Fetal circulation Flashcards
MCQ 1-Ductus aretriosus areis from 2-Bracchiocephalid develop from ? 3-preductal coarctation of the aorta is usually accopmnied by? 4-common carotid artereis arise from ? 5-the left subvlavian ?
1-distal of left 6th arch 2-right horn of aortic sac 3-patetnt ductus arterosus 4- 3rd arch 5-left 7th intersegmental art
- Synthesis of mevalonic acid (mevalonate) and what are the requirements?
the reduction of HMG CoA to mevalonate, is catalyzed by HMG CoA reductase, and is the ratelimiting and key regulated step in cholesterol synthesis. It uses two molecules of NADPH as the reducing agent, and releases CoA
ratelimiting and key regulated step
in
cholesterol synthesis.
Synthesis of mevalonic acid (mevalonate)
HMG CoA
reductase
Short term regulation of cholestrol synthesis ?
• Feedback inhibition to HMG CoA Redutase
•Covalant modification Phosphorylation/Dephosphorylation The active form of the HMG CoA Redutase enzyme is the dephosphorylated one.
In chronic use of hydralazine what happen ?
Rapid tolerance: due to reflex activation of sympathetic & renin angiotensin system → reflex ↑HR & salt retention → ↓ its antihypertensive effect
Mention indications of Na nitroprusside
Very potent and rapid (IVI)
- Most of hypertensive emergencies
- Severe acute heart failure (esp. with rise in BP: S > 100)
Mention adverse effects of Na nitroprusside .,
- Severe hypotension & myocardial ischemia (due to reflex tachycardia)
- Cyanide toxicity (in liver dysfunction)
- Thiocyanate toxicity (in renal dysfunction)
Mention precasutions of Na niroprusside.
Precautions:
• Slowly IV with BP monitoring (Avoid drop < 95/70 mmHg)
• Solution should be freshly prepared & protected from light by opaque foil
• Avoid prolonged use especially in hepatic & renal dysfunction to avoid toxicity
The following features are typical of asthma
and if present, increase the probability that
the patient has asthma:
• - More than one symptom (wheeze, shortness of
breath, cough, chest tightness)
• - Symptoms often worse at night or in the early
morning
• - Symptoms vary overtime and in intensity
• - Symptoms are triggered by viral
infections(colds), exercise, allergen exposure,
weather changes, or irritants such as fumes,
smoke or strong smells.
the main difference in fetal circulation /
the lung are not functioining intrauterinelife
the oxygenated blood come from ?>
the placenta through umblical vein !
إن الحكم إلا لله أمر إلا تعبدوا إلا إياه
ذلك الدين القيم ولكن أكثر الناس لا يعلمون
how many types of blood in fetal circulation ?
3
1- highly oxyxgenated
2-deoxygenated
3-mixed blood that perfuses tissues
Describe the fetal circulation !
first stage of the fetal circulation :
umbilical vein carries higly oxygenated blood from the placenta to reach the liver then 2 pathways appear:
1- most flows through the ductucs vensus to IVC
2-SOME TO The left portal branch to supply the liver end in IVC
___________________________________________________
2n stgage inside heart
the higly oxygenated blood enters heart through the rudmentary valve of IVC
and then fates:
1-most go through foramen ovalie to left atrium aided by lower border of septum scandum crista dividens
2-reflected to the RA
IN case of 1 it is mixed with blood from pulmonary veins then enters the left ventricle
IN case of 2 it is mixed with blood from SVC entering right ventricle >pulmonary trunk>lungs only for some perfusion >pulmnary veins>left atrium connecting with the higly oxygenated blood entering left ventricle
so the blood in right ventricle is mixed
so the blood in left ventricle is highly oxygenated
blood of left ventricle will flows into ascending aorta>arch of aorta and its 3 branches the brachiocephalic and the left common carotid and subclavian arteres then it is mixed in the arch with the blood from the ductus arteroius that pass the blood coming from the left pulmnary artery so the blood enters the descending aorta Mixed .supplying the abdomen and lower limb and then returns placenta through right and left umbilical arteries
IVC recevies blood from ?
1-umbilical vein through ductus arteriosus
2-the liver after been supplied through left branch of portal vein
3-the draining of the abdomen and lower limbs