DLA 22 + lecture 28 Flashcards
What are the permanent residents of the connective tissue?
- fibroblasts
- adipose tissue
- macrophages / monocytes
- mast cells
- mesenchymal stem cells
What are the transient cell population of the CT?
- lymphocytes
- plasma cells
- eosinophils
- basophils
- neutrophils
explain fibroblasts?
they are the most common cell in connective tissue
synthesize fibers and ground substance
spindle-shaped
What are myofibroblasts?
wound healing
presence of contractile filaments
explain adipocytes?
signet ring cell
large fat inclusion
rich blood supply
What is an unilocular adipocyte?
One large fat droplet- white fat
What is an Multilocular Adipocyte?
considered brown fat
What is multilocular adipocytes characterized by?
- many lipid droplets
- central nucleus
- rich in mito
- highly vascular
- rich in innervation
- lipochrome pigments
- heat production
Where is brown fat found?
body neck and abdomen of neonates
What are macrophages derived from?
monocytes
they migrate to CT to differentiate
Macrophages in CT?
liver - Kupffer cells
brain - microglia
bone - osteoclasts
properties of macrophages?
- irregular cell membrane
- have pseudopodia
- phagocytic; produce cytokines
- antigen presenting cells
Explain mast cells?
they originate in the bone marrow from precursor cells
they proliferate in the lamina propria of CT
mast cells and basophils come from the same progenitor cells
Explain lymphocytes?
small and spherical
condensed basophilic nucleus
immune cells - B and T
B cells develop into plasma cells
Explain plasma cells?
come from B lymphocytes
secretes single class of IG
basophilic cytoplasm
clock-face nucleus
negative golgi
eosinophils?
red granules in the cytoplasm
condensed, bilobed nucleus
phagocytosis of antibody
kills parasitic worms
What are the classifications of connective tissue?
- embryonic connective tissue
- CT proper
- specialized CT
What is the embryonic connective tissue
mesenchyme- mucous connective tissue
What are the types of CT proper?
loose connective tissue (areolar) and dense connective tissue
What are the subsections of dense connective tissue?
regular and irregular
What are the specialized connective tissue?
- cartilage
- bone
- adipose tissue
- blood
- hemopoietic tissue
- lymphatic tissue
What are the components of connective tissue?
cells
fibers and ground substance in the ECM
Why is CT important?
- support (stroma- supporting structures)
- repair
- Defense (immune function)
- Nutrition (storage and transport)
What are the characteristics of mesenchyme?
a lot of ground substance
cells have a tapered spindle appearance
sparsely arranged reticular fibers
characteristics of mucous CT?
ground substance is a gelatinous consistency
few cells and fibers
mainly ground substance
Where is mucous CT found?
umbilical card (Wharton’s jelly)
features of LCT?
large number of cells compared to fibers
rich blood supply
found below most epithelial linings
features of Dense irregular CT?
fewer cells, more fibers
no orientation of fibers
usually organ capsules, dermis, periosteum
features of dense regular CT?
specific orientation of fibers
imparts tensile strength
found in: tendons and ligaments
components of dense regular CT?
fibroblasts and type 1 collagen fibers
what is the structure of a tendon?
epitendineum- covering the whole tendon
peritendineum - surrounds a group of fascicles
endotendineum- covering around a group of fibers
components of reticular CT?
fibroblasts
reticular fibers
function of reticular CT?
forms a framework for tissues
thin branching fibers
Ex: liver, lymph nodes
features of elastic connective tissue?
elastic fibers (yellow)
they are connected by desmosine and isodesmosine
adipose CT?
cells nucleus is pushed to the periphery
one big fat droplet
used for storage
Brown adipose CT?
smaller
central nucleus
heat conduction
more common in babies
What is a hypertrophic scar?
Scar when more raised than normal, but within original wound boundary (fibrosis)
what is a keloid scar?
the scar is surrounding into surrounding tissue (keloid)
What leads to fibrosis and keloids?
increased collagen production
What occurs due to a vitamin C deficiency?
scurvy due to the decreased production of collagen due to the lack of vitamin C
What is anaphylactic shock?
increased mast cell release of histamine
What is edema?
swelling due to increased tissue fluid
