Which of the following germinal layer that develop bones, cartilage, kidney and pleural cavity of fetus?

Appeared in: NVS Staff Nurse - 2022

Explanation

The mesoderm is the middle of the three primary germ layers formed during gastrulation.
It differentiates into various connective tissues, including bone and cartilage, which arise from the paraxial and lateral plate mesoderm.
The urogenital system, which includes the kidneys, develops from the intermediate mesoderm.
The lining of the body cavities, such as the pleura of the pleural cavity, is also a mesodermal derivative, specifically from the lateral plate mesoderm.

Option A: The ectoderm is the outermost germ layer and is not responsible for the structures listed.
Option B: The periderm is not one of the three primary germ layers. It is a temporary, superficial layer of cells that covers the embryonic epidermis and is later shed.
Option C: The endoderm is the innermost germ layer and does not form skeletal, urinary, or cavity-lining structures.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Derivatives of embryonic germ layers as background academic context rather than a clinical decision trigger.
Understanding embryology is crucial for nurses to comprehend the origins of congenital anomalies. Defects in mesodermal development can lead to skeletal abnormalities (e.g., limb defects), congenital heart diseases, or kidney malformations (e.g., renal agenesis).
This knowledge helps in anticipating potential associated defects when one anomaly is identified and in providing accurate information to families.
What if? If a newborn presents with anencephaly (absence of a major portion of the brain and skull), the nurse would recognize this as a severe defect in the development of the ectoderm, specifically a failure of the neural tube to close.

How to Approach the Question

This is a factual recall question testing knowledge of basic embryology.
First, identify the key structures listed in the question stem: bones, cartilage, kidney, and pleural cavity.
Next, recall the three primary germ layers: ectoderm, mesoderm, and endoderm, and their main derivatives.
Systematically associate each structure with its germ layer of origin. Remember that mesoderm forms 'middle' structures like muscle, bone, and connective tissues.
Bones, cartilage (connective tissue), kidneys (urogenital system), and the lining of body cavities are all classic derivatives of the mesoderm.
Eliminate the other options based on their known derivatives: ectoderm (nervous system, skin), endoderm (gut/respiratory lining), and recognize that periderm is not a primary germ layer.

Concept Tested & Keywords

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E6 Anatomy Grays 43e Vol 1 Part 2 pp. 32-34, 33-35

Practise the full NVS Staff Nurse - 2022

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