Structure of kidney and ureter

Question 1

Muscular cavity where digestive waste and urine leave the embryo

Answer 1

Cloaca

Question 2

The kidneys present in embryo development

Answer 2

Pronephros, mesonephros and metanephros

Question 3

Pronephros

Answer 3

First set of kidneys which regress after 4 weeks and are non functional. They are located in the region of the cervical vertebrae.

Question 4

What is the composition of the pronephros?

Answer 4

Nephric tubules and nephrotomes

Question 5

Mesonephros

Answer 5

Temporary and first functional kidneys that form urine. Become part of the urogenital system. They drain into the mesonephric duct/Wolffian duct which eventually regresses. Located in the thoracic/lumbar region.

Question 6

What does the mesonephros composed of?

Answer 6

Forms urogenital ridge.

Question 7

Where is the mesonephric system derived from?

Answer 7

Segmented intermediate mesoderm

Question 8

Metanephros

Answer 8

Located in lower sacral/lumbar region. Contains uretic bud and later, the metanephric blastema.

Question 9

Where does the bladder develop?

Answer 9

From urogenital region with opening to the allantosis.

Question 10

Mesonephric duct

Answer 10

Contains the uretic bud to forms the minor calcyx, major calcyx, collecting duct, collecting tubules and ureter

Question 11

Effect of uretic bud?

Answer 11

Induces differentiation of the mesoderm for formation of the metanephric blastema caps

Question 12

Renal vesicle

Answer 12

First epithelial derivative of the metanephric blastema. It will from the PCT and DCT first, and develop into the glomerulus, bowman’s capsule and DCT.

Question 13

Metanephric blastema

Answer 13

Cap forms due to signals from the uretic bud. It gives rise to the nephron from the glomerulus to the DCT via formation of renal vesicle

Question 14

Renal blood supply during development

Answer 14

Branches from the abdominal aorta and as kidney ascends, it comes directly off abdominal aorta.
Renal artery-> interlobar -> arcuate -> interlobular artery -> afferent arteriole

Question 15

What are abnormalities that can occur to the kidneys during development?

Answer 15

Kidney develops in pelvis because it does not migrate up
Fusion of the kidneys
Aberrant renal arteries (multiple)

Question 16

Where does the ureter drain into the bladder?

Answer 16

Superior and posterior

Question 17

Region where urethra crosses the pelvic floor?

Answer 17

Membranous

Question 18

What is the majority of the spongy urethra lined with?

Answer 18

Pseudostratified columnar epithelia.

Question 19

Which part of the urethra is lined with stratified squamous epithelia?

Answer 19

End of urethra in glans penis

Question 20

Location of kidney anatomically

Answer 20

Retroperitoneal organ from T12 to L3. Right side is lower than the left. Hilum opens anteromedially to abdominal aorta. It is divided into the cortex and the medulla. The functional unit of the kidney is the nephron

Question 21

What are the anatomical coverings of the kidney?

Answer 21

Enveloped in a tough fibrous connective tissue capsule called the renal capsule which contains perirenal fat. The renal capsule is separated from surrounding pararenal fat by the renal fascia.
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Renal capsule
Renal fascia
Pararenal fat

Question 22

Which vessel does reabsorption take place in the kidney?

Answer 22

Peritubular capillaries, a branch of the efferent arteriole which surround the PCT and DCT. They drain into the interlobular veins. They are therefore located in the cortical regions of the nephron.

Question 23

What is pararenal fat?

Answer 23

White adipose tissue located anteriorly to renal fascia

Question 24

Which vessels are a branch of the afferent arteriole?

Answer 24

Vasa recta capillaries that surround the Loop of Henle for reabsorption in the countercurrent mechanisms. They drain into the renal veins.

Question 25

Which vessels are a branch of the efferent arterioelle?

Answer 25

Peritubular capillaries, surrounding the PCT and DCT in the cortical region for reabsorption of solutes and secretion into the nephron. They drain into the veins.

Question 26

Renal fascia

Answer 26

Connective tissue sheath which encloses the kidneys and its structures, extending into the pelvis urethra. It has a midline attachment which prevents inward movement of vessels in renal hilum.

Question 27

What is perinephric fat?

Answer 27

Brown adipose tissue surrounding kidneys and adrenal glands, separated from pararenal fat via the renal fascia.

Question 28

What are the important posterior anatomical relations?

Answer 28

Diaphragm is superior to kidney Medial: psoas major and minor Posterior: quadratus lumborum

Question 29

Anterior relations of kidney-right side

Answer 29

Right lobe, hepatic flexure of colon, descending D2 duodenum and hepatorenal pouch

Question 30

What is the hepatorenal pouch?

Answer 30

AKA pouch of Morrison which is the potential space between the kidney and liver which fills with fluid

Question 31

How many lobes are in the kidney?

Answer 31

7-9 lobes

Question 32

What is the blood supply to apical kidney?

Answer 32

Apical segmental -> interlobar -> arcuate -> interlobular

Question 33

Blood supply to superior lobe of kidney

Answer 33

Anterior Superior segmental -> interlobar -> arcuate -> interlobular

Question 34

What are the branches of the renal artery?

Answer 34

Renal artery comes off the abdominal aorta and gives off the 5 segmental arteries. Apical segmental artery Anterior superior segmental artery Anterior inferior segmental artery Posterior segmental artery Inferior segmental artery.

Question 35

Blood supply to middle lobe of kidney

Answer 35

Anterior inferior segmental -> interlobar -> arcuate -> interlobular

Question 36

Blood supply to inferior lobe of kidney

Answer 36

Inferior segmental -> interlobar -> arcuate -> interlobular

Question 37

Kidney venous drainage

Answer 37

Interlobular vein drains the renal lobe -> arcuate vein -> interlobar vein -> segmental vein -> renal vein

Question 38

Mesangial cells

Answer 38

Contractile smooth muscles close to the glomerulus which are connected via gap junctions in the kidney. There are two types of mesangial cells: Intraglomerular Extraglomerular

Question 39

What is the intraglomerular mesangial cells?

Answer 39

They are located between the capillaries in the glomerulus and control GFR via vasodilation/constriction.

Question 40

Which renal vein is longer?

Answer 40

Left renal vein which has two important branches: Left suprarenal vein. Left gonadal vein

Question 41

What is the extraglomerular mesagnial cells?

Answer 41

Forms part of the juxtaglomerular apparatus. It is located between the macula densa and the afferent arteriole. They respond to signals from the macula dens via contraction to release ATP. This will inhibit renin release.

Question 42

Function of mesangial cells

Answer 42

They are component of the glomerulus which attach to capillaries via cell process to control size of capillary lumen for GFR regulation. They are responsible for pathogen surveillance in the glomerulus and response to glomerular injury by secreting platelet factor

Question 43

What is the role of the intraglomerular mesangial cells?

Answer 43

They control GFR via vasodilation/constriction that affects the arterioles.

Question 44

What are the components of the juxtaglomerular apparatus?

Answer 44

Macula densa Extraglomerular mesangial cells Juxtaglomerular epitheliod cells

Question 45

Which structure produces renin?

Answer 45

Juxtaglomerular epitheliod cells which are located in the walls of the afferent arteriole that synthesise renin.

Question 46

What is the role of the macula densa?

Answer 46

Monitors the Na/CL content of the DCT. In the tuberoglomerular feedback mechanism, high levels of Na/CL means macula densa will inhibit renin production by releases adenosine to act on the extraglomerular mesangial cells to cause vasoconstriction of the afferent arteriole.

Question 47

Ureter location

Answer 47

Extends from the renal pelvis and is divided into Abdominal segment Pelvis segment Intramural segment

Question 48

Ureter- descent

Answer 48

Begins from renal pelvis and descends anterior to the psoas major. It crosses pelvic brim when the common iliac artery branches. In the pelvis, it is posterolateral in close proximity to the reproductive organs.

Question 49

Mesoureter

Answer 49

Sheet of connective tissue surrounding ureter

Question 50

Structure of ureter

Answer 50

Muscular wall consisting of: Mucosa: innermost layer formed of transitional epithelia Inner circular and outer longitudinal Smooth muscle for peristalsis of urine Adventitia: fibrous connective tissue

Question 51

What are the natural constrictions of the ureter?

Answer 51

Ureter has 3 natural constrictions: At the renal pelvis Crossing of the common iliac into the external iliac artery Entrance of ureter into bladder wall

Question 52

What is the innervation to the ureter?

Answer 52

Sympathetic system from T12 -> L1 from the coeliac and renal ganglia. Parasympathetic supply: pelvic sphlachnic

Question 53

What is the lymphatic drainage of the kidney?

Answer 53

Aortic and caval lymphatic

Question 54

What is the pars recta?

Answer 54

Straight descending portion

Question 55

Composition of Loop of Henle

Answer 55

Simple squamous epithelia

Question 56

Composition of DCT

Answer 56

Cuboidal epithelia with a few very microvilli with less numerous tubules. Contains granular cells and macula densa cells.

Question 57

What does the PCT secrete?

Answer 57

Urea, creatinine, drugs and H+ to the lumen to form the filtrate for excretion via the urine.

Question 58

What does the collecting duct secrete?

Answer 58

H+, drugs and NH4+.

Question 59

What are the branches of the efferent arterioles?

Answer 59

Peritubular capillaries which reabsorb nutrients from the nephron.

Question 60

When is prostaglandin stimulated?

Answer 60

Sympathetic system is activated.

Question 61

How do podocytes prevent protein loss?

Answer 61

Podocyte have long foot processes in contact with the glomerular basement membrane, and contain the negatively charged glycocalcyx protein rich in sialic acid to form a layer that repels proteins.

Question 62

What is the histology of the prostatic urethra?

Answer 62

Transitional epithelia.

Question 63

What is the histology of the membranous urethra?

Answer 63

Pseudostratified columnar epithelia

Question 64

What is the histology of the spongy urethra?

Answer 64

Stratified squamous epithelia.

Question 65

What is the histological structure of the kidneys?

Answer 65

Formed of the glomerulus, a network of capillaries lined with a thin endothelium that is fenestrated with a central mesangium and a basement membrane .The basement membrane is important for the repulsion of macromolecules and is formed of type IV and V collagen and glycosaminoglycans which regulate the movement of charged molecules.

Question 66

What is the role of the mesangium?

Answer 66

Responds to signals from angiotensin II and thromboxane in order to contract and prevent filtration of substances in the glomerulus and reduce GFR. Prostaglandin inhibits the contraction of the mesangium and promotes a higher GFR.

Question 67

What are the components of the glomerulus?

Answer 67

Podocyte, mesangium, endothelium and glomerular basement membrae

Question 68

What is the primary innervation to the kidneys?

Answer 68

Coeliacs plexus and greater splanchnic nerves, from the thoracolumbar splanchnic nerves.