Lecture 16 9/19/23 Flashcards
What is connective tissue?
tissue whose main function is to provide structure and support for other tissues
What are the different types of connective tissue (for our class)?
-connective tissue proper
-elastic connective tissue
-reticular connective tissue
-adipose tissues
-embryonic connective tissues
What are the characteristics of connective tissue proper?
-basic connective tissue
-holds other tissues together
-main cells are fibroblasts
-extracellular matrix contains collagen and ground substance
What are the characteristics of fibroblasts?
-spindle-shaped
-produce the extracellular matrix
-important in tissue repair
What happens with fibroblasts in tissue repair?
-they transform into myofibroblasts
-have contractile ability
-secrete more extracellular matrix; brings wound together
What are the characteristics of collagen?
-long, strong protein fibers
-provide tensile strength
-different arrangements of a-chains lead to different collagen types
What are the two main types of collagen (for our class)?
-type 1; main structural collagen
-type 3; reticulin
What are the characteristics of type 1/main structural collagen?
-forms ligaments, tendons, dermis, and bone
-shows up as pink fibers on histology
What is the main characteristic of type 3/reticulin?
forms lacy structure of parenchymal organs
What are the characteristics of ground substance?
-complex carbohydrate and protein meshwork
-attracts water to form a gel
-provides compression resistance
-lubricates and hydrates
-provides nutrient and waste transport
What are glycosaminoglycans?
-long, unbranched polysaccharide chains
-complex with proteins to form bottlebrush-shaped proteoglycans in ground substance
What is hyaluronic acid?
a large glycosaminoglycan that will bind multiple proteoglycans to provide additional structure
What are the two structural glycoproteins?
-integrins
-fibronectin
What is the role of integrins?
to be embedded in the cell membrane and attach to various molecules, including fibronectin
What is the role of fibronectin?
bind integrins to collagen
What is the location/purpose of loose connective tissue?
-surrounds vessels/nerves, underlies epithelia, and forms mesentery
-loosely holds tissue together
How can loose connective tissue be identified?
-lots of ground substance
-fewer, irregularly arranged collagen fibers
-sparse fibroblasts
What is the location/purpose of dense irregular connective tissue?
-forms dermis of skin, submucosa of intestines, and organ capsules
-resists forces/stretch in different directions
How can dense irregular connective tissue be identified?
-lots of collagen fibers with many intersecting bundles
-less ground substance
-few fibroblasts
What is the location/purpose of dense regular connective tissue?
-forms tendons, ligaments, and aponeuroses
-resists forces in one direction
How can dense regular connective tissue be identified?
-lots of parallel collagen fibers
-less ground substance
-few fibroblasts