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Body Tissues and Membranes. Chapter 5. What are tissues?. Cells are organized into groups and layers called TISSUES Each tissue is composed of similar cells that are specialized to carry on a particular function Secretion Absorption Support. Tissue Types. Epithelial Connective. Muscle
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Body Tissues and Membranes Chapter 5
What are tissues? • Cells are organized into groups and layers called TISSUES • Each tissue is composed of similar cells that are specialized to carry on a particular function • Secretion • Absorption • Support
Tissue Types • Epithelial • Connective • Muscle • Nervous
Epithelial Tissue • Covering of all major body surfaces • Makes up glands • Always has one free surface and one that’s attached to connective tissue • Basement Membrane Free Surface Basement Membrane Connective Tissue
Epithelial Tissue • Lacks blood vessels • Nutrients diffuse from capillaries of underlying tissue • Rapid rate of reproduction • Constantly sloughed off • Tightly packed • Create good barriers
Epithelial Terms • Shape • Squamous-flat, thin cells • Cuboidal-cube shaped cells • Columnar-tall, elongated cells • Layers • Simple-single layer • Stratified-two/more layers
Types of Epithelial Tissue • Simple Squamous Epithelium • Single layer of “pancake” cells • Easy diffusion • Lung alveoli (air sacs), capillaries Nucleus
Types of Epithelial Tissues • Simple Cuboidal • Single layer of cube-shaped cells • Primarily secretory cells • Ovaries, kidneys, salivary glands Centrally located nucleus
Types of Epithelial Tissue • Simple Columnar • Protection / Absorption • Microvilli • Increase surface area • Digestive tract Nuclei located on same level
Types of Epithelial Tissue • Pseudostratified Columnar • Similar to S.C. • Have cilia along edge • Line respiratory system • Note: how nuclei are at two or more layers Goblet cell: secretes mucus ?
Types of Epithelial Tissue • Stratified Squamous • Many layers thick • New ones push old ones up • Epidermis • Stratified Cuboidal • 2 or 3 layers of cuboidal cells • Stratified Columnar • 2 or 3 layers of columnar cells
Types of Epithelial Tissue • Transitional Epithelium • Responds to tension - stretches out • Creates protective barriers • Lining of bladder & ureters
Glandular Epithelium • Specialized to produce and secrete substances • Make up glands • Exocrine glands - dump secretions into ducts • Endocrine glands - dump secretions into bloodstream
Epithelial Tissue • -Cells readily divide • -Cells are continually • replaced • -Cells are tightly • packed • -Classified by shape • and number of layers
Connective Tissue • Most abundant type of tissue by weight • Functions: • Support • Stores fat • Produces blood cells • Protection from infection
Connective Tissue • Cells spaced further apart than epithelia
Types of Fibers • Collagenous fibers - thick, made of collagen • Strong, slightly elastic, flexible • Ligaments, tendons • Elastic fibers- made of elastin • Branched, stretch easily • Vocal cords
Loose Connective Tissue • Binds skin to underlying tissue • Lies beneath most epithelial tissue
Adipose Tissue (FAT) • Form of loose connective tissue • Protective cushion • Stores energy
Dense Connective Tissue • Binds body parts together • Make up tendons, ligaments
Cartilage • Rigid • Protection, support • Ends of bones, nose, external ears, larynx, between vertebrae
Bone • Most rigid • Functions: • Internal structure • Attachment for muscles • Blood formation • Inorganic mineral storage
Other Connective Tissues • Blood • Transports substances between cells and externalenvironment
Muscle Tissue • Contractile - tissue can contract, becoming shorter and longer • Causes body parts to move • 3 types: • Skeletal muscle-bones • Smoothmuscle-organs • Cardiac muscle-heart only
Nervous Tissue • Found in brain, spinal cord, nerves • Neurons - basic nerve cells • Respond to changes in environment and send messages
Epithelial tissue Smooth muscle