HISTOLOGY Four Basic Types of Tissue 1 Epithelial
HISTOLOGY Four Basic Types of Tissue 1. Epithelial 2. Connective 3. Muscle 4. Nerve
Epithelial Tissue • It protects us from the outside worldlike skin • Absorbs-stomach and intestinal lining of the gut • Filters-like the kidneys • Secretes-forming glands
Connective Tissue • Wraps around and cushions and protects organs • Stores nutrients • Internal support for organs • As tendons and ligaments, protects joints and attached muscles to bones and each other • Runs through organ capsules and in deep layers of skin
Muscle Tissue • Responsible for movement • Moves blood, food and waste through body’s organs • Responsible for mechanical digestion
Nervous Tissue • Conducts impulses to and from body organs via neurons
Category One: Epithelial
EPITHELIAL TISSUE v Cells are bound tightly together v Little extracellular material v Arranged in sheets v. Cover internal and external surfaces v. Often control passage of material v. Classified by shape of cells and number of layers
EPITHELIAL TISSUE CELL SHAPE v. Squamous shape v. Thin, flat cells v. Look like fried eggs v Cubodial shape vsquare shape- cross section v 6 sided polygon- surface v Columnar v. Rectangular- cross section v. Polygonal- surface view CELL NUMBER v. Simple v. Single layer v Stratified v 2+ layers v Pseudostratified v. Appear stratified- but not v. Transitional v. Change shape
EPITHELIAL TISSUE SIMPLE SQUAMOUS v. Single layer of flat cells v. Function: v. Location: Lining of body cavity, lungs, blood vessels
EPITHELIAL TISSUE SIMPLE CUBOIDAL v. Single layer of cube cells v. Kidney tubules, glands
EPITHELIAL TISSUE SIMPLE COLUMNAR v. Single layer v. Columnar shape v. Lining of digestive tract v. Modified by presence of cilia
EPITHELIAL TISSUE STRATIFIED SQUAMOUS v. Multi layer v. Outer most layer- squamous cells v. Inner- cuboidal or columnar v. Function: Protection v. Location: Lining of mouth, esophagus, skin
EPITHELIAL TISSUE PSEUDOSTRATIFIED COLUMNAR v. Shape: v. One layer but appears stratified v. Little triangular shapes near basement membrane v. Function: v. Absorption and filtration v. Location: v. Respiratory tract
Epithelial Tissue Transitional v. Shape: v. Multiple layers of various shapes v. Function: v. Expand contract v. Location: v. Urinary bladder, kidneys, ureter
Category 2: Connective Tissue
CONNECTIVE TISSUE CHARACTERISTICS 1. Most abundant tissue in your body, found throughout 2. Binds structures together 3. Provides support, protection, framework, fills space, stores fat, produces blood cells, fights infection, and helps repair tissue. 4. Composed of more scattered cells with abundant intercellular material/matrix 5. Made up of a ground substance (fluid, semi-solid) and fibers 6. Most has a good blood supply 7. Cells can reproduce
Types of Cells in Connective Tissue These cells are found throughout the matrix • Mast cells (prevents clots) • Macrophages (consumers) • Fibroblasts (produce fibers)
Connective Tissue
Extracellular Matrix • If the space between cells (extracellular matrix) is gel-like, the tissue is considered loose. • Like areolar, adipose, and reticular • If the space has some tough fibers of proteins, it is considered dense. The fibers give the tissue more strength. • Like cartilage
CONNECTIVE TISSUE v. Loose or areolar Connective Tissue v. Matrix: Loose v. Fibers: Collagen and elastic fibers v. Location: Binds epithelial (basement membrane) v. Extra: Delicate arrangement
CONNECTIVE TISSUE v. Fibrous Connective Tissue v. Matrix: Dense v. Fibers: Abundant, well organized fibers (collagen and elastic) v. Location: Found in tendon, ligaments v. Other: Can be regular or irregular
CONNECTIVE TISSUE ADIPOSE CONNECTIVE TISSUE v. Matrix: Loose connective v. Fibers: Elastic v. Location: Throughout body v. Extra: v. Store large droplets of fat v. Lipid pushes nuclei to side
Connective Tissue BLOOD v Matrix: Unique liquid matrix v Fibers: Specialized called platelets v Location: In blood vessels, made in long bones v Other: There are 2 kinds of cells v. RBC- Red Blood Cells v. WBC- White Blood Cells
Sickle Cell Anemia- An inherited Disease Tissue Characteristics • Matrix: Loose or liquid Platelets are specialized fibers • RBC and WBC cells are found throughout matrix • RBC are sickle-shaped • Sickle cell anemia is caused by an abnormal type of hemoglobin called hemoglobin S. (Hemoglobin is a protein inside red blood cells that carries oxygen. ) • Hemoglobin S changes the shape of red blood cells, especially when the cells are exposed to low oxygen levels. (The red blood cells become shaped like crescents or sickles. ) • • The fragile, sickle-shaped cells deliver less oxygen to the body's tissues. They can also get stuck more easily in small blood vessels, and break into pieces that interrupt healthy blood flow. Sickle cell disease is much more common in people of African and Mediterranean descent. It is also seen in people from South and Central America, the Caribbean, and the Middle East.
CONNECTIVE TISSUE CARTILAGE CONNECTIVE TISSUE v. Matrix: Dense, rubbery v. Location/Fibers: (There are 2 kinds) v. Hyaline: Collagen fibers, found in costal cartilage between ribs, nose v. Elastic: Elastic fibers, found in ears v. Extra: v. Also called Chondrocytes (the cells) v. Small holes cells rest in are lacunae
CONNECTIVE TISSUE BONE v. Matrix: Hardest, calcified, dense v. Fibers: Collagen fibers v. Extra: v. Cells are called Osteocytes (small black dots) v. Cells rest in small holes called lacunae v. Each series of circles is called a Haversian system. There is a central opening for blood vessels called a Haversian Canal
v. There are two types of bone: v. Spongy v. Loose rods of bones v. Ends of arms and legs v. Compact v. Shafts of long bones v. Tightly organized
Category 3: Muscle Tissue
MUSCLE TISSUE v Cells have ability to contract v. Function: v. Locomotion (Movement) v. Breathing v. There are 3 varieties v. Cardiac, smooth, and skeletal
MUSCLE TISSUE SKELETAL MUSCLE CELLS v. Voluntary movement v. Attached to bones v. Long and cylindrical v. Transverse striation v. Each fiber is multi-nuclear
MUSCLE TISSUE SMOOTH MUSCLE CELLS v. Involuntary movement v. Internal organs, iris of the eye v. Long, spindle shape v. No striations (appear “smooth”) v. Single nucleus
MUSCLE TISSUE CARDIAC MUSCLE CELLS v. Involuntary v. Heart muscle v. Branched and long shaped v. Striations v. One nucleus, deep center v. Contain Intercalated Discs between connecting cells
NERVE TISSUE v Cells have a very high ability to: v. Respond to stimuli v. Transmit nerve impulses
NERVE TISSUE NEURON v. Cell has 3 parts v. Cell Body that contains the nucleus v. Dendrites are the little branches v. Axon is the one long branch
INFLAMMATION • 5 symptoms – Redness • Dilation of blood vessels (to increase blood flow (WBC) – Heat – Swelling • Clotting proteins diffuse from blood into tissue, along with water and causes adema – Pain • Caused by adema, increased pressure – Disturbance of function • Limitation of movement
Tissue Repair • Cells are divided on 3 groups based upon their ability to regenerate – Labile Cells • Divide throughout life and regenerate • Skin – Stable Cells • Do not divide after growth but can regenerate if needed • liver – Permanent Cells • Cannot replicate • neurons
• Can occur by – Regeneration • New cells are the same as those that were destroyed – Replacement • A new type of cells develop (scar)
Primary Union Tissue Repair • Wound fills with blood and clot forms (fibrin) • Scab forms, seals off area • Neutrophils (WBC) phagocytize bacteria • Fibroblasts migrate to clot and produce extracellular matrix – Replace clot with tissue: Granulation Tissue • Scar forms
- Slides: 38