[PCOL-SEMIS-01-PT4] AUTACOIDS: H2 RECEPTORS

THIS FLASHCARDS IS ABOUT [PCOL] AUTACOIDS.

Triple Response of Lewis

This happens upon intradermal injection of histamine.

Skin part

Intradermal means between the?

1. Red Dot (Flush)

2. Localized Swelling (Edema)

3. Spreading Erythema (Flame)

What are the Triple Response of Lewis?

Hint: RLS

Wheal

What is the medical term for edema?

Red Dot (Flush)

IDENTIFY THE TRIPLE RESPONSE OF LEWIS:

A localized, small red spot on the skin caused by increased blood flow to superficial capillaries.

Local Swelling (Edema)

IDENTIFY THE TRIPLE RESPONSE OF LEWIS:

A localized accumulation of fluid in tissues leading to visible swelling.

Spreading Erythema (Flame)

IDENTIFY THE TRIPLE RESPONSE OF LEWIS:

A widening area of redness that radiates outward from a site due to vasodilation of surrounding blood vessels.

Gs linked receptors

What type of linkage does the H2 receptor have?

Parietal Cells (Stomach)

(This is where H2 receptors are dominantly present)

H2 Receptors are found in?

• Secretes HCl and

• Intrinsic Factor for the absorption of Vitamin B12

What are the functions of H2 receptors in the parietal cells (stomach)?

Cyanocobalamin

Vitamin B12 is also known as?

Increase of Basal Gastric Acid secretion

(Thus increasing the HCl in our stomach)

What is the result once histamine binds to the H2 receptors?

Night

(That is why it is not recommended to eat anything between 11 pm to 3 am because the stomach secretes even more acid)

The basal gastric acid secretion usually peaks at what time?

Hungry

What is the ultimate result in the morning after eating during the peak secretion of basal gastric acid (HCl)?

Mast and Basophil Cells

Aside from the parietal cells (stomach), H2 receptors are also found in?

Degranulation

Once H2 receptors are activated in the mast and basophil cells, there is a release of histamine, called?

Blood Vessels

Aside from the mast and basophil cells, H2 receptors are also found in?

Vasodilation

Once H2 receptors are activated in the blood vessels, there is?

• Stimulation or

• Wakefulness

Once H2 receptors are activated in the CNS (Brain), there is?

Frequent Heartbeats

Once H2 receptors are activated in the heart, there is?

• Blood Vessels

• CNS

The H2 receptors are not significantly observed in the (2)?

Decrease of HCl

(Because H2 receptors are mostly found in the parietal cells or stomach)

What is the ultimate effect if the drug is H2 blockers?