R2 LOCO4 Flashcards by patrick ellis

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

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Stratum corneum

Label A

Corneodesmosome

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Label the different arrows [4]

Yellow: basal layer
Green: stratum spinosum
Blue: Granular layer
Red: Stratum corneum

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What type of collagen is found in the papillary layer [1] and reticular layer [1] of the dermis?

Papillary: Type 3

Reticular: Type 1

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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

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Where are the stem cells found in the hair follicle? [1]

Bulge region

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What are the 3 main phases of the hair cycle? [3]

3 main phases:
Anagen-active
Catagen-regressive
Telogen-resting

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Merkel cells are found in which layer? [1]

Function? [1]

Stratum basale

Sensory perception

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Mast cells are found whhere in the skin? [1]

Function? [2]

Dermis
Immune response: secretes histamine

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What are the 3 stages of normal wound healing of the skin? [3]

Phases
Inflammation
Proliferation
Maturation

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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

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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

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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

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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)

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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

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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

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Which pathway do NSAIDs specifically inhibit? [1]

Stop AA to Prostaglandin G2

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State two functions of homeostatic COX-1 [2]

. Protect the lining of the stomach & increase bloodflow of the kidney

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State when each of the following are produced

PGD
PGE
PGF
PGI2
TXA2

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Which prostaglandin causes the most bronchoconstriction in asthma patients?

PGE2
PGD2
PGI2
PGF2α
TXA2

PGD2

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Describe the differences of action of COX-1 and COX-2

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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

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Which COX enzyme is mainly present in the stomach? [1]
Which prostaglandin does this make? [1]

Explain the affect of NSAIDs on the stomach [1]

Mainly COX1 isoform: normal PGE2 helps gastric mucosa

But NSAIDS inhibit COX-1 and and induce COX-2: reduce the protection of the stomach and can lead to the development of gastric ulcers, gastritis

Increases chance of gastric ulcer

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

Describe the normal MoA of aspirin [2] Describe the DDI of aspirin and ibupofren in CV system [2]

Aspirin binds to COX-1 and binds to **serine**; produces i**rreversible covalent chain**. Stops the platelet from producing **thromboxane A2**; which is an **anti-coagulant effect.** **Ibuprofen**; binds to same **serine chain**; but is **reversible**; which is why is not an **anti-coagulant.** When **ibuprofen is given**, **aspirin** **cant** bind to **COX-1** and **produce anti-coagulant affect**

# Spinal Cord & CNS What is the role of COX2 in this location? [1] Under what conditions is COX-2 found in the spinal cord and CNS? [1]

Find both COX1 & COX2 in **resting conditions** COX2 is important in spinal **nociceptive transmission**

Role of COX-1 [2] and COX-2 [1] in the kidney? Via which prostaglandins? [2]

COX1: produces **PGE2** and **PGI2** * PGE2: regulates sodium reabsoprtion * PGI2 regulates potassium excretion COX2: * present in small amounts in **macula densa** but increases in salt deprivation

What type of NSAID is diclofenac Acetic acid derivative Propoinic acid derivative Selective COX-2 inhibitor Salicylates

What type of NSAID is diclofenac **Acetic acid derivative** Propoinic acid derivative Selctive COX-2 inhibitros Salicylates

What type of NSAID is aspirin Acetic acid derivative Propoinic acid derivative Selective COX-2 inhibitor Salicylates

What type of NSAID is aspirin Acetic acid derivative Propoinic acid derivative Selctive COX-2 inhibitros **Salicylates**

What type of NSAID is ibuprofen Acetic acid derivative Propoinic acid derivative Selective COX-2 inhibitor Salicylates

**Propoinic acid derivative**

What type of NSAID is naproxen Acetic acid derivative Propoinic acid derivative Selctive COX-2 inhibitor Salicylates

**Propoinic acid derivative**

What type of NSAID is celecoxib Acetic acid derivative Propoinic acid derivative Selective COX-2 inhibitor Salicylates

**Selective COX-2 inhibitor**

Which prostaglandin causes has mixed vascular effects (constriction and dilation)? PGE2 PGD2 PGI2 PGF2α TXA2

**PGF2α**

Which prostaglandins cause uterine contraction? [2] PGE2 PGD2 PGI2 PGF2α TXA2

**PGF2α**; **TXA2**

Which prostaglandin causes uterine relaxation? PGE2 PGD2 PGI2 PGF2α TXA2

Which prostaglandin causes uterine relaxation? **PGE2** PGD2 PGI2 PGF2α TXA2

Which prostaglandin causes inhibits platelet aggregation? PGE2 PGD2 PGI2 PGF2α TXA2

**PGI2**

Which prostaglandin causes induces platelet aggregation? PGE2 PGD2 PGI2 PGF2α TXA2

TXA2

Which prostaglandin suppresses lymphocytes? PGE2 PGD2 PGI2 PGF2α TXA2

**PGE2**

In the stomach, NSAIDs for long periods blocks which prostaglandin generation? PGE2 PGD2 PGI2 PGF2α TXA2

**PGE2**

Describe the process of aseptic loosening

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

Tendon transfer for wrist extension (radial nerve palsy)? [2]

**PT (pronator teres)** to **ECRB (extensor carpi radialis brevis)**

Tendon transfer for finger MCP extension? (radial nerve palsy)? [2]

**FCU** to **EDC** (extensor digitorum communis)

Tendon transfer for thumb extension? [2]

**PL (palmaris longus)** to rerouted **EPL (extensor pollicis longus)**

What type of fracture occurs from an object dropping on you and breaking the bone burst fracture transverse fracture impacted fracture spiral fracture greenstick fracture

**transverse fracture**

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**

Which bone in the foot is common for an avulsion fracture to occur in? [1]

**The fifth metatarsal in the foot**, which is the bone at the base of the little toe, can be vulnerable to avulsion fractures. Dancers often experience this type of injury

What type of fracture is highlighted? [1]

**subluxion**

A colles fracture is what type of fracture? [1] burst fracture transverse fracture impacted fracture spiral fracture greenstick fracture

A colles fracture is what type of fracture? [1] burst fracture transverse fracture **impacted fracture** spiral fracture greenstick fracture

Name this type of fracture [1]

Torus fracture (aka buckle fracture)

Stress fractures are difficult to assess on an x-ray. State 3 other imaging techniques used to assess a stress fracture [3]

**Bone scintigraphy** becomes positive at same time or sooner than plain films Low false positive **CT and MRI scans**

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