All types of Cells and their Secretions

Question 1

What do serous and mucous acinar cells secrete, and what is their role in digestion?

Answer 1

Serous acinar cells: Secrete water, electrolytes, and enzymes (amylase and lipase) to begin carbohydrate and fat digestion.

Mucous acinar cells: Secrete mucins for lubrication, aiding in swallowing.

Question 2

What do parietal cells secrete, and what are their functions?

Answer 2

Secretion: Hydrochloric acid (HCl) and intrinsic factor.

Functions:
- HCl lowers pH, activates pepsinogen, denatures proteins, and kills pathogens.

• Intrinsic factor is essential for vitamin B12 absorption.

Question 3

What do chief cells secrete, and what is their role in digestion?

Answer 3

Secretion: Pepsinogen (inactive form of pepsin) and gastric lipase.

Functions:
- Pepsinogen is converted to pepsin by HCl to digest proteins.
- Gastric lipase aids in lipid digestion.

Question 4

What do mucous in the stomach cells secrete, and why is it important?

Answer 4

Secretion: Mucus and bicarbonate.

Function: Protects the stomach lining from acidic and enzymatic damage.

Question 5

What do enteroendocrine G-cells release

Answer 5

Secrete gastrin, stimulating HCl secretion and motility.

Question 6

What do enteroendocrine D-cells release

Answer 6

Secrete somatostatin, inhibiting HCl secretion.

Question 7

What do Enterochromaffin-like (ECL) secrete

Answer 7

Secrete histamine, stimulating parietal cells to produce HCl.

Question 8

What do enterocytes secrete, and what are their functions?

Answer 8

Secretion: Digestive enzymes (disaccharidases, peptidases) and transport proteins.

Function: Aid in nutrient digestion and absorption.

Enterocytes are intestinal absorptive cells

Question 9

What do goblet cells secrete, and why is it important?

Answer 9

Secretion: Mucus.

Function: Protects and lubricates the lining of the GI tract.

Question 10

What do Paneth cells secrete, and what is their role?

Answer 10

Secretion: Antimicrobial peptides (e.g., defensins, lysozyme).

Function: Maintain gut microbiota and protect against pathogens.

Question 11

What do enteroendocrine I-cells release

Answer 11

Cholecystokinin (CCK) - stimulates bile release and pancreatic enzymes.

Question 12

What do enteroendocrine S-cells release

Answer 12

Secretin - stimulates bicarbonate secretion.

Question 13

What do enteroendocrine K-cells release

Answer 13

GIP - enhances insulin release.

Question 14

What do enteroendocrine L-cells release

Answer 14

GLP-1 - regulates insulin secretion and appetite.

Question 15

What do pancreatic acinar cells secrete, and what is their function?

Answer 15

Secretion: Digestive enzymes (amylase, lipase, trypsinogen, chymotrypsinogen).

Function: Break down carbohydrates, fats, and proteins.

Question 16

What do pancreatic ductal cells secrete, and why is it important?

Answer 16

Secretion: Bicarbonate-rich fluid.

Function: Neutralizes acidic chyme entering the duodenum.

Question 17

What do hepatocytes secrete, and what are their roles?

Answer 17

Secretion: Bile components (bile salts, bilirubin, cholesterol).

Function: Emulsify fats and excrete waste products.

Question 18

What is the role of Kupffer cells in the liver?

Answer 18

Function: Phagocytose pathogens and debris; immune surveillance.

Question 19

What do colonocytes secrete, and what is their function?

Answer 19

Secretion: Electrolytes (e.g., K+, HCO3−).

Function: Reabsorb electrolytes and water to form feces.

Question 20

What are podocytes and where are they

Answer 20

Podocytes are specialized cells in the glomerulus that wrap around capillaries and form filtration slits, preventing proteins and cells from entering the filtrate. They maintain the filtration barrier with their negatively charged glycocalyx.

Question 21

Where are juxtaglomerular cells located, and what is their function?

Answer 21

Located in the afferent arteriole, JG cells store and release renin in response to low blood pressure or sympathetic stimulation, activating the RAAS system to regulate blood pressure and GFR.

Question 22

What do macula densa cells sense and regulate?

Answer 22

Located in the distal convoluted tubule, macula densa cells sense NaCl concentration and signal JG cells to adjust renin secretion, maintaining GFR via tubuloglomerular feedback.

Question 23

What are principal cells, and how do they function?

Answer 23

Found in the collecting duct, they reabsorb Na+ and water (regulated by aldosterone) and secrete K+, responding to ADH for water reabsorption.

Question 24

What are the two types of intercalated cells, and what do they do?

Answer 24

Alpha Intercalated Cells: Secrete H+ and reabsorb bicarbonate to regulate blood pH.

Beta Intercalated Cells: Secrete bicarbonate and reabsorb H+ for pH balance.

Question 25

What do the interstitial cells of cajal do

Answer 25

Location: Throughout the GI tract (especially in the muscularis propria). Function: Act as pacemakers, coordinating smooth muscle contraction for peristalsis. Relevance to Renal Function: Smooth muscle dysfunction in other systems, like the kidneys, can be mirrored by GI motility issues.

Question 26

What do enterochromaffin cells do adn secrete

Answer 26

Location: GI tract (especially small intestine and colon). Function: Produce serotonin (5-HT) to regulate gut motility and fluid secretion. Relevance: Serotonin promotes peristalsis and can affect gut disorders like IBS. Clinical Relevance: Overproduction of serotonin (e.g., in carcinoid syndrome) leads to increased excretion of its metabolite, 5-HIAA, in urine.

Question 27

5 types of cells in the islets of langerhan

Answer 27

- Beta - Alpha - Delta - PP - Epsilon

Question 28

What do beta cells secrete

Answer 28

Insulin

Question 29

What do alpha cells secrete

Answer 29

Glucagon

Question 30

What do delta cells secrete

Answer 30

Somatostatin Inhibits insulin and glucagon (and PP) secretion as well as suppresses gastric secretions (primarily parietal cells)

Question 31

What do PP/F cells secrete

Answer 31

PP (pancreatic polypeptide) inhibits pancreatic enzyme and bicarbonate secretion

Question 32

What do Epsilon cells secrete

Answer 32

Grelin acts on the hypothalamus to increase hunger / stimulates appetite, also promotes energy storage