ch 4 Tissues Flashcards
-Connect epithelium to the rest of the body (basal lamina)
-Provide structure (bone)
-Store energy (fat)
-Transport materials (blood)
Have no contact with environment
Connective Tissues
Specialized cells
Solid extracellular protein fibers
Fluid extracellular ground substance
Characteristics of Connective Tissues
The extracellular components of connective tissues (fibers and ground substance):
- majority of cell volume
- Is the specific product of the cells and is what determines specialized function
Matrix
connect and protect
Connective tissue proper
- transport
- distinctive population of cells suspended in a watery matrix that contains disolved proteins
- blood and lymph
fluid connective tissues
- structural strength
- less diverse cell population and a matrix containing much more densely packed fibers
- protect soft tissues
- support the weight of part or all of the body
- cartilage and bone
Supportive connective tissues
more ground substance, less fibers
e.g., fat (adipose tissue)
loose connective tissues
more fibers, less ground substance
e.g., tendons
Dense connective tissue
- The most abundant cell type:
- found in all connective tissue proper
- secrete proteins and hyaluronan (cellular cement)
Fibroblasts
- Large, amoeba-like cells of the immune system:
- eat pathogens and damaged cells
Macrophages
large cells of the immune system that stay in tissue
fixed macrophages
large cells of the immune system that migrate
free macrophages
Fat cells:
each cell stores a single, large fat droplet
Adipocytes
-Stem cells that respond to injury or infection:
differentiate into fibroblasts, adipocytes, etc.
-divide and differentiate:
to produce more fat cells
when more storage is needed
(adipose cells)
Mesenchymal Cells
- Synthesize and store the brown pigment melanin
- gives tissues a dark color
Melanocytes
Stimulate inflammation after injury or infection:
release histamine and heparin
Mast Cells
Specialized immune cells in lymphatic system:
e.g., plasma cells which produce antibodies
Lymphocytes
Phagocytic blood cells:
- respond to signals from macrophages and mast cells
e. g., neutrophils and eosinophils - attracted to the site of infection or injury
Microphages
- most common fibers in CTP
- long, straight, and unbranched
- strong and flexible
- resists force in 1 direction
e. g., tendons and ligaments
Collagen fibers
- network of interwoven fibers (stroma)
- strong and flexible
- resists force in many directions
- stabilizes functional cells (parenchyma) and structures
e. g., sheaths around organs
Reticular fibers
contain elastin
branched and wavy
return to original length after stretching
e.g., elastic ligaments of vertebrae
Elastic fibers
is clear, colorless, and viscous
fills spaces between cells and slows pathogens
ground substance
Least specialized Open framework Viscous ground substance Elastic fibers Holds blood vessels and capillary beds: e.g., under skin (subcutaneous layer)
Areolar Tissue
Contains many adipocytes (fat cells)
Adipose Tissue
White fat: most common stores fat absorbs shocks slows heat loss (insulation)
Adipose Tissue
Brown fat: more vascularized adipocytes have many mitochondria breaks down fat produces heat
Adipose Tissue
-in adults do not divide:
-expand to store fat
-shrink as fats are released
(Adipose cells)
Adipocytes
attach muscles to bones
tendons
connect bone to bone and stabilize organs
ligaments
attach in sheets on large, flat muscles
aponeuroses
erythrocytes
Red blood cells
leukocytes
white blood cells
Extracellular fluid between blood cells
Plasma
Extracellular fluid between cells of the tissues
interstitial fluid
Extracellular fluid carried by lymphatic vessels from tissues back to the blood Extracellular fluid: collected from interstitial space monitored by immune system transported by lymphatic system returned to venous system
Lymph
gel-type ground substance
for shock absorption and protection
cartilage
calcified (made rigid by calcium salts, minerals)
for weight support
bone
- translucent matrix
- no prominent fibers
- stiff, flexible support
- reduces friction between bones
- found in synovial joints, rib tips, sternum, and trachea
Hyaline cartilage
- tightly packed elastic fibers
- supportive but bends easily
- found in external ear and epiglottis
Elastic cartilage
- very dense collagen fibers
- Limits movement
- Prevents bone-to-bone contact
- Pads knee joints
- Found between pubic bones and intervertebral discs
Fibrocartilage
Also called osseous tissue:
strong (calcified: calcium salt deposits)
resists shattering (flexible collagen fibers)
Bone
-
- arranged around central canals within matrix
- small channels through matrix (canaliculi) access nutrients
- bone cells
Osteocytes
