chapter 21

Question 1

what are the 5 functions of the kidneys?

Answer 1

1. excretion
2. homeostasis of body fluids
3. BP regulation
4. hormone production
5. blood glucose control

Question 2

what hormones do the kidneys excrete?

Answer 2

1. EPO for RBC production
2. hormone to activate vitamin D for bone health

Question 3

gluconeogenesis

Answer 3

synthesizing of glucose from non-carb sources (amino acids, glycerol, pyruvate, lactate)
mostly done in the liver, but kidneys can produce 10-20% as needed

Question 4

renal pelvis vs renal pyramids

Answer 4

renal pelvis is funnel-shaped basin that forms upper end of ureter
renal pyramids are cone-shaped structures of tubes that drain into the renal pelvis with the help of calyces

Question 5

glomerular filtration

Answer 5

movement under pressure from blood to glomerular capsule
water and dissolved materials pass while blood cells and proteins stay in blood
diameter of afferent is larger than efferent increasing hydrostatic pressure

Question 6

glomerular filtrate definition and what it contains

Answer 6

fluid that enters the glomerular capsule and passes to renal tubule
may include water, soluble substances, vitamins, drugs
should NOT include RBCs or proteins in a normal person

Question 7

tubular reabsorption definition and methods

Answer 7

filtration that occurs in nephron(proximal tubule mostly)
as filtrate moves, H2O and needed substances pass back to circulation into IF
done through diffusion (high to low concentration), osmosis (water from low solute to high solute), and active transport (needs ATP)

Question 8

tubular secretion with examples

Answer 8

active transport of specific substances from the peritubular capillary into the nephron tubule
substances that were not filtered or were reabsorbed in a more proximal portion of the tubule are forced into urine this way
Ex: K+, H+, penicillin

Question 9

juxtamedullary nephrons

Answer 9

long nephron loops dipping deep into the renal medulla that help create concentrated urine
establish the medullary osmotic gradient

Question 10

medullary osmotic gradient

Answer 10

different solute concentration (osmotic pressure) in different parts of the renal medulla
IF in deeper medullary regions have more solutes and more osmotic pressure than regions closer to the cortex
all collecting ducts use this to produce concentrated urine (because as H2O moves down, it encounters more and more concentrated IF drawing it out)

Question 11

what is H2O reabsorption controlled by and how does it work?

Answer 11

ADH from the posterior pituitary (triggered by hypothalamus sensing BP)
ADH modifies resistance, not the osmotic gradient
it makes the walls of collecting ducts more permeable by stimulating insertion of aquaporins

Question 12

steps of urine formation

Answer 12

1. glomerular filtration moves H2O and solutes from blood to nephron tubule
2. tubular reabsorption moves H2O and useful substances back into blood
3. tubular secretion moves unfiltered or reabsorbed substances from blood into nephron for elimination
4. with ADH, collecting duct concentrates urine so less volume is secreted

Question 13

at what location does urine stop being modified?

Answer 13

renal pelvis

Question 14

what structures are lined with transitional epithelium?

Answer 14

ureters, renal pelvis, bladder, and proximal urethra

Question 15

trigone

Answer 15

triangular-shaped region in bladder floor marked by ureter and urethra openings
stable here preventing stretching of ureteral openings and backflow of urine

Question 16

normal constituents of urine

Answer 16

1. nitrogenous waste products (urea, uric acid, creatinine)
2. electrolytes
3. pigments (urochrome, bilirubin, beets or other foods/vitamins)

Question 17

abnormal constituents of urine

Answer 17

1. glucose (DM)
2. albumin
3. blood
4. ketones (starvation and DM)
5. WBCs (infection)
6. casts (solid materials of cells/proteins could indicate nephron disease)

Question 18

hydronephrosis

Answer 18

distention of renal pelvis and calyces with accumulated fluid
could be from obstructions/abnormalities

Question 19

renal hypoplasia vs dysplasia

Answer 19

both congenital and can lead to renal failure
hypoplasia: kidneys small, but normally formed
hyperplasia: kidneys with malformed nephrons or connective tissue

Question 20

stricture

Answer 20

constricted or abnormally narrow parts

Question 21

ureterocele

Answer 21

end of ureter bulges into bladder

Question 22

interstitial cystitis

Answer 22

tissues bellow mucosa of bladder involved causing pain before/after urination
almost always in women, idiopathic

Question 23

pyelonephritis

Answer 23

inflammation of renal pelvis/kidney tissue
acute: bacteria spreads there from UTI
chronic: seen in patients with persistent stasis/backflow - causes kidney damage

Question 24

what bacterial infection can cause glomerulonephritis?

Answer 24

strep throat
acute poststreptococcal glomeruloneophritis

Question 25

Dialysis and different types

Answer 25

separation of dissolved molecules based on ability to pass through semipermeable membrane
hemodialysis: urea and other waste products removed in people with decreased renal function (uses synthetic membrane and regulatable fluid called dialysate)
peritoneal dialysis: in abdominal cavity (surface area of peritoneum acts as dialysis membrane)

Question 26

stress incontinence

Answer 26

results from urethral incompetence (weakness)
allows small amounts of urine to be released when abdomen pressure increases

Question 27

urge incontinence

Answer 27

“overactive bladder”
inability to control bladder contractions once fullness perceived

Question 28

overflow incontinence

Answer 28

arises from neurological damage or obstruction causing bladder to overfill
can result in involuntary urine loss

Question 29

enuresis

Answer 29

involuntary urination, usually during the night
“bed-wetting”