Biology

Question 1

1. Parietal Cells

Answer 1

🧪 Found in: Gastric glands (mainly in the upper part of the stomach)
👉 Makes:
Hydrochloric acid (HCl): This is a very strong acid that kills bacteria and helps digest food.
Intrinsic factor: A protein that helps your small intestine absorb vitamin B12, which is important for red blood cells and nerves.
💡 Think of them as the “acid makers.”

Question 2

Chief Cells

Answer 2

Found in: Gastric glands
👉 Makes:
Pepsinogen: An inactive enzyme. Once it touches stomach acid, it turns into pepsin, which breaks down proteins into smaller parts.
💡 These are the “protein digesters.”

Question 3

Mucous Cells (including Mucous Neck Cells)

Answer 3

Found in: Both gastric and pyloric glands
👉 Makes:
Mucus: This slimy substance protects the inside of your stomach from being burned by the acid.
💡 Think of mucus as the “stomach’s safety jacket.”

Question 4

. G Cells

Answer 4

🧪 Found in: Pyloric glands (bottom part of the stomach)
👉 Makes:
Gastrin: A hormone that tells the stomach to make more acid and get ready to digest food.
💡 These are the “signal senders” – they tell the stomach when to go!

Question 5

D Cells

Answer 5

Found in: Pyloric glands
👉 Makes:
Somatostatin: A hormone that tells the stomach to slow down acid production when it’s not needed.
💡 These are like the “brakes” of the stomach.

Question 7

Breakdown in the stomach

Answer 7

Mechanical digestion = peristaltic mixing waves

Chemical digestion =protiens broken down into peptides by pepsin(optimal PH=2)
-lipase breaks down large fats into TG’s,monoglycerides, and FA’s

Only a few substances are absorbed thru the stomach wall(some water,electrolytes,certain drugs (aspirin) alcohol,etc.)

Question 8

Cephalic phase

Answer 8

You smell or think about food
→ Your brain sends signals to your stomach through the vagus nerve (a big nerve that connects the brain to the stomach).
Stomach starts getting ready
Gastric juices start to form even if food hasn’t arrived yet.
G cells release gastrin, which tells parietal cells to make HCl (acid).
Chief cells get ready to release pepsinogen.
Salivary glands in your mouth also start working, making saliva to help with chewing and digestion.

Question 9

Gastrin phase

Answer 9

When food reached the stomach stretch receptors and chemoreceptors inside the stomach get stimulated(food raises PH) this causes ps impulses to increase peristalsis and continue gastric secretions

-gastric ph becomes more acidic due to increased HCL secretion(negative feedback leads to decrease gastric secretions)

Question 11

Intestinal phase

Answer 11

le (helps break down fats)
3. GIP (Gastric Inhibitory Peptide)
Responds to: Food in the small intestine
Slows stomach contractions and acid production
📉 Why Does the Stomach Slow Down?

The small intestine can’t handle all the food at once, so it tells the stomach:
🛑 “Slow down! I need time to digest and absorb this!”