Unit II TISSUES

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Unit IITISSUES
Biology 220 Anatomy Physiology I

• Chapter 4
• pp. 114-143

http//www.usc.edu/hsc/dental/ghisto/index.html h
ttp//medicine.creighton.edu/medschool/VideoAtlas/
Cart.202620Bone20Tissue20source/webstuff/Fibr
ocartiage203.html
E. Gorski/ E. Lathrop-Davis/S. Kabrhel
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Definitions and Types

• Group of cells with similar origin and function
• 4 types
• Epithelial tissues cover surfaces, line
  cavities, form secretory parts of glands
• Connective tissues connect other tissues
  support, protect transport (blood) insulate
  (fat)
• Muscle tissues movement
• Nervous tissue coordinates activities by
  recognizing and responding to stimuli (changes in
  environment) transfer information

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Epithelial Tissues

• Features
• Closely packed cells with little extracellular
  matrix

• Not innervated (receptors found in connective
  tissue underlying them)
• Highly able to regenerate (mitotic cell division)
• Avascular (no blood vessels blood supplied by
  underlying connective tissue)
• Polarized
• Cells joined by cell junctions

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Epithelial Tissues Polarity
Lumen
http//www.usc.edu/hsc/dental/ghisto/epi/c_24.html
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Cell Junctions

• Desmosomes
• aka. anchoring junctions
• loose connections
• help maintain integrity of epithelial tissue
• allow materials to pass between cells

• Tight junctions
• tight seals between cells prevent movement of
  substances between cells

Fig. 3.4, p. 71
Gap Junctions - allow transfer of chemicals
including ions from one cell to another adjacent
cell important to communications between some
neurons
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Classification of Epithelial Tissues
Based on number of layers
shape of cells
Fig. 4.1, p. 116
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Types of Epithelial Tissues

• Simple Tissues
• Simple Squamous
• Simple Cuboidal
• Simple Columnar
• Pseudostratified Columnar
• Stratified Tissues
• Stratified Squamous
• Stratified Columnar
• Stratified Cuboidal
• Transitional

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Simple Epithelial Tissues

• Simple squamous epithelium
• Filtration, exchange of materials, secretion
• Locations
• kidneys (glomerulus filtration of solutes from
  blood)
• lungs (alveoli exchange of gases between blood
  and air)
• endothelium (lining of blood and lymphatic
  vessels, heart)
• mesothelium (serous membranes of ventral body
  cavity)

http//www.usc.edu/hsc/dental/ghisto/epi/c_3.html
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Simple Epithelial Tissues

• Simple cuboidal epithelium
• Secretion and absorption
• kidneys (controllable change of materials between
  blood and urine)
• glands (secrete chemicals into ducts or blood)

http//www.usc.edu/hsc/dental/ghisto/epi/d_9.html

• Modifications
• Cilia (movement of materials e.g., uterine
  tubes)
• Microvilli (increase surface area for absorption
  small intestine)
• Goblet cells (secrete mucous lubrication)

http//www.usc.edu/hsc/dental/ghisto/epi/d_14.html
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Simple Epithelial Tissues

• Pseudostratified columnar epithelium
• secretion
• all cells rest on basement membrane, but nuclei
  at different levels give the appearance of being
  multilayered
• cilia (respiratory system -- moves mucus upward)
• goblet cells (respiratory system -- secrete mucus
  that traps airborne particles)

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Stratified Epithelial Tissues
Defined by the shape of the outer cells

• Stratified squamous epithelium
• protection against abrasion
• Keratinized (epidermis of skin)
• contains keratin (water-proof protein) that
  protects against water loss
• Non-keratinized (mouth, esophagus, vagina, anus)
• lacks keratin water may be lost across these
  surfaces

http//www.usc.edu/hsc/dental/ghisto/epi/d_29.html
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Stratified Epithelial Tissues
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Transitional Epithelium
http//neuromedia.neurobio.ucla.edu/campbell/epith
elium/wp_frame.htm
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Connective Tissues (CT)

• Features
• generally, well-innervated and highly vascular
  (except cartilage)
• consist of relatively few cells embedded in large
  amount of extracellular (outside the cell) matrix
• each type of CT has its own associated cell
  type(s) and matrix

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Connective Tissues (CT)

• Classification
• is based on structure (type of matrix ground
  substance, type and amount of fibers and cells)
  and function
• cells each CT group has its own associated cell
  type(s)
• -blast mitotically active (produce new cells
  e.g., fibroblasts, osteoblasts)
• -cyte mature cell (e.g., adipocytes,
  osteocytes)
• all connective tissues arise from an embryonic
  form called mesenchyme

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Connective Tissues Matrix

• Matrix consists of ground substance and fibers
• Ground substance thick (generally), amorphous
  (undefined structure), non-staining interstitial
  fluid (generally) consistency varies from
  rock-hard (bone) to watery fluid (plasma)
• Fibers -- proteins of differing structure (and
  function)
• collagenous -- most abundant strong resists
  pulling tension composed of thick strands of
  collagen
• reticular -- fine strands of collagen forming
  continuous network around blood vessels, soft
  organs, basement membrane
• elastic -- consists of elastin stretch and
  recoil without breakage found in skin, lungs,
  blood vessels

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Connective Tissues

• Types of connective tissues
• Connective tissue proper
• A. Loose connective tissue
• - areolar, adipose, reticular
• B. Dense connective tissue
• - dense regular, dense irregular
• Cartilage
• A. Hyaline cartilage
• B. Elastic cartilage
• C. Fibrocartilage
• Bone
• Blood

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Connective Tissue Proper

• Two subclasses A. Loose connective tissues
• B. Dense connective tissues
• Defined by
• fiber content varies with type of tissue
• ground substance hyaluronic acid
  (hyaluronidase - enzyme)
• classification depends on type, amount,
  orientation of fibers

• A. Loose CTs
• Areolar CT
• all three types of fibers
• fibroblasts, macrophages, mast cells
• water and solute reservoir
• associated with most epithelial membranes
• forms lamina propria of mucous membranes
• forms papillary layer of dermis

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Connective Tissue ProperA. Loose CTs (cont)
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Connective Tissue ProperB. Dense CTs
Provide strength and elasticity
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Connective Tissue ProperB. Dense CTs (cont)

• Dense Irregular CT
• fibers irregularly arranged
• resists tension in many directions
• lower dermis, perichondrium, periosteum, and
  fibrous capsules around some organs (kidneys,
  testes, heart fibrous pericardium

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Cartilage

• Features
• avascular
• perichondrium dense irregular CT surrounding
  cartilage supplies blood (brings
  nutrients/oxygen, removes wastes)
• lack innervation
• cells chondroblasts (during cartilage
  formation) and chondrocytes (mature) found in
  openings called lacunae (lacuna)
• Types
• A. Hyaline Cartilage
• B. Elastic Cartilage
• C. Fibrocartilage

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Cartilage A. Hyaline

• most abundant
• collagen fibers make it strong, yet pliable
  (fibers not visible)
• tip of nose, trachea, epiphyseal plate (growing
  bone), much of the fetal skeleton, articular
  cartilage

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Cartilage B. Elastic Cartilage and C.
Fibrocartilage
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Cartilage Comparison

• Two types of cartilage are seen here what are
  they?

http//medicine.creighton.edu/medschool/VideoAtlas
/Cart.202620Bone20Tissue20source/webstuff/Fib
rocartiage203.html
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Blood

• Features
• cells cell fragments (suspended in liquid
  matrix plasma)
• leukocytes white blood cells WBCs
• erythrocytes red blood cells RBCs and
• platelets (cell fragments)
• contains solutes (ions, nutrients, wastes) and
  suspended substances (e.g., large proteins)
• fights disease (WBCs)

• transports substances (e.g., nutrients, wastes,
  hormones, respiratory gasses)

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Bone

• forms the skeletal system (along with cartilage)
• Functions
• provides support,
• leverage for movement (muscle attachment),
• protection,
• hemopoiesis ( hematopoiesis) blood cell
  formation
• Features
• cells in hard matrix (calcium and magnesium
  carbonate and phosphate salts) collagen fibers
  and other proteins
• Types
• spongy bone (plates of bone called trabeculae)
• compact bone
• based on osteon (formerly Haversian system)

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Compact Bone
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/Cart.202620Bone20Tissue20source/webstuff/Den
se20Bone20Hav20Sys203.html
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Muscle Tissue

• Features
• high rate of metabolic activity when active
• highly vascular (needs good supply of oxygen and
  nutrients when active)
• structure specialized for contraction to produce
  movement of body parts (including movement of
  materials through tubes)
• cells muscle fibers
• Types
• A. Skeletal
• B. Cardiac
• C. Smooth

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Muscle Tissue A. Skeletal Muscle

• attached to bones
• movement of skeleton voluntary control of
  sphincters
• striated (banding pattern), voluntary,
  multinucleate (develops from union of cells)

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Skeletal Muscle/Tendon Comparison

• Compare the skeletal muscle (m) with the tendon
  (t) tendon is composed of dense regular CT

http//www.usc.edu/hsc/dental/ghisto/musc/c_15.htm
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Muscle Tissue B. Cardiac Muscle
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Muscle Tissue C. Smooth Muscle

• no visible striations, involuntary, uninucleate
• walls of hollow organs, including blood vessels

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Nervous Tissue

• Features
• specialized for recognizing environmental changes
  (stimuli receptors sensory function)
• integrates sensory inputs and motor outputs
• controls motor outputs (muscle contraction,
  glandular secretion

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Nervous Tissue
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Epithelial Membranes

• Features
• Consist of epithelial tissue and CT
• Three types
• A. Serous Membranes
• B. Cutaneous Membrane
• C. Mucous Membranes

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Epithelial MembranesA. Serous Membranes

• Consist of simple squamous epithelium
  (mesothelium) areolar CT
• Secrete serous fluid (lubricates to prevent
  friction and allow freer movement)
• Line ventral body cavity (except pelvic cavity)
• parietal layer - lines wall of cavity
• visceral layer - overlies organs

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A. Serous Membranes (cont)

• Three ventral body cavities with a serosa
• pericardium surrounds and covers heart
• pleura overlies lungs and line thoracic cavity
• peritoneum lines abdominal cavity and covers
  organs
• Inflammation of serosa due to irritation and/or
  disease
• in pleural cavity (pleurisy)
• in abdominal cavity (peritonitis)
• in pericardium (pericarditis)

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Epithelial Membranes B. Cutaneous Membrane

• forms skin
• consists of
• keratinized stratified squamous epithelium
  (epidermis)
• connective tissue (dermis)
• areolar CT papillary layer, and
• dense irregular CT reticular layer)

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Epithelial Membranes C. Mucous Membranes

• line body cavities open to the outside (digestive
  tract, respiratory tract, reproductive tract,
  urinary tract)
• mostly non-keratinized stratified squamous
  epithelium (or stratified columnar) or simple
  columnar (absorptive areas of gut)
• wet membranes (bathed in secretions-mucus,
  urine)