Crop - Anatomy and Physiology

Introduction

The crop is a food storage device present in avian species. It is usually used when the muscular stomach (gizzard) is full. The crop also softens food.

It is a useful tool for avian veterinarians and owners for assessing when the bird last ate and it is especially important to ensure young chicks always have full crops. It is also a common site for impactions and surgical entry to remove foreign bodies.

Structure and Function

Crop of fowl(Copyright RVC)

• Muscular chamber

• Fusiform enlargement of the oesophagus

• Thoracic inlet of ventral wall of oesophagus

• Bulges and lies against the breast muscles

Innervation

• Vagus nerve (CN X)

Species Differences

• Crop small in ducks and geese

• Crop much larger and muscular in seed eating birds

• Pigeons have epithelial cells in their crop sensitive to prolactin which slough when chicks (squabs) hatch producing crop milk

• Owls have no storage facility in their crops, so produce a pellet of indigestible material after every meal

Test yourself with the Avian Alimentary Tract flashcards

Avian Alimentary Tract Flashcards

Links

Oesophagus - Anatomy & Physiology