Development of the Urogenital system and Kidney Flashcards Preview

Structure and Function Test 1 > Development of the Urogenital system and Kidney > Flashcards

Flashcards in Development of the Urogenital system and Kidney Deck (102):
1

Most of the urogenital system develops from the

-located between paraxial and lateral plate mesoderm

Intermediate mesoderm

2

The urinary system develops mostly between weeks

4 and 7

3

By the end of week 6, the genital system is virtually the same in

Both sexes (called indifferent stage)

4

The intermediate mesoderm forms an elevation in the posterior wall of the embryo known as the

Urogenital ridge

5

Most of this ridge (the more lateral portion) is the

-will develop into kidney-like structures

Nephrogenic ridge

6

At the caudal end of the nephrogenic ridge (in the
lumbosacral region), there is additional intermediate mesoderm known as the

-forms into partof the adult kidney

Metanephrogenic blastema

7

A more medial (and shorter) portion of the urogenital ridge is known as the

-will develop into gonad

Gonadal ridge

8

Rudimentary filtration structures (renal tubules) in the cervical region that degenerate soon after forming and do not serve an excretory function

Pronephros

9

Differentiation of the nephrogenic ridge occurs in a

Cranial-caudal direction

10

As more caudal regions differentiate, more cranial regions degenerate. The resulting structure is the

Mesonephros

11

Has somewhat more fully developed renal tubules (nephrons) and these do serve an excretory function

Mesonephros

12

The mesonephros serves as the kidney for the embryo until the definitive kidney is formed at about

10 weeks

13

Caudal end of the hindgut

Cloaca

14

Forms in the lateral portion of the nephrogenic ridge, runs the length of the ridge, and enters the anterior portion of the cloaca

Mesonephric (Wolffian) duct

15

The urine formed by the mesonephros passes through mesonephric tubules to enter the

Mesonephric duct

16

This urine passes down the mesonephric duct, enters the cloaca, and, after rupture of the cloacal membrane (week 7), exits the embryo and enters the

Amniotic cavity

17

Envagination from the mesonephric duct that grows towards the metanephrogenic blastema and invades it

Ureteric bud

18

The metanephrogenic blastema induces the ureteric bud to begin

Branching

19

The ureteric bud induces the metanephrogenic blastema to

Differentiate into nephrons

20

The initial branches of the ureter bud form the

Renal pelvis and major calyces

21

Later branches of the bud form the

Minor calyces and collecting tubules of the kidneys

22

The unbranched portion of the ureteric bud becomes the

Ureter

23

The adult kidney forms from two embryonic structures. What forms the
1.) Filtration elements
2.) Conducting elements

1.) Metanephrogenic blastema
2.) Ureter bud

24

Filtration elements, which are mostly in the cortex of the kidneys

Nephrons

25

The collecting tubules, calyces, and renal pelvis are the conducting elements of the kidneys and are mostly located in the

Medulla of the kidney

26

The result of failure of the ureteric bud to reach the metanephrogenic blastema

Renal agenesis

27

The kidneys initially develop in the pelvis but then ascends to reach their adult position at the

Upper lumbar levels

28

The initial blood supply to the kidney arises from the

Median sacral artery

29

As the kidneys ascend, the lose their arteries and gain a pair of

Renal arteries (from L2 level of aorta)

30

Sometimes, the kidneys do not lose their initial arteries. These arteries are of high important to a surgeon because they are

End arteries (can not be ligated)

31

During ascention, the kidneys rotate so that the hilus rotates from anterior to

Medial

32

The result of failure of the kidney to ascend

Pelvic kidney

33

If the kidneys fuse during ascention, there will be a single kidney on one side of the abdomen. The most common fusion defect is the

Horseshoe kidney

34

When the lower poles of the kidney fuse and interfere with the ascent of the kidney

-Frequency of 1:500

Horseshoe kidney

35

The fusion seen in horseshoe kidney prevents the kidneys from ascending any highers than the

-hooked over fused portion of kidney

Inferior mesenteric artery (L3)

36

Has a reported frequency of 1:4000 to 1:10,000 and results in oligohydraminos

-incompatible with life

Bilateral renal agenesis

37

Babies with bilateral renal agenesis are born with multiple abnormalities, which is called the

Potter sequence

38

Has a frequency of 1:450 to 1:1000 and usually results in normal excretory function

Unilateral renal genesis

39

If there is interference in the process of fetal swallowing of amniotic fluid and/or its transport to the small intestine for absorption, the resulting excess of amniotic fluid is called

Polyhydraminos

40

GI tract abnormalities and neurological defects that interfere w/ swallowing are associated with

Polyhydraminos

41

The cloaca becomes divided during weeks 4-7 into an anterior portion and a posterior portion, by the

Urorectal septum

42

What do the following become?
1.) Posterior portion of cloaca
2.) Anterior portion of cloaca

1.) Rectoanal canal
2.) Urogenital sinus

43

Formed where the urorectal septum joins the cloacal membrane

Perineal body

44

Forms an extends into the connecting stalk during the 3rd week

-envagination of future cloaca with no function in humans
-included in the umbilical cord

Allantois

45

When the cloaca is divided by the urorectal septum, the allantois remains as an evagination of the

Urogenital sinus

46

Forms from the upper portion of the urogenital sinus and initially remains continuous with the allantois

Urinary bladder

47

The allantois fuses to become a fibrous cord called the urachus, which in the adult is called the

Median umbilical ligament

48

Passes from the dome of the bladder to the umbilicus

Median umbilical ligament

49

If the allantois does not fuse, urine escaped from the bladder and appears at the umbilicus of the infant by way of a

Urachal fistula

50

Can result in a urachal sinus opening into the bladder or at the umbilicus, or a urachal cyst somewhere along the length of the median umbilical ligament

Incomplete fusion of allantois

51

Derived from the urogenital sinus

-incorporates caudal portions of mesonephric ducts and ureter buds as it enlarges

Urinary bladder

52

The portion of the bladder wall which is formed by the incorporated mesonephric ducts becomes the

Trigone of the bladder

53

Initially, the epithelium of the trigone is derived from mesoderm. But eventually, ALL of the epithelium of the baldder is derived from

Endoderm

54

What does the caudal portion of the urogenital sinus become in
1.) Males
2.) Females

1.) Most of urethra
2.) All of urethra and lower portion of vagina

55

What portions of the urethra in males come from the caudal portion of the urogenital sinus?

Prostatic, membranous, and most of the spongy

56

The most distal portion of the urethra in the male, the portion within the glans penis, is derived from the

Glandular plate

57

An ectodermal in growth from the tip of the glans penis

Glandular plate

58

In the male, most of the epithelium of the urethra is derived from endoderm, but the distal portion, the navicular fossa, is derived from

Ectoderm

59

There is a region on the Y chromosome known as the

Sex-Determining Region of the Y chromosome (SRY)

60

The SRY codes for the

-Will cause gonadal ridge to develop into a testis

Testis Determining Factor

61

In the absence of TDF, the gonadal ridge will develop into an

Ovary

62

When the testis develops, testosterone starts being produced by the 8th week from

Leydig cells

63

Produce Müllerian Inhibiting Factor (MIF) which prevents the paramesonephric (Müllerian) ducts from developing into the female genital tract

Sertoli Cells

64

Thus, the development of a normal male genital system is dependent on

TDF, testosterone, and MIF (which are dependent on SRY)

65

What happens in the absence of TDF, testosterone, and MIF

A female develops

66

Can result in overproduction of testosterone in a female resulting in male phenotypic characteristics despite having ovaries and a female genital system

Congenital adrenal hyperplasia

67

Arise from the wall of the yolk sac in the fourth week
and then migrate along the dorsal mesentery of the hindgut to enter the gonadal ridge in the sixth week

Primordial germ cells

68

Give rise to the cells that enter the meiotic cycle to form gametes

Primordial germ cells

69

This process of gametogenesis begins prior to birth in females and after puberty in

Males

70

The undifferentiated gonad includes a cortex comprised of mesodermally derived epithelial cells and a medulla comprised of

Mesenchyme

71

The cortical epithelium forms finger-like epithelial
cords, called

-grow into the medulla

Primitive sex cords

72

If the gonad becomes a testis under the influence of TDF, the sex cords elaborate in the medulla and become the

-cortex largely regresses

Seminiferous tubules and rete testes

73

In the absence of TDF, the gonad becomes an ovary and the epithelial cells of the cortex develop into

Follicles

74

Which part of the gonad regresses in the development of
1.) Males
2.) Females

1.) Cortex
2.) Medulla

75

The testis develops from the gonadal ridge which is on the medial side of the

Mesonephros

76

In males, some mesonephric tubules are retained and serve as a pathway to carry sperm from the testis to the mesonephric duct. These are called the

Efferent ductules

77

The mesonephric duct, which had been carrying urine when the mesonephros was an excretory organ, now will be used to carry sperm and becomes the

Epididymyus and ductus deferens

78

The caudal portions of the mesonephric ducts form a pair of evaginations called the

Seminal vesicles

79

The portion of the mesonephric duct immediately distal to this evagination becomes the

Ejaculatory duct

80

Develop from endodermal envaginations in the prostatic urethra

Parenchymal cells of the prostate

81

More caudally, the portion of the urogenital sinus
that becomes the spongy urethra forms a pair of endodermal evaginations which become the

Bulbourethral glands

82

The male and female genital systems are derived mostly from

Mesoderm (some ectoderm (males) and endoderm (both))

83

Gives rise to the testis, efferent ductules, epididymis, ductus deferens, seminal vesicles and ejaculatory ducts

Mesoderm

84

Gives rise to most of the urethra, the prostate and the
bulbourethral glands

Endoderm

85

Gives rise to the terminal portion of the urethra in males

Ectoderm

86

A second duct formed in females in the lateral portion of the urogenital ridge

-retained in females
-degenerates in males

Paramesonephric (Müllerian) duct

87

The Paramesonephric (Müllerian) duct is retained in females and becomes much of the

Female genital tract

88

Lateral to the mesonephric duct at its craial end

Paramesonephric duct

89

The right and left paramesonephric ducts meet and fuse in the midline. The fused paramesonephric ducts from the

Uterus

90

Defects in the fusion of the paramesonephric ducts may result in duplication of the uterus or formation of a

Bicornuate uterus

91

The medialward movement of the paramesonephric ducts raises folds of the peritoneum to form the

Broad ligament

92

The cranial portions of the paramesonephric ducts which remain unfused become the

Uterine tubes

93

The fused paramesonephric ducts come into contact with the urogenital sinus, causing the endodermal wall of the sinus to thicken and form a pair of

Sinus tubercles

94

These sinus tubules fuse and lengthen, growing in the cranial direction. This lengthened structure is the

Vaginal plate

95

By the 5th month, the vaginal plate canalizes to become the

Lower 2/3 of the vagina

96

Failure of the sinus tubules to fuse may result in a

Double vagina

97

Failure of the vaginal plate to canalize completely results in

Atresia of the vagina

98

The upper portion of the vagina (the region of the cervix and fornix) is derived from the

Caudal end of fused paramesonephric ducts

99

After this canalization, a caudal remnant of the vaginal plate remains as the

-partially separates vaginal canal from vestibule

Hymen

100

Evaginations of the portion of the urogenital sinus that forms
the vestibule form the

Greater vestibular glands

101

Gives rise to the ovary, the uterine tubes, uterus, cervix and the upper part of the vagina

Mesoderm

102

Gives rise to the lower part of the vagina and the vestibule

Endoderm

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