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Phys Lect 19
Question | Answer |
---|---|
Effect on Smooth muscle: Alpha 1 receptors | CONTRACTION. (secondary messanger is IP3) |
Effect on Smooth muscle: Beta 2 receptors | RELAXATION. (secondary messanger is cAMP) |
Effect on Smooth muscle: Muscarinic receptors (mAChR) | CONTRACTION. (secondary messanger is IP3) |
Effect on Glands: Muscarinic receptors (mAChR) | SECRETION |
Effect on Heart: Muscarinic receptors (mAChR) | Inhibit electrical conduction |
Effect on Heart: Beta 1 receptors | Stimulatory |
Sympathetic NS affect on pupil | 1.Acts on Iris Radial smooth muscle with Alpha1 receptors. 2.Postsynp symp neuron releases norepi. 3.Alpha1:Norepi causes contraction of smooth muscle. 4.Pupil DILATES |
Sympathetic NS affect on lens | 1.Acts on ciliary muscle using Norepi. 2.Binds to B2 receptor and Muscle relaxes. 3.Increases tension in suspensory ligaments. 4.Lens flattens for far vision. |
Parasympathetic NS affect on pupil | 1.Acts on Iris sphincter smooth muscle. 2.ACh binds to M receptors causing contraction. 4.pupil constricts. |
Parasympathetic NS affect on lens | 1.Acts on ciliary muscles. 2.ACh binds to M receptors causing contraction. 3.Decreases tension in suspensory ligaments. 4.Lens becomes more round/convex for near vision. |
Horner's syndrome | Damaged sympathetics, effects on ipsilateral side: 1.Miosis. 2.Ptosis. 3.Anhydrosis. 4.Erythema. **Trauma/tumor around T1 & T2 can cause this. |
Which ANS system controls salivary glands? | PARASYMPATHETIC. Therefore it releases ACh onto M receptors causing the salivation. |
What receptors are targeted during an acute asthma attack in order to cause bronchiodilation? | Beta 2 receptors (also seen on the ciliary muscles of the eye). This causes bronchiole smooth muscle to relax and the for the airway to open up. |
What is the agonist used for most asthma attacks and why shouldn't you abuse it? | Agonist for the B2 receptor acting like Norepi/epi is ALBUTEROL. **If used too much, the B2 receptors will be removed from the membrane making the inhailer useless. |
Which ANS system is most active in COPD? what does it cause? | Parasymp. is overactive, releases ACh onto Muscarinic receptors which are responsible for smooth muscle contraction and bronchial gland secretion. **Atropine is the antigonist used to treat. |
What is the intrensic automaticity of the heart responsible for it being myogenic? | SA node |
What happens to physiologic diastolic depolarization rate when the sympathetic NS extrensically controls it? | Depolarization occurs faster, the contraction is completed faster, and therefore the HR goes up. |
What type of receptors are found at the SA node? | Beta 1 receptors. Cause Sympathetic Stimulation of the heart |
Why do the Atria and Ventricles not contract at the same time? | Because the electrical signal from the SA travels to the atria via fast conductance, but then the signal must pass through the AV node to reach the ventricles. The AV node has a SLOW conductance compared to the atria and ventricles. |
Sympathetics: What are the 3 locations of Beta 1 receptors in the heart? | 1.SA node (Inc depolar rate & HR). 2.AV node (Inc Conduction velocity). 3.Ventricular myocytes (Inc force of contraction and CO). |
What is a Beta blocker and why is it important after an MI? | Beta receptor antagonists (propanolol) that decrease the rate (SA and AV nodes) and contractile force/CO of the heart (ventricular myocytes). **if B2 receptors get blocked: side effects. |
Parasympathetics: What are the 3 locations of Muscarinic receptors in the heart? | 1.SA node (Dec depolar rate & HR). 2.AV node (Dec conduction velocity). **Essential no M receptors in ventricular myocytes |
Which ANS system is responsible for changing the Contractile Force and CO of the heart? | SYMPATHETICS. B1 receptors in ventricular myocytes. |