Week 3

Questions and Answers

What is the primary role of noradrenaline in the sympathetic nervous system?

Inhibits the release of acetylcholine

Increases heart rate and dilates pupils (correct)

Stimulates salivary gland secretion

Promotes digestion and reduces heart rate

Which method can be used to manipulate neurotransmitter activity for therapeutic effects?

Increasing neurotransmitter synthesis exclusively

Decreasing neurotransmitter degradation only

Blocking receptor binding sites (correct)

Producing excess neurotransmitter without effect

Which of the following accurately describes the function of adrenergic receptors?

They are responsible for responses like increased heart rate and blood vessel constriction. (correct)

They primarily respond to acetylcholine.

They prevent muscle contractions in the brain.

They are only involved in the parasympathetic nervous system.

How are neurotransmitters typically removed from the synaptic cleft?

By enzymatic degradation or reuptake mechanisms Signup and view all the answers

Inhibitory neurotransmitters primarily function by:

Hyperpolarizing neurons, making them less likely to fire Signup and view all the answers

What is the purpose of reflex testing in a clinical setting?

To evaluate the functioning of peripheral and central neurons Signup and view all the answers

What effect does excess acetylcholine have on the body?

Enhanced muscle contraction and possible spasms Signup and view all the answers

Which neurotransmitter is primarily associated with the parasympathetic nervous system?

Acetylcholine Signup and view all the answers

Study Notes

Neurotransmitters & Receptors

Each neurotransmitter has distinct functions; key examples include dopamine, serotonin, and GABA, involved in mood regulation, motor control, and inhibition, respectively.
Dysregulation of neurotransmitters can lead to diseases such as depression (serotonin), Parkinson's (dopamine), and epilepsy (GABA).

Therapeutic Manipulation of Neurotransmitters

Drug therapies can enhance or inhibit neurotransmitter receptor activities, such as SSRIs increasing serotonin availability for depression.
Antipsychotics may block dopamine receptors to reduce symptoms of schizophrenia.

Removal of Neurotransmitters

Drugs can influence the breakdown or reuptake of neurotransmitters in the synaptic cleft, e.g., MAO inhibitors prevent the degradation of monoamines, enhancing their effects.

Mechanisms of Analgesia

Analgesia can be achieved through various pathways, including opioid receptor activation, non-steroidal anti-inflammatory drugs (NSAIDs), and the modulation of descending pain pathways.

Autonomic Nervous System Neurotransmitters

The sympathetic division primarily utilizes norepinephrine, leading to fight-or-flight responses; parasympathetic division primarily uses acetylcholine for rest-and-digest activities.

Receptor Subtypes

Major adrenergic receptor subtypes include alpha (α1, α2) and beta (β1, β2, β3) receptors; cholinergic receptor subtypes include nicotinic and muscarinic.

Receptor Functions

α1 receptors promote vasoconstriction; β1 receptors enhance heart rate; muscarinic receptors facilitate slower heart rates and increased glandular secretion.

Predicting Effects of Receptor Activation

Activating norepinephrine receptors increases heart rate; blocking them may lead to bradycardia. Excess acetylcholine can result in muscle spasms, while inadequate amounts can cause muscle weakness.

Inhibitory vs. Excitatory Signals

Inhibitory neurotransmitters (e.g., GABA) suppress neuronal activity, while excitatory neurotransmitters (e.g., glutamate) increase it; their balance is essential for proper neuronal function.

Neuron Interactions

Neurons communicate through synapses for coordinated responses, enabling complex control over body systems, such as reflexes and voluntary movements.

Reflex Arc Components

A reflex arc consists of a sensory receptor, sensory neuron, integrating center (spinal cord), motor neuron, and effector (muscle or gland).

Reflex Mechanisms

Reflex examples include the patellar reflex (knee-jerk) and withdrawal reflex, both serving to protect the body from harm and maintaining posture.

Diagnostic Use of Reflex Testing

Reflex testing helps assess the integrity of the nervous system; abnormal reflex responses may indicate peripheral or central nervous system damage.

Reflex Responses and Neuron Function

Simple reflex responses indicate functional pathways between peripheral sensory neurons and central interneurons, reflecting the health of these connections.

Reflex Development Over Lifespan

Some reflexes are present at birth (e.g., grasp reflex) but diminish as the nervous system matures; others develop later, reflecting the complexity of neurological development.

Description

Explore the roles of various neurotransmitters and the impact of their dysregulation on mental health and diseases. Understand how drug therapies manipulate neurotransmitter activities to treat conditions like depression and schizophrenia. Learn about the mechanisms involved in analgesia and neurotransmitter removal.