Lecture 79 Flashcards
The ______ nervous system innervates vascular smooth muscle, whereas the _____ nervous system does not.
SYMPATHETIC innervates, whereas PARASYMPATHETIC does not.
Activation of alpha1 receptors on vascular smooth muscle causes _______, while activation of beta2 receptors causes ______. When both alpha1 and beta2 receptors are activated, the effect of _____ is dominant.
Alpha1 activation causes VASOCONSTRICTION, while activation of beta2 causes VASODILATION. The effect of ALPHA1 is dominant.
There are muscarinic receptors in the vascular smooth muscle, but no Parasymp innervation. Instead, locally produced ____ can bind muscarinic receptors on vascular smooth muscle causing _____.
ACh
VASODILATION
The bronchial smooth muscle contains beta2 receptors for ____ innervation and muscarinic receptors for ____ innervation. Actiavtion of beta2 receptors cause ______, whereas activation of muscarinic causes _____ and mucous formation.
beta2 for SYMPATHETIC and Muscarinic for PARASYMPATHETIC. Activation of beta2 causes BRONCHODILATION, whereas activation of muscarinic causes BRONCHOCONSTRICTION and mucous formation.
Sympathetic activation of beta2 receptors on GI tract smooth muscle ______ contraction/peristalsis and defecation, while Parasympathetic activation of muscarinic receptors does the opposite.
DECREASES peristalsis and defecation
Sympathetic activation of alpha1 receptors on sphincters causes _____ while Parasympathetic activation of muscarinic receptors on sphincters causes _____.
Sympathetic activation causes CONTRACTION while Parasympathetic activation causes RELAXATION.
The uterus has alpha1 and beta2 receptors, activation of which cause ____ contractions and ____ contractions respectively.
alpha1 INCREASES contractions, beta2 DECREASES contractions.
Activation of alpha1 and beta2 receptors in Salivary glands increase _____ secretions, whereas activation of Muscarinic receptors increases ______ secretions.
Activation of alpha1 and beta2 increase VISCOUS secretions, whereas activation of Muscarinic increases WATERY secretions.
The prejunctional Neural uptake transporter on postganglionic adrenergic neurons is responsible for about 95% of the uptake of ____ while the postjunctional extraneuronal transporter is only responsible for about 5%. If taken back into the neuron, ____ can be broken down by _____, or repurposed. If taken into the effector cell (post-junctional), it can be broken down by ____ or ____.
Prejunctional neuronal uptake transporters are responsible for about 90% of NE uptake.
If taken back into the neuron, NE can be broken down by MAO or repurposed. In effector cell, it can be broken down by MAO or COMT.
Direct acting Adrenergic Agonists bind to receptors on _____, while indirect acting adrenergic agonists _____ levels of NE.
Bind to receptors on EFFECTOR, while indirect INCREASE levels of NE.
Epi is a _____-selective adrenergic agonist, meaning it can bind to all adrenergic receptors. However, it preferentially binds ____ receptors (they have greater affinity), so at low doses it would cause vaso______, and thus a ______ (increase or decrease?) in diastolic BP. Which receptors does it bind in the heart, and what does that mean for CO and systolic BP? Keep in mind any catecholamine must be injected; if taken orally, they would be broken down by ____ in the GI tract.
Epi is NON-selective.
Beta2
Dilation
Decrease in diastolic
It binds Beta1 in the heart, so increase in CO and systolic BP
Any catecholamine must be injected because they can be broken down by MAO in the GI tract.
Epi can activate beta2 receptors on hepatocytes, signalling breakdown of _____.
Breakdown of GLYCOGEN.
Epi is indicated for treatment of ____ emergencies and hypersensitivity reactions (anaphylaxis.) It is also co-administered with local _____ because of its vaso_____ effects at higher than endogenous doses. Epi can be used to treat glaucoma bc it reduces the amount of aqueous humor produced, but it is contraindicated in patients with ___-___ glaucoma. Why?
Treatment of CARDIAC emergencies –> increases both systolic and diastolic BP. It is also co-administered with local ANESTHETICS because of its VASOCONSTRICTION effect at higher than endogenous doses.
Closed-angle glaucoma –> alpha1 receptors would be activated –> dilation of the pupil –> worsening the drainage of aqueous humor into the canal of Schlemm.
NE is a selective adrenergic agonist and binds all adrenergic receptors EXCEPT _____2.
Except BETA2
DA is also selective, and binds only ___ and ___ adrenergic receptors. It also binds DA receptors on vascular endothelium, causing vaso______ at low doses. This is overridden by its binding to _____1 receptors at high doses, leading to vaso____ EXCEPT in renal arteries –> a nice healthy blood flow is maintained to the kidneys.
DA binds only ALPHA1 and BETA1 adrenergic receptors. It also binds DA receptors on vascular endothelium, causing VASODILATION at low doses. This is overridden by its binding to ALPHA1 receptors at high doses, leading to VASOCONSTRICTION.
