Histology

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Histology

• pass the tissues please

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I. Intro to Histology

• Tissue definition A group of similar cells
  working towards one unifying goal
• Tissues components
• Similar cells
• Extracellular Matrix
• - water, NaCl, ions, calcium, fibers, nutrients,
  etc..

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I. Intro to Histology

• The 4 types of tissues
• Epithelial        covers body surfaces       
  lines hollow organs        lines body
  cavities and ducts        forms glands and
  secretions
• Connective        protection and
  support        binding together (like
  glue)        energy storage
• Muscle
• movement and force (including peristalsis)
• Nervous
• coordinates body activities

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I. Critical Thinking Question?

• What tissue type does blood belong to?
• A. Epithelial
• B. Connective
• C. Muscle
• D. Nerve
• E. Blood isnt a tissue

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II. Epithelial Anatomy

• Location
• Covers external surfaces
• Lines internal surfaces such as cheeks, blood
  vessels, organs etc
• Glands

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II. Epithelial Anatomy

• Basic Anatomy
• Cells bound tightly together
• Classified by shape of cells and number of layers
• Avascular
• Contain Stem cells
• Has an exposed surface (Apical membrane)
• Has a surface bound to connective tisuuse (basal
  membrane)

Apical Surface
Basal (basement)
Connective tissue
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III. Epithelia Physiology

• Function
• Provides protection internally and externally
• Controls permeability
• Provides for touch/stimuli
• Produces secretions
• exocrine released onto surfaces
• digestive enzymes, sweat
• endocrine releases into tissue fluid and blood
• Hormones (chemical messengers) from pancreas,
  thyroid, pituitary, etc

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II. Epithelial Anatomy

• Basic Anatomy
• Apical Surface may contain specialized structures
• Cilia for movement
• Microvilli for increased absorption (Brush
  Borders)

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II. Epithelial Anatomy

• The Brush Border

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II. Epithelial Anatomy

• Basic Anatomy
• Basal Membrane Basement
• Provides strength to epithelium
• Creates barriers to prevent molecules from
  entering connective tissue

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II. Epithelial Anatomy
Classification Systems

• Shape
• Squamous Flat
• Cubodial cube-like
• Columnar column-like
• Transitional changes

• By Layers
• Simple single
• Stratified multiple
• Pseudostratified appears multiple, but really
  simple

Example. Simple cubodial 1 cell thick of cube
shaped cells
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IV. Epithelial Tissues Simple Squamous

• Simple Squamous
• Anatomy
• Lining of body cavities, organs, blood vessels,
  alveoli lung surface
• Serous Membranes
• Physiology
• Diffusion
• Secretions

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IV. Epithelial Tissues Simple Squamous

• Simple Squamous

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IV. Epithelial Tissues Simple Squamous
Simple Squamous
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IV Epithelial Tissues Simple Cuboidal

• Simple Cuboidal
• Anatomy
• Digestive tract, Kidney tubules, glands
• Physiology
• Absorption and Secretions

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IV Epithelial Tissues Simple Cuboidal

• Simple Cuboidal

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IV Epithelial Tissues Simple Columnar

• Simple Columnar
• Anatomy
• Lining of digestive tract
• Modified by presence of cilia
• Contains Goblet cells
• Physiology
• Help move surface material
• Absorption

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IV Epithelial Tissues Simple Columnar

• Simple Columnar

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IV Epithelial Tissues Simple Cuboidal

• Simple Columnar

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IV Epithelial Tissues Simple Columnar

• Simple Columnar

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IV Epithelial Tissues Stratified Squamous

• Stratified Squamous
• Anatomy
• Outer most layer- squamous cells
• Inner- cuboidal or columnar
• Lining of mouth, esophagus, skin
• Can be keratinized
• Physiology
• Protection
• Secretion
• Moistens membranes

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IV Epithelial Tissues Stratified Squamous

• Stratified Squamous non keratinized

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IV Epithelial Tissues Stratified Squamous

• Keratinized Stratified Squamous
• Keratin Waxy protective coverings
• Waterproofs

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IV Epithelial Tissues Pseudostratified Columnar

• Pseudostratified Columnar
• Anatomy
• One layer
• All attach to the basal membrane
• Appears stratified
• Upper respiratory tract
• Physiology
• Move material

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IV Epithelial Tissues Pseudostratified Columnar

• Pseudostratified Columnar

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V. Connective Tissue

• Abundant extracellular material
• Matrix (dominant part) or ground substance
• Fiber, cells in liquid, gel, or solid matrix
• Never exposed to outside environment
• If exposed, causes a response for damage
  control (ie. Bleeding)
• Functions
• Bind and/or support other tissue
• Energy storage
• Defense of the body

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V. Connective Tissue

• Classification is based on the composition of
  matrix
• 1. Connective Tissue Proper loose and dense.
  subcutaneous, fat, tendons and ligaments
• 2. Fluid connective tissue
• 3. Supporting connective tissue

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V. Connective Tissue
Connective Tissue
Tissue Proper
Fluid
Supporting
Blood
Lymph
Dense
Loose
Cartilage
Bone
Dense Regular
Dense Irregular
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VI. Connective Tissue Proper

• Tissue Proper
• - Either loose or dense
• - Examples subcutaneous, fat, tendons and
  ligaments
• Tissue Proper is composed of
• Fibroblasts homeostasis of tissue
• Macrophages engulf waste
• Fat cells permanent residents
• Mast cells near blood vessels, release
  chemicals to elicit injury response

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VI. Connective Tissue Proper

• 3 Fibers
• Collagen - long and straight, most common
  fibers, strong but flexible
• Elastic branched and wavy, contains elastin,
  are elastic
• Reticular less common, thin, branching,
  interwoven framework of fibers

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VI. Connective Tissue Proper

• Loose or areolar
• Fewer fibers but all kinds
• Cushioning and support
• Deep to skin, between muscles, around vessels
• Dense Fibrous
• abundant, organized collagen fibers
• Tendons and ligaments
• Dense Regular or Dense irregular

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VI. Connective Tissue Proper

• Dense Regular
• collagen runs parallel, packed tightly, aligned
  with forces
• Tendons and ligaments
• Provides attachements
• Dense Irregular
• with collagen to provide support and strength
• Gives skin its strength

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VII. Adipose

• Adipose Connective Tissue
• Loose connective
• Store large droplets of fat
• Large marshmellow looking cells
• Nuclei squished to one side

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VIII. Fluid Connective Tissue

• Blood
• Plasma Liquid matrix
• RBCs
• WBCs
• Lymphatic System
• Lymph fluid portion
• Part of your immune system

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IX. Supporting Connective

• Cartilage Connective Tissue
• Rubbery consistency (matrix)
• Avascular

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IX. Supporting Connective

• Types of Cartilage
• Hyaline most common
• Joints, rib cage, respiratory tract
• Elastic
• Mostly elastic fibers, Very flexible
• Outer ear, nose, epiglottis
• Fibrocartilage
• Mostly collagen fibers, durable, strong, tough
• Backbone (resist compression, absorb shock)

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IX. Supporting Connective

• Bone
• Osteocytes bone cells
• Hardest connective tissue
• Spongy bone
• Ends of long bones
• Compact
• Shafts of long bones
• Tightly organized

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Bone Connective Tissue
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X Muscle

• Three types
• 1. Skeletal
• 2. Smooth
• 3. Cardiac
• Functions
• Cells have ability to contract
• Locomotion
• Support
• Other body movement

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X Muscle Skeletal

• Voluntary movement
• Long and cylindrical (up to 25 cm)
• Transverse striation
• multi-nucleated

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X Muscle Smooth

• Involuntary movement
• Long, spindle shape
• Single nucleus
• Internal organs

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X Muscle Cardiac

• Striations
• Involuntary
• One nucleus
• Intercalated disks
• Heart muscle

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XI Nervous

• Cells very high ability to
• Respond to stimuli
• Transmit impulses
• Two types of cells
• Neurons conduct nerve impulses
• Neuroglia provide physical support, maintain
  chemical composition of tissue fluids, nutrients

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XI Nervous

• Cell Body(3)
• Dendrites (5)
• Axon(1)

• Cant be replaced
• Very LONG cells
• Create the human electrical system