1.
Most primitive renal structures in humans?
Correct Answer
A. PronepHros
Explanation
The most primitive renal structure in humans is the pronephros. This is the earliest form of the kidney that develops during embryonic development. It is a temporary structure that functions in the production of urine, but is not fully functional in terms of filtration. The pronephros is eventually replaced by the mesonephros and then the metanephros, which are more developed and functional kidney structures. Therefore, while the mesonephros and metanephros are also renal structures in humans, they are more advanced and not considered the most primitive.
2.
Arises from intermediate mesodermic tissue.
Correct Answer
A. PronepHros
Explanation
Pronephros arises from intermediate mesodermic tissue.
3.
Adjacent to somites 4 through 14.
Correct Answer
C. PronepHros
Explanation
The explanation for the correct answer, Pronephros, is that it is located adjacent to somites 4 through 14. This suggests that the Pronephros is the structure that is present in close proximity to these specific somites.
4.
Composed of as many as ten pairs of simple straight tubules.
Correct Answer
A. PronepHros
Explanation
The correct answer is Pronephros because it is the only option that is composed of as many as ten pairs of simple straight tubules. Mesonephros and Metanephros do not have this characteristic.
5.
Which developmental stage disappears after week 4 of life?
Correct Answer
B. PronepHros
Explanation
The pronephros is the first developmental stage of the kidney that appears during embryonic development. It forms in the early weeks of life but disappears after week 4. The pronephros is eventually replaced by the mesonephros, which is the next stage of kidney development. Therefore, the correct answer is Pronephros.
6.
Choose the correct order for developmental stages.
Correct Answer
C. PronepHros, MesonepHros, MetanepHros
Explanation
The correct order for developmental stages is Pronephros, Mesonephros, Metanephros. This is because in the development of the urinary system in vertebrates, the pronephros is the first stage to form, followed by the mesonephros, and finally the metanephros. The pronephros is a temporary kidney structure that forms early in development, followed by the mesonephros which functions as the main kidney during embryonic development. The metanephros is the final and permanent kidney structure that forms later in development.
7.
Final Stage of renal development.
Correct Answer
A. MetanepHros
Explanation
The correct answer is Metanephros. The three terms listed represent different stages of renal development. Pronephros is the initial stage, followed by Mesonephros, and finally, Metanephros is the final stage. Therefore, Metanephros is the correct answer as it represents the last stage of renal development.
8.
It is the principal excretory organ during early embryonic life.
Correct Answer
B. MesonepHros
Explanation
The mesonephros is the correct answer because it is the principal excretory organ during early embryonic life. The mesonephros is a temporary kidney structure that develops in the embryo and functions to filter waste products from the blood and excrete them as urine. It is eventually replaced by the metanephros, which becomes the permanent kidney in later stages of development. The pronephros, on the other hand, is the most primitive and non-functional form of kidney in vertebrate embryos.
9.
Originates as buds from mesonephric duct that joins the cloaca during the 8th week of life.
Correct Answer
A. MetanepHros
Explanation
During the 8th week of life, the metanephros originates as buds from the mesonephric duct, which then joins the cloaca. This process leads to the development of the metanephros, which is the permanent kidney in humans. The mesonephros and pronephros are also involved in kidney development, but the metanephros is the final and functional kidney in the adult stage.
10.
Contains structures similar to the nephron of the mature kidney.
Correct Answer
B. MesonepHros
Explanation
The mesonephros is the correct answer because it contains structures that are similar to the nephron of the mature kidney. The mesonephros is an embryonic structure that functions as the temporary kidney in early development. It consists of nephrons, which are the functional units of the kidney responsible for filtering blood and producing urine. These nephrons in the mesonephros have similar structures to those found in the mature kidney, making it the correct choice.
11.
Metonephric cap continues to grow.
Correct Answer
A. MetanepHros
Explanation
The correct answer is Metanephros. The metanephros is the final stage of kidney development in vertebrates. It is derived from the metonephric cap, which continues to grow and differentiate into the functional adult kidney. The metanephros is responsible for urine production and waste filtration in the body.
12.
Composed of metemorphic tubules.
Correct Answer
C. MetanepHros
Explanation
The correct answer is Metanephros. The explanation for this answer is that the metanephros is composed of metemorphic tubules. This means that the metanephros is made up of tubular structures that have undergone metamorphosis or transformation. The pronephros and mesonephros are not composed of metemorphic tubules, so they are not the correct answer.
13.
Develops a cup-like outgrowth into which a knot of capillaries is pushed. AKA: Bowman's capsule.
Correct Answer
B. MesonepHros
Explanation
The correct answer is Mesonephros. Mesonephros is a temporary kidney structure in vertebrate embryos that develops a cup-like outgrowth called Bowman's capsule, into which a knot of capillaries is pushed. This structure plays a crucial role in the filtration of blood and the formation of urine in the developing embryo.
14.
Degenerates around the 8th week of life.
Correct Answer
B. MesonepHros
Explanation
The mesonephros is a temporary kidney structure that develops in the embryo around the 8th week of life. It is the second stage of kidney development, following the pronephros. The mesonephros functions as an interim kidney before the permanent kidney, the metanephros, develops. Therefore, the given answer is correct as it accurately identifies the stage at which the mesonephros degenerates during embryonic development.
15.
Remnants contribute to development of male genital system.
Correct Answer
B. MesonepHros
Explanation
The mesonephros is the middle stage of kidney development in vertebrates, including humans. It plays a crucial role in the development of the male genital system, as it gives rise to the Wolffian ducts, which are responsible for the formation of the epididymis, vas deferens, and seminal vesicles. The mesonephros also produces hormones that are important for the development of the male reproductive organs. Therefore, the mesonephros is directly involved in the development of the male genital system.
16.
The ureteral bud expands to form renal pelvis.
Correct Answer
B. MetanepHros
Explanation
The correct answer is metanephros. The metanephros is the final form of the kidney in vertebrates, including humans. It develops from the ureteral bud, which is an outgrowth of the mesonephric duct. The ureteral bud expands and gives rise to the renal pelvis, which is the central collecting region of the kidney. This process occurs during embryonic development and is essential for the formation of functional kidneys. The pronephros and mesonephros are earlier stages of kidney development, but it is the metanephros that ultimately forms the renal pelvis.
17.
Numerous outgrowth from renal pelvis from the primary collecting ducts occurs in what stage?
Correct Answer
C. MetanepHros
Explanation
The correct answer is Metanephros. The metanephros stage is characterized by the development of numerous outgrowths from the renal pelvis, which are derived from the primary collecting ducts. This stage represents the final stage of kidney development in mammals, where the functional nephrons are formed.
18.
What stage are ureters developed in?
Correct Answer
A. MetanepHros
Explanation
The correct answer is Metanephros. The metanephros is the final stage of kidney development in mammals, including humans. It is during this stage that the ureters, which are the tubes that connect the kidneys to the bladder, are fully developed. The metanephros is responsible for the production of urine and the regulation of electrolyte balance in the body.
19.
The ureteral bud originates from where?
Correct Answer
D. Wolffian Duct
Explanation
The ureteral bud originates from the Wolffian Duct. The Wolffian Duct is a structure that develops in the embryo and gives rise to the male reproductive system. It also plays a role in the development of the urinary system, including the formation of the ureteral bud. The ureteral bud eventually grows and differentiates into the ureter, which connects the kidneys to the bladder.
20.
What tissue forms the loop of Henle?
Correct Answer
B. MethanepHric
Explanation
The correct answer is Methanephric. The loop of Henle is a structure found in the kidney and is part of the nephron, which is the functional unit of the kidney. It plays a crucial role in the reabsorption of water and electrolytes. The loop of Henle is formed by the methanephric tissue, which is derived from the metanephros, the permanent kidney that develops during embryonic development. The mesonephric tissue forms the mesonephros, which is a temporary kidney in early embryonic stages. The pronephros is the most primitive kidney that develops in the embryo but does not contribute to the formation of the loop of Henle.
21.
The ureter ascends and rotates to a _____degree angle from the kidney.
Correct Answer
B. 90
Explanation
The ureter ascends and rotates to a 90-degree angle from the kidney. This means that the ureter, which is the tube that carries urine from the kidney to the bladder, moves upwards and turns at a 90-degree angle as it leaves the kidney. This angle allows for proper urine flow and prevents backflow of urine into the kidney.
22.
The renal pelvis pushes into the developing ___________ to form collecting ducts.
Correct Answer
A. Parenchyma
Explanation
During development, the renal pelvis, which is part of the kidney, extends into the parenchyma. The parenchyma is the functional tissue of an organ, in this case, the kidney. This extension forms the collecting ducts, which are responsible for transporting urine from the nephrons to the renal pelvis.
23.
The urinary bladder develops from what tissue?
Correct Answer
C. Endodermal
Explanation
The urinary bladder develops from endodermal tissue. During embryonic development, the endoderm layer gives rise to various organs and tissues, including the urinary bladder. This tissue layer forms the innermost layer of the embryo and is responsible for the development of the digestive and respiratory systems, as well as the urinary system. Therefore, the correct answer is endodermal.
24.
The ventral portion of the urogenital sinus forms the _______________.
Correct Answer
A. Bladder
Explanation
The ventral portion of the urogenital sinus forms the bladder. The urogenital sinus is a structure that develops during embryonic development and eventually gives rise to the urinary and reproductive systems. The ventral portion specifically contributes to the formation of the bladder, which is an organ responsible for storing urine before it is eliminated from the body. The bladder is located in the pelvic region and has the capacity to expand and contract as urine is produced by the kidneys and transported through the ureters.
25.
The ventral portion of the urogenital sinus forms ___________.
Correct Answer
B. Proximal urethra of males
Explanation
The ventral portion of the urogenital sinus forms the proximal urethra of males. This is because during embryonic development, the urogenital sinus gives rise to various structures of the urinary and reproductive systems. In males, the urogenital sinus differentiates into the urethra, which is the tube that carries urine from the bladder to the external opening. The proximal urethra refers to the portion of the urethra closest to the bladder. Therefore, the correct answer is the proximal urethra of males.
26.
The ventral portion of the urogenital sinus forms ___________.
Correct Answer
A. Bladder and entire urethra of females
Explanation
The ventral portion of the urogenital sinus forms the bladder and entire urethra of females. This means that in females, the ventral portion of the urogenital sinus is responsible for the development of both the bladder and the entire urethra.
27.
Endodermal tissue from the dorsal portion of the urogenital sinus forms what?
Correct Answer
A. Distal urethra
Explanation
The endodermal tissue from the dorsal portion of the urogenital sinus forms the distal urethra. The urogenital sinus is a structure that develops during embryonic development and gives rise to the urinary and reproductive systems. The urethra is a tube that carries urine from the bladder to the external environment. The distal urethra refers to the portion of the urethra that is closer to the external opening, while the proximal urethra is closer to the bladder. Therefore, the correct answer is the distal urethra, as it is formed from the endodermal tissue of the dorsal portion of the urogenital sinus.
28.
The ____________ is formed by mesodermal tissue that lays between common excretory duct and the ureteral bud.
Correct Answer
B. Trigone
Explanation
The trigone is formed by mesodermal tissue that lays between the common excretory duct and the ureteral bud. The trigone is a triangular region in the urinary bladder that is important for maintaining proper urine flow and preventing reflux of urine back into the ureters. It is composed of smooth muscle fibers and is lined with transitional epithelium, which allows for stretching and contraction of the bladder. The trigone also serves as a landmark for identifying the internal urethral orifice and the ureteral orifices.
29.
During embryogenesis, the fetus develops genital structures that are influenced by the presence or absence of _____________.
Correct Answer
D. Hormones
Explanation
During embryogenesis, the fetus develops genital structures that are influenced by the presence or absence of hormones. Hormones play a crucial role in the development of reproductive organs in both males and females. They regulate the differentiation of the genital tissues, the formation of external genitalia, and the development of secondary sexual characteristics. In the absence or imbalance of hormones, the fetus may develop ambiguous or incomplete genital structures. Therefore, the correct answer is hormones.
30.
When does the Mullerian ductile system start to turn into ovaries?
Correct Answer
B. Week 7
Explanation
During embryonic development, the Mullerian ductile system is responsible for the formation of female reproductive structures. At around week 7, the Mullerian ducts start to differentiate into ovaries in females. This process involves the development of primordial germ cells and the formation of ovarian follicles. Therefore, week 7 marks the beginning of the transformation of the Mullerian ductile system into ovaries.
31.
What do the ovaries attach to?
Correct Answer
A. Gubernaculum
Explanation
The correct answer is "gubernaculum." The gubernaculum is a ligament-like structure that helps to guide the descent of the ovaries during fetal development. It attaches the ovaries to the developing uterus and aids in their proper positioning within the pelvic cavity. The mullerian and mesonephric are other structures related to the development of the reproductive system, but they do not directly attach to the ovaries.
32.
The Gubernaculum is located where?
Correct Answer
A. Between the uterus and ovary
Explanation
The Gubernaculum is a structure located between the uterus and ovary. It plays a role in the descent of the ovaries during fetal development. It helps guide the ovaries from their original position near the kidneys to their final position in the pelvis. This structure eventually degenerates in females, but in males, it develops into the ligament that helps guide the testes into the scrotum.
33.
The gubernaculum becomes what
Correct Answer
C. Ovarian ligament
Explanation
The gubernaculum is a structure in the fetal development of both males and females. In males, it guides the descent of the testes into the scrotum. In females, it becomes the ovarian ligament, which attaches the ovary to the uterus. This ligament plays an important role in stabilizing the position of the ovary within the pelvic cavity.
34.
The location between the uterus and labia majora becomes what?
Correct Answer
B. Round ligament
Explanation
The round ligament is a ligament that connects the uterus to the labia majora. During pregnancy, this ligament helps to support the uterus and keeps it in its proper position. It also plays a role in the movement and positioning of the uterus during various activities. Therefore, the location between the uterus and labia majora becomes the round ligament.
35.
'what do the uterine/fallopian tubes develop from?
Correct Answer
A. Mullerian duct
Explanation
The correct answer is mullerian duct. The uterine/fallopian tubes develop from the mullerian duct. The mullerian duct is a structure that forms during embryonic development and gives rise to the female reproductive system, including the fallopian tubes, uterus, and upper part of the vagina. The sinus duct, round ligament, and gubernaculum are not involved in the development of the uterine/fallopian tubes.
36.
The two mullerian ducts join together but have?
Correct Answer
A. A partial fusion with a septum
Explanation
The two mullerian ducts join together but have a partial fusion with a septum. This means that while the ducts come together, they do not fully merge and instead have a septum, or dividing wall, between them. This partial fusion with a septum allows for the formation of separate structures within the ducts, such as the uterus and fallopian tubes, which are essential for reproductive function in females.
37.
The mullerian ducts form the uterovaginal canal and the septum disappears?
Correct Answer
A. True
Explanation
The statement is true because during embryonic development, the mullerian ducts in females give rise to the uterovaginal canal, which includes the uterus and vagina. As the development progresses, the septum that initially separates the mullerian ducts disappears, allowing for the formation of a single uterovaginal canal.
38.
The mullerian ducts fuse when?
Correct Answer
A. 13th week
Explanation
The mullerian ducts fuse during the 13th week of embryonic development. The mullerian ducts are initially two separate structures that form in the early stages of fetal development. They eventually merge and develop into the female reproductive organs, including the uterus, fallopian tubes, and upper part of the vagina. This fusion process occurs during the 13th week, marking an important milestone in the development of the female reproductive system.
39.
The sinovaginal node receives a limited contribution from what?
Correct Answer
A. Urogenital sinus
Explanation
The sinovaginal node receives a limited contribution from the urogenital sinus. The urogenital sinus is a structure that forms during embryonic development and gives rise to the lower part of the urinary system and the reproductive system in females. The sinovaginal node is a lymph node located near the vaginal opening, and it plays a role in the immune response in the female reproductive system. While the urogenital sinus contributes to the development of the reproductive system, it only provides a limited contribution to the sinovaginal node.
40.
The Hymen is the what?
Correct Answer
B. The remains of the mullerian tubercle
Explanation
The hymen is the remains of the mullerian tubercle. The mullerian tubercle is a structure that forms during fetal development and gives rise to the female reproductive organs. In females, the hymen is a thin membrane located at the opening of the vagina. It is a remnant of the mullerian tubercle and can vary in shape and size among individuals. The hymen is often associated with virginity and can be stretched or torn during sexual intercourse or other activities, but its presence or absence does not determine a person's sexual history.
41.
The Labia minora is formed from?
Correct Answer
A. Urethral folds
Explanation
The Labia minora is formed from the urethral folds. During fetal development, the urethral folds in the genital region fuse together and give rise to the Labia minora in females. These folds develop alongside the urogenital sinus and eventually differentiate into various structures of the female reproductive system, including the Labia minora.
42.
The gonad forms into either the testis or ovary at what week?
Correct Answer
A. 7
Explanation
During fetal development, the gonad, which is the precursor to the reproductive organ, starts to differentiate into either a testis or an ovary at around the 7th week. This is a critical stage in sexual development where the genetic sex of the individual is determined. Therefore, the correct answer is 7.
43.
The gland (gonad) does what if it became a testis?
Correct Answer
D. A and C
Explanation
If the gland (gonad) became a testis, it would increase in size and become more caudal located. Additionally, it would shorten into a compact organ.
44.
The network of strands forms that is continuous with the testis cords.
Correct Answer
A. True
Explanation
The network of strands that is continuous with the testis cords refers to the structure of the male reproductive system. The testis cords are structures within the testes that contain the developing sperm cells. These cords are connected to a network of strands, which are responsible for transporting the sperm cells to the epididymis and eventually to the vas deferens. Therefore, it is true that the network of strands is continuous with the testis cords.
45.
The functioning unit of the testis is the seminiferous tubules
Correct Answer
A. True
Explanation
The seminiferous tubules are the functional units of the testis. They are responsible for the production of sperm through a process called spermatogenesis. These tubules are lined with specialized cells called Sertoli cells, which support and nourish the developing sperm cells. The seminiferous tubules also contain Leydig cells, which produce testosterone, a hormone necessary for the development and maintenance of male reproductive organs and secondary sexual characteristics. Therefore, it is true that the functioning unit of the testis is the seminiferous tubules.
46.
Spermatozoa is produced in the seminiferous tubules.
Correct Answer
A. True
Explanation
Spermatozoa, also known as sperm cells, are indeed produced in the seminiferous tubules. These tubules are located within the testes and are responsible for the production of sperm through a process known as spermatogenesis. Spermatogenesis involves the division and maturation of germ cells within the seminiferous tubules, resulting in the formation of spermatozoa. Therefore, the statement that spermatozoa is produced in the seminiferous tubules is correct.
47.
The testis remain where until the seventh month?
Correct Answer
A. Abdominal end of the inguinal canal
Explanation
During fetal development, the testes initially form in the abdominal cavity near the kidneys. As the fetus grows, the testes gradually descend through a structure called the inguinal canal into the scrotal sac. This descent typically occurs by the seventh month of pregnancy. Therefore, the correct answer is the "abdominal end of the inguinal canal" as the testes remain there until the seventh month before descending into the scrotal sac.
48.
Passes through the inguinal canal at the 8th month.
Correct Answer
A. Testis
Explanation
During fetal development, the testis descends from the abdomen into the scrotum through a passage called the inguinal canal. This process typically occurs around the 8th month of pregnancy. Therefore, the correct answer is testis.
49.
The Genital tubercle forms what?
Correct Answer
A. pHallus
Explanation
The genital tubercle is a structure that forms during embryonic development and gives rise to the phallus, which is the male external genitalia. It is responsible for the development of the penis in males. The other options, corpora cavernosa and urogenital sinus orifice, are not directly formed by the genital tubercle.
50.
Paired mesenchymal columns within the shaft of the penis.
Correct Answer
A. Corpora cavernosa
Explanation
The paired mesenchymal columns within the shaft of the penis are known as the corpora cavernosa. These columns are responsible for the erectile function of the penis. When stimulated, they fill with blood and cause the penis to become erect. The corpora cavernosa are surrounded by a fibrous sheath and are located on the dorsal side of the penis.