Life Maintenance cram

Anions in pancreatic juice:

• HCO3^-

• Cl^-

• SO4^2-

• HPO4^2-

Cations in pancreatic juice:

• Na+

• K+

• Ca2+

• Mg2+ 

Secretin … the volume of pancreatic juice produced by the pancreas.
HCO3- … under it, which makes sense cos secretin promotes it and this makes the juice for alkaline. 
Cl- … because they are exchanged for biocarb ions.
Amylase … because there is a dilution effect as the volume of pancreatic juice increases. 

inc

inc

dec

dec

In the cephalic and ductile phases, explain what happens in the stimulation of acinar and duct cells

🧠 1. Cephalic and Gastric Phases (Top Left)

• Cephalic phase: Triggered by sight, smell, taste, or thought of food.

  • Sensory input → brain → Dorsal motor nucleus of the vagus.

  • Vagal stimulation (orange line) leads to parasympathetic outflow to the stomach and pancreas.

• Gastric phase: Triggered by presence of food in the stomach.

  • Particularly important in the antrum, which senses peptides and amino acids.

  • Stimulates G cells (see below).

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🧬 2. Stimulation of G Cells in the Antrum (Purple Box)

• Peptides and amino acids from digested proteins stimulate G cells.

• G cells release gastrin, which:

  • Enhances acid secretion.

  • Indirectly promotes pancreatic enzyme secretion.

• The vagus nerve also stimulates G cells via Gastrin-Releasing Peptide (GRP).

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💧 3. Acinar Cells (Bottom Right – Yellow Cells in “Acinus”)

• These cells secrete digestive enzymes (yellow blobs in the duct).

• Stimulated by:

  • ACh (vagus nerve) → binds to M₃ receptors.

  • CCK from I cells (not shown here, but released in the small intestine in response to fats and proteins) → binds to CCK_A receptors.

• Together, ACh and CCK boost enzyme secretion to digest proteins, fats, and carbs.

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💨 4. Pancreatic Duct Cells (Bottom Left – lining the duct)

• These cells secrete:

  • Bicarbonate (HCO₃⁻) and water into the ducts.

  • This neutralizes acidic chyme coming from the stomach.

• Stimulated by:

  • ACh (via M₃ receptors).

  • Secretin (not shown in this diagram, but secreted by S cells in the duodenum when pH drops).

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📉 Reciprocal Changes (from your earlier question):

• As bicarbonate secretion increases, chloride (Cl⁻) is reabsorbed (Cl⁻/HCO₃⁻ exchanger).

• So, high secretin → high HCO₃⁻, low Cl⁻ in the pancreatic juice.

Boundaries of the epiploic foramen
Ant, post, dup, inf

Ant: hepatoduodenal ligament  (inc portal triad)

Post: IVC and right crus of diaphragm (parietal peritoneum)

Sup: Liver

Inf: Superior duodenum