CV Flashcards
oncotic pressure
the pressure pulling fluid back into vessels- caused mainly by albumin and large negatively charged proteins
haemostasis
the stoppage of bleeding
intrinsic pathway
everything necessary for it is in the blood. necessary for continuation of the coagulation cascade
extrinsic pathway
needs a cellular component outside the blood (tissue factor) most important in the initiation of the coagulation cascade
poiselles law
flow= 1/radius to the power of 4
Cardiac output
CO= HR X Stroke Volume
Blood pressure
BP= CO X total peripheral resistance
determinants of total peripheral resistance
radius of the vessel which is determined by the contraction of the smooth muscle within the cell
Ohm’s Law
Flow= pressure gradient/ resistance
Frank Starlings Law
The stroke volume increases as the end diastolic volume increases
reactive hyperemia
when an organ or tissues blood flow is occluded the blood flow increases by flow autoregulation and active hyperemia to the organ/ tissue until the occlusion is removed
Active hyperemia
a manifestation of increased blood flow to an organ or tissue when its metabolic activity increases
flow autoregulation
the control of blood pressure in response to changes
isovolumetric contraction
when the ventricles are contracting but all the valves are closed so no blood is ejected
medullary tonic activity
an increased tonic activity is increased activity within the organ/tissue.
Describe the 4 forces that affect starlings Law
plasma hydrostatic pressure, interstitial hydrostatic pressure, osmotic pressure in the capillary, and osmotic pressure in the interstitial fluid.
Sickle Cell anamenia key point
autosomal recessive transmission
glutamate is replaces by valine due to a change in base sequence
this mutation is at the recognition site for the cleavage of B-globulin gene
b-globulin gene is not cleaves thus produces a misfolded protein, this affects the stucture of the Haemoglobin and thus the red blood cell. Sickle Shaped!
Total peripheral resistance
The sum of all the resistance in peripheral vasculature in the systemic circulation
Mean arteriole pressure
Cardiac output X total peripheral resistance
Time interval of the p wave
0.1 s
Time interval of the PR complex
0.12-0.2 s
Length of the QRS complex
0.06- 0.1s
Length of the ST segment
0.2s-0.4 s
Length of the T wave
0.4 s
