Chapter 7: Urinary System Flashcards
Nitrogenous wastes
Filtered in our urine.
Nitrogenous wastes found in urine as waste products
- Urea
- Creatinine
- Uric acid
Functions of the kidney
- Filter nitrogenous wastes to form urine; about 200 quarts of blood are filtered every day to form 2 quarts of urine
- Maintain proper balance of water, electrolytes (sodium, potassium), and acids
- Release hormones:
•Renin: enzymatic hormone important in adjusting blood pressure
•Erythropoietin (EPO): hormone that stimulates red blood cell production in the bone marrow
•Calciferol: active form of vitamin D necessary for the absorption of calcium from the intestine - Degrade and eliminate hormones from the bloodstream
How Kidneys Produce Urine
• Blood enters the kidneys through the right and left renal arteries
• Arterioles carry blood to the capillaries
• Glomeruli filter the blood
Glomerulus and glomerular / Bowman capsule
• Blood passes through the glomeruli
• Glomerular (Bowman)
capsule surrounds each glomerulus
• Renal tubule is attached to each Bowman capsule
Glomerulus
Network or collection of capillaries.
Three Steps in the Formation of Urine
• Glomerular filtration (water, sugar, wastes, salts)
• Tubular reabsorption (water, sugar, some salts)
• Tubular secretion (acids, potassium, and drugs)
How Kidneys Produce Urine (Cont’d)
• The glomerulus and a renal tubule combine to form a unit called a nephron.
How Kidneys Produce Urine (cont’d)
- All collecting tubules lead to the renal pelvis.
- Calyces or calices are small, cuplike regions of the renal pelvis; the term comes from the Greek, kalux, meaning a cup or case surrounding a flower bud.
Process of forming and expelling urine
- Bloodstream (through the renal arteriole)
- Glomerulus (through filtration of water, sugar, salts, and urea / other wastes)
- Glomerular capsule
- Renal tubule (through urea/wastes, salts, water, acids & drugs (urine))
- Renal pelvis
- Ureter
- Bladder
- Urethra
- Urinary Meatus (urine leaves the body)
Note: Bloodstream to the renal tubule is secretion of acids, potassium, & drugs. From the renal tubule to the bloodstream is reabsorption of water, sugar, and salts.
Arteriole
Small artery
Calyx or calix
Cuplike collecting region of the renal pelvis; the term comes from the Greek, kalux, meaning a cup or case surrounding a flower bud
Catheter
Tube for injecting or removing fluids.
Cortex
Outer region of an organ.
Creatinine
Nitrogenous waste excreted in urine.
Electrolyte
Chemical element that carries an electrical charge when dissolved in water.
Erythropoietin (EPO)
Hormone secreted by the kidney to stimulate production of red blood cells by bone marrow;
-poietin means a substance that forms.
Filtration
Process whereby some substances pass through a filter.
Glomerular capsule
Enclosing structure surrounding each
glomerulus; also called Bowman capsule.
Glomerulus
Tiny ball of capillaries in the kidney.
Hilum
Depression in the part of an organ where blood vessels and nerves enter and leave; comes from the Latin meaning a small thing.
Kidney
One of two bean-shaped organs that filter nitrogepous waste from the bloodstream to form urine.
Meatus
Opening or canal.
Medulla
Inner region of an organ; the term comes from the Latin, medulla, meaning marrow.
Nephron
The functional unit of the kidney where filtration, reabsorption, and secretion take place.
Nitrogenous waste
Substance containing nitrogen and excreted in urine;
examples are urea, uric acid, and creatinine.
Potassium (K+)
An electrolyte regulated by the kidney.
Reabsorption
Renal tubules return materials necessary to the body back into the bloodstream.
Renal artery
Blood vessel that carries blood to the kidney.
Renal pelvis
Central collection region in the kidney.
Renal tubules
Microscopic tubes in the kidney where urine is formed after filtration.
Renal vein
Blood vessel that carries blood away from the kidney.
Renin
Hormone secreted by the kidney that raises blood pressure.
Sodium (Na+)
An electrolyte regulated in the blood and urine by the kidneys; a common form of sodium is sodium chloride (salt).
Trigone
Triangular area in the urinary bladder.