The development of the kidney initially takes place in the?

Appeared in: BSF Staff Nurse - 2015

Explanation

The definitive human kidney, the metanephros, first appears in the sacral region during the 5th week of gestation.
This permanent kidney then undergoes a process of ascent to reach its final position in the lumbar region by the 9th week.
The question asks for the initial location of development, which for the permanent kidney is the sacral region.

Option A: The cervical region is the site of the pronephros, the first and most primitive kidney structure. It is non-functional in humans and degenerates completely.
Option B: The thoracic region (along with the upper lumbar area) is the site of the mesonephros, which acts as a temporary kidney during early fetal life before it largely degenerates.
Option C: The lumbar region is the final destination of the permanent kidney after its ascent from the pelvis. It is not the initial site of development.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Embryological development and ascent of the kidney as background academic context rather than a clinical decision trigger.
Understanding renal embryology is crucial for recognizing congenital anomalies. A failure of the kidney to ascend from the pelvis results in a pelvic kidney, which can be mistaken for a pelvic tumor or cause urinary obstruction.
If the lower poles of the two kidneys fuse during development, their ascent is blocked by the inferior mesenteric artery. This results in a 'horseshoe kidney,' which is located lower than normal and may be associated with an increased risk of kidney stones or infection.
What if the question asked for the location of the final functioning kidney in an adult? The answer would be the lumbar region, specifically between the T12 and L3 vertebrae.

How to Approach the Question

This is a factual recall question about embryology.
First, identify the key terms in the question: 'kidney development' and 'initially'.
Recall the three sequential stages of kidney development: pronephros, mesonephros, and metanephros.
Recognize that in a clinical or nursing context, questions about 'the kidney' typically refer to the permanent, functional structure, which is the metanephros.
Differentiate between the initial location of the metanephros (sacral region) and its final, ascended location (lumbar region).
Select the option that corresponds to the initial site of development for the permanent kidney.

Concept Tested & Keywords

Q0y83F5lzarKLWxzphy4IP

E6 Physiology Ganong 27e Vol 2 Part 3 p. 128-130

E6 Anatomy Applied Ashalatha 4e p. 367-369

E6 Anatomy BDChaurasia V2 10e Part 2 p. 109-111

Practise the full BSF Staff Nurse - 2015

Attempt every question from this paper in a timed mock, then review the full solution for each one.