48 Hour Chick Embryo Development

Study Notes

The maxillary pouch is a rounded or flattened mass on either side of Rathke's pouch.
The 3rd pharyngeal pouches are large outpocketings of the pharynx, giving a laterally oriented oral cavity.
The 3rd aortic arches are located beneath the 3rd pharyngeal pouches, but posterior to the hyoid arch.
The 3rd visceral arch lies between the 2nd and 3rd pharyngeal pouches.

The descending aorta is a fused dorsal aorta.
The dorsal intersegmental arteries are small blood vessels arising at intervals from the dorsal aorta and the somite.
The conus arteriosus is a chamber of the heart at the right side of the embryo.
The atrium is a left-side chamber and the forerunner of the future auricles.
The ventricle is a large loop chamber of the heart.
The bulbus cordis is the first heart cavity, extending forward as a finger-like diverticulum anterior to the first mouth.

The laryngotracheal groove is a deep V-shaped depression in the floor of the foregut.
The thyroid rudiment is a depression in the floor of the pharynx.
The trachea arises as a ventrocaudal diverticulum of the pharynx, with the lung buds as paired bilateral expansions of the laryngotracheal groove.

The 1st aortic arch lies beneath the 1st pharyngeal arch.
The carotid loop is an extension of the 1st aortic arch.
The internal carotid arteries are paired vessels extending from the carotid loops alongside the forebrain and medial to the optic cups.
The dorsal aorta is a blood vessel on either side of the notochord, lying above the 1st pharyngeal pouch.
The 2nd aortic arch lies beneath the 2nd pharyngeal pouches, contained within the 2nd visceral arches (hyoid arches).
The ventral aorta/aortic sac/truncus arteriosus is the caudal part of the slides when the 1st aortic arch approaches one another and becomes continuous.