Where is the bursa of a chicken located?

Infectious bursal disease in broilers.

Open it to see if you don't hit the antibodies to solve the bursa.

The tissue structure of the supraluminal capsule originates from the cloaca, and its sac wall still retains a structure similar to that of the digestive canal. The supraluminal sac of different birds varies in the order and timing of occurrence.

It has been suggested that the primordium of the upper cavity of the chicken cavity is formed by the merging of small vacuoles between the epithelium on the back of the cloaca into large vacuoles. From the 11th to the 12th day, 8-11 leaf-like folds appeared in the superior cavity capsule, and lymphepithelial buds appeared on the mucosal surface. In about 16 to 17 days, the number of primary lobules increases to 16-20, and the medulla of lymphatic follicles in the lobules is formed.

At 18 to 21 days, lymphocytes within the follicular medulla migrate to the monolayer of epithelium, forming cortex. The mucosal surface of the follicle differentiates into an absorbent epithelium, and the interfollicular is called the secretory epithelium.

Some believe that during the 6th day of incubation, it originates from the endoderm, and during the 6th day of incubation, the supraluminal cyst primordium protrudes from the posterior margin of the urogenital membrane, which contains many voids. The 7-day spatiotemporal gap merges into a cystic cavity, which is then connected to the anal canal. The supraluminal capsule then rotates anteriorly, is located on the dorsal vertical plane of the cloaca, and communicates with the anal canal with a short stalk.

Supraluminal sac lymphocytes are formed by the migration of hematoblasts into the supraluminal sac with the bloodstream. Kinkade et al. reported that the supraluminal sac began to wrinkle on the 11th day of embryonic life, and Glick suggested that the folds began to form on the 13th to 14th day. Yang Yinfeng et al. believed that there was a mound-shaped uplift on the 10th day, and by the 12th day, it had differentiated into 8-11 leaf-like folds, which was earlier than the time reported above.

Regarding the time when the supraluminal capsule communicates with the cloaca, Kdwards believes that it is on the 10th day, while Yang Yinfeng et al. believe that it is on the 8th day.

Wang Shuilian et al. believe that with the growth of chicken age, the area of the bursa increases significantly, the single-layer columnar epithelial cells and single-layer cubic epithelial cells of the mucosal epithelium continue to increase, the arrangement changes from loose to compact, and its nuclei are neatly arranged in a straight line on the basal surface, and the lymphatic follicles are composed of dark cortex and light-colored medulla, and the follicular area gradually increases, the number increases, and the corresponding immune function is also enhanced.

The bursa is a lymphoid organ unique to birds, located at the end of the rectum and above the cloaca, so it is also called the supraluminal sac or cloacal sac.

The bursa is a central organ.

The cell population is acted upon by hormones in organs or tissues that resemble bursa, matures and differentiates into another subset of lymphocytes, known as B lymphocytes. The "b" character for B cells is named after the first letter of the Latin word for "sac". The bursa is a structure unique to birds, located posterior and superior to the cloaca, and the walls of the sac are filled with lymphoid tissue.

B cells work by producing antibodies. Antibodies are present in body fluids, so the immune function of B cells is called "humoral immunity".

So it should be the second answer, humoral immunity central organs.