Bird Animal Reproduction System
A bird excretion tool is a pair of metanerfous kidneys. The kidney is connected by the ureter to the cloaca because the bird does not have a urinary vesicle. More than a mammal kidney tube of a mammal because the speed of bird metabolism is very high. Every 1ml cubic tissue of the renal cortex of birds contains 100 to 500 of these kidney tubes forming a small henle arch.
Water in the body is stored through tubules reabsorption. In the cloaca water reabsorption also occurs which increases the amount of water in the body. Nitrogen waste is discarded as uric acid released through the cloaca as white crystals mixed with feces.
Especially in seabirds, for example gulls, in addition to excreting uric acid also salt. This is because seabirds drink salt water and eat sea fish that contain salt. Seabirds have salt excretion glands above the eyes. The salt solution flows through the nasal cavity then exits through the outer nares and finally the salt comes out through the end of the beak.
The nervous system in birds is similar to the nervous system in humans and mammals. All nerve activities are regulated by the central nervous system. The central nervous system consists of the brain and spinal cord. Bird brain also consists of four parts, the cerebrum, midbrain, cerebellum and advanced marrow.
In addition to the cerebellum, the cerebrum in birds can also grow well. Big brains of birds are different from big brains in humans. The surface of the cerebrum in birds does not multiply, so the number of neurons in birds develops by forming two bubbles. This development is related to the function of vision.
The cerebellum of birds has folds that extend the surface so that it can accommodate a large number of neurons. The development of the cerebellum is useful for regulating bird balance when flying.
In the retina of the bird's eye there are two kinds of sensory cells receiving light stimuli, namely stem cells and cone cells. Stem cells are sensitive to light stimuli while cone cells are sensitive to strong light. Night birds have many retinas that contain stem cells. Day birds have lots of cone cells. Eye lenses in birds have good accommodation.
Bird groups are oviparous animals. Although the group of birds do not have external genitals, fertilization still occurs in the body. This is done by attaching cloaca to each other.
a. Male Genital System.
The testes are a pair, oval or round in shape, the surface is slippery, located next to the ventral lobe of the penis most cranial. In mating season, the size gets bigger. This is where spermatozoa are made and stored.
Reproductive tract. Mesonephrus tubules form afferent ducts and epididymis. The wolf ducts curl and form the duct deferens. In small birds, the very long distal ductal distal ducts form a spindle called a glomere.
Near the posterior glomere of the afferent duct dilates to form the ampulla duct which empties into the cloaca as the ejaculatory duct. The efferent duct is associated with a small epididymis and then towards the deferent duct. Deferent duct has nothing to do with the ureter when entering the cloaca.
b. Female Genital System.
Ovary In addition to eagles, the ovaries that develop only the left, and are located in the dorsal abdominal cavity.
Reproductive tract, oviducts that develop only on the left, long, curled, attached to the body wall by mesosilfing and divided into sections; the anterior part is the infundibulum which has an open part that leads to the cavity of the selom as an ostium surrounded by fimbre-fimbre.
On the posterior is the magnum which will secrete albumin, then the istmus
secrete inner and outer egg cells. Uterus or shell gland to produce lime shells.
c. Festilization Process
In female birds there is only one ovary, the left ovary. The right ovary does not grow perfectly and remains small, called a rudimentary.
The ovary is attached by an ovum recipient funnel followed by the oviduct. The tip of the oviduct enlarges to become a uterus which empties into the cloaca. In male birds there is a pair of testicles which coincide with the ureter and empties into the cloaca.
Fertilization will take place in the tip of the oviduct when sperm enters the oviduct. The fertilized ovum will move close to the cloaca. On the way to the cloaca in the oviduct, the fertilized ovum will be surrounded by shell material in the form of lime.