Urinary System Vocab

kidneys

major homeostatic organ of the body; functions to remove nitrogenous wastes from blood stream, maintain fluid balance, maintain electrolyte (ion) balance, and maintain acid-base balance

urinary bladder

reservoir for urine; contains RUGAE so it can stretch as it fills with urine

ureters

transports waste fluids from kidneys to urinary bladder

urethra

connects bladder to external environment

trigone

triangular area delineated by the openings of the ureters and urethra

renal cortex

OUTER portion of the kidney

renal medulla

INNER portion of the kidney

segmental arteries

enters the kidney; receives blood from the renal arteries

cortical radiate arteries

receives blood from the arcuate arteries

arcuate arteries

receives blood from the interlobar arteries

interlobar arteries

receives blood from the segmental arteries

nephron

functional unit of the kidney; usually found within the cortex

juxtamedullary nephron

nephron found in the loop of Henle in the medulla

glomerulus

a capillary knot formed by the afferent arteriole where blood is filtered; where fluid filtration occurs

renal tubule

forms the glomerular (Bowman’s) capsule, proemial and distal convoluted tubules, and loop of Henle

Bowman’s capsule

surrounds glomerulus; visceral (inner) wall composed of podocytes

podocytes

forms porous membrane so fluid can pass through renal tubule

collecting duct

dumps urine from renal tubule into calyces and pelvis of kidney

afferent arteriole

has HIGH pressure/resistance and LARGE diameter

efferent arteriole

drains glomerulus; has HIGH resistance but a SMALLER diameter

peritubular capillary bed

LOW pressure porous capillary network formed from efferent arteriole that LEAVES glomerulus; in close proximity to renal tubule to reabsorb water/ions

vasa recta

found by juxtamedullary nephrons'; helps reabsorb fluids/ions

juxtaglomerular apparatus region

functions to CONCENTRATE urine

juxtaglomerular cells

found in arteriole walls; senses blood pressure

macula densa

area of specialized columnar chemoreceptors cells in distal convoluted tubule

filtration

PASSIVE process in glomerulus

reabsorption (tubular)

ACTIVE and PASSIVE (i.e. osmosis) process; 75%-80% occurs in PROXIMAL convoluted tubule; highly selective (glucose, amino acids and some ions reabsorbed); filtrate components resorbed through tubule wall and into peritubular capillaries

secretion

substances NOT filtered in glomerulus (i.e. left in the blood) are secreted from peritubular capillaries and absorbed into tubules

micturition

emptying the bladder

internal urethral sphincter

composed of SMOOTH muscles; INvoluntary

external urethral sphincter

composed of skeletal muscles; voluntary; located at the urogenital diaphragm

urochrome pigment

result of hemoglobin destruction; gives urine its yellow color

increase

most solutes ________ the specific gravity of urine

renal calculi

kidney stones; can be caused by high specific gravity of urine

urea

waste product created by the breakdown of proteins in the liver; is the main nitrogenous component of urine

urea, sodium, potassium, phosphate, sulfate ions, creatinine, and uric acid

majority of solutes found in urine

glycosuria

the presence of GLUCOSE in urine; can be cuased by diabetes mellitus

albuminuria

the presence of ALBUMIN in urine; often indicates kidney damage or disease

ketonuria

the presence of KETONES in urine; often associated with low carb diet, stravation

bilirubinuria

the presence of BILE PIGMENTS in urine; often indicates liver dysfunction or hemolysis.

pyuria

the presence of WHITE BLOOD CELLS in urine; often indicates urinary tract infection or inflammation

nitrites present in urine

indicates a urinary tract infection, typically caused by certain bacteria

hematuria

the presence of RED BLOOD CELLS in urine; often signifies injury, kidney stones, or other urinary tract issues.

hemoglobinuria

the presence of HEMOGLOBIN in urine; can indicate hemolytic anemia, poisonous snake bites or renal disease

ketonuria

glycosuria coupled with _______ is diagnostic for diabetes mellitus

hydrostatic

the ______ force pushes fluid out of the glomerular capillaries; influences the glomerular filtration rate (GFR) of blood

higher

the ______ the hydrostatic pressure, the higher the GFR is

OUT; INTO

as filtrate passes through the loop of Henle, water flows ___ of the loop and ___ the interstitial fluid in the medulla

increase; concentrates

as you _____the osmolarity of the interstitial fluid surrounding the nephron tubules, you can draw out even more water from filtrate; this _____ the urine