Changes

==Introduction==

==Introduction==

The oesophageal groove is present in newborn ruminants. It is a channel taking milk from the oesophagues into the rumen, omasum and then abomasum, bypassing the reticulum.

The oesophageal groove is present in newborn ruminants. It is a channel taking milk from the [[Oesophagus - Anatomy & Physiology|oesophagus]] into the [[The Rumen|rumen]], [[The Omasum|omasum]] and then [[The Abomasum|abomasum]], bypassing the [[The Reticulum|reticulum]].

*Water consumption does not usually iniatiate groove closure

*Water consumption does not usually iniatiate groove closure

*Age when the rumen becomes fully functional and the oseophageal groove closes differs between ruminants

*Age when the [[The Rumen|rumen]] becomes fully functional and the oseophageal groove closes differs between ruminants

**In calves 20 weeks

**In calves 20 weeks

**In lambs 8 weeks

**In lambs 8 weeks

**In goats 12 weeks

**In goats 12 weeks

*Closes by reflex stimulation of the cranial laryngeal branch of the vagus nerve (takes 2-5 seconds)

*Closes by reflex stimulation of the cranial laryngeal branch of the vagus nerve ([[Nervous System - CNS - Anatomy & Physiology#Innervation - Cranial Nerves|CN X]]) (takes 2-5 seconds)

*With time becomes a conditioned reflex

*With time becomes a conditioned reflex

*The groove is stimulated in adult ruminants by ADH

*The groove is stimulated in adult ruminants by ADH

*The groove can also be closed in adult ruminants by the administration of drugs, e.g copper sulphate, which is of use to prevent drugs becoming diluted in the forechambers. Instead, it directs the drugs directly to the reticulum.

*The groove can also be closed in adult ruminants by the administration of drugs, e.g copper sulphate, which is of use to prevent drugs becoming diluted in the forechambers. Instead, it directs the drugs directly to the [[The Reticulum|reticulum]].