Development Of Renal System

Question 1

Where does the renal and genital system develop from

Answer 1

Intermediate mesoderm (between paraxial and lateral plate)

Question 2

What is the intermediate mesoderm

Answer 2

Ridge of tissue on the posterior abdominal wall

Question 3

What is the cloaca

Answer 3

Common cavity for urogenital and digestive systems

Question 4

What is the allantois

Answer 4

An extension of the cloaca into the umbilicus

Question 5

What 2 things does the urorectal septum divide the cloaca into

Answer 5

Urogenital sinus

Anal canal

Question 6

What are the 3 parts of the urogenital sinus and what do they develop into

Answer 6

Upper - bladder
Middle - prostate and membranous urethra in males
Lower - phallic part (differs between male and female)

Question 7

What happens when the allantois obliterates

Answer 7

Remnant is the urachus which connects the bladder to the umbilicus

Question 8

What are the 3 overlapping kidney systems formed in a cranial to caudal sequence

Answer 8

Pronephros
Mesonephros
Metanephros

Question 9

What is the pronephros

Answer 9

Originates in the cervical and develops in week 4
Disappears by week 5
It is non functional

Question 10

What is the origin of the mesonephros

Answer 10

Thoracic and lumbar intermediate mesoderm

Question 11

What does the mesonephros consist of

Answer 11

Consists of a ridge of tissue and the mesonephric duct

Question 12

What happens to tubules and mesonephric duct in females

Answer 12

They degenerate

Question 13

What do the excretory tubules and capillaries give rise to

Answer 13

Tubules - bowman’s capsule

Capillaries - glomerulus

Question 14

What happens to the tubules and mesonephric duct in males

Answer 14

A few remain and form part of the genital system
Mesonephric duct - vas deferens
Tubules - efferent ducts of testis

Question 15

Where does the metanephros develop

Answer 15

Definite kidney develops in the Pelvic region

Question 16

What’s the relationship between the development of the collecting and excretory system

Answer 16

Develop differently but are Dependent on each other for development

Question 17

When does the kidney start to function

Answer 17

Week 12 of gestation

Question 18

Where does the collecting system develop from

Answer 18

Outgrowth from the mesonephric duct called the ureteric bud

Question 19

What covers the ureteric bud

Answer 19

Cap of metanephric tissue

Question 20

What gives rise to the renal pelvis and major calyces

Answer 20

Renal pelvis - ureteric bud grows into the cap of metanephric tissue
Major calyces - when above splits into 2 (ie further branching)

Question 21

In the excretory system, how are glomeruli formed

Answer 21

Metanephric tissue forms renal vesicles

Vesicles become tubular and capillaries develop at one end - glomerulus

Question 22

What drives development of the excretory system

Answer 22

Interaction between the epithelium of the uterus bud and metanephric tissue
Factors produced by metanephric tissue induce ureteric bud to branch
Factors produced by the bud promote continued growth of the metanephric tissue

Question 23

What happens during the ascent of kidneys in utero

Answer 23

Ascend from pelvis to abdomen and body grows

New vessels derived from more proximal parts of the aorta and lower vessels regress

Question 24

Where is urine excrete in the fetus

Answer 24

Into the amniotic fluid which is swallowed by the fetus

Question 25

Where are fetal waste products excreted

Answer 25

Via the placenta

Question 26

What is renal agenesis and what causes it

Answer 26

Where the nephrons and collecting ducts don’t develop

Can result if signalling between uterus bud epithelium and mestanephric tissues fails

Question 27

As the bladder forms from the urogenital sinus, what happens to the mesonephric ducts

Answer 27

Distal parts are pulled towards the bladder

Question 28

What gives rise to the ejaculatory ducts

Answer 28

Distal parts of the mesonephric ducts