Developmental abnormalities

1 It is common for one or more distally placed arteries to persist (aberrant renal arteries) and one may even run to the kidney from the common iliac artery.

2 Occasionally the kidney will fail to migrate cranially, resulting in a persistent pelvic kidney.

3 The two metanephric masses may fuse in development, forming a horseshoe kidney linked across the midline.

4 In 1 in 2400 births there is complete failure of development of one kidney (congenital absence of the kidney).

5 Congenital polycystic kidneys (which are nearly always bilateral) are believed to result from failure of metanephric tissue to link up with some of the metanephric duct collecting tubules; blind ducts therefore form which subsequently become distended with fluid. This theory of origin does not explain their occasional association with multiple cysts of the liver, pancreas, lung and ovary.

6 The mesonephric duct may give off a double metanephric bud so that two ureters may develop on one or both sides. These ureters may fuse into a single duct anywhere along their course or open separately into the bladder (where the upper ureter enters below the lower ureter).

Aberrant Renal Artery

Fig. 86 Renal abnormalities.

(a) Polycystic kidney.

(b) Horseshoe kidney.

(c) Pelvic kidney and double ureter.

(d) Aberrant renal artery and associated hydronephrosis.

Fig. 86 Renal abnormalities.

(a) Polycystic kidney.

(b) Horseshoe kidney.

(c) Pelvic kidney and double ureter.

(d) Aberrant renal artery and associated hydronephrosis.

Rarely, the extra ureter may open ectopically into the vagina or urethra resulting in urinary incontinence.

The urinary bladder of a normal subject is uncomfortably distended by half a pint of fluid. When fully distended, the adult bladder projects from the pelvic cavity into the abdomen, stripping the peritoneum upwards from the anterior abdominal wall. The surgeon utilizes this fact in carrying out an extraperitoneal incision or suprapubic puncture into the bladder. In children up to the age of about 3 years, the pelvis is relatively small and the bladder is, in fact, intra-abdominal although still extraperitoneal.

How To Get Perfect Abs

How To Get Perfect Abs

The Complete Guide To How to Get Perfect Abs is Here. While other books gear you towards buying a product or a service, this book actually tells you exactly what you need to do to get the abs of your dreams. Getting a six pack and looking good is easier than ever if you follow the instructions in this book. This book does not just tell you what workout machines to use, but how to think, what to eat, what not to eat and how to exercise to get the six pack abs that you have longed for but never thought that you would get.

Get My Free Ebook


Responses

  • yonatan
    Does collecting duct lead to ureter?
    7 years ago

Post a comment