Abstract This paper examines the nervous and digestive systems of reptiles, emphasizing their main characteristics and briefly compare them to the nervous and digestive systems at other vertebrates including humans. The author points out that the anatomical characteristics of the reptile's nervous system, such as the position of the brain or the spinal cord, resemble closely those of the human and higher vertebrates; the reptilian nervous system has developed to provide the best adaptation of the reptiles' necessities, with emphasis on sight, smell and motor functions. The paper relates that birds and reptiles are the only vertebrates to have the cloacae chamber, the removal system of the body, is where the faeces is discharged; the urodaeum receives the urogenital tract ducts and the proctodaeum acts as a common collecting area prior to evacuation.
From the Paper "As such, the reptilian nervous system is formed of two different components: the central nervous system (CNS) and the peripheral nervous system (PNS). The central nervous system is composed of the brain and the spinal cord, while the peripheral nervous system is composed of all nervous tissues and structures that do not actually belong to the CNS. As at other vertebrates, the brain, constituent part of the central nervous system, is protected by the skull. The bones forming the skull similarly have names such as parietal and occipital, which also form the human skull, for example."
Abstract The paper gives a thorough description of the anomalies that can occur due to the maldevelopment of fetal tissues with the use and abuse of cocaine during pregnancy. It discusses malformations and medical procedures performed on fetuses and babies with certain malformations.
From the Paper "In order to understand the negative affects of cocaine on fetal development, you must first understand normal fetal development. Cocaine mostly affects central nervous system development and urogenital development, of which I will elaborate on the urogenital system. The terminal part of the hindgut in the fetus is the cloaca, which is lined with endoderm and is in contact with the surface ectoderm at the cloacal membrane. The cloaca receives the allantois. Between the allantois and the hindgut, the cloaca is divided into dorsal and ventral parts by a group of mesenchymal cells called the urorectal septum. This septum grows caudally towards the cloacal membrane, and extensions of the septum produce infoldings in the walls of the cloaca that eventually fuse together forming a partition. The cloaca is now divided into a ventral urogenital sinus and a dorsal rectum. The urogenital sinus is then divided into three parts: the vesical, pelvic, and phallic parts. The bladder develops from the vesical part and from parts of the mesonephric ducts and the urethra develops from the phallic part. The mesonephric ducts are incorporated into the wall of the bladder and a ureteric bud forms at the base of these ducts. From this bud the ureters are formed and enter the bladder in a different location than the mesonephric ducts. The metanephros at the end of the ureters will eventually form the permanent kidneys. (Moore and Persaud, 1998)."
