Test 2 Flashcards
This type of Massive thromboembolus are often lethal because they prevent the entry of blood into the lungs and cause acute anoxia. They block both branches.
saddle emboli
Emboli that originate in the left atrium or ventricle, aorta, and the major arteries and carried by arterial blood
● Arterial emboli
Liquid emboli are?
fat emboli that occur after bone fracture, and amniotic fluid emboli caused by the entry of amniotic fluid into the uterine veins during delivery
what is a Fat embolism?
Describes the release of emboli of fatty marrow into damaged blood vessels following severe trauma to fat-containing tissue, particularly with bone fractures
appear 1-3 days after injury, and in its most severe form is characterized by respiratory failure
fat embolism syndrome
Occurs in 90% of patients with severe skeletal injuries, and less than 10% have clinical findings
fat embolism syndrome
What is the fat embolism Triad?
○ Respiratory issues (ARDS)
○ Neurological problems
○ Thrombocytopenia
What is Amniotic Fluid Embolus
Refers to entry of amniotic fluid containing fetal cells and debris into the maternal circulation through a tear in the placental membranes and rupture of the uterine and cervical veins
Describe Gaseous emboli
an air embolism produced by injected air into the veins; or air that is liberated under pressure, as in decompression sickness
What is Hyperemia ?
● Denotes an accumulation of blood in the peripheral circulation
● Resultant influx of blood into the capillaries
● Typically occurs in acute inflammation, blushing, or exercise
● Separated into two types:
What is Active hyperemia
■ Consequence of dilation of the arterioles mediated by neural signals that lead to the relaxation of arteriolar smooth muscle
Describe Passive congestive Hyperemia
■ Caused by increase in venous back pressure and most often occurs in a chronic form
■ Typically a consequence of congestive heart failure, where the stagnation of venous oxygenated blood contributes to a bluish discoloration of the tissues (cyanosis)
■ Often associated with peripheral or pulmonary edema
in the lungs, leads to formation of edema and extravasation of RBC in the alveoli…
In chronic form of Passive congestive hyperemia
Leads to NUT MEG lung
Chronic form of Passive congestive hyperemia Disintegration of RBC are taken up by the alveolar macrophages and the hemoglobin of the RBC is degraded into a brown pigment (hemosiderin) that accumulates in the lysosomes of the macrophages
The transformation of the fluid blood into a solid aggregate encompassing blood cells and fibrin
Fibrin is polymerized fibrinogen and forms a meshwork of thin filaments that bind together the cellular elements of the blood, forming a…
thrombus or CLOT
■ Attached to the mural endocardium of the heart chambers
■ Found overlying a myocardial infarction
Intramural thrombi
■ Are composed of tightly intermixed RBCs and fibrin
■ Thrombi in small vessels tend to be red
○ Red thrombi
○ Layered thrombi
■ Show distinct layering of cellular elements and fibrin
● The white layer in these are called Lines of Zahn
● Thrombi in larger arteries, veins, and mural thrombi tend to be layered
○ With time, the thrombus stimulates ingrowth of inflammatory cells and vessels, producing granulation tissue that provides more firm anchorage:
■ This process is called …
organization
■ Results from a pump failure of the heart (congestive heart failure), most often secondary to an MI that destroys a large part of the functioning myocardium
● Similar results from myocarditis, valvular heart disease
○ Cardiogenic Shock: pump failure of the heart
■ Results from loss of circulatory volume, attributed to massive hemorrhage or water loss related to massive burn, vomiting, or diarrhea
○ Hypovolemic Shock: loss of fluid from the circulation
results from a loss of vascular tone and pooling of blood in peripheral blood vessels
■ Hypotonic shock
■ Hypotonic shock Can also occur when…
● Occurs in anaphylactic shock caused by exposure to an allergen and in neurogenic stimuli, such as pain caused by trauma or a spinal cord injury
resulting from the spread of bacteria from a severe localized infection in the blood stream
● Abscesses, pneumonia, or peritonitis
■ Can occur with gram positive and fungal infections
● Staph aureus, candida
○ Septic Shock: from severe Gram Negative Bacteremia
■ Gram negatives involved include:
● E. Coli→ number 1!! ● Proteus ● Serratia ● Pseudomonas ● K. pneumoniae ● Bacteroides
● Complex binds to receptors on WBC and tissue cells, causing the release of inflammatory mediators
Gm- Bacteria that all have LPS
● Stages of Shock:
○ Non-Progressive Stage
○ Progressive Stage
○ Irreversible Stage
○ Non-Progressive Stage of shock
■ An initial phase during which the reflex compensatory mechanisms are activated and perfusion of vital organs is maintained
■ Vasoconstriction of the renal blood vessels results in renal hypoperfusion, decreased GFR, and activation of RAS for conservation of fluid
● This increases cardiac output and blood pressure
■ This stage is reversible and treatable
○ Progressive Stage of shock
■ Characterized by tissue hypoperfusion and the onset of worsening circulatory and metabolic imbalances (acidosis)
■ Low pH also has depressive effect on HR, potentiating pump failure
● Left ventricular insufficiency raises the intrapulmonary venous pressure, causing stagnation of blood in the pulmonary circulation
● Forms pulmonary edema and ARDS aka Shock Lungs
■ Urinary output begins to fall, marking the transition between reversible and irreversible stages
