Pharmacotherapy Exam 1 September 27: Lecture 2 - Introduction To Autonomic ETC

The correct answer is acetylcholine. Acetylcholine is the synapse neurotransmitter common to all neurons exiting the spinal cord towards their synapses, whether in ganglions or at effector organs. This means that acetylcholine is the chemical messenger that is released by these neurons to transmit signals to other cells. Norepinephrine is not the correct answer because it is not the neurotransmitter common to all neurons exiting the spinal cord.

Most commonly, if the drug name ends in "-olol", it is a beta-blocker. Beta-blockers are a class of medications that work by blocking the effects of adrenaline on beta receptors in the body. They are commonly used to treat conditions such as high blood pressure, angina, and certain heart rhythm disorders. The "-olol" suffix is a common naming convention used for drugs in this class, making it a useful indicator for identifying beta-blockers.

If a drug name ends in "-alol", it is most commonly a combined alpha and beta blocker. Alpha blockers work by blocking the alpha receptors in the body, which leads to relaxation of blood vessels and a decrease in blood pressure. Beta blockers, on the other hand, block the beta receptors, which reduces the effects of adrenaline and helps to lower heart rate and blood pressure. Therefore, a drug ending in "-alol" is likely to have both alpha and beta blocking properties.

The characteristics listed in the question, such as miosis, increased secretions, bronchoconstriction, decreased heart rate, increased gastric acid and motility, increased urination, and erection, are all associated with the parasympathetic nervous system. This branch of the autonomic nervous system is responsible for controlling the body's rest and digest functions, as well as promoting sexual arousal and reproduction.

The parasympathetic effector junctions are all connected to muscarinic receptors. These receptors are part of the cholinergic system, which is responsible for the parasympathetic nervous system's actions. Muscarinic receptors are found in various organs and tissues, including the heart, smooth muscles, and glands. When activated by acetylcholine, they cause a variety of responses, such as slowing heart rate, stimulating smooth muscle contraction, and increasing glandular secretions. Therefore, the correct answer is muscarinic.

β2 receptors are primarily found in smooth muscle tissues, such as those in the bronchioles of the lungs and blood vessels. When these receptors are activated, they cause relaxation or dilation of the smooth muscles. This leads to bronchodilation, which helps in improving airflow in the lungs, and vasodilation, which results in the widening of blood vessels. Therefore, the more common function of β2 receptors on their effector organs is dilation/relaxation.

The characteristics of the SOMATIC nervous system include having one neuron chain, no ganglion, no hormones, nicotinic receptors on some or all effectors, and the use of Acetylcholine in at least one junction or synapse. This means that the signals from the brain or spinal cord directly go to the effectors without any intermediate ganglion, and there are no hormones involved in the transmission. The presence of nicotinic receptors suggests that nicotine can bind to these receptors and affect the functioning of the effectors. Acetylcholine is used as a neurotransmitter in at least one junction or synapse, facilitating the transmission of signals between neurons.

The characteristics of the parasympathetic nervous system include ganglions that are located nearer to the effectors, muscarinic receptors on some or all effectors, nerves that exit the spinal cord only in the cranial and sacral regions, and the use of acetylcholine in at least one junction or synapse.

Acetylcholine, cevimeline, bethanechol, pilocarpine, and muscarine are all direct-acting muscarinic receptor agonists. These substances directly bind to and activate muscarinic receptors, leading to various physiological effects. They mimic the action of the neurotransmitter acetylcholine, which is the endogenous ligand for muscarinic receptors. By activating these receptors, direct-acting muscarinic receptor agonists can elicit responses such as increased smooth muscle contraction, decreased heart rate, and increased glandular secretions.

The sympathetic nervous system is characterized by having one neuron chain, with no ganglion present. It releases epinephrine and norepinephrine hormones, which act as neurotransmitters at synapses. Some or all effectors have α and β receptors, which respond to these hormones. The nerves of the sympathetic nervous system exit the spinal cord only in the thoracic and lumbar regions. Norepinephrine is used in at least one junction or synapse, and acetylcholine is also used in at least one junction or synapse.

The sympathetic nervous system is characterized by ganglions that are closer to the spinal cord, indicating that the preganglionic neurons have shorter axons. It also follows a one neuron chain, meaning that there is no ganglion involved in the pathway. There are no hormones involved in the sympathetic nervous system, distinguishing it from the sympathoadrenal NS. The presence of α and β receptors on some or all effectors suggests that the sympathetic system can have different effects on different target tissues. The nerves of the sympathetic system exit the spinal cord only in the thoracic and lumbar regions. Norepinephrine is used in at least one junction or synapse, indicating its role as a neurotransmitter in the sympathetic system. Additionally, acetylcholine is also used in at least one junction or synapse, suggesting the involvement of cholinergic synapses in the sympathetic system.

The correct answer is "nicotinic, cholinergic smooth and cardiac muscle, glands, adrenergic smooth and cardiac muscle, glands." According to the handout, all the neurons in the systems discussed synapse to junctions that are muscarinic or nicotinic, except for the ones junctioning to cholinergic smooth and cardiac muscle, glands, and adrenergic smooth and cardiac muscle, glands.