General pathophysiology - hemodynamic disorders, stress/shock Flashcards
bradykinin
is a potent endothelium-dependent vasodilator and mild diuretic, which may cause a lowering of the blood pressure.
promotes inflammation
Regulation of blood flow is based on
the metabolic requirements of the tissues
Blood circulation control centres are located in the
diencephalon and cortex.
name 3 Vasoconstrictors
adrenalin
noradrenalin
vasopressin, also called antidiuretic hormone
name 6 Vasodilators
acetylcholine
bradykinin
histamine
CO2
ATP
lactic acid produced in the muscles
Thrombosis
blood clotting at inappropriate sites
Embolism
migration of a solid, liquid or gaseous foreign material within the intravascular space, capable of causing occlusion with injurious consequences.
blood clot (thrombus),
a fat globule (fat embolism),
a bubble of air or other (gas embolism),
or foreign material (even bullets, broken off iv catheters can cause embolisms).
Blood hydrostatic pressure is
the force exerted by the blood against the wall of a capillary that drives fluid out of capillaries and into the tissues.
Colloid osmotic (oncotic) pressure exerted by plasma proteins tends to
pull fluid INTO capillaries.
body fluid makes up what percentage of total body weight
60%
body fluids are grossly divided into what two compartments?
what are their percentages?
extracellular fluid 20% of all body fluid
&
intracellular fluid 40% of all body fluid
extracellular fluid is further divided into?
interstitial fluid
&
intravascular fluid
if extracellular fluid makes up 20% of body fluids, what portion of this is interstitial fluid
& intravascular fluid?
interstitial fluid 15%
&
intravascular fluid 5%
Anasarca
is a medical condition that leads to general swelling of the whole body. It happens when your body tissues retain too much fluid due to several reasons.
It differs from other types of edema that affect one or two parts of the body. The condition is also known as extreme generalized edema or massive edema.
another word for Noninflammatory oedema
transudate
another term for Inflammatory oedema
exudate
Hyperemia & congestion
increased tissue INflow because of arteriolar dilation/ excess blood builds up
impaired venous OUTflow from a tissue (may include cyanosis)
Arterial inflow to the venous-hyperemic area is impeded due to low blood flow rate.
TYPES OF ARTERIAL HYPEREMIA (2)
- Physiological or functional arterial hyperemia
- Pathological arterial hyperemia
Postischemic hyperemia
The rapid reactive hyperemia response to ischemia in a certain region may cause brain ischemia and loss of consciousness.
In case of ruminal dilatation rapid elimination of vascular compression factors; fast removal of transudates from thoracic and abdominal cavities, etc.
What type of heart disease will cause venous hyperemia?
right-sided heart failure
When the right side loses pumping power, blood backs up in the body’s veins.
emphysema
the alveoli become abnormally inflated, damaging their walls and making it harder to breathe.
causes shortness of breath
Induration
+ name 3 causes
hardening of tissue
Induration follows, e.g.:
chronic venous congestion;
impaired cellular nutrition
and cellular atrophy;
the above stimulate proliferation of connective tissue.
Induratio fusca pulmonum
chronic pulmonary congestion/edema leading to brown induration
hardening of the pulmonary tissue due to the increase in pulmonary connective tissue.
Diapedesis of RBCs results in the release of pigments and brownish discoloration of the tissue (hemosiderin).
ischaemia
interruption in the arterial blood supply to a tissue/organ
Ischemic (hypoxic) injury (name 2 reasons for the cell damage)
Inadequate tissue perfusion leads to cell damage for two reasons:
- Tissue hypoxia
- The absence of blood flow causes the accumulation of cellular metabolic by-products which cause cellular acidosis
what is reperfusion injury
what negatives effects does it involve (5)
Cellular damage after restoration of blood flow of previously viable ischemic tissues.
Involves
* Formation of oxygen-derived free radicals
* Excessive intracellular calcium-ion overload
* Worsening of the mitochondrial damage
* Progression of inflammation
* Microvascular damage – decreased or ceased tissue perfusion (a condition referred to as “no-reflow phenomenon”).
name 5 types of ischemia
- Compressive ischemia – is the result of artery compression by tumour, scar, foreign body, etc.
- Endogenous ischemia – narrowing of the arteries caused by a build-up of plaque – atherosclerosis
- Hematogenous /Occlusive ischemia – Changes in the blood – thromboses, embolism
- Collateral / Redistributive ischemia – Acute hyperemia in some other parts of the body
or organs, e.g. postprandial intestinal hyperemia - Neurotonic / Neurogenic ischemia - Stimulation of vasomotor centres and vasoconstrictors: temperature, electrical stimulation, drugs, hormones, etc.
differnce between Petechiae and purpura
petechiae (1-2 mm)
purpura (slightly larger >3 mm)
Suggillation/Ecchymosis
bruises >1-2 cm
Haemorrhagia per rhexin
Is a cause of hemorrhage/classification.
It means bleeding due to rupture of a blood vessel
(cuts/incision, stab/puncture wounds, etc.)
Haemorrhagia per diabrosin
A cause of hemorrhage
Erosion of vascular walls due to pathological processes
Haemorrhagia per diapedesin
A cause of hemorrhage
Bleeding due to increased permeability of the (undamaged) (micro)vessel wall
Cardiac tamponade
is pressure on the heart that occurs when blood or fluid builds up in the pericardial sac
Physiological hemostasis broadly involves what (2)
a) Reflex vasoconstriction
b) Blood coagulation
Surgical treatment of hemorrhage broadly involves what (2)
- Vascular compression to promote hemostasis
- Ligation of blood vessels; coagulation products
The three factors of Virchow’s triad include
intravascular vessel wall damage/endothelial injury,
stasis or turbulence of bloodflow, and
the presence of a hypercoagulable state/blood hypercoagulability
Mural thrombi are
thrombi that attach to the wall of a blood vessel and cardiac chamber.
Mural thrombus occurrence in a normal or minimally atherosclerotic vessel is a rare entity in the absence of a hypercoagulative state or inflammatory, infectious, or familial aortic ailments.
Occlusive thrombi can be classified as either (2)
– Arterial thrombi,
– Venous thrombi or phlebothrombi
Parietal thrombi are what
(arterial) thrombi adhering to one side of the wall of a vessel; restricts blood flow but does not block it entirely
describe central thrombi
cause partial obstruction
thrombus adheres to opposite sides of the vessel wall leaving open spaces inside the lumen between the thrombus and the vessel walls