chapter 4 tissues Flashcards
what are the four types of tissues ?
Epithelial
Connective
Muscle
Nervous
what is epithelial tissues
Covers exposed surfaces
Lines internal passageways
Forms glands
what is connective tissues
Fills internal spaces
Supports other tissues
Transports materials
Stores energy
what is the function of epithelial
Provide physical protection
Control permeability
Provide sensation
Produce specialized secretions
what are the characteristics of epithelial
Polarity (apical and basal surfaces)
Cellularity (cell junctions)
Attachment (basement membrane)
Avascularity (avascular)
Regeneration
what are Specializations of epithelial cells
Move fluids over the epithelium (protection)
Move fluids through the epithelium (permeability)
Produce secretions (protection and messaging
what does mircovilla do?
increase absorption or secretion
what do cilia do on ciliated epithelium
move fluids
Integrity of epithelia is maintained by
Intercellular connections
Attachment to the basement membrane
Epithelial maintenance and repair
what are the protein for intercellular connections
Cell adhesion molecules (CAMs)
Transmembrane proteins
Proteoglycans act as intercellular cement
the functions of gap junction
Allow rapid communication
Cells held together by interlocking
transmembrane proteins (connexons)
Allow small molecules and ions to pass
Coordinate contractions in heart muscle
the function of tight junction
Between two plasma membranes
Adhesion belt attaches to terminal web
Prevent passage of water and solutes
Keep enzymes, acids, and wastes in the
lumen of the digestive tract
what are the two types of desmosmomes
Spot desmosomes
Tie cells together
Allow bending and twisting
Hemidesmosomes
Attach cells to the basement membrane
the types of basement membrane
Basal lamina
Closest to the epithelium
Reticular lamina
Deeper portion of basement membrane
Provides strength
what types of cells are used to repair and maintenance
stem cells
the types of squamous tissues
Simple squamous epithelia
Absorption and diffusion
Mesothelium
Lines body cavities
Endothelium
Forms inner lining of heart and blood vessels
Stratified squamous epithelia
Protect against mechanical stresses
Keratin adds strength and water resistance
the types of cuboidal
Simple cuboidal epithelia
Secretion and absorption
Glands and portions of kidney tubules
Stratified cuboidal epithelia
Relatively rare
Ducts of sweat glands and mammary glands
the function of transitional epithelia
Tolerate repeated cycles of stretching without damage
Appearance changes as stretching occurs
Found in urinary bladder
the types of columnar
Simple columnar epithelia
Absorption and secretion
Found in stomach, small intestine, large intestine
Pseudostratified columnar epithelia
Typically have cilia
Found in nasal cavity, trachea, bronchi
Stratified columnar epithelia
Relatively rare
Provide protection in pharynx, anus, urethra
what is the difference of endo and exocrine
endocrine has no duct enter hormones into the bloodstream, exocrine has ducts
define the unicellular gland
Goblet cells are unicellular exocrine glands
In epithelia of intestines
Secrete mucin, which mixes with water to form mucus
what does merocrine do ?
Released by secretory vesicles (exocytosis)
Example: merocrine sweat glands
wha does apocrine do
Released by shedding cytoplasm
Example: mammary glands
what is the function of holocrine
Released by cells bursting, killing gland cells
Gland cells replaced by stem cells
Example: sebaceous glands, associated with hair follicles
what are the components of connective tissues
Specialized cells
Extracellular protein fibers
Fluid called ground substance
define fibroblasts
The most abundant cell type
Found in all types of connective tissue proper
Secrete proteins and hyaluronan (cellular cement)
the functions of connective tissues
Establishing a structural framework for the body
Transporting fluids and dissolved materials
Protecting delicate organs
Supporting, surrounding, and interconnecting other types of tissue
Storing energy reserves, especially triglycerides
Defending the body from invading microorganisms
define fibrocytes
Second most abundant cell type
Maintain connective tissue fibers
connect with other cells
define mesenchymal cells
Stem cells that respond to injury or infection
Differentiate into fibroblasts, macrophages, etc.
define macrophages cells
Large phagocytic cells of the immune system
Engulf pathogens and damaged cells
Fixed macrophages stay in tissue
Free macrophages migrate
define mast cells
Stimulate inflammation after injury or infection
Release histamine and heparin
Basophils are leukocytes that also contain histamine and heparin
defin microphages
Phagocytic blood cells (neutrophils, eosinophils)
Attracted to signals from macrophages and mast cells
the function of collagen fibers
Most common fibers in connective tissue proper
Long, straight, and unbranched
Strong and flexible
Resist force in one direction
Abundant in tendons and ligaments
the fucntion of reticula fibers
Form a network of interwoven fibers (stroma)
Strong and flexible
Resist forces in many directions
Stabilize functional cells (parenchyma) and structures
Example: sheaths around organs
define the ground substance
Is clear, colorless, and viscous
Fills spaces between cells and slows pathogen movement
define the loose connective tissues
Packing materials”
Fill spaces between organs, cushion cells, and support epithelia
what is the areolar tissues
Least specialized
Open framework
Viscous ground substance
Elastic fibers
Holds capillary beds
Example: under skin (subcutaneous layer)
what is dense regular
Tightly packed, parallel collagen fibers
Tendons attach muscles to bones
Ligaments connect one bone to another and stabilize organs
Aponeuroses are tendinous sheets that attach a broad, flat muscle to another structure
what is the dense irregular
Interwoven network of collagen fibers
Provides strength to dermis
Forms sheath around cartilages (perichondrium) and bones (periosteum)
Forms capsules around some organs (e.g., liver, kidneys, and spleen)
what is the function of the connective tissues
Provide strength and stability
Maintain positions of internal organs
Provide routes for blood vessels, lymphatic vessels, and nerves
in cartilage what are the polysaccharide derivatives called
chondroitin sulfates
cartilages avascular function is
Chondrocytes produce antiangiogenesis factor that discourages formation of blood vessels
define the hyaline cartilage
Most common type
Tough and somewhat flexible
Reduces friction between bones
Found in synovial joints, rib tips, sternum, and trachea
what is the fibrocartilage
Very durable and tough
Limits movement
Prevents bone-to-bone contact
Found around joints, between pubic bones, and between spinal vertebrae
