Which compartment of the ruminant stomach is characterized by its internal mucosa arranged in numerous longitudinal folds or leaves, and is primarily responsible for water and electrolyte absorption?

In the ruminant stomach, which compartment is lined with a glandular mucosa containing parietal and chief cells, making it physiologically analogous to the monogastric stomach?

Which specific anatomical structure in the ruminant forestomach features a mucosa lined with small, pointed protrusions called papillae and lacks a muscularis mucosae, allowing for efficient volatile fatty acid (VFA) absorption?

The 'honeycomb' appearance of the ruminant forestomach is a defining characteristic of which compartment, and what is its primary role in the sorting of feed particles?

In the neonatal ruminant, which anatomical structure forms a muscular tube to shunt milk directly from the esophagus to the omasum and abomasum, bypassing the fermentation vats?

Which specific anatomical feature serves as the primary external boundary between the dorsal and ventral sacs of the rumen?

Which specific anatomical structure marks the internal transition between the rumen and the reticulum, helping to define the craniodorsal opening of the rumen?

Which specific histological layer is notably absent in the mucosa of the rumen and reticulum, but first appears in the forestomach within the laminae of the omasum?

The cranial and caudal 'blind sacs' of the rumen are demarcated from the main dorsal and ventral sacs by which specific set of external grooves?

Regarding the innervation of the ruminant stomach, which nerve is primarily responsible for the coordination of the complex cycles of rumination, eructation, and forestomach motility?