Physiology of Blood Pressure Control, Tyrosine Kinases, Fetal Circulation, and Chemoreflex Pathways

Flashcards covering central pathways of blood pressure regulation, tyrosine kinase signaling in vascular smooth muscle, fetal circulatory dynamics, chemoreflex mechanisms, and general blood pressure regulation.

What formula defines Mean Arterial Pressure (MAP)?

$$\text{MAP} = \text{Cardiac Output} \times \text{Total Peripheral Resistance}$$

Where are sympathetic preganglionic neurons located in the spinal cord?

They are located in the intermediolateral cell column.

How is tonic sympathetic nerve activity measured?

It is measured by burst amplitude and burst frequency driven by multiple inputs.

What characterizes Respiratory Sinus Arrhythmia (RSA)?

An increase in heart rate during inspiration caused by pulmonary afferent inhibition of parasympathetic drive.

Which anatomical site in the medulla contains presympathetic vasomotor neurons including C1 neurons?

The rostral ventrolateral medulla (RVLM).

What effect does dorsal PAG inactivation have on the baroreflex in unanesthetized rats?

Inactivation of the dorsal PAG augments the baroreflex.

How is GABAergic activity altered in the NTS and PVN during cardiovascular disease?

GABAergic activity is increased in the NTS and attenuated in the PVN.

Which specific amino acid sequence motif is phosphorylated by Dual Specificity Kinases?

The Thr-Glu-Tyr motif.

In what year was protein tyrosine phosphorylation first reported, and with which protein?

It was first reported in 1979 with v-Src.

Which pharmacological inhibitor of Jak2 reduces VSMC growth and neointimal formation following balloon injury?

AG490.

What effect does deleting VSMC-derived Jak2 have on vascular remodeling after injury in SM22Cre(+) Jak2FL/FL mice?

It significantly reduces injury-induced neointimal formation, decreases pSTAT5, and protects vessels from the loss of elastin and $\alpha\text{-SMA}$.

What unexpected cardiac outcome results from targeted overexpression of GFP in cardiomyocytes under the $\alpha\text{-MHC}$ promoter?

Dilated cardiomyopathy.

What are the baseline physiological values for fetal blood pressure, heart rate, combined ventricular output, and blood volume?

Fetal blood pressure is ~50 mm Hg, fetal heart rate is ~150 min^-1, combined ventricular output is ~400 ml/kg/min, and blood volume is ~110 mk/kg.

What acute effect does fetal hypotension have on heart rate, and what intervention abolishes this response?

Fetal hypotension acutely causes bradycardia, which is abolished by sinoaortic denervation (SAD).

How do hypoxia and hypercapnia differentially affect fetal heart rate?

Hypoxia detected by arterial chemoreceptors decreases fetal heart rate, whereas increased PaCO2 detected by central chemoreceptors increases fetal heart rate.

What effect does vasopressin infusion have on fetal lung liquid secretion?

Vasopressin reduces or halts the rate of fetal lung liquid production and can induce reabsorption.

How does an infusion of cortisol at $4\,\mu g/min$ alter fetal blood pressure and blood volume?

It increases fetal arterial blood pressure and increases blood volume relative to vehicle infusion.

Where are aortic chemoreceptors located in the dog?

In an infraaortic position lying between the aorta and the pulmonary artery, with afferent fibers entering both vagi along with the recurrent laryngeal nerves.

What cellular mechanism in glomus cells leads to neurotransmitter release during hypoxia?

Hypoxia inhibits K+ channels leading to cell depolarization, opening of Ca2+ channels, Ca2+ influx, and release of ATP, Acetylcholine, and Dopamine.

How does carotid chemosensory activity in newborn kittens under 10 days of age compare to kittens 10 days or older?

Chemosensory activity is significantly lower in kittens under 10 days old, with the hypoxic response curve displaced to the left and the hypercapnic response curve displaced to the right.

Which local metabolic byproducts cause local arteriolar vasodilation to increase blood flow?

CO2, ADP, and extracellular K+.

Why are RAG1-/- and SCID mouse models resistant to hypertension?

Because RAG1-/- and SCID mice lack functional mature T cells and B cells, demonstrating that adaptive immune cells and inflammatory cytokines such as IL-6 are required for hypertension.

How does increased renal nerve activity affect Mean Arterial Pressure (MAP)?

Increased renal nerve activity stimulates renin production, which leads to increased MAP.