Tissues Flashcards
What is the definition of a tissue?
Groups of Cells/Common
Embryonic Specialized function
What are the four different types of tissues?
Epithelial- Covering/lining of glands
Connective: Connect/support/filling spaces
Muscle- Generate forces that provide for movement
Nervous- cell to cell communication
Where do cell junctions typically exist?
Between Epithelial cells
Define Tight Junctions
- Trans-membrane proteins that fuse outer services of plasma membranes
- Water Tight seal
- Contributes blood/brain barrier
- Example: Bladder/stomach
Adherens Junction
Holds Epithelial cells
Plaque: Dense layer of linker proteins/attaches to membrane proteins cytoskeleton
Cadherins
Transmembrane proteins
Desmosomes
Have plaque, connect to intermediate filaments/common in epidermis and cardiac muscle
Hemidesosomes
Half of a Desosomes/Transmembrane Glycoproteins/ anchors an epithelial cell to the basement membrane
Gap Junctions
Connexins form channels/ channels used to transfer nutrients/cell signals, Ions pass from one cell to the next
General Characteristics of Epithelial Tissue
- Sheets, Signals, Multiple Layer
- High Cell Division Rate
- Avascular
What are the 5 functions of the epithelial tissue?
Protection, Filtration, Secretion, Absorption Excretion
What are the Two General Types of Epithelium?
Covering/Lining
Glandular
Simple Squamous Epith.
Location: Endothelium, Bowman's Capsule; kidney Thin segment of the loop - Alveoli Functions: - Transport/Diffusion
Simple Cuboidal Epith
Locations:
- Tubules: Kidney
- Covering Ovary
- Ducts
Functions:
- Secretion
- Transport
- Absorption
Simple Columnar Epith.
Locations: - Lining GI Tract/Uterus/oviduct Functions: - Protection - Lubrication - Absorption - Secretion
Pseudostratified Columnar Epith.
Locations:
- Respiratory Tract
Functions:
- Protection
- Secretion
Keratinized
Keratin is a tough, fibrous protein deposited/intracellulary/waterproofs and protects the skin from heat, microbes and chemicals.
Non-Keratinized Stratified Squamous
Locations:
- Mouth
- Esophogus
- Vagina
Function:
- protection from abrasion
Keratinized Stratified Squamous
Locations:
- Skin
- Gingiva
- Hard Palate
Function: Protection from
- Abrasion
- Desiccation
- UV
Stratified Cuboidal Epith.
- Ducts of adult sweat glands
- Esophageal glands
Stratified Columnar Epithelium
Only in Apical Layer
- Lines part of the Urethra
- Esophogeal Glands
- Part of Conjunctiva of the eye
Transitional Epith.
Location:
- Urinary System
- Permits stretching
Glandular Epithelium
Exists in the glad
Glands
- Single cell/group Cells that secrete substances into a duct/onto a surface or into the blood
- Uni/multicellular
- Secrete:
- Ducts/Surface/Blood
Define Exocrine
- Secrete to surface/lumen
- Typically are multicellular/have ducts
- Sweat, oil, mucus, enzymes
Define Endocrine
- Secrete to extracellular space
- Ductless
- Diffuse into Blood Stream
- Hormones
Define Holocrine Secretion
Whole cell secreted (Sebaceous Oil Glands)
Define Merocrine Secretion
- Discharges Secretory Product
- Most Exocrine Gland
Define Apocrine Secretion
- Apical portion discharged/cell repaired
- Only in mammary glands (might be Merocrine)
Describe the Functions of Connective Tissue
- Binds, supports, strengthens body tissue
- Projects and insulates organs
- Compartmentalizes
- Transports Blood
- Stores Energy (Adipose)
- Main source of immune responses
What are the characteristics of Connective Tissue?
- Few Cells
- Abundent/Varied
- Mainly extracellular matrix
- Highly Vascular
- Not on body surface
- Supplied with nerves
What is the difference in nomeclature of immature and mature cells?
- Blasts: Immature
- Cyte: Mature
(Osteoblast, Osteoclast)
What is the most common cell of connective tissue?
Fibroblast, secrete and maintain matrix
What are some characteristics of Mast Cells?
Slightly pagocytic, cotains stores and releases granules
What is the difference between Primary and Secondary Mediators?
Primary- stored and released upon request
Secondary- synthesized on the spot and used immediately
Adipose Cells
- Synthesizes and stores lipid
- Filler
- Large/Spherical
- Signet Ring
Describe the Matrix of Connective Tissue
Occupies the space between cell and fibers /provides structural support and connective tissue/Large molecules of hydrated amorphous material
What is ground substance?
Comprised of water and an assortment of large molecules that are typically combination of polysaccharides and proteins
What Polysaccharides are in ground substance?
Hyaluronic acid Chrondroitin Sulfate Dermatan Sulfate Keratan Sulfate Fibronectin
Define Hyaluronic acid
viscous slippery substance that binds cells together, lubricates joints, helps maintain shape of eyeballs (vitreous body)
Define Chrondroitin Sulfate
provides support and adhesiveness in cartilage, bone, skin and blood vessels
Define Dermatan Sulfate
found in skin, tendons, blood vessels and heart valves
Define Keratan Sulfate
found in bone, cartilage and the cornea of the eye
Define Fibronectin
the man adhesion protein of connective tissue
Collagen Fibers
Most abundant protein in body; inelastic; flexibletensile strength greater than steel; arranged in parallel bundles
What are Elastic Fibers, there composition, and location?
Small branching fibers; form network within tissues; distensible; stretched up to 150%; resume original configuration when tension is released.
Composition: elastin (protein), fibrillin (glycoprotein); fibrillin surrounds the elastin
Locations: Skin, walls of blood vessels, lung tissue
Describe Reticular fibers
fine bundles of collagen (type III) coated with glycoprotein; fibers are much thinner than collagen fibers and form a branching network; provide support and strength
Mesenchyme
Composition: Irregular shapped, semifluid ground substance and reticular fibers
Location: Along developing bones of the embryo and under the skin
Mucus Connective Tissue (Wharton’s Jelly)
Composition: Widely scattered fibroblasts, more viscous jelly-like ground substance and collagen fibers
Location: Umbilical cord of fetus/High turgor resists compression
Loose Connective Tissues
Located deep to skin, deep to mesothelial lining of internal body cavities, around blood vessels, surrounds glandular parenchyma
Areolar CT
- one of most widely distributed CT in body; fibers arrange randomly throughout tissue; forms subcutaneous layer attaching skin to underlying tissues
Adipose CT
generally found wherever areolar CT is located; good insulator and reduces heat loss; fat storage; major energy reserve as well as protects various organs
Reticular CT
consists of fine interlacing reticular fibers (type III) and reticular cells; forms the stroma/supporting framework of liver, spleen and lymph nodes; spleen reticular fibers remove effete RBCs and lymph node reticular fibers filter lymph and remove bacteria
Dense Regular CT
densely packed bundles of collagen fibers regularly arranged in parallel patterns providing tensile strength along the axis of fibers; fibroblasts in rows between fibers; found in tendons
Dense irregular CT
collagen fibers are abundant and not arranged in symmetrical or parallel fashion; generally found in parts of body where pulling forces are exerted in various directions like dermis of skin, pericardium, heart valves, perichondrium, periosteum, sheath of nerves, kidney and lymph nodes
Elastic CT
predominantly branching elastic fibers; fibroblasts present in spaces between fibers; has property of elasticity; form sheets or fenestrae; located in large blood vessels and lung tissue
Mucous Membranes
line body cavity that opens directly to the exterior (digestive tract, respiratory tract, reproductive tracts, much of urinary tract); provide barrier that is an important component of body’s defense mechanism
What is the most common Autoimmune disorders?
Rheumatoid Arthritis
