Urinary System

Question 1

What is the significance of renal fascia & fat?

Answer 1

• perinephric fat (adipose capsule)- surrounds the kidneys suprarenal glands
• Renal fascia - is a membranous layer that surrounds the periphrenic fat, kidneys, and suprarenal gland
• Paraphrenic fat-external to the renal fascia

Clinical significance- nephroptosis

Question 2

What are the functions of the kidneys?

Answer 2

Removal of unwanted substances from the body by formation of urine
-What substances? Toxins, metabolic wastes, excess ingested water, excess mineral salts

Regulation of blood pressure and fluid urine
-How? Reabsorption and secretion of salts, secretion of renin

Maintains constant plasma Ph
How? Excretion of H+ and HCO3

Formation and release certain hormones —> erythropoietin, renin, vit D3
These substances are produced or activated by the kidneys and secreted into the blood

Question 3

How much urine is secreted?

Answer 3

About 150 quarts of blood plasma

Question 4

Describe the anatomy of kidneys

Answer 4

Kidneys are bean shaped organs

• superior pole
• inferior pole

Lateral margin-convex

Medial margin-concave and it contains:
-renal sinus(arrows)

-renal hilum

Question 5

What is the relationship between renal vein and artery at the hilum? Do you see a difference in the length of left and right renal veins?

Answer 5

At the hilum:

1. Renal artery enters renal vein and ureter leaves
2. Artery divides at the hilum to give five segmentalarteries
3. Ureter is posterior

Question 6

What is the renal capsule?

Answer 6

A connective tissue which protects the kidneys

Question 7

Renal tissue is organized into:

Answer 7

Medulla: inner striated(stripped) —> arranged in medullary pyramids

Cortex: outer granular

Renal columns is cortical tissue between pyramids

Question 8

What are the excretory structures?

Answer 8

• Minor calyx
• Major calyx
• Renal pelvis

Renal pelvis continues as a ureter

Question 9

What is the nephron?

Answer 9

The functional unit of the kidney is the nephron

• renal corpuscle
• renal tubules

Question 10

Summarize the events at the nephron

Answer 10

1. Filtration from blood plasma into nephron
2. Tubular reabsorption from fluid into blood
3. Tubular secretion from blood into fluid

Question 11

What is the order of flow through the nephron?

Answer 11

Glomerulus (filtration) —> bowman’s capsule—> proximal convoluted tubule (Reabsorption and secretion)—> loop of henle (concentration)—> Distal convoluted tubule (has macula densa)(Reabsorption and secretion) —> collecting ducts

Question 12

Outline renal circulation

Answer 12

Renal artery—> segmental artery —> interlobar artery —> arcuate artery—> interlobular arteries—> Afferent arterioles—> Glomerular capillaries—> efferent arterioles —> peritubular capillaries—> interlobular veins—> arcuate veins—> interlobar veins—> renal vein—> inferior vena cava

Question 13

What are the ureters?

Answer 13

Muscular tube that conducts urine into the bladder

Question 14

What are the 3 constrictions of the ureter?

Answer 14

• At the junction of the ureters and renal pelvis
• External iliac just beyond the bifurcation of the common iliac artery (pelvic inlet)
• Through it’s passage through the wall of the urinary bladder

Ureter constrictions are potential sites for kidney stones

Question 15

What are the layers of the ureter?

Answer 15

1. Mucosa
2. Muscularis
3. Adventitia (it is retroperitoneal like the kidney

Question 16

Describe the mucosa of the ureter

Answer 16

Transitional epithelium or urothelium

-connective tissue

Question 17

Describe the muscularis of the ureter

Answer 17

3 layers

• Inner longitudinal
• Middle circular
• Outer longitudinal

Question 18

Describe the anatomy of the urinary bladder

Answer 18

Hollow, muscular organ located within a fat filled, retro pubic space

Can withstand great distention

Histology:

• transitional epithelium
• Smooth detrusor muscle
• urethra
• internal urethra sphincter= smooth m.
• external urethral sphincter- skeletal

Question 19

Describe the urinary bladder trigone

Answer 19

Bladder trigone- smooth area of the bladder in the non-distended state

1. Ureters- open into the posterior, inferolateral aspect of the bladder
2. Urethra- commences at the neck of the bladder as the internal urethral orifice

Question 20

Describe the internal urethral sphincter

Answer 20

• located at neck of the bladder
• detrusor muscle (smooth muscle.)
• autonomic innervation

Question 21

Describe the sphincter urethrae (aka: external urethral sphincter)

Answer 21

• associated with membranous urethra
• skeletal muscle.
• innervated by pudendal nerve

Question 22

Contrast the bladder when it is full and empty

Answer 22

The bladder extends into the abdomen when full

Full- ovoid; protrudes anteriorly & superiorly into the abdominal cavity

Empty- 4-sided pyramid, resides in true pelvis

Question 23

What are the parts of the male urethra?

Answer 23

1. Pre-prostatic
2. Prostatic: receives semen form ejaculatory duct
3. Membranous: in the deep perineal pouch associated with external urethral sphincter
4. Penile: longest part, 2 bends and openings for the bulbourethral glands

Question 24

What is catheterization of a male?

Answer 24

When inserting a catheter the penis must be manipulated to “straighten out” the bends in the penile urethra

Question 25

Describe the female urethra

Answer 25

Female urethra is approx. 4cm in long

-external urethral Orifice opens into vesicle

Question 26

Why is UTI more common in females?

Answer 26

• short urethra
• proximity to vagina and anus
• intercourse (honeymoon cystitis)

Question 27

Describe suprarenal (adrenal) glands

Answer 27

Lie on supero-medial pole of each kidney surrounded by renal fascia

• three arteries (superior, middle and inferior suprarenal )(each artery has a different source)
• one vein (suprarenal), left one into left renal vein, right one into IVC
• Preganglionic sympathetic innervation to medulla

Question 28

What is intravenous Pyelogram (IVP)?

Answer 28

A diagnostic imaging technique which uses an x-ray to view the structures of the urinary tract. An intravenous contrast is given so that the structures can be seen on film. An IVP also reveals the rate and path of urine flow through the urinary tract

Question 29

What problem does kidney stones cause?

Answer 29

Get stuck at ureter constrictions

Question 30

What problems do urinary tract infections cause?

Answer 30

Short wide urethra predisposes women to urinary tract infections