Embryology and Development Practice Questions

Q: Which of the following is a derivative of ventral mesogastrium ?

Lesser omentum. ***Lesser omentum*** - The **lesser omentum** is formed from the **ventral mesogastrium**, which connects the developing stomach to the anterior abdominal wall [1]. - It specifically derives from the part of the ventral mesogastrium that encloses the developing liver and extends to the lesser curvature of the stomach and the duodenum [1]. *Greater omentum* - The **greater omentum** develops from the **dorsal mesogastrium**, which means it is a derivative of the dorsal rather than the ventral mesentery [1]. - It arises from a rapid growth and fusion of the **dorsal mesogastrium**, hanging from the greater curvature of the stomach. *Splenorenal ligament* - The **splenorenal ligament** develops from the **dorsal mesogastrium**, specifically from the portion that connects the spleen to the posterior abdominal wall (near the kidney). - Its formation is a consequence of the rotation of the stomach and the development of the spleen within the dorsal mesentery. *Gastrosplenic ligament* - The **gastrosplenic ligament** is also derived from the **dorsal mesogastrium**, connecting the greater curvature of the stomach to the hilum of the spleen. - As the stomach rotates, the dorsal mesogastrium expands, eventually forming both the gastrosplenic and splenorenal ligaments.

Q: Prolactin secreting gland develops from -

Rathke's pouch. ***Rathke's pouch*** - The **anterior pituitary gland**, which secretes prolactin [2], develops embryologically from **Rathke's pouch**. - Rathke's pouch is an **ectodermal evagination** from the roof of the primitive oral cavity (stomodeum). *Infundibulum* - The **infundibulum** is also known as the pituitary stalk, connecting the hypothalamus to the posterior pituitary [1]. - It is derived from **neuroectoderm** and forms part of the posterior pituitary, not the prolactin-secreting anterior pituitary [1]. *Tuber cinereum* - The **tuber cinereum** is a part of the **hypothalamus**. - It is involved in regulating several bodily functions but does not directly give rise to the prolactin-secreting gland. *3rd ventricle* - The **3rd ventricle** is one of the four ventricles of the brain, filled with **cerebrospinal fluid**. - It is a part of the central nervous system and is not involved in the embryological development of the pituitary gland.

Q: Which of the following statements about the limbus fossa ovalis is false?

Derived from septum primum. ***Derived from septum primum*** - The **limbus fossa ovalis** (or annulus ovalis) is a structure in the right atrium that forms the prominent rim of the **fossa ovalis**. - It is derived from the inferior border of the **septum secundum**, not the septum primum, which primarily forms the floor of the fossa ovalis. *Forms the rim around fossa ovalis* - The **limbus fossa ovalis** is indeed the thickened, crescent-shaped border of tissue that surrounds the **fossa ovalis** in the interatrial septum. - This anatomical arrangement is a remnant of the **foramen ovale** from fetal circulation [1]. *In right atrium* - The **fossa ovalis** and its surrounding limbus are located on the septal wall of the **right atrium** [1]. - This position is crucial for its role as a key landmark in interatrial septum anatomy. *Also called Annulus ovalis* - The term **annulus ovalis** is a widely accepted synonym for the **limbus fossa ovalis**. - Both terms describe the same anatomical structure, the fibrous rim surrounding the fossa ovalis.

Q: Which is the first bone to start ossifying?

Clavicle. ***Clavicle*** - The **clavicle** is the **first bone to begin ossification** in the human body, starting around the **5th-6th week of gestation**. - It ossifies via **intramembranous ossification**, making it unique among long bones [1]. - This early ossification is a key landmark in fetal skeletal development and is consistently taught across medical curricula. *Mandible* - The **mandible** begins ossification around the **6th week of gestation**, shortly after the clavicle [1]. - While it is one of the earliest bones to ossify, it is **not the first**. - It also undergoes intramembranous ossification [1]. *Femur* - The **femur**, a long bone, begins ossification around the **7th-8th week of gestation** [1]. - It ossifies via **endochondral ossification**, which typically occurs later than intramembranous ossification [1]. *Tibia* - The **tibia** also begins ossification around the **7th-8th week of gestation**. - Like the femur, it follows the endochondral ossification pathway.

Q: The trigone of urinary bladder is primarily derived from which germ layer?

Mesoderm. ***Mesoderm*** - The trigone of the urinary bladder is primarily derived from the **mesoderm**, specifically from the caudal parts of the **mesonephric ducts** which are incorporated into the bladder wall [1]. - This mesodermal origin distinguishes it from the rest of the bladder, which is endodermal, and explains its histological difference [1]. *Ectoderm* - The ectoderm gives rise to structures like the **skin**, **nervous system**, and **sensory organs**, not internal urinary structures like the bladder trigone. - It is responsible for the formation of the **external genitalia** and the terminal part of the urethra, but not the bladder itself. *Endoderm of urachus* - The urachus is a remnant of the **allantois**, which is endodermal in origin, but it forms the **median umbilical ligament** and does not contribute to the trigone. - The main body of the bladder (excluding the trigone) is derived from the **endoderm of the cloaca**, but the trigone has a distinct mesodermal origin [1]. *Endoderm of urogenital sinus* - The urogenital sinus gives rise to the **main body of the bladder** (endodermal), but not the trigone [1]. - The trigone's mesodermal origin from the mesonephric ducts makes it histologically and embryologically distinct from the endoderm-derived bladder wall [1].

Q: Intramembranous ossification is primarily seen in which of the following bones?

Maxilla and mandible. ***Maxilla and mandible*** - **Intramembranous ossification** directly forms bone from mesenchymal tissue without a cartilaginous precursor [1]. - This process is characteristic of most **flat bones of the skull**, including the maxilla and mandible [1]. - The **clavicle** also undergoes intramembranous ossification (though it uniquely combines both intramembranous and endochondral processes) [1]. *Pelvis* - The pelvis develops primarily through **endochondral ossification**, where a cartilage model is first formed and then replaced by bone [1]. - While some parts might involve intramembranous ossification to a limited extent, it is not the primary mode of formation for the pelvis as a whole. *Long bones* - **Long bones** (e.g., femur, tibia, humerus) develop almost exclusively through **endochondral ossification** [1]. - This process is essential for the longitudinal growth of bones at the **epiphyseal plates** [2]. *None of the options* - This option is incorrect because the **maxilla and mandible** are clear examples of bones that primarily undergo intramembranous ossification.

Q: Which is the earliest secondary ossification center to develop chronologically?

Lower end of femur. ***Lower end of femur*** - The **distal femoral epiphysis** is typically the first secondary ossification center to appear, often present at birth or shortly before [1]. - Its presence at birth is an indicator of **fetal maturity**, making it a key developmental landmark [1]. *Upper end of humerus* - The **proximal humeral epiphysis** typically ossifies around 6 months of age, significantly later than the distal femur. - This center contributes to the growth of the humeral head and greater tubercle. *Lower end of fibula* - The **distal fibular epiphysis** appears around the first year of life, after both the distal femur and proximal humerus. - It forms part of the ankle joint and contributes to its stability. *Upper end of tibia* - The **proximal tibial epiphysis** typically ossifies around 6-12 months of age, well after the distal femur. - This center is crucial for the growth of the upper tibia and knee joint development.

Q: What anatomical structure is formed after the obliteration of the umbilical vein?

Round ligament of the liver (ligamentum teres). ***Round ligament of the liver (ligamentum teres)*** - The **umbilical vein** carries oxygenated blood from the placenta to the fetus during development [1]. - After birth, the umbilical vein obliterates and forms the **round ligament of the liver**, also known as the **ligamentum teres hepatis**. *Ligamentum venosum* - This structure is the obliterated remnant of the **ductus venosus**, which shunted blood from the umbilical vein to the inferior vena cava, bypassing the fetal liver [1]. - It is located in a fissure on the posterior surface of the liver, separate from the round ligament. *Ligamentum arteriosum* - This ligament is the remnant of the **ductus arteriosus**, a fetal blood vessel connecting the pulmonary artery to the aorta. - Its obliteration allows blood to flow through the lungs after birth. *Medial umbilical ligament* - This ligament is formed from the obliterated **umbilical arteries**, which carry deoxygenated blood from the fetus back to the placenta. - There are two medial umbilical ligaments, one from each umbilical artery.

Q: Medulla oblongata arises from which of the following?

Myelencephalon. ***Myelencephalon*** - The **myelencephalon** is the most caudal of the three primary brain vesicles and is the developmental origin of the **medulla oblongata**. - It differentiates from the **rhombencephalon** (hindbrain) and is responsible for vital autonomic functions. *Rhombencephalon* - The **rhombencephalon** is the hindbrain and is a primary brain vesicle that further divides into the **metencephalon** and **myelencephalon**. - While it is the parent structure, it does not directly give rise to the medulla oblongata as a final differentiated structure without further division. *Mesencephalon* - The **mesencephalon** is the midbrain, a primary brain vesicle that develops into structures like the **tectum** and **tegmentum** [1]. - It is located rostral to the rhombencephalon and is not involved in the development of the medulla oblongata [1]. *None of the options* - This option is incorrect because the **myelencephalon** is the direct embryonic precursor of the medulla oblongata.

Q: The primary oocyte remains arrested in which stage until ovulation?

Diplotene stage. ***Diplotene stage*** - The primary oocyte enters **meiosis I** during fetal development but arrests in the **prophase I substage of diplotene**. - This arrest is maintained until **puberty** and **ovulation**, when hormonal surges trigger the completion of meiosis I. *Pachytene stage* - The **pachytene stage** of prophase I is when **crossing over** (recombination) occurs between homologous chromosomes. - While an important step in meiosis, it precedes the **diplotene arrest** point. *Metaphase* - **Metaphase** is a stage where chromosomes align at the metaphase plate, either in meiosis I or meiosis II. - The primary oocyte's arrest occurs much earlier, during **prophase I**, not metaphase. *Telophase* - **Telophase** is the final stage of mitosis or meiosis where chromosomes decondense and nuclear envelopes reform. - The oocyte's initial arrest point is in **prophase I**, long before telophase.

Question 1

Which of the following is a derivative of ventral mesogastrium ?

Accepted Answer

Lesser omentum

Answer

Splenorenal ligament

Answer

Greater omentum

Answer

Gastrosplenic ligament

Question 2

Prolactin secreting gland develops from -

Accepted Answer

Rathke's pouch

Answer

Infundibulum

Answer

Tuber cinereum

Answer

3rd ventricle

Question 3

Which of the following statements about the limbus fossa ovalis is false?

Accepted Answer

Derived from septum primum

Answer

Also called Annulus ovalis

Answer

In right atrium

Answer

Forms the rim around fossa ovalis

Question 4

Which is the first bone to start ossifying?

Accepted Answer

Clavicle

Answer

Femur

Answer

Tibia

Answer

Mandible

Question 5

The trigone of urinary bladder is primarily derived from which germ layer?

Accepted Answer

Mesoderm

Answer

Endoderm of urachus

Answer

Ectoderm

Answer

Endoderm of urogenital sinus

Question 6

Intramembranous ossification is primarily seen in which of the following bones?

Accepted Answer

Maxilla and mandible

Answer

Pelvis

Answer

Long bones

Answer

None of the options

Question 7

Which is the earliest secondary ossification center to develop chronologically?

Accepted Answer

Lower end of femur

Answer

Upper end of humerus

Answer

Lower end of fibula

Answer

Upper end of tibia

Question 8

What anatomical structure is formed after the obliteration of the umbilical vein?

Accepted Answer

Round ligament of the liver (ligamentum teres)

Answer

Ligamentum venosum

Answer

Ligamentum arteriosum

Answer

Medial umbilical ligament

Question 9

Medulla oblongata arises from which of the following?

Accepted Answer

Myelencephalon

Answer

Mesencephalon

Answer

Rhombencephalon

Answer

None of the options

Question 10

The primary oocyte remains arrested in which stage until ovulation?

Accepted Answer

Diplotene stage

Answer

Pachytene stage

Answer

Metaphase

Answer

Telophase

Embryology and Development — MCQs

Embryology and Development — MCQs

On this page

Practice by Chapter

Want unlimited practice?