Chapter 24 – Urinary System (Fill-in-the-Blank Practice)

A collection of fill-in-the-blank flashcards covering structures, functions, pressures, regulatory mechanisms, and urinary tract anatomy for Chapter 24 of the urinary system.

The organs that form urine are the , whereas urine is stored in the .

kidneys; urinary bladder

Two major ways the kidneys help regulate blood pressure are (1) releasing the enzyme and (2) adjusting urine .

renin; volume

The kidneys lie to the parietal peritoneum in the region of the abdomen.

retroperitoneal; superior lumbar

From innermost to outermost, the kidney is wrapped by the renal capsule, perinephric fat, _, and paranephric fat.

renal fascia

The outer superficial region of the kidney is the , while the inner region containing renal pyramids is the .

renal cortex; renal medulla

Minor calyces merge to form major calyces, which combine to create the funnel-shaped _.

renal pelvis

Unlike other sinuses, the renal sinus is filled with _ tissue and vessels instead of air.

adipose (fat)

A renal corpuscle consists of the and the surrounding .

glomerulus; glomerular (Bowman) capsule

The three parts of a renal tubule are the PCT, the nephron loop, and the _.

distal convoluted tubule (DCT)

nephrons have short loops confined mostly to the cortex, whereas nephrons have long loops that extend deep into the medulla.

Cortical; juxtamedullary

The juxtaglomerular apparatus is located where the _ contacts the afferent arteriole.

distal convoluted tubule (or ascending limb)

Granular (JG) cells both contract to regulate blood flow and secrete the enzyme _.

renin

Cells of the _ monitor NaCl concentration in the filtrate and signal granular cells.

macula densa

Blood enters the kidney through the renal artery, then segmental, interlobar, arcuate, _, and finally afferent arterioles.

cortical radiate (interlobular) arteries

Blood leaving the glomerulus first enters the _ arteriole.

efferent

The two capillary beds in a nephron are the glomerulus and the _ capillaries.

peritubular (or vasa recta)

Venous blood exits the kidney through cortical radiate, arcuate, interlobar, and finally the _ vein.

renal

Fluid inside the tubules prior to the collecting ducts is called , whereas once it reaches the papillary duct it is termed .

filtrate (or tubular fluid); urine

The three layers of the filtration membrane are the fenestrated endothelium, the basement membrane, and the _ of the podocytes.

filtration slits (slit membrane)

Substances such as glucose, amino acids, and ions are filtered, whereas large proteins are filtered.

freely; not

Glomerular hydrostatic pressure (HPg) is higher than other capillaries because the arteriole is wider than the arteriole.

afferent; efferent

Two pressures that oppose HPg are blood _ pressure (OPg) and capsular hydrostatic pressure (HPc).

colloid osmotic

Net filtration pressure equals HPg minus the sum of _ and HPc.

OPg (blood colloid osmotic pressure)

GFR stands for _ and represents the volume filtered per minute by both kidneys.

glomerular filtration rate

Intrinsic control that keeps GFR constant despite BP changes is called renal _.

autoregulation

The myogenic mechanism responds to stretch of the arteriole, while tubuloglomerular feedback relies on signals from the densa.

afferent; macula

Sympathetic stimulation causes afferent arteriole , which GFR.

constriction; decreases

Atrial natriuretic peptide (ANP) _ GFR by dilating the afferent arteriole and relaxing mesangial cells.

increases

Transport maximum is the maximum rate at which a substance can be _ and depends on carrier saturation.

reabsorbed (or transported)

Renal threshold is the plasma concentration at which a substance first appears in _.

urine

Glucose is reabsorbed via secondary active transport with _ across the apical membrane and facilitated diffusion across the basolateral membrane.

sodium (Na⁺)

Proteins filtered into the filtrate are reclaimed by _ and digested into amino acids in tubule cells.

pinocytosis (endocytosis)

Sodium reabsorption is stimulated by the hormone _ and inhibited by atrial natriuretic peptide.

aldosterone

Water reabsorption in collecting ducts is increased by the insertion of aquaporins under the influence of _ hormone.

antidiuretic (ADH)

Parathyroid hormone phosphate reabsorption while calcium reabsorption in the DCT.

inhibits; increasing

The three main nitrogenous wastes are urea, _, and creatinine.

uric acid

The countercurrent multiplier occurs in the _ loop of juxtamedullary nephrons.

nephron (loop of Henle)

Vasa recta preserve the medullary gradient through the countercurrent _ system.

exchange

Urea is recycled from the collecting duct to the thin segment of the loop, contributing to the _ gradient.

osmotic (medullary)

When GFR increases, urine volume generally ; when GFR falls, urine volume

increases; decreases

A fall in systemic BP causes the afferent arteriole to _ to maintain glomerular pressure.

dilate

The two hormones that coordinate Na⁺ and water reabsorption are aldosterone and _.

antidiuretic hormone (ADH)

During dehydration urine specific gravity and color becomes concentrated.

increases; more (darker)

Specific gravity compares the density of urine to the density of _.

water

The ureters employ smooth-muscle _ to propel urine toward the bladder.

peristalsis

The urinary bladder’s mucosa is lined by _ epithelium, permitting distension.

transitional

The female urethra is about 4 cm, whereas the male urethra averages about _ cm.

20

Micturition is the process of _ the urinary bladder.

emptying (urination)

The _ reflex promotes continence by relaxing the detrusor and contracting the internal urethral sphincter.

storage

Voiding begins when stretch receptors trigger the _ reflex, causing detrusor contraction.

micturition

Voluntary control of micturition is exerted via the _ urethral sphincter innervated by the pudendal nerve.

external

The three portions of the male urethra are prostatic, _, and spongy.

membranous

The concentration gradient in the kidney is maintained by the loop multiplier, vasa recta exchange, and _ cycling.

urea

Urine typically contains water, ions, nitrogenous wastes, and lacks significant amounts of _ or blood cells.

protein

When systemic BP rises, the afferent arteriole constricts to keep GFR from _.

increasing excessively

Phosphate reabsorption is inhibited by PTH, whereas Ca²⁺ reabsorption is _ by PTH.

stimulated

Secretion is the movement of substances from the peritubular into the renal .

blood; tubule

Filtration occurs only in the _ corpuscle, while reabsorption and secretion occur along the tubule and collecting duct.

renal

The detrusor muscle is composed of _ layers of smooth muscle.

three

Urine leaves the bladder via the urethra when both the internal and external urethral sphincters _.

relax