Connective Tissue Flashcards
What is areolar CT?
low density tissue w/ both fixed and wandering cells; widespread
loose ct
How are type 1 collagen fibrils organized?
aligned and crosslinked - to increase tensile strength
can see banding in electron micrographs
What is reticular CT?
loose CT
rich in reticular fibers; forms an open framework to create a supportive mesh for holding free cells
Where is dense irregular CT found?
dermis of skin
capsules that surround internal organs
perichondrium and periosteum
fascia
Where is adipose CT found?
under skin
around organs
w/in abdomen, breasts, and buttocks
What separates CT cells?
extracellular matrix (ECM)
What is the function of brown fat?
thermogenic tissue = produces heat
abundant in newborns, reduced in adults
What is dense regular CT?
dense CT collage fibers in highly regular pattern fibroblasts principle cell type poorly vascularized resists tension - wave when loose
What is the function of chondrocytes?
produce bone components
What are the wandering cells in Loose areolar ct?
macrophages
mast cells
leukocytes/lymphocytes
plasma cells
What do adipocytes look like?
closely packed with nuclei pushed to the side by large fat droplet
What is elastic CT?
contains high proportion of elastic fibers = allows recoil
in blood vessel walls, bronchioles, and special ligaments
What is dense irregular CT?
dense CT
ECM of tightly packed collagen fibers in random pattern
fibroblasts are principle cell type
Where is reticular connective tissue found?
liver
bone marrow
lymph nodes
spleen
What are the cells of connective tissue? (6)
fibroblasts mesenchymal cells adipocytes chondrocytes osteoblasts hematopoietic stem cells
What is the function of hematopoietic stem cells?
produce red blood cells and immune cells
What are the main components of the ECM of fibrous connective tissue?
Collagens
elastin
reticular fibers
What are the fixed cells in loose areolar CT?
fibroblasts
adipocytes
mesenchymal cells
What is embryonic connective tissue like?
rich in ECM and mesenchymal stem cells
not as much collagen or reticular fibers
Where is dense regular CT found?
tendons ligaments aponeuroses dense fascia joint capsules
What is the function of Loose CT?
Where is it located?
supports and binds other tissues, hold body fluids, defends against infection
found beneath membranous epithelia; around blood vessels, muscles, and nerves
What are reticular fibers?
supportive meshwork
type 3 collagen is a component
What are the 2 types of fat?
white fat
brown fat
What are macrophages?
differentiate from blood monocyte
phagocytose
What characterizes adipose CT?
Loose Ct w/ abundant adipocytes and sparse ECM
reserve energy source and insulation against heat loss
pads organs
What is the function of mesenchymal cells?
CT stem cells, pleuripotent
What are the types of dense connective tissue?
dense irregular
dense regular
elastic
What do mast cells do?
secrete histamine = allergic response
and heparin = anti-coagulant
What is the state of ECM in bone?
mineralized
What are the types of loose connective tissue?
areolar
adipose
reticular
What is Marfan’s syndrome?
Autosomal dominant mutation in fibrillin-1 gene –> weak elastin
affects ocular, skeletal, and cardio systems
life threatening cardio anomalies (aneurysms)
tall w/ long arms/legs
What is the function of ECM that is overlooked (mentioned by Brauer in lecture)?
carries O2, CO2, nutrients, and wastes
What is collagen’s main function?
Which type is most common?
resists tension (leather belt) type 1 is most common
What are the 3 types of glycoproteins mentioned?
cytokines growth factors (TGF-Beta) structural proteins (fibronectin, laminins, etc)
What is Ehlers-Danlos syndrome?
mutation that causes abnormal collagen synthesis –> weak collagen fibers
What is the principle cell type of dense irregular CT?
fibroblast
What is the function of white fat?
energy storage and insulation
cushioning vital organs
hormone secretion
What is the lamina propria?
loose ct immediately beneath membranous epithelia
What are plasma cells?
differentiate from B-lymphocytes
produce antibodies that mediate immunity
What is the function of adipocytes?
remove lipids from blood, store it, and release when needed
What are the elastin subunits?
tropoelastin
fibulin-1
fibrillins 1/2
What is the function of fibroblasts?
produce collagens, elastin, proteoglycans, and glycoproteins
in the ECM
What are the types of ECM ground substance molecules mentioned? (4)
Proteoglycans
hyaluronan
glycoproteins
extracellular proenzymes
What are the 2 main classes of fibrous CT?
loose CT
Dense CT
What is warton’s jelly?
embryonic CT in umbilical cord
What is vitamin C a cofactor for?
cross-linking collagen fibers
