R2 LOCO4 Flashcards
The basement membrane is made of which 3 structures? [3]
Which structures connect the keratin cytoskeleton to the basement membrane? [1]
Consists of Laminin 332, Collagen IV, and Collagen VII
Hemidesmosomes (integrin receptors) link keratin cytoskeleton to basement membrane
Stratum corneum
Label A
Corneodesmosome
Label the different arrows [4]
Yellow: basal layer
Green: stratum spinosum
Blue: Granular layer
Red: Stratum corneum
What type of collagen is found in the papillary layer [1] and reticular layer [1] of the dermis?
Papillary: Type 3
Reticular: Type 1
What are the two types of hair in the body? [2]
What is innervation like? [1]
Two types
Vellus - body hair
Terminal - scalp and secondary sexual hair
All have innervation
Where are the stem cells found in the hair follicle? [1]
Bulge region
What are the 3 main phases of the hair cycle? [3]
3 main phases:
Anagen-active
Catagen-regressive
Telogen-resting
Merkel cells are found in which layer? [1]
Function? [1]
Stratum basale
Sensory perception
Mast cells are found whhere in the skin? [1]
Function? [2]
Dermis
Immune response: secretes histamine
What are the 3 stages of normal wound healing of the skin? [3]
Phases
Inflammation
Proliferation
Maturation
Describe the inflammation stage of skin wound healin
Hemostasis
Fibrin clot
Leakage of neutrophils
Activation of resident immune cells
Active immune cell recruitment
* Blood vessel dilation
* Neutrophils then macrophages
* Mediated by ILs and TNFα etc
Describe the inflammation stage of skin wound healing [4]
Hemostasis
Fibrin clot
Leakage of neutrophils
Activation of resident immune cells
Active immune cell recruitment
* Blood vessel dilation
* Neutrophils then macrophages
* Mediated by ILs and TNFα etc
Describe the proliferation stage of skin wound healing [4]
Fibroblasts:
* Granulation tissue (type III collagen)
* Myofibroblasts
Angiogenesis
* Endothelial cells
Keratinocytes
* Re-epithelialization
* Altered adhesions and cell shape
Describe the maturation process of skin wound healing [3]
Collagen re-modelling (type 3 –> type 1 collagen)
Removal of cells
* Myofibroblasts, immune cells, redundant blood vessels
Appendages do not normally re-generate (i.e. hair follicles)
What type of NSAID is indomethacin
Acetic acid derivative
Propoinic acid derivative
Selective COX-2 inhibitros
Salicylates
What type of NSAID is indomethacin
Acetic acid derivative
Propoinic acid derivative
Selctive COX-2 inhibitros
Salicylates
do more
State the role of COX-1 & COX-2 enzymes [4]
Take arachidonic acid and convert to prostaglandin G2
Prostaglandin G2 converts to Prostaglandin H2
PH2 then converted to tissue specific prostaglandins
Different prostaglandins are found in different tissues and have different effects.
Prostaglandins are local tissue hormones; made in the tissue where you need it
Which pathway do NSAIDs specifically inhibit? [1]
Stop AA to Prostaglandin G2
State two functions of homeostatic COX-1 [2]
. Protect the lining of the stomach & increase bloodflow of the kidney
State when each of the following are produced
PGD
PGE
PGF
PGI2
TXA2
Which prostaglandin causes the most bronchoconstriction in asthma patients?
PGE2
PGD2
PGI2
PGF2α
TXA2
PGD2
Describe the differences of action of COX-1 and COX-2
Describe the mechanism of action of COX enzymes in joint pathology [2]
COX2 mRNA and protein is increased in joints with osteo or rheumatoid arthritis:
* IL1, TNF and IL17: stimulates iNOS, which induces COX2
* Mechanical stress may directly activate production of PGE2
Describe the affects of COX enzymes in CV system [2]
PGI2 (prostacyclin) from COX2 in endothelial cells prevents platelet aggregation and vasodilation
Thromboxane A2 from COX1 in platelets promotes aggregation and vasoconstriction
Difference between hybrid and reverse hybrid fixations? [2]
Hybrid fixation
Femoral component inserted without cement while acetabular is
Reverse hybrid fixation
Acetabular component inserted with cement while femoral isn’t
Difference between hybrid and reverse hybrid fixations? [2]
Hybrid fixation
Femoral component inserted without cement while acetabular is
Reverse hybrid fixation
Acetabular component inserted with cement while femoral isn’t
What type of fracture occurs if somone jumps off a building and lands on their legs
burst fracture
transverse fracture
impacted fracture
spiral fracture
greenstick fracture
burst fracture
the red arrow points to a
burst fracture
transverse fracture
spiral fracture
greenstick fracture
burst fracture
What type of fracture is highlighted? [1]
subluxion
Name this type of fracture [1]
Torus fracture (aka buckle fracture)
Describe characteristics of torus fracture [2]
In children
Children have lots of woven bone
Axial loading causing trabecular compression; bulging of the cortex
Incomplete fractures of the shaft of a long bone that is characterised by bulging of the cortex. They result from trabecular compression due to an axial loading force along the long axis of the bone
Describe the mechanism of bone healing after a fracture [5]
Fracture hematoma:
* Blood from broken vessels forms a clot 6-8 hours after injury
* Creates hypoxia; low pH
* Dead cells present cause pro-inflam cytokines
* Swelling
Fibrocartilaginous callus
* Angiogensis occurs (due to previous hypoxia)
* Fibroblasts and osteogenic precursors invade procallus
* Chondroblasts makes fibrocartilage
Inflammatory, granulation and soft callus
* Organisation and resorption of clot as new capillaries form
* Fibroblasts enter and differentiate as chondrocytes
* Chondrocytes produce collagen that bridges fracture site cartilage and trabecular bone laid down
Bony callus
* osteoblasts make woven bone
* Excess bone can form and create a bridge or a pseudo-arthrosis especially in the foot
Bone remodelling
* Osteoclasts remodel woven bone into compact bone and trabecular bone
* Often no trace of fracture line on X-rays.
State what is represented by blue, the dot and the hashtage in this bone remodelling
= remodelling
Blue = calcified cartilage
dot = woven bone
hashtag = remodelling
