extracellular: collagen, elastin, wound healing

Question 1

purpose of collagen

Answer 1

strengthen the ECM

Question 2

type I collagen

Answer 2

ONE = bONE (made by osteoblasts)
skin 
tendon
dentin
scar tissue - late woundhealing

Question 3

↓ production of this type of collagen in osteogenesis imperfecta

Answer 3

type I collagen

Question 4

type II collagen

Answer 4

TWO = carTWOlage
cartilage
vitreous body (eye)
nucleus pulposus

Question 5

type III collagen

Answer 5

BLOODY:
blood vessels
reticulin (skin)
uterus
fetal tissue
granulation tissue (shiny, red)

Question 6

type IV collagen

Answer 6

basement memberane

Question 7

vascular type of Ehlers-Danlos syndrome features

Answer 7

deficient type III collagen
arterial rupture
organ rupture
hemorrhage
easy bruising
berry aneurysm
aortic aneurysm

Question 8

this type of collagen is defective in Alport Syndrome

Answer 8

type IV collagen

Question 9

characteristics of keloid scars

Answer 9

LOTS of COLLAGEN synthesis
disorganized collagen arrangement
tx: glucocorticoid: inhibits collagen synthesis

Question 10

osteogenesis imperfecta keywords

Answer 10

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

Question 11

osteogenesis imperfecta

Answer 11

most common form = AD = OI type I

AR = OI type II = fatal in utero or after birth

Question 12

classical type of ehlers-danlos syndrome features

Answer 12

mutated type V (mostly) + type I (some) collagen
hypermobility - joints → dislocated joints
hyperextensible skin

Question 13

defect in fibrillin (glycoprotein that forms a sheath around elastin) causes this condition:

Answer 13

Marfan syndrome

Question 14

features of Marfan Syndrome

Answer 14

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

Question 15

locations of elastin (stretchy protein in extracellular matrix)

Answer 15

alveoli
arteries
vocal cords
ligamenta flava (connect vertebrae)

Question 16

emphysema (panacinar) in young, non-smoker

Answer 16

α1 antitrypsin deficiency

Question 17

α1 antitrypsin deficiency features

Answer 17

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

Question 18

mutation in this type of collagen in alport syndrome

Answer 18

type IV collagen - defective basement membrane

Question 19

features of alport syndrome

Answer 19

can’t see: cataract, lenticonus (thinning of capsule around lens)
can’t pee: hereditary glomerulonephritis
can’t hear a high C: sensorineural hearing loss

Question 20

cutaneous wound healing:

0-3 hrs

Answer 20

hemorrhage + clot

Question 21

cutaneous wound healing:

12-24 hrs

Answer 21

acute inflammation: neutrophils

Question 22

cutaneous wound healing:

1-3 days

Answer 22

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

Question 23

post-op bandages stay on for 48 hrs to allow for

Answer 23

epithelialization (occurs 1-3 days)

Question 24

cutaneous wound healing:

wks - mos

Answer 24

type III collagen → type I collagen (scar, ↑ strength)

Question 25

poor wound healing
anemia
swollen gums
bleeding

Answer 25

scurvy: vitamin C deficiency

no hydroxylation of proline + lysine of collagen → no collagen