Changes

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

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

[[Image:Calf Suckling.jpg|thumb|right|150px|''Calf suckling'' <Br> David Monniaux 2005, WikiMedia Commons]]

[[Image:Calf Suckling.jpg|thumb|right|250px|''Calf suckling'' <Br> David Monniaux 2005, WikiMedia Commons]]

==Formation of the Groove==

==Formation of the Groove==

*Posture- lifting head to suckle

The groove is formed by posture of the animal lifting its head to suckle. Calcium ions are obtained from the milk. A teat or teat-shaped experience aids the formation. The formation of the groove can be overridden, e.g. bucket feeding calves.

 

*Calcium ions from the milk

 

*Teat or teat-shaped experience

 

*The formation of the groove can be overridden, e.g. bucket feeding calves

==Groove Closure==

==Groove Closure==

*Unconditioned reflex when the animal is eager for milk

An unconditioned reflex when the animal is eager for milk. Water consumption does not usually iniatiate groove closure. The age when the [[Rumen - Anatomy & Physiology|rumen]] becomes fully functional and the oseophageal groove closes differs between ruminants; In calves 20 weeks, in lambs 8 weeks, in deer 16 weeks and in goats 12 weeks. It closes by reflex stimulation of the cranial laryngeal branch of the '''vagus nerve''' ([[Cranial Nerves - Anatomy & Physiology|CN X]]) (takes 2-5 seconds). With time it becomes a conditioned reflex. The closure consists of two movements, the lips of the groove become firmly opposed and shorten and the lips become inverted and twisted around the axis of the right lip of the groove, drawing the reticular mucosa over the right [[Lips|lip]].

 

*Water consumption does not usually iniatiate groove closure

 

*Age when the [[Rumen - Anatomy & Physiology|rumen]] becomes fully functional and the oseophageal groove closes differs between ruminants

**In calves 20 weeks

**In lambs 8 weeks

**In deer 16 weeks

**In goats 12 weeks

 

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

 

*With time becomes a conditioned reflex

 

*Closure consists of two movement

**Lips of the groove become firmly opposed and shorten

**Lips become inverted and twisted around the axis of the right lip of the groove, drawing the reticular mucosa over the right [[Lips|lip]]

==Function in the Adult Ruminant==

==Function in the Adult Ruminant==

*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 - Anatomy & Physiology|reticulum]].

==Test yourself with the Oesophageal Groove flashcards==

'''Click here for information on [[Oesophageal Groove - Histology|histology]]'''

[[The Stomachs of the Ruminant - Anatomy & Physiology - Flashcards#The Oesophageal Groove|The Oesophageal Groove Flashcards]]

'''Test yourself with the [[The Stomachs of the Ruminant - Anatomy & Physiology - Flashcards#The Oesophageal Groove|The Oesophageal Groove Flashcards]]'''

[[Category:Stomach - Anatomy & Physiology]]

[[Category:Stomach - Anatomy & Physiology]]

[[Category:To Do - A&P]]

[[Category:To Do - AimeeHicks]]