systemic pathology 400 (CV class 4) Flashcards
telangiectasis
aka “ spider veins”
what are spider veins (telangiectasia)
Vascular lesion formed by dilation of a group of small blood vessels
where can spider veins occur? whre are they most common
Can occur anywhere on the skin
Most frequently seen on the face and thighs
is spider veins a serious issue
generally just a cosmetic condition –> generally no functional effect on health
how can spider veins appear?
spider veins vs childhood
May appear as a birthmark or become apparent in young children
“Spider telangiectasias are fairly common and look like little red lines on a child’s skin. They are usually nothing more than a cosmetic problem. They form as a result of abnormal blood vessels (a.k.a. a vascular anomaly). Spider telangiectasias don’t cause any health problems.”
risk factors / associated factors (telangiectasis)
May be associated with
long term sun exposure,
standing,
age,
varicose veins,
gender,
pregnancy,
trauma,
steroid treatment,
rosacea, etc.
telangiecstasis etymology
telos = end
angeion = vessel
ektasis = dilatation
frostbite
Localized medical condition whereby damage is caused to skin and other tissues due to extreme cold.
frostbite – etiology / risk factors
Extreme cold/wind chill
Wet clothes
Poor circulation
Blood vessel d/o
Low body fat
Age
Medications
Smoking, alcohol, drugs
Homelessness
frostbite – pathogenesis
Vasoconstriction upon exposure to cold
—> This helps to preserve core body temperature
Ice crystals form in tissues and expand into extracellular spaces
—> cell membrane rupture
—> disruption of enzyme activity
—> tissue death
retrostasis vs hunting response
retrostasis at first
hunting response after 10-15 or 20 (?) minutes
—> alternating vasodilation/constriction to prevent superficial tissue damage
when cold continue however, – body goes back to RETROSTASIS –> b/c the vital organs need to maintain temperature to prevent death
—> thus superficial tissue loses blood supply, and can die d/t anoxia
frostbite classification
(superficial classification)
Superficial frostbite affects skin and subcutaneous tissue
—> Discoloration of the skin, burning and/or tingling, swelling
(deep frostbite)
Deep frostbite extends beyond the superficial tissue
—> White skin, pain, blisters, tissue necrosis, gangrene
—> ultimately turns black (?) when dead
frostbite Dx
Based on history and clinical presentation
Bone scan
frostbite and bone scan
if frostbite/necrosis has reached bone –> then amputation must take place
“It is concluded that scintigraphy is an excellent means of evaluating patients with severe frostbite of the extremities: as early as day 2 after the injury it can indicate whether amputation is necessary, and between days 2 and 8 it provides valuable information on the efficacy of treatment.”
scintigraphy
a technique in which a scintillation counter or similar detector is used with a radioactive tracer to obtain an image of a bodily organ or a record of its functioning.
frostbite tx
Vasodilators
Rewarm the area without rubbing or massaging
—> Reperfusion injury is a serious complication
Pain meds
Surgery, amputation
reperfusion ?
“Reperfusion is the restoration of blood flow to an organ or tissue after having been blocked, and may refer to: Reperfusion injury, tissue damage caused when blood supply returns to the tissue.
Reperfusion therapy, the medical treatment that restores blood flow through blocked arteries, typically after a heart attack.”
why does reperfusion cause tissue damage
The inflammatory response is partially responsible for the damage of reperfusion injury. White blood cells, carried to the area by the newly returning blood, release a host of inflammatory factors such as interleukins as well as free radicals in response to tissue damage.
diabetic microangiopathy
Years of poorly controlled hyperglycemia leads to vascular complications that affect small (microvascular) vessels, large (macrovascular) vessels, or both.
pathogenesis (diabetic microangiopathy)
Vascular disease due to:
Glycosylation of serum and tissue proteins
Superoxide production
Activation of signaling molecules
—> increase vascular permeability
—> endothelial dysfunction
Hypertension
Arterial microthromboses
Hyperglycemia/hyperinsulinemia
—> inflammation and prothrombotic effects
—> impaired vascular autoregulation
Hyperglycemia
—> impaired cellular immunity
—> immune dysfunction
glycoxidation
“Glycoxidation is a process whereby glycated proteins chemically generate oxygen free radicals.”
why superoxide production
However, in diabetic conditions, the uncoupling of eNOS in diabetic vascular endothelial cells leads to the overproduction of superoxide anion (O2* −), which decreases NO availability, impairs the endothelium and ultimately increases superoxide in blood vessels [23].
1) diabetic microangiopathy VS Diabetic retinopathy
No early symptoms or signs, but blurring, retinal detachment, and partial or total vision loss eventually develop
diabetic retinopathy is…
Most common cause of adult blindness in the US
2) diabetic microangiopathy vs Diabetic neuropathy
The result of nerve ischemia from microvascular disease, direct effects of hyperglycemia on neurons, and intracellular metabolic changes that impair nerve function
diabetic retinopathy pathogenesis (?)
The pathologic process involved in DME is the resultant fluid leaking into the retina and depositing under the macula. Sediment left behind from this edema leads to waxy, yellow lipid byproducts referred to as hard exudates.
(Diabetic macular edema (DME))
diabetic nephropathy
Involves glomerular sclerosis and fibrosis caused by the metabolic and hemodynamic changes of diabetes
diabetic nephropathy is
The number one cause of renal failure in the US
note about diabetic neuropathy (as a result of diabetic microangiopathy)
also recall CHARCOT’S neuropathy
decompression sickness
AKA caisson disease, the bends, divers disease
what is decompression sickness?
Decompression sickness occurs when rapid pressure reduction (e.g. during ascent from a dive, or ascent to altitude) causes gas previously dissolved in blood or tissues to form bubbles in blood vessels.
decompression sickness and Henry’s law
The solubility of a gas in a liquid is directly proportional to the pressure exerted on the gas and liquid.
steps during decompression sickness
during descent (diving)
—> nitrogen moves from high pressure in lungs too blood (low pressure)
swimming up too quickly doesn’t give nitrogen enough time to leave blood
—> forms bubbles that lead to SSx
whereas a slow ascent would let the nitrogen gradually return to lungs where it is breathed out
decompression sickness – incidence
Approximately 2 to 4/10,000 dives
Men > women
decompression sickness – RISK FACTORS
Cold temperature dives
Prolonged or deep dives
Rapid ascent
Dehydration
Flying after diving
Obesity
Older age
why is it called the bends?
DCS often causes air bubbles to settle in major joints like knees or elbows, causing individuals to bend over in excruciating pain, hence its common name, the bends.
caisson
a large watertight chamber, open at the bottom, from which the water is kept out by air pressure and in which construction work may be carried out under water.
why called caisson disease
The original name for DCS was “caisson disease”. This term was introduced in the 19th century, when caissons under pressure were used to keep water from flooding large engineering excavations below the water table, such as bridge supports and tunnels.
decompression sickness SSx
Dependent on which tissue is affected:
Joint and muscle pain
N/V
dyspnea (shortness of breath)
Numbness, tingling, formication
Seizures
Itching and/or rash
Hearing loss
formication define
Formication is a symptom where you hallucinate the feeling of insects crawling in, on or under your skin. This symptom can be very upsetting or disturbing, leading to other issues like self-injury from scratching or trying to get the insects out from under or inside of your skin.
