Urinary

Question 1

What are the main functions of the kidneys?

Answer 1

Regulating total water volume and electrolyte concentration, regulating ion concentration in the ECF, regulating long term acid base balance, excreting metabolic wastes, toxins, and dugs. Secreting erythropoietin and renin( hormones produced by kidney) activating vitamin D and gluconeogenesis

Question 2

What are the organs of the urinary system?

Answer 2

Kidney, ureter, urinary bladder and urethra

Question 3

Where are these kidneys located?

Answer 3

Kidneys are located retroperitoneally from T12 to L5 and the ureters and urinary bladder are located in the abdomen and pelvis.

Question 4

What are the coverings of the kidney that protect it?

Answer 4

Renal capsule, perirenal fat and renal fascia.

Question 5

What are three distinct regions of the kidney?

Answer 5

Renal cortex, renal medulla, and renal pelvis

Question 6

Describe details of each of these regions

Answer 6

Renal cortex is the out superficial region; medulla is deep to the cortex and contains medullary pyramids (renal pyramids are separated by renal columns, extensions of the renal cortex) renal pelvis is the funnel shaped tube continuous with the ureter. The pelvis contains the minor calyx and major calyx.

Question 7

What is the flow of urine through the kidney?

Answer 7

Nephron>renal pyramid> minor calyx> major calyx> renal pelvis> ureter>urinary bladder> urethra

Question 8

What is the functional unit of the kidney?

Answer 8

Nephron

Question 9

What are the main parts of the nephron?

Answer 9

Renal corpuscle (glomerulus) and renal tubule (bowman’s capsule, proximal convoluted tubule> nephron loop/loop of Henle> distal convoluted tubule)

Question 10

What are the blood vessels that lead from the glomerulus to the inferior vena cava?

Answer 10

Glomerulus> efferent arteriole> peritubular capillaries or vasa recta> cortical radiate veins> arcuate vein> interlobar vein> renal vein> inferior vena cava

Question 11

What are the two types of nephrons in the kidney?

Answer 11

Cortical nephrons - 85% of each, juxtamedullary nephrons 15%

Question 12

What are the types of capillaries in each nephron?

Answer 12

Cortical- glomerulus and peritubular capillaries; juxtamedullary -glomerulus and vasta recta

Question 13

What is the juxtaglomerular complex? ( jgc)

Answer 13

Involved modified portions of distal portion of ascending limb of nephrons loop and afferent arteriole

Question 14

Describe the functions of this comple and the cells found here

Answer 14

This complex Is important in regulating the rate of filtrate formation and blood pressure. The cells in the JGC are the macula densa cells, granular or JG cells, and extraglomerular mesangial cells

Question 15

What are the functions of the cells in the JGC?

Answer 15

Macula densa- chemoreceptors that sense and monitor electrolyte content of filtrate granular cells- mechanoreceptors to sense BP and secrete renin, extraglomerular mesangial cells- pass signals between macula densa and granular cells

Question 16

What is filtrate and what does it contain?

Answer 16

Filtrate is the fluid formed at the glomerulus via filtration. It contains blood plasma minus proteins and whole cells.

Question 17

What are the major processes that occur within the nephron? Describe each of these.

Answer 17

Glomerular filtration is the forced movement of solutes and water from the glomerulus into the bowman’s capsule. Tubular reabsorption is the selective return of 99% of the substances from the blood to the filtrate

Question 18

What are the layers of the filtration membrane?

Answer 18

Visceral layer of the glomerulus (bowman’s capsule), fused membranes and capillary endothelium of glomerulus

Question 19

What are the factors that affect the net filtration pressure? Which one is the most significant?

Answer 19

The most significant factor that affects net filtration pressure is the glomerular capillary osmotic pressure due to the glomerular capillary blood pressure (specifically, the afferent arteriolar hydrostatic pressure). The net filtration pressure is 10mmHg from the glomerular capillary into the glomerular capsular space.

Question 20

How does the myogenic mechanism work to regulate BP?

Answer 20

Increased BP causes muscle dilation of afferent arterioles

Question 21

How does the tubuloglomeeular feedback mechanism work? Provide examples of what happens when GFR increases and decreases

Answer 21

It’s a flow dependenr mechanism directed by macula densa cells. If GFR increases, the flow rate of the filtrate increases leading to decreased reabsorption time cause high electrolyte (Nacl) levels in the filtrate. To counteract this, the feedback mechanism causes construction of the afferenr arteriole lowering GFR to allow more time for NaCL reabsorption. If GFR decreases the flow rate of filtrate decreases leading to higher reabsorption time causing low electrolyte (NaCL) levels in the filtrate. To counteract this , the feedback mechanism causes dilation of the afferent arteriole kncreasing GFR to allow less time for NaCL reabsorption.