Tissue Notes

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Tissue Notes
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Types of Tissue

• 1. Epithelial Tissue - lines all surfaces of the
  body including organs. Protects, secretes,
  absorbs, excretes.
• Ex outer layer of skin, inside of mouth and
  stomach, tissue surrounding the body's organs,
  vessels, ducts.
• Characteristics of Epithelium
• All have one exposed surface
• Lack blood vessels-get nutrients by diffusion
• Divide rapidly
• Tightly packed to form barriers
• Classified by shape and of layers

Shapes Layers
Squamous-flattened Simple-one layer
Cuboidal-cube shaped Stratified-multiple layers
Columnar-column shaped Psuedo-stratified-looks layered
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• TYPES OF EPITHELIAL TISSUE
• Simple squamous epithelium-One layer, flattened
  shape, lines air sacs of lungs, capillaries,
  diffusion occurs easily. Easily damaged.

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• Simple cuboidal epithelium- one layer, cube
  shaped, covers ovaries, lines ducts of kidneys
  and other glands. Nuclei are central.(Free
  surface faces a lumen or hollow channel).
  Secretes and absorbs.

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• Simple columnar epithelium- One layer, elongated
  shape, some have cilia, made for absorption,
  secretion, lines uterus and digestive tract
  organs. ( contain goblet cells to secrete mucus
  to protect). Thick tissue protects underlying
  layers.

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• Pseudostratified columnar epithelium- appear
  layered but are not. Line respiratory system
  passages and have cilia to sweep away dust etc.
  (Goblet cells-also secrete mucus to trap
  particles). Protects and secretes. Moves things
  along.

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• Stratified squamous epithelium -thick
  multi-layered, forms outer layer of skin (which
  keratinizes-hardens), line oral cavity,
  esophagus, vagina, and anal canal ( all which are
  moist and dont keratinize). Protects.

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• Stratified cuboidal epithelium -lines lareger
  ducts, salivary and sweat glands, mammary glands,
  ovarian follicles and seminiferous tubules ( all
  have lumen). Protects.

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• Stratified columnar epithelium -urethra of males,
  pharynx. Protects and secretes.

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• Glandular Epithelium -secretes substances into
  ducts or body fluids.
• Exocrine glands-secrete products into ducts that
  open onto surfaces. Example skin, lining of
  digestive tract.
• Endocrine glands-secrete products into tissue or
  blood.

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Transitional Epithelium- specialized to change
shape in response to increased tension. Found in
bladder, urethra, ureters (all stretch and
prevent a barrier)
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• 2. Connective Tissue - adds support and structure
  to the body.  Contains fibrous strands of the
  protein collagen that add strength to connective
  tissue. 
• Examples inner layers of skin, tendons,
  ligaments, cartilage, bone, blood and fat tissue.
  

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Types of Connective Tissue

• Loose connective
• Dense connective
• Hyaline cartilage
• Elastic cartilage
• Fibrocartilage
• Bone
• Blood

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• 3. Muscle Tissue specialized tissue that can
  contract. Contains actin and myosin filaments. 
• Examples Heart muscle, muscles lining digestive
  canal and muscles throughout your body.

Smooth muscle
Striated muscle
Cardiac muscle
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• 4. Nerve Tissue -nerve tissue that has the
  ability to generate and conduct electrical
  signals in the body. 
• Examples neurons and glial cells