Question

Question 36

Which of the following will happen as a result of stimulating α1 receptors?

Question 36 options:

	peripheral vasoconstriction
	vasoconstriction of heart and skeletal muscle arteries
	bronchodilation
	increased contractility of the heart
	peripheral vasodilation

Answer 1

Answer:-

Introduction-

The Autonomic Nervous System consist of the hypothalamus.

The ANS consist of two divisions:-

1. Sympathetic Nervous System- regulated by the posterior and lateral nuclei of the Hypothalamus.

2. Parasympathetic Nervous System- it is regulated by the anterior and medial nuclei of the Hypothalamus.

Most of the organs in the body receive both (sympathetic and parasympathetic) innervations. These two are functionally antagonistic to each other.

Nerves transmit their impulses by the release of chemical messengers . This process is called Neurohumoral Transmission.

​​​​​​The peripheral and central neurons release transmitters and cotransmitters when stimulated.

The primary transmitters are acetylcholine and Noradrenaline.

These neurotransmitters act on their specific receptors.

Adrenergic transmission is related to the sympathetic nervous system.

There are three endogenous catecholamines named as Noradrenaline, Adrenaline and Dopamine.

Adrenergic receptors are of two types-

1.Alpha type- further classified into alpha 1 and alpha 2 subtypes.

2. Beta type- further classified into beta 1 and beta 2 subtypes.

Both alpha and beta receptors have different responses on the body.

The answer of the above question is option 1.

Peripheral Vasoconstriction occurs as a result of alpha 1 stimulation.

It results in rise in the blood pressure.

Alpha receptors have a little effect on heart. Cardiac stimulation occurs as a result of beta 1 stimulation.

Bronchodilation occurs as result of Beta 2 stimulation.

All cardiac actions are mediated by Beta 1 receptor.

Peripheral vasodilation is mediated by Beta 2 receptor.