tissue presentation
TRANSCRIPT
Tissue
• Group of cells similar in structure and function
• Four types of tissue – Epithelial, Connective, Muscle, and Nervous
Epithelial Connective Nervous Muscle
Epithelial
• Covers surfaces• Functions include protection,
absorption, filtration, excretion, secretion, and sensory reception
• Distinguishing characteristics include polarity, cellularity, specialized contacts, support by connective tissue, avascularity, regeneration
• Types include cuboidal, squamous, and columnar in both simple and stratified
Simple
Simple Epithelia
• Single layers of cells• Four main types which
include squamous, cuboidal, columnar, and pseudostratified
Simple Squamous
• Single layer• Flattened cells• Disc Shaped nuclei• Sparse cytoplasm• Simplest epithelia
Simple Cuboidal
• Single layer• Cube-like cells• Large spherical central
nuclei• Functions are to
secrete and absorb
Simple Columnar
• Single layer• Tall cells• Round to oval nuclei• Some cells bear cilia• Layer may contain
goblet cells• Absorbs, secretes
mucus, enzymes, and other substances
• Ciliated type propels mucus
Pseudostratified Columnar
• Single layer of cells• Differing heights of cells
and nuclei• Some cells do not reach
free surface• May contain goblet cells
and bear cilia• Functions are secretion
mostly of mucus but also propulsion of mucus
Stratified Epithelia
• Contains multiple layers of cells
• 4 main types which include squamous, cuboidal, columnar, and transitional
Stratified Squamous
• Thick membrane with several layers of cells
• Basal cells are cuboidal or columnar
• Surface cells are flattened• In Keratinized type surface
cells are full of keratin and dead.
• Basal cells are active in mitosis
• Function is to protect tissues
Stratified Cuboidal
• Mostly two layers• Cubelike cells• Protects• Rare in the body
Stratified Columnar
• Several layers• Basal cells mostly
cuboidal• Superficial cells
elongated and columnar• Protects and Secretes
Transitional Epithelium
• Resembles stratified squamous and stratified cuboidal
• Basal cells cuboidal or columnar
• Surface cells dome shaped or squamouslike
• Depends on organ stretch
Connective Tissue
• Found in all parts of body• Performs variety of functions
like protecting, supporting, and binding other tissues.
• Main types include connective tissue proper, cartilage, bone, and blood.
• Characteristics include many types of cells, great deal of noncellular, nonliving material between cells of connective tissue
• Connective tissues have a rich supply of blood vessels
Mesenchyme Embryonic
• Gel-like ground substance with fibers and start shaped mesenchymal cells
• Found in embryo• Functions gives rise to
other connective tissue types
Areolar
• Gel-like matrix with three fiber types, cells, fibroblasts, macrophages, mast cells, and some white blood cells.
• Wraps organs and cushions them
Adipose
• Matrix, very sparse, closely packed adipocytes , with nucleus pushed to side by fat droplet
• Provide reserve fuel, insulates, supports and protects organs
Reticular
• Network of reticular fibers in a loose ground substance
• Cells lie on network• Fibers form stroma that
supports other cell types
Dense Regular
• Mostly collagen fibers with few elastin fibers
• Major cell is fibroblast• Attaches muscle to
bone, muscle to muscle, or bone to bone
• Withstands great tensile stress when force is applied in one direction
Dense Irregular
• Mainly irregularly arranged collagen fibers and some elastic fibers
• Major cell is the fibroblast
• Withstand tension in several directions
• Provides structural strength
Cartilage Hyaline
• Amorphous but firm• Collagen fibers form
imperceptible network• Supports and reinforces• Has cushioning
properties• Can resist compressive
stress
Cartilage elastic
• Similar to hyaline• More elastic fibers in
matrix• Maintains shape of
structure with flexibility
Fibrocartilage
• Matrix is similar to hyaline but less firm
• Thick collagen fibers• Tensile strength can
absorb compressive shock
Osseous
• Hard, calcified matrix, with many collagen fivers
• Very well vascularized• Supports and protects• Marrow inside bones is
site for bone formation
Blood
• Red and white blood cells
• Contained in a fluid matrix
• Transport substances
Nervous Tissue
• Composed of two major cell populations, Neuroglia and Neurons
• Neurons are branching cells
• The neuroglia are special supporting cells that protect, support, and insulate the more delicate neurons
Muscle Tissue
• Muscle tissue is specialized in contracting and producing body movement
• There are three main types of muscle tissue which include skeletal muscle, cardiac muscle, and smooth muscle
Skeletal Muscle
• Long cylinders• Multinucleate cells• Used for voluntary
movement, locomotion, and facial expression
Cardiac Muscle
• Branching, striated, usually uninucleate cells
• When contracting it shoots blood into circulation by involuntary control
Smooth Muscle
• Spindle shaped cells• Central nuclei• No striation• Cells form close sheets• Smooth muscle moves
substances and/or objects along internal passageways