Lec 1 - Introduction to urinary

Question 1

What are the function of the kidney?

Answer 1

1. Regulation - control the concentrations of key substances in extracellular fluid.
2. Excretion - excretes waste products.
3. Endocrine - synthesis of renin, erythropoietin, prostaglandins
4. Metabolism - active form of vitamin D, catabolism of insulin, PTH and calcitonin.

Question 2

Where is the location of the kidney?

Answer 2

Kidneys are retroperitoneal, so have to move all the GI stuff out of the way to see it.
Between T12 and L2/L3.

Question 3

Why does the left kidney sit slightly higher than the right?

Answer 3

This is because the liver is on the right and it pulls the right kidney down.

Question 4

What is the ureter and describe its pathway?

Answer 4

• The ureter is smooth muscle that joins the kidney to the bladder. - joins the kidney by the hilum.
• The ureter then descend down the spinal column down to the bladder.
• The ureter runs along the tips of the transverse process.
• The ureters bend around the pelvic bone and enter the back of the bladder around the level of the ischial spine.

Question 5

Which rib lays across the kidneys?

Answer 5

• The 12th rib.

Question 6

What is the internal urethral meatus?

Answer 6

It is the entry point on the bladder that leads to the urethra.

Question 7

What are the entry points of the bladder?

Answer 7

• The internal ureteric entrance

- The internal urethral meatus

Question 8

What is the gap behind the bladder called in men and women?

Answer 8

In men - recto-vesical pouch

In women - uterine-vesico pouch

Question 9

What is the detrusor?

Answer 9

It is a muscle that ,makes up the bladder.

In urinary retention sufferers, the muscle is very thin.

Question 10

What is the trigone?

Answer 10

It is the triangular base of the bladder,

It is not distensible unlike the rest of the bladder.

Question 11

Why can you not palpate an empty bladder?

Answer 11

this is because when the bladder is empty, it is around the same level as the pubic symphysis, so it sits in the pubic bowl as a result you can’t distend it.

Question 12

What is the blood supply to the kidneys?

Answer 12

both kidneys are served by renal artery

Question 13

What is the drainage of the right and left kidney?

Answer 13

right - short renal vein - short as it is next door to the IVC
left - long renal vein - long as need to go above the aorta.

Question 14

What are the components of the nephron?

Answer 14

• filter of huge amounts of ECF at the glomerulus.
• Proximal convoluted tubule - in cortex - obligatory reabsorption of most substances.
• Loop of henle - dips into and out of the medulla.
• Distal convoluted tubule - In cortex - controlled reabsorption of salts and water here
• Collecting duct - passes through medulla to the pelvis.

Question 15

What are the different electrolyte compositions of the intra and extra cellular fluids?

Answer 15

Intracellular - High K+, low Na+, many large organic anions.

Extracellular - low K+, high Na+, main anion Cl- and HCO3-

Question 16

What does oncotic refer to?

Answer 16

osmotic force due to proteins.

Question 17

Define osmolality

Answer 17

osmolality is solute per kilogram of solvent.

osmolarity is number of osmoles of solute per litre.

Question 18

What is the glomerular filtration rate?

Answer 18

125 ml/min or 180 L/day

Question 19

What is epithelium and its role in the kidneys?

Answer 19

• epithelium is a continuous sheet of cells covering exposed surfaces and lining internal cavities.
• epithelial tissues in the kidney excrete waste products from the body and reabsorb needed materials from the filtrate.

Question 20

Describe the role of the PCT?

Answer 20

• major site of reabsorption
  —60-70% of sodium and water.
  —80-90% of potassium
  —90% of bicarbonate
  —100% of glucose and amino acids.
  water follows osmotic gradients so filtrate remains isotonic with plasma.
  Reabsorbed materials leave by peritubular capillaries.

Question 21

What do sodium pumps do?

Answer 21

• extrude sodium across basolateral membrane.
• sodium enters across luminal membrane down conc grad.
• energy from sodium movement drives reabsorption of other substances such as glucose.
• water follows electrolytes osmotically.

Question 22

What is the function of the Loop of Henle?

Answer 22

• further site of reabsorption of salts.
• creates a gradient of increasing osmolarity in the medulla by counter-current multiplication.
• —-this allows formation of concentrated urine if water has to be observed.

Question 23

What is the function of the DCT?

Answer 23

-site of variable reabsorption of electrolytes and water.
- fluid leaving the loop is hypotonic.
- the distal tubule removes yet more sodium and chloride.
- it actively secretes hydrogen ions.
if water does not follow reabsorption then large volumes of dilute urine are formed - diuresis.

Question 24

What is the function of the Collecting duct?

Answer 24

• The collecting duct passes through the high osmolarity environment of the medulla, that is created by the loop of henle.

Question 25

How is sodium recovery controlled?

Answer 25

controlled by a hormone system

- The Renin angiotensin system, which controls the ECF volume.

Question 26

How is water recovery controlled?

Answer 26

controlled by Anti-diuretic hormone

• it controls the permeability of the DCT and collecting duct to water.
• controls ECF osmolarity.