Anatomy Long Quiz 6

Hypospadias is defined as the incomplete fusion of urethral folds, which results in abnormal openings along the inferior aspect of the shaft of the penis. This means that the urethra does not develop properly and instead opens in a location that is not typical. The other options provided in the question are unrelated to hypospadias and describe different conditions or abnormalities in the development of the reproductive system.

During male development, the testis cords, which are located near the hilum (the area where blood vessels and nerves enter and exit an organ), break up into rete testis, which is a network of tubules. These tubules then establish a connection with the mesonephric duct, also known as the Wolffian duct, through efferent ductules. This process is a normal part of male reproductive development. Therefore, the statement is true.

The correct answer is "failure of paramesonephric ducts to fuse resulting in formation of 2 horns of uterus in a common vagina." This explanation states that a bicornuate uterus occurs when the paramesonephric ducts, which are responsible for the development of the uterus, fail to fuse properly. This leads to the formation of two separate horns of the uterus instead of a single, fully formed uterus. These two horns share a common vagina.

The mesonephric ducts, also known as Wolffian ducts, are present in both males and females during embryonic development. In males, these ducts develop into the reproductive structures such as the epididymis, vas deferens, and seminal vesicles. However, in females, the mesonephric ducts typically degenerate and do not contribute to the formation of reproductive structures. Instead, their remnants give rise to certain structures in the female reproductive system, including the epoophoron and paroophoron within the broad ligament, as well as Gartner's glands. Therefore, the statement that the mesonephric ducts in females degenerate and their remnants form the epoophoron and paroophoron of the broad ligament and Gartner's glands is true.

The paramesonephric ducts, also known as Müllerian ducts, are embryonic structures that develop in females. These ducts give rise to the uterine tube, uterus, and upper portion of the vagina. These reproductive organs play crucial roles in the female reproductive system. The uterine tube transports the egg from the ovary to the uterus, where fertilization can occur. The uterus is where the fertilized egg implants and develops into a fetus. The upper portion of the vagina connects the uterus to the external genitalia. Therefore, the correct answer is the formation of the uterine tube, uterus, and upper portion of the vagina.

The explanation for the given correct answer is that in females, the absence of the testis determining factor leads to the dissociation of the primitive sex cords. This dissociation results in the formation of follicular cells that surround the oogonia. This process is a crucial step in the development of female reproductive structures and supports the statement that the given answer is true.

The correct answer is failure of sinovaginal bulb to develop or vaginal plate to canalize. Vaginal atresia occurs when there is a failure in the development of the sinovaginal bulb or the vaginal plate, which leads to the absence or obstruction of the vaginal canal. This can result in the formation of two horns of the uterus in a common vagina due to the failure of the paramesonephric ducts to fuse.

Androgens secreted by the testes are responsible for the rapid elongation of the genital tubercle (phallus). Androgens are a group of hormones that include testosterone, and they play a crucial role in the development of male reproductive organs during embryonic development. The genital tubercle is a structure that will eventually develop into the penis in males. The presence of androgens stimulates the growth and elongation of the genital tubercle, leading to the formation of the male external genitalia.

The correct answer is "Initial". This stage refers to the early phase of development where the intermediate mesoderm proliferates and condenses on both sides of the midline to form the genital ridges. This stage occurs before the differentiation of the genital ridges into male or female structures takes place.

Epispadias is a condition characterized by the abnormal opening(s) along the inferior aspect of the shaft of the penis. This occurs when the caudal genital tubercle is positioned too far back, causing an opening on the dorsum of the penis and exposing the urethra. This abnormal fusion of the urethral folds during development leads to the formation of an abnormal urethral opening.

Penile part: arises from urethral folds
glandular parts: arises from surface (glans penis) epithelial proliferation

Inborn deficiency of 21beta hydroxylase enzyme leads to a disruption in the conversion of progesterone to deoxycorticosterone. As a result, progesterone is converted to DHEA, which can further be converted to testosterone. This leads to the development of male external genitalia despite the presence of ovarian development. Additionally, the deficiency also causes low cortisol levels but high levels of ACTH. The decrease in aldosterone production results in symptoms such as hypotension, hyponatremia, hyperkalemia, and increased plasma renin levels.

Turner's syndrome is the most common cause of primary amenorrhea. This condition occurs in females when one of the X chromosomes is partially or completely missing. This genetic disorder leads to various physical and developmental abnormalities, including the absence of menstruation. Androgen insensitivity syndrome and Klinefelter's syndrome are also genetic disorders, but they are not as commonly associated with primary amenorrhea as Turner's syndrome.

IVP stands for Intravenous Pyelogram, which is a diagnostic test used to visualize the renal pelvis, ureters, and bladder. In this procedure, contrast media is administered to the patient intravenously, which helps in enhancing the visibility of these structures during imaging. The use of contrast makes IVP more sensitive and allows for better visualization compared to other imaging techniques like CT scans.

They are not usually painful, but do cause blood in the urine

Renal/uteric/vesicular calculi are caused by infection, urinary stasis, and several systemic diseases. Uteric calculi, specifically, are known to be very painful but typically pass within 3-4 days. Additionally, it is mentioned that 40-50% of these calculi are visible on plain film.

They are usually found in the pelvis

The given answer provides a comprehensive explanation of uterine fibroids. It states that uterine fibroids are also known by various names such as leiomyoma, myoma, or fibromyoma. It further explains that these fibroids are a common benign tumor found in the female reproductive tract, affecting 40% of women over the age of 40. Additionally, it mentions that while uterine fibroids are usually asymptomatic, they can cause symptoms such as heavy menstruation, pelvic pressure, frequent urination, or constipation.

The uriniferous tubule is the functional unit of the kidney, made up of a collecting tubule and its associated nephrons

The nephrons in the kidney are composed of several structures, including the renal corpuscle, proximal convoluted tubule, Henle's loop, and distal convoluted tubule. The renal corpuscle is responsible for filtering blood and forming urine, while the proximal convoluted tubule reabsorbs water and important substances back into the bloodstream. Henle's loop helps to concentrate urine by creating a concentration gradient in the kidney, and the distal convoluted tubule further adjusts the composition of urine by reabsorbing or secreting specific substances. Together, these structures play a crucial role in the filtration and excretion of waste products from the body.

The renal pyramids contain the loops of Henle, lower part of collecting tubules, and Bellini ducts. These structures are all part of the renal tubules, which play a crucial role in the filtration and reabsorption of substances in the kidney. The loops of Henle are responsible for creating a concentration gradient in the kidney, allowing for the reabsorption of water and electrolytes. The lower part of the collecting tubules continues this reabsorption process, while the Bellini ducts help transport urine from the collecting tubules to the renal pelvis. Therefore, all of these structures are present in the renal pyramids.

Medullary rays are part of the cortex and are also called collecting tubules. The medullary rays are structures that extend from the medulla into the cortex of the kidney. They consist of a collection of tubules that help transport urine from the collecting ducts in the medulla to the renal pelvis. These tubules are responsible for reabsorbing water and certain solutes from the urine, allowing the body to maintain water and electrolyte balance. Therefore, the statement that medullary rays are part of the cortex and are also called collecting tubules is correct.

In Males: XY chromosomes express SRY, which leads to SOX9. SOX9 inhibits the expresson of WNT 4 (the primary gene in females), and leads to SF1 ultimately forming the testis. The testis secrete testosterone from Leydig cells leading to the stiimulation of mesonephric ducts (efferent ductules, epididymis, vas deferens, seminal vesicles). Dihydrotestosterone leads to formation of external genitalia. Testis also secrete Mullerian inhibiting substance from Sertoli cells which will suppress paramesonephric ducts (which in female lead to the formation of uterine tube, uterus, and upper portion of the vagina).

Medullary cords are another term for testis cords, as such they will NOT form in the female.
Tunica albuginea is a dense layer of FIBROUS tissue that separates testis cords from surface epithelium.

Although it is correct to say Mesonephric ducts develop under the effect of testosterone, they develop with the urinary system in males.

The paramesonephric ducts degenerate in males EXCEPT at the prostatic utricle (a small blind ending pouch in the seminal colliculus of the prostatic urethra)

The paramesonephric ducts do not form the myometrium and perimetrium. Those developm from the surrounding splanchnic mesoderm

testis cords remain solid until puberty when they canalize to form seminiferous tubules

The development of a double uterus and vagina occurs due to the failure of fusion of the paramesonephric ducts and sinovaginal bulbs. The paramesonephric ducts are responsible for the formation of the uterus and fallopian tubes, while the sinovaginal bulbs contribute to the development of the vagina. If these structures fail to fuse properly, it can result in the formation of two separate horns of the uterus along with a common vagina. This condition is known as uterus didelphys and can occur due to genetic or developmental abnormalities.

Cranial part develops from the most caudal part of fused paramesonephric tubules that canalize forming vaginal fornices & upper 1/3 of vagina.
Most distal part of vaginal tube is enclosed by a DOUBLE layer membrane (hymen) that has small holes for passage of
vaginal secretions & menstruation

Persistence of connection between processus vaginalis cavity & scrotal sac describes a congenital inguinal hernia.
↓ ↓ testosterone causes failure of one or both testicles to descend in the scrotum with failure to produce mature sperms describes cryptochidism

During female development, estrogen release plays a crucial role in regulating the growth of various reproductive structures. It slows down the growth of the genital tubercle, leading to the formation of the clitoris, which is a solid structure. Similarly, estrogen also affects the growth of the urethral folds, causing them to undergo slow growth and remain separated from each other. This results in the formation of the labia minora, which surrounds the vestibule or urogenital groove. Furthermore, the urethra in females is derived from only one part, known as the membranous urethra, which is short and wide. The genital swellings also experience rapid growth but stay separated and in place from the labia majora.

Androgen Insensitivity Syndrome (AIS) is the most common form of male pseudohermaphroditism. In this condition, individuals with XY chromosomes have a partial or complete inability to respond to androgens, which are male sex hormones. As a result, their external genitalia may appear female or ambiguous, despite having testes instead of ovaries internally. AIS can range from mild to severe, with individuals having varying degrees of feminization of their bodies. This condition is caused by mutations in the androgen receptor gene and can affect the development of both primary and secondary sexual characteristics.

Brachytherapy is a form of internal radiation therapy commonly used to treat prostate cancer. It involves the placement of radioactive sources directly into or near the tumor, delivering a high dose of radiation while minimizing damage to surrounding healthy tissues. This targeted approach allows for more effective treatment with fewer side effects compared to external beam radiation therapy. Brachytherapy can be delivered through permanent implants or temporary sources, depending on the specific case and treatment goals.

The correct answer is magnetic resonance angiogram. This is because conventional angiography involves the insertion of a catheter into the blood vessels, which can be invasive and carries a risk of complications. On the other hand, magnetic resonance angiogram uses magnetic fields and radio waves to create detailed images of the blood vessels without the need for invasive procedures. Additionally, magnetic resonance angiogram is often more cost-effective compared to conventional angiography, as it eliminates the need for hospital stays and anesthesia.

The glomerulus and Bowman's capsule make up the renal corpuscle. The renal corpuscle is a vital part of the kidney responsible for the initial filtration of blood to form urine. The glomerulus is a network of tiny blood vessels where filtration occurs, and Bowman's capsule surrounds the glomerulus, collecting the filtered fluid. Together, they form the renal corpuscle, playing a crucial role in the filtration process in the kidney.

The urinary and genital systems develop from a structure called the intermediate mesoderm urogenital ridge. This ridge is formed during embryonic development and gives rise to both the urinary and genital systems.

During the developing stage, primordial germ cells undergo proliferation and migrate into the underlying mesenchyme. This process leads to the formation of primitive sex cords. This occurs specifically during the 7th week of development.

The myometrium and perimetrium are layers of the uterus. They develop from the surrounding splanchnic mesoderm. The splanchnic mesoderm is one of the two layers of the lateral plate mesoderm, which gives rise to the internal organs. In the development of the uterus, the splanchnic mesoderm differentiates into the myometrium, which is the muscular layer, and the perimetrium, which is the outer layer. Therefore, the correct answer is splanchnic.

The persistence of processus vaginalis refers to a condition where the embryonic structure in the groin area fails to close properly. This can lead to the development of an indirect inguinal hernia. In this type of hernia, the abdominal contents protrude through the inguinal canal, which is a passageway in the groin region. Therefore, the correct answer is indirect inguinal hernia.