1. Abdo 10 Renal and Urinary

Question 1

Functions of the renal and urinary system

Answer 1

The kidneys maintain homeostasis by the production of urine, which is the removal, from the circulating blood, of excess water and electrolytes, and toxic, metabolic waste products such as urea and creatinine.
The kidneys monitor and affect acid/base balance by excreting hydrogen ions during acidosis, or bicarbonate ions during alkalosis.
The kidneys secrete renin, which (indirectly) raises blood pressure, and erythropoietin, which accelerates red blood cell production.
The ureters conduct urine to the bladder, where it is stored.
The urethra is for the passage of urine out of the body.

Question 2

What layers encapsulate the kidneys?

Answer 2

They are encapsulated and protected by layers - firm (perirenal/nephric) fat and then renal fascia, derived from extra-peritoneal fascia (and inc. the suprarenal gland), then pararenal/nephric fat

Question 3

Kidney position?

Answer 3

Bean shaped 
Retroperitoneal
Extend from T12 - L3 
Right lower than the left 
Left kidney longer

Question 4

Anterior and posterior relations of the kidney?

Answer 4

Anterior: Duodenum, liver, suprarenal glands, stomach, pancreas, Lt colic flexure, Rt colic flexure

Posterior: Ribs 10-12, Diaphragm medially, transversus abdominus, quadratus lumborum, psoas major

Question 5

The functional unit within the kidney is the nephron that consists of?

Answer 5

1. Renal corpuscle; (glomerulus)
2. Proximal convoluted tubule (PCT);
3. Loop of Henlé;
4. Distal convoluted tubule (DCT);
5. Collecting duct

Question 6

A section through the kidney shows its cortex and medulla, with the renal ______ (housing the nephrons with their function of filtration and reabsorption) projecting as renal papillae into the _____ of the collecting system
Minor calyces converge on major calyces, which themselves form the ____ _____ that tucks in to the sinus of the kidney
At the hilum, the pelvis becomes the ______ that transports urine to the bladder

Answer 6

A section through the kidney shows its cortex and medulla, with the renal pyramids (housing the nephrons with their function of filtration and reabsorption) projecting as renal papillae into the calyces of the collecting system
Minor calyces converge on major calyces, which themselves form the renal pelvis that tucks in to the sinus of the kidney
At the hilum, the pelvis becomes the ureter that transports urine to the bladder

Question 7

Renal hilum, ant to post?

Answer 7

Vein, Artery, Pelvis of ureter

Question 8

Arterial supply of kidneys?

Answer 8

Renal arteries, from Ao at L 1, 2 (left higher than right), divide at hilum, usually ant and post, often additional, accessory, extrahilar arteries from Ao

Question 9

The renal vein all receives which two veins?

Answer 9

Suprarenal

Gonadal

Question 10

Shorter renal vein?

Answer 10

The right is shorter as it’s closer

Question 11

What are the stages of renal artery division?

Answer 11

Each renal artery usually divides into five segmental arteries that enter the kidney at its hilum

Lobar arteries arise from each segmental artery, one for each renal pyramid

Before entering the renal substance, each lobar artery gives off two or three interlobar arteries

The interlobar arteries run toward the cortex on each side of the renal pyramid

At the junction of the cortex and the medulla the interlobar arteries give off the arcuate arteries, which arch over the bases of the pyramids

The arcuate arteries give off several interlobular arteries that ascend in the cortex
The afferent glomerular arterioles (that give blood directly into the renal corpuscle) arise as branches of the interlobular arteries

Question 12

Kidney nerve supply?

Answer 12

Derived from T 12 and L 1, referring pain to the back and lumbar region, as well as loin to groin. Afferents in the vagus may cause the nausea and vomiting associated with such pain

Question 13

Ureter narrowings?

Answer 13

Pelvi-ureteric junction
Crossing the pelvic brim
Passing through the bladder wall

Question 14

Relations of the ureter?

Answer 14

The ureters lie anterior to psoas major, and therefore anterior to the branches of the lumbar plexus; they cross the bifurcation of the common iliac artery
Inc. the gonadal and left and right colic vessels
But lie posterior to everything else

Question 15

Difference between pelvic relations of the ureter in males and females?

Answer 15

Male, between vas and seminal vesicle

Female, posterior to ovary, inferior to uterine artery, passing cervix and lateral fornix of vagina

Question 16

Relations of ureter in pelvis?

Answer 16

Medial to:

• Internal iliac vessels and branches
• Lumbosacral trunk
• SI joint; Ischial spine
• Must also pass the rectum

Question 17

Vascular and lymph supply of ureter?

Answer 17

Vascular:

• Aorta
• Renal
• Gonadal
• Common and internal iliac
• Uterine, vaginal
• Vesical

Lymph to para-aortic and iliac nodes

Question 18

What is the relevance of the ureters oblique entry into the bladder?

Answer 18

The ureters pass through the bladder wall obliquely, creating a flap valve that prevents urine that is in the bladder from backing up and returning into the ureter (ureteric reflux)
Pressure of urine in the full bladder, forcing the ureters closed
The ureters pass 1.5 to 2 cms obliquely thro’ the bladder wall to prevent reflux

Question 19

The walls of the ureters and bladder are essentially ________. Peristaltic waves propel urine down the ureter (hence the ____ pain of ureteric calculi) and the bladder fills by relaxation of its muscular wall (_______). Of course, bladder emptying is by muscular contraction, aided by raised ____-______ pressure.
The epithelial lining is ______ Epithelium, or urothelium, which is urine-proof and allows distension. The cells are _____ and piled on top of each other, but flatten and spread out to cope with distension.
The muscle is smooth and _______, controlled by the autonomic, particularly parasympathetic system. However, the external sphincter around the urethra is ______ and under voluntary control.

Answer 19

The walls of the ureters and bladder are essentially muscular. Peristaltic waves propel urine down the ureter (hence the colicy pain of ureteric calculi) and the bladder fills by relaxation of its muscular wall (detrusor). Of course, bladder emptying is by muscular contraction, aided by raised intra-abdominal pressure.
The epithelial lining is Transitional Epithelium, or urothelium, which is urine-proof and allows distension. The cells are rounded and piled on top of each other, but flatten and spread out to cope with distension.
The muscle is smooth and involuntary, controlled by the autonomic, particularly parasympathetic system. However, the external sphincter around the urethra is striated and under voluntary control.

Question 20

Nerve supply of the ureter

Answer 20

Complex, autonomic supply, more at the lower end
Nerves are not required for peristalsis; there are many “pacemakers” in the renal calyces; muscle cell to muscle cell propagation of conduction, contraction; modulated by autonomics
Derived segmentally: T10, 11, 12, L1, S2,3, 4 from aortic, renal and pelvic plexuses
Referred pain is mainly T11 to L2: loin to groin and scrotum or labia

Question 21

Filling and emptying of bladder controlled by?

Answer 21

Fills by its detrusor muscle relaxing, empties by its contraction
Detrusor is under the control of parasympathetic nerves derived from S2, 3, 4

Question 22

Anatomically, how do men prevent semen back flow into bladder?

Answer 22

The male has a preprostatic, internal sphincter (sympathetic) to prevent semen backflowing into the bladder.

Question 23

How does female anatomy relate to urinary continence

Answer 23

In the female the bladder neck is above the pelvic floor, so that pressure of pelvic organs, as well as levator ani contribute to urinary continence.

Question 24

4 parts of male urethra?

Answer 24

1. Preprostatic at bladder neck (position of smooth Internal Sphincter)
2. Prostatic
3. Membranous, surrounded by striated External Sphincter
4. Spongy or Penile Urethra

Question 25

Arterial supply of bladder and urethra?

Answer 25

Arteries: branches of the internal iliac artery - sup. and inf. vesical; internal pudendal; also branches from arteries to adjacent structures, e.g. vaginal, uterine

Question 26

Venous drainage of bladder and urethra?

Answer 26

Veins: Vesical (and prostatic) plexuses converging on internal pudendal and internal iliac veins

Question 27

Lymph drainage of bladder and urethra?

Answer 27

Lymph: to internal and external iliac nodes

Question 28

From the prostate there are communications with the valveless veins of the vertebral plexuses (Batson) facilitating ______ _______

Answer 28

From the prostate there are communications with the valveless veins of the vertebral plexuses (Batson) facilitating tumour spread

Question 29

Nerve supply of bladder and urethra

Answer 29

Require:
Somatic motor for control of striated muscle (ext. sph.)
Autonomic (motor) both sympathetic and parasympathetic (male pre-prostatic sphincter; detrusor)

Sensation:
S2, 3, 4 (Pudendal nerve and its branches)
Sympathetic and Parasympathetic in Pelvic Plexus

Question 30

What are the 3 stages of micturition?

Simultaneous relaxation/contraction

Answer 30

1. Storage
Parasympathetic to detrusor “switched off” in spinal cord to allow bladder to relax and fill
Usual volume (male) about 400 ml, if reach 500 ml – pain in lower abdomen and perineum

2. “Full”, causes desire to micturate
   Afferents (sensory) to spinal cord, then “M” Centre in pons – stimulates preganglionic, parasympathetic neurones at S 2, 3, 4
3. Void
   1y neurones stimulate 2y neurones in bladder wall ganglia, causing detrusor contraction

Simultaneous relaxation of external urethral sphincter (striated muscle) – pudendal nerve (S 2, 3, 4) and contraction of abdo. wall; sensation of urine in urethra maintains the reflex