smooth Muscle Skeletal Muscle
Connective Tissue Connective tissue location: Most abundant & widely distributed tissue Connective tissue has non-living extra-cellular material (matrix between its cells Connective Tissue Functions: Connects, binds and supports structures, Tendons, ligaments, etc. Protects & cushions organs and tissues, Insulates (fat) and Transports substances (blood).
Connective Tissue • Major classes: • Bone • Cartilage • Loose • Dense • Blood • All connective tissues consist of two basic components: • Living cells • Extracellular matrix
Fibers Collagen gives structure Reticular fibers (crossed collagen) gives order Elastin gives elasticity Ground substance Jelly-like material made of sugar-protein molecules (proteoglycans) Allows connective tissue to retain water and serve as support and protection of organs Extracellular Matrix
Type: Loose, adipose Type: Loose, areolar
Loose Fibrous • Contains elastin • Nourishes & stretches • Provides blood vessels to skin • Fills muscle gaps • Adipose • Stores energy (fat) & insulates • Mostly under the skin • Areolar • Wraps the organs • Cushions & protects
Dense Fibrous Collagen is the main matrix element Thick fibers running in many planes Dermis, fibrous capsules around organs Aligned parallel fibers that resists tension Tendon, ligaments Dense Fibrous
Specialized connective tissue • Perform specific functions essential to homeostasis • The body contains three types of specialized connective tissue: • Bone • Cartilage • Blood
Osseous • Bone • Consists of bone cells (osteocytes) and a calcified cartilage matrix • Two types of bone tissue exist: spongy and compact • Tree ring-like appearance • Supports & protects • Mineral storage • Fat storage • Blood cell production
Cartilage • Supports while providing flexibility • Hyaline cartilage absorbs compression between bones in joints (bone ends) • Most abundant type of cartilage found in the body • Fibrocartilageforms cushion like disks between the vertebra • The ears and nose are more flexible and are elastic cartilage
Blood • Blood • Red & white blood cells • Platelets • Plasma • Regulates temperature • Transportation system
Nervous Tissue: Main component of the nervous system ie., brain, spinal cord & nerves. Nervous Tissue Functions: Regulates & controls body functions Generates & transmits nerve impulses Supports, insulates and protects impulse generating neurons. Nervous Tissue
Nervous Tissue • Contains specialized cells that conduct impulses • Conducting cells, called neurons, transmit impulses from one region of the body to another. • Nonconducting cells, neuroglia, are a type of nervous system connective tissue.