Unit 3 Flashcards
What does the health of cells and tissue depend on?
circulation of blood
What is delivered to cells and tissues by the circulatory system?
Oxygen and glucose`
What does Hyperemia entail?
Too much blood volume within tissue
_____ Is an active process resulting from arteriolar dilation and increased blood inflow._____ causes Erythema in inflammation and it is also a result of inflammation
Hyperemia
______ is a passive process which results in lowered venous outflow and causes tissue cyanosis
Congestion
What does congestion result from?
venous obstruction
Ex. Congestive heart failure, DVT, testicular torsion
What does acute pulmonary congestion entail?
blood-engorged alveolar capillaries and variable degrees of alveolar septal edema and intra-alveolar hemorrhage
What does Chronic pulmonary congestion entail?
The alveolar septa becomes fibrotic and thhe alveolar spaces contain numerous macrophages laden with hemosiderin (“heart failure cells”)
What are hemosderin derived from?
phagocytosed red cells
What happens to the central veins and sinusoids in acute hepatic congestion ?
The central veins and sinusoids are distended with blood.
What happens to the periportal hepatocytes in acute hepatic congestion?
experience less severe hypoxia and may develop only reversible fatty change
What is the most common result of congestive heart failure?
acute hepatic congestion
What is edema?
abnormal accumulation of ISF within tissues or cavities
What are examples of localized edemas?
LE, Ascites and Hydrothroax
What are examples of generalized edemas?
anasarca
Approximately ___ of lean body weight is water, two thirds of which is intracellular.
60%
only ___ of the bodys water is in blood plasma
5%
What is anasarca?
severe, generalized edema marked by profound swelling of sub- cutaneous tissues and accumulation of fluid in body cavities.
What is fluid movement within between the vascular and Interstitial spaces governed by?
Vascular hydrostatic pressure and colloid osmotic pressure
What is produced by hydrostatic pressure at the arteriolar end of the microcirculation?
outflow of fluid
The edema fluid that accumulates owing to increased hydrostatic pressure or reduced intravascular colloid typi- cally is _____
Transudate
What are the causes of EDEMA?
Increased hydrostatic pressure, Lymphatic obstruction, sodium and water retention
Local impaired venous return increases in intravascular pressure can result from _______
impaired venous return
What could cause edema to the distal portion of a leg?
a deep venous thrombosis in the lower extremity
Generalized impaired venous returns might result in ____
congestive heart failure
In order to reverse damage to the heart caused by Gen. Impaired venous return what would need to happen?
restoration of cardiac output or reduction of renal water retention
Under normal circumstances ______accounts for almost half of the total plasma protein
albumin
What is one cause for reduced plasma osmotic pressure?
syndromes where albumin is either lost from the circulation or synthe- sized in inadequate amounts
in ___ ____ damaged glomerular capillaries become leaky, leading to the loss of albumin (and other plasma proteins) in the urine and the development of generalized edema. Reduced albumin synthesis occurs in the setting of severe liver disease
neprotic syndrome
What could lead to cirrhosis?
nephrotic syndrome
What usually results from a localized obstruction of the lymph canal?
Lymphedema
What is lymphedema generally caused by?
Inflammatory or neoplastic conditions
What is peau d’ orange?
Edema on the skin that is superficial to the lymph canal (typically in breast cancer) the skin has pitted appearance
One complication of therapy could be _____
lymph edema
What could excessive retention of salt and water lead to?
Edema
How does excessive retention of salt and water lead to edema?
By increasing hydrostatic pressure and reducing plasma osmotic pressure
What diseases cause retention of salt and water?
Acute renal failure
Where does subcutaenous edema usually happen?
accumulates preferentially in parts of the body positioned the greatest distance below the heart where hydrostatic pres- sures are highest
What is dependent edema?
Pooling of the edema fluid is dependent on gravity or gravity pull
Wound healing is decreased in edema because
Blood has to push harder through the edema fluid in order to get to the target tissue
Edema may indicate pathologies such as___
CHF, Renal failure
In pitting edema vs non pitting edema, which would have more protein content and capacity for osmosis?
non pitting edema
What is the definition of a hemorrhage?
extravasation of blood from vessels which causes external or internal bleeding
What is a hematoma?
accumulation of blood within tissue (product of internal hemorrhage)
What determines the severity of hemorrhage?
The extent of damage and the site where injury occurs
Losing more than 20% of blood rapidly or slowly causes no damage to healthy adults (t or F)
true, greater losses cause Hypovolemic Shock
What three elements are involved in hemostasis and thrombosis?
the vascular wall, platelets, and the coagulation cascade.
What are the regulators of hemostasis?
Endothelial cells
What facilitates platelet adherence, activation, and aggregation?
Exposure of ECM caused by endothelial injury
which cells express anticoagulant factors?
Endothelial cells
What are the three primary abnormalities that lead to Thrombosis?
Endothelial injury, Stasis or turbulent of blood flow, and hypercoagulability of the blood
What is Thrombosis?
Clot formation inside of a blood vessel
What are inherited mutations that could cause Thrombosis?
Factor V which is Antithrombotic or Prothrombrin which is pro thrombotic
what contributes to arterial and cardiac thrombosis by causing endothelial injury or dysfunction, as well as by forming countercurrents and local pockets of stasis?
Turbulence
a major factor in the development of venous thrombi would be turbulence and/or _______
stasis
Abnormal aortic and arterial dilations called _______create local stasis and consequently a fertile site for thrombosis
Aneurysms
Arterial thrombosis usually occurs in the site of _____ and grows ______ of flow
injury; against
Venous thrombosis usually occurs in the site of ______ and grows ______of flow
in direction
What are types of infective thrombosis?
Fungal infections and bacterial infections
What are the fates of the Thrombi if the patient survives?
Propagation, embolization, dissolution, organization and recanalization
What is propagation when talking about thrombii?
Enlargement of the thrombus ; Increase risk for embolism
What is embolization?
A thrombus is dislodged and transported elsewhere in the vascular system
What is dissolution?
shrinkage and complete dissolution of thrombus due to activation of fibronolytic factors
How can older thrombi become organized?
the ingrowth of endothelial cells, smooth muscle cells, and fibroblasts into the fibrin-rich throm- bus
What is an Embolism?
a travelling detached intravascular mass could be a thrombus or anything else
What are the risks of embolism?
Vascular occlusion
Less common types of emboli include
fat droplets, bubbles of air or nitro- gen, atherosclerotic debris (cholesterol emboli), tumor frag- ments, bits of bone marrow, and amniotic fluid.
What is a pulmonary embolism?
• Embolic occlusion of a pulmonary artery
What is the incidence of PE?
The incidence of pulmonary embolism is 2 to 4 per 1000 hospitalized patients
Where do the emboli to the lung usually come from?
95% from DVT (femoral vein, thigh)
Are pulmonary thromboembolisms usually silent?
yes 80% of them are usually silent
What are some symptoms of pulmonary embolism?
Dyspnea, tachypnea (>20 BPM), cough, chest pain,
cyanosis, hypoxia, collapse
• Pulmonary HTN → cor pulmonale
What are the risks of developing a pulmonary embolism?
previous PE (30% recur), bedrest, burns, CHF, CA, surgery (knee, hip)
What is a systemic thromboembolism?
an embolism within the arterial system (not venous though)
80% of systemic thromboembolisms arise from?
cardiac mural thrombi
2/3 LT Ventricle after MI
1/4 LT atrial dilation after mitrial stenosis
20% of systemic thromboembolisms arise from ____ and ____
aortic aneurysms and atheromas
The most common embolization site for systemic thromboembolisms are
Lower Extremities with a 75% prevalence
What is a paradoxial embolism?
Emboli that cross from venous system to the arterial system they originate as a DVT and cross to the arterial system
A common way for emboli to cause paradoxical embolism is
Atrial Septal defect
A paradoxical embolism could typically cause _____
stroke
What is an infarction?
area of ischemic necrosis caused by occlusion of the vascular supply to the affected tissue; the process by which such lesions form termed infarction
What underlies the majority of infarctions?
Arterial thrombosis or arterial embolism
What affects the severity of an infarct?
(1) the anatomy of the vascular supply; (2) the time over which the occlusion develops; (3) the intrinsic vulnerability of the affected tissue to ischemic injury; and (4) the blood oxygen content.
What is a red infarct?
Infarct that typically occurs in (1) with venous occlu- sions (such as in ovarian torsion); (2) in loose tissues (e.g., lung) where blood can collect in infarcted zones; (3) in tissues with dual circulations such as lung and small intestine
Also known as a hemorrhagic infarct
What is a white infarct?
occur with arterial occlusions in solid organs with end-arterial circulations (e.g., heart, spleen, and kidney), and where tissue density limits the seepage of blood from adjoining patent vascular beds
wedge-shaped
Infarcts resulting from arterial occlusions in organs without a dual circulation typically become progressively paler and sharply defined with time
What is shock?
final common pathway for several potentially lethal events, including exsanguination, extensive trauma or burns, myocardial infarction, pulmonary embolism, and sepsis.
What is shock characterized by?
hypoperfusion of tissues; it can be caused by diminished cardiac output or by reduced effective circulating blood volume which could lead to dysfunction or death due to celullar hypoxia
What is the most common or prevalent “Shock” occurence or pathology?
Cardiogenic shock results from low cardiac output due to myocardial pump failure. It may be caused by myo- cardial damage (infarction), ventricular arrhythmias, extrinsic compression (cardiac tamponade)
cyanosis and sns stimulation
What is hypovolemic shock?
Hypovolemic shock results from low cardiac output due to loss of blood or plasma volume (e.g., due to hemor- rhage or fluid loss from severe burns).
Cyanosis and sns stimulation
What is septic shock?
results from arterial vasodilation and venous blood pooling that stems from the systemic immune response to microbial infection.
What is neurogenic shock?
result from loss of vascular tone associated with anesthesia or secondary to a spinal cord injury
What is anaphylactic shock?
Anaphylactic shock results from systemic vasodilation and increased vascular perme- ability that is triggered by an immunoglobulin E–mediated hypersensitivity reaction
What could shock lead to?
Shock is a progressive disorder that leads to death if the underlying problems are not corrected because of widespread hipoxia and thrombosis
What are the stages of shock?
- An initial nonprogressive stage, during which reflex com- pensatory mechanisms are activated and vital organ perfusion is maintained
- A progressive stage, characterized by tissue hypoperfu- sion and onset of worsening circulatory and metabolic derangement, including acidosis
- An irreversible stage, in which cellular and tissue injury is so severe that even if the hemodynamic defects are corrected, survival is not possible
