extracellular: collagen, elastin, wound healing Flashcards
purpose of collagen
strengthen the ECM
type I collagen
ONE = bONE (made by osteoblasts) skin tendon dentin scar tissue - late woundhealing
↓ production of this type of collagen in osteogenesis imperfecta
type I collagen
type II collagen
TWO = carTWOlage
cartilage
vitreous body (eye)
nucleus pulposus
type III collagen
BLOODY: blood vessels reticulin (skin) uterus fetal tissue granulation tissue (shiny, red)
type IV collagen
basement memberane
vascular type of Ehlers-Danlos syndrome features
deficient type III collagen arterial rupture organ rupture hemorrhage easy bruising berry aneurysm aortic aneurysm
this type of collagen is defective in Alport Syndrome
type IV collagen
characteristics of keloid scars
LOTS of COLLAGEN synthesis
disorganized collagen arrangement
tx: glucocorticoid: inhibits collagen synthesis
osteogenesis imperfecta keywords
brittle bones → multiple fractures (may occur during birth, R/O CHILD ABUSE)
bowing of long legs in utero
blue sclera: see underlying choroidal veins
hearing loss: no ossicle bones of ME
no dentin
osteogenesis imperfecta
most common form = AD = OI type I
AR = OI type II = fatal in utero or after birth
classical type of ehlers-danlos syndrome features
mutated type V (mostly) + type I (some) collagen
hypermobility - joints → dislocated joints
hyperextensible skin
defect in fibrillin (glycoprotein that forms a sheath around elastin) causes this condition:
Marfan syndrome
features of Marfan Syndrome
tall long arms/legs arachnodactyly (spidery fingers) hypermobile joints heart valve problems aortic dissection lens dislocation pectus carinatum - sternum protrudes anteriorly \+ steinberg sign: distal phalynx sticks out with a fist
locations of elastin (stretchy protein in extracellular matrix)
alveoli
arteries
vocal cords
ligamenta flava (connect vertebrae)
emphysema (panacinar) in young, non-smoker
α1 antitrypsin deficiency
α1 antitrypsin deficiency features
elastase breaks down elastin;
break down of elastin in alveoli → panacinar in young, non-smoker
accumulation of defective AT1 in hepatocytes → hepatitis, cirrhosis, hepatocellular carcinoma
mutation in this type of collagen in alport syndrome
type IV collagen - defective basement membrane
features of alport syndrome
can’t see: cataract, lenticonus (thinning of capsule around lens)
can’t pee: hereditary glomerulonephritis
can’t hear a high C: sensorineural hearing loss
cutaneous wound healing:
0-3 hrs
hemorrhage + clot
cutaneous wound healing:
12-24 hrs
acute inflammation: neutrophils
cutaneous wound healing:
1-3 days
macrophages clear debris
granulation tissue (type III collagen): fibroblasts lay down collagen + vascular endothelial cells reestablish a blood supply
epithelialization (within first 48 hrs): epithelial cells migrate in
post-op bandages stay on for 48 hrs to allow for
epithelialization (occurs 1-3 days)
cutaneous wound healing:
wks - mos
type III collagen → type I collagen (scar, ↑ strength)
poor wound healing
anemia
swollen gums
bleeding
scurvy: vitamin C deficiency
no hydroxylation of proline + lysine of collagen → no collagen
