Learning Activity Essay Example

  • Category:
  • Document type:
    Case Study
  • Level:
  • Page:
  • Words:

Question and Answer Activity

Receptors have been illustrated to be like the aerial which when it receives a signal transmits it enabling people to see a picture. Here the receptors receive signal from the affected area and use the Acetylcholine transmitter to rely message to brain. There are four major receptors that accomplish this objective namely:

Nicotinic receptors (Ligand-Gated Ion Channels)

These are receptors are categorized as neuronal and muscular. Examples of this receptor include GABA A receptors, Adrenergic or Beta receptors found in the blood vessels, heart, kidneys, salivary glands. Adipose tissues (Knights & Bryant). The neuronal are found in the sensory tissues.

Opioid Receptors (G-protein coupled receptors)

These receptors can also be called pain receptors and they are activated by Morphine, An example of the receptors include the Alpha 1 and Alpha 2 receptors, they are found embedded in the many tissues including ureter, seminal tract,bronchioles (.http://pharmacologycorner.com/alpha-receptors-1-2/). Others are GABAB receptors, adenosine receptors found throughout body including heart, GI tract and brain. 5HT (Jacobson and Gao 2006). Adenosine receptors as therapeutic targets, 5HT receptors found in the nerves (Trescot et.al 2008).

Enzyme-linked receptors

An example is the insulin receptors that fall in the tyrosine- kinase receptor groups. It is activated by insulin, it is found in the pancreatic cells of the pancreas. Another example is the Glycosyl-phosphatidylinositol-anchored folate receptor found in cancer and embryonic cells (Antony 1996).

Intracellular receptors

These are agonistic activated transcription factors that bind to the DNA to alter gene expression, thus producing slow changes in cell functions that can occur in hours or days. They are also known as nuclear receptors

List of community drug- receptor- paramedic drug interaction

  1. Salbutamol is a short acting Beta2 agonist which activates the B2 adrenoreceptors for muscle relaxation. The same Salbutamol has effect on Alpha and Beta1 adrenoreceptors leading to bronchoconstriction. Any drug containing calcium would thus lead to bronchoconstriction.

  2. Temazepam is classed as 1,4 benzodiazepine and the pharmacological action is enhancement of GABAa. Midazolam is categorized as a short acting benzodiazepine

  3. Viagra (Sildenafil) works by inhibiting cGMP specific phosphodiesterase type 5 breakdown thus preventing muscle constriction. GTN works by producing Nitric oxide which regulates cGMP, hence in combination with Slidenafil can cause a patient to be in a fatal hypotensive state.

  4. Morphine is an agonist at the mu and Kappa receptors. Naloxone is an antagonist affecting the same receptors mu and Kappa receptors.

  5. Beta Blockers inhibit the Beta 1 and Beta 2 receptors effect on the heart and peripheral vasculature. Adrenaline acts on the alpha receptors due to the Beta blockers blocking the effect of Beta 1 and 2 receptors, this leads to massive vasoconstriction.

Drug Molecular Interactions

There are two types of drug –molecular interactions namely;


This interaction involves lock and key mechanism where the drug locks into the receptor and initiates a conformational change that causes required reactions within the particular cells. They mimic the neurotransmitters and hormones. An example is the binding of morphine to the mu and Kappa receptors which conform and this result in activation of the G proteins which in turn cause the ion channels to open and the out flux of potassium ions occurs leading to hyperpolarisation of the inner membrane and this stops any messages of pain being relayed. Muscarine and Nicotine are also agonists as well as Acetylinecholine.


Antagonistic or inhibitors work to compete with the agonists for the receptor site their purpose being to prevent activation of the cellular response. An example is sertraline which is used as an anti depressant. It blocks the serotonin transport proteins from attaching to the receptor. Another example is the Muscarinic receptor which binds to the acetylcholine. This action is inhibited by Atropine while the Nicotinic receptor where acetylcholine also binds for contracting of muscles are inhibited or antagonized by Curare. Metoclopramide is a mild 5HT3 antagonist that blocks the serotonin receptors at the vagus nerve.


Antony, A.C. (1996). ‘Folate Receptors’, Annual Review of Nutrition, Vol. 16, pp. 501-521

Jacobson KA & Gao ZG (2006). Adenosine receptors as therapeutic targets, Nature Reviews of Drug Discovery, Vol. 5, No. 3, pages 247-264.

Knights & Bryant Pharmacology for health professionals, 3rd Edition, 2011.pp. 225,226)

Trescot, AM., Datta, S., Lee, M & Hansen, H (2008), ‘Opioid pharmacology’, Pain Physician Journal, vol. 11, no. 2, pp. 133-153.