Foundation year BIOLOGY-BIOL (101) Organization & Regulation of Body Systems (Tissues) Dr. Huda Kassem

Points to think 1.What is a tissue? 2.What are the 4 main types of tissue? 3.What do these tissues look like? 4.How do they function ? 5.Where are they found?

What is a tissue? Defined as : A collection of cells of the same type that perform a common function. There are 4 major tissue types in the body: 1.Connective tissue. 2.Muscular tissue. 3.Nervous tissue. 4.Epithelial tissue. 4.1 Types of tissues

1. Connective tissue a.Binds and supports parts of the body. b.All have specialized cells, ground substance and protein fibers. c.Ground substance is noncellular and ranges from solid to fluid. d.The ground substance and proteins fibers together make up the matrix of the tissue. e.There are three main types of connective tissue: A. fibrous, B. supportive and C. fluid. 4.2 Connective tissue connects and supports

3 main types of connective tissue A. Fibrous B. Supportive C. Fluid 4.2 Connective tissue connects and supports Fibrous connective tissue Supportive connective tissue Fluid connective tissue Loose Fibers create loose, open framework Dense Fibers are densely packed Cartilage Solid yet flexible matrix Bone Solid and rigid matrix Blood Contained in blood vessels Lymph Contained in lymphatic vessels

A. Fibrous connective tissue  There are two types: dense and loose, but both contain fibroblast cells with a matrix of collagen and elastic fibers.  Loose fibrous tissue: is found supporting epithelium and many internal organs.  Adipose tissue: is a special loose fibrous tissue where fat is stored. 4.2 Connective tissue connects and supports

What does loose fibrous connective tissue look like? 4.2 Connective tissue connects and supports adipose cell stores fat mast cell releases chemicals after an injury or infection ground substance fills spaces between cells and fibers stem cell divides to produce other types of cells fibroblast produces fibers and ground substance reticular fiber branched, thin, forms network white blood cell produces antibodies elastic fiber branched and stretchable white blood cell engulfs pathogens collagen fiber unbranched, strong but flexible Loose fibrous tissue elastic fiber fibroblast collagen fiber Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

B. Supportive connective tissue: A. Cartilage  Cells are in chambers called lacunae  Matrix is solid but flexible  3 types are distinguished by types of fibers 1. H yaline cartilage: fine collagen fibers Location: Nose, ends of long bones and fetal skeleton 2. Elastic cartilage: more elastic fibers than cartilage fibers Location: Outer ear 3. Fibro cartilage: strong collagen fibers Location: Disks between vertebrae 4.2 Connective tissue connects and supports

B. Supportive connective tissue: B. Bone Cells are in chambers called lacunae Matrix is solid and rigid that is made of collagen and calcium salts 2 types are distinguished by types of fibers 1. Compact : made of repeating circular units called osteons which contain the hard matrix and living cells and blood vessels Location: Shafts of long bone 2. Spongy: an open, latticework with irregular spaces Location: Ends of long bones 4.2 Connective tissue connects and supports

What do bone & cartilage look like? 4.2 Connective tissue connects and supports Hyaline cartilage matrix cell within a lacuna © Ed Reschke

C. Fluid connective tissue: A. Blood Made of a fluid matrix called plasma and cellular components that are called formed elements 3 formed elements: 1. Red blood cells: cells that carry oxygen 2. White blood cells: cells that fight infection 3. Platelets: pieces of cells that clot blood 4.2 Connective tissue connects and supports white blood cells platelets red bloodcell plasma

C. Fluid connective tissue: B. Lymph i.Matrix is a fluid called lymph. ii.White blood cells congregate in this tissue. 4.2 Connective tissue connects and supports

2. Muscle tissue 1.Allows for movement in the body 2.Made of muscle fibers/cells and protein fibers called actin and myosin 3.There are 3 types of muscle tissue in humans: A. Skeletal B. Smooth C. Cardiac 4.3 Muscle tissue moves the body

A. Muscle tissue - Skeletal 1. Appearance: long, cylindrical cells, multiple nuclei, striated fibers 2. Location: attached to bone for movement 3. Nature: voluntary movement 4.3 Muscle tissue moves the body Skeletal muscle nucleus striation muscle fiber 250  occurs in muscles attached to skeleton. has striated cells with multiple nuclei. functions in voluntary movement of body.

B. Muscle tissue - Smooth 1. Appearance: spindle- shaped cell with one nucleus, lack striations 2. Location : walls of hollow organs and vessels. 3. Nature: involuntary movement 4.3 Muscle tissue moves the body © The McGraw-Hill Companies, Inc./Dennis Strete, photographer Smooth muscle is involuntary. 400  nucleus smooth muscle cell has spindle-shaped cells, each with a single nucleus. functions in movement of substances in lumens of body. is found in blood vessel walls and walls of the digestive tract. cells have no striations.

C. Muscle tissue – Cardiac 1. Appearance: branched cells with a single nucleus, striations with darker striations called intercalated disks between cells 2. Location: heart 3. Nature: involuntary movement 4.3 Muscle tissue moves the body Place “New” Figure 4.5c here The inset was removed. Cardiac muscle occurs in the wall of the heart. functions in the pumping of blood. is involuntary. 250  nucleusintercalated disk c. has branching, striated cells, each with a single nucleus. © Ed Reschke

3. Nervous tissue  Allows for communication between cells through sensory input, integration of data and motor output.  Made of 2 major cell types: A. Neurons B. Neuroglia 4.4 Nervous tissue communicates

A. Nervous tissue - neurons Made of dendrites, a cell body and an axon Dendrites and Axons: are carry information toward the cell body 4.4 Nervous tissue communicates axon dendrite nucleus cell body Astrocyte Neuron Oligodendrocyte nucleus cell body dendrite myelin sheath Microglia Capillary Micrograph of neuron © Ed Reschke

A. Nervous tissue - Neuroglia  A collection of cells that support and nourish neurons  Outnumber neurons 9:1  Examples are oligodendrocytes, astrocytes and microglia 4.4 Nervous tissue communicates axon dendrite nucleus cell body Astrocyte Neuron Oligodendrocyte nucleus cell body dendrite myelin sheath Microglia Capillary Micrograph of neuron © Ed Reschke

4. Epithelial tissue 1.A groups of cells that form a tight, continuous network. 2.Lines body cavities, covers body surfaces and found in glands. 3.Cells are anchored by a basement membrane on one side and free on the other side. 4.Named after the appearance of cell layers and the shape of the cells. 5.There is transitional epithelium that changes in appearance in response to tension. 4.5 Epithelial tissue protects

How do we name epithelial tissue? Number of cell layers: a. Simple: one layer of cells b. Stratified: more than one layer of cells c. Pseudo stratified: appears to have layers but only has one layer Shape of cell: a. Cuboidal: cube-shaped b. Columnar: column-shaped c. Squamous: flattened 4.5 Epithelial tissue protects

What does epithelial tissue look like? 4.5 Epithelial tissue protects basement membrane protects Simple cuboidal absorbs molecules Simple squamous lining of kidney tubules, various glands lining of lungs, blood vessels © Ed Reschke Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stratified squamous protects basement membrane Simple columnar lining of small intestine, oviducts absorbs nutrients cilia lining of trachea Pseudostratified, ciliated columnar lining of nose, mouth, esophagus, anal canal,vagina sweeps impurities toward throat goblet cell secretes mucus basement membrane goblet cell secretes mucus basement membrane © Ed Reschke

How are cells connected within a tissue? 1. Tight junctions: proteins join and form an impermeable barrier between plasma membranes in a zipper-like fashion. 2. Adhesion junctions: cytoskeleton fibers join between cells and have flexibility. 3. Gap junctions : a fusion of adjacent plasma membranes with small channels between them that allow small molecules to diffuse. 4.6 Cell junction types

Cell junctions 4.6 Cell junction types a. Tight junction b. Adhesion junction c. Gap junction microvilli plasma membranes tight junction proteins plasma membranes cytoplasmic plaque intercellular filaments cytoskeletal fibers basement membrane channels plasma membranes

The End Any Questions???