Urinary System Flashcards
Nitrogenous waste products
Urea, creatinine, Uric acid
Urinary system removes these from the blood so they do not accumulate and become harmful
Urine
Composed of water, salts, and acids.
Leaves the body through ureters, urinary bladder, and urethra. Kidney processes 200 quarts of blood to filter out 2 quarts urine
Functions of kidneys
- Remove nitrogenous wastes: urea, creatinine, uric acid
- Balance water and electrolytes (sodium, potassium)
- Release hormones: renin, erythropoietin, calciferol
- Degrade and eliminate hormones from bloodstream
Renin
Enzymatic hormone important in adjusting blood pressure
Erythropoietin
Hormone that stimulates red blood cell production in bone marrow
Calciferol
Active form of vitamin D necessary for the absorption of calcium from the intestine
Electrolytes
Sodium (Na+) and potassium (K+) are small molecules that conduct an electrical charge.
Electrolytes are necessary for proper functioning of muscle and nerve cells
Example of homeostasis
Kidney adjusts amount of water and electrolytes by secreting some substances into the urine and holding back others in the bloodstream for use in the body .
Homeostasis = bodies ability to maintain an equilibrium within its internal environment
Home/o means sameness
Size and weight of a normal kidney
Each kidney weighs about 4 to 6 ounces
What function is performed by the ureters?
Ureters carry urine in peristaltic waves from the kidney to the urinary bladder
What function is performed by the urinary bladder?
Holding urine
Which function is performed by the urethra?
Excrete urine
Difference between male and female urination system?
Smaller urethra for women
Voiding
Urination
How do kidneys produce urine
Blood enters kidneys through right and left renal arteries.
Arterioles carry blood to capillaries.
Glomeruli filter the blood.
Kidneys produce urine through filtration
Glomerulus
Collection of tiny capillaries formed in the shape of a small ball
Renin
Increases blood pressure and restores blood flow in the kidneys to normal
How kidneys produce urine contd.
As blood passes through the many glomeruli the thin walls of each of the glomerulus will filter sugar, water, salts, urea & wastes to leave the bloodstream.
Bowman capsule is a cup like shaped structure that will capture the substances.
Walls of glumeruli prevent proteins and big substances from leaving the bloodstream or appearing in urine
Renal tubule is attached to each bowman capsule at the bottom
Three steps in the formation of urine
- Glomerular filtration
- Tubular reabsorption
- Tubular secretion
Tubular reabsorption
The flow of the water, sugar, salt, urea and other wastes passing through the renal tubule, most of the water, all the sugar, and almost all the secreationthe sodium return to the bloodstream through tiny capillaries surrounding each tubule.
This ensures the body retains essential substances such as glucose, water , sodium
Nephron
Functional unit of the kidney. It is the combination of glomerulus and renal tubule where filtration, reabsorption, and secretion take place in the kidney. Each nephron is capable of forming urine by itself. There are about 1 million nephrons in a kidney.
Renal pelvis
a basin-like area in the central part of the kidney.
Calyces or calices
(Singular calyx or calix)
Small, cup-like regions of the renal pelvis
Contd.
The renal pelvis narrows into the ureter, which carries the urine to the urinary bladder. The bladder, a muscular sac, temporarily stores urine. Sphincter muscles control the exit area of the bladder to the urethra. As the bladder fills and pressure increases at its base, an individual notices a need to urinate and voluntarily relaxes sphincter muscles.
Catheter
Tube for injecting or removing fluids. A bladder catheter drains urine from the bladder
Cortex
Outer region of an organ; the renal cortex is the outer region of the kidney (cortical means pertaining to the cortex).
Glomerular capsule
Enclosing structure surrounding each glomerulus. The glomerular capsule is also known as Bowman capsule and collects the material that is filtered from the blood through the walls of the glomerulus.
Hilum
Depression in the kidney where blood vessels and nerves enter and leave. Hilum comes from the Latin meaning a small thing. It is also used in the respiratory system to mark the depression in the lung where blood vessels, bronchus, and lymphatic vessels enter and leave.
Meat is
Opening or canal
Kidney
One of two bean-shaped organs on either side of the backbone in the lumbar region. It filters nitrogenous wastes from the bloodstream to form urine.
Medulla
Inner region of an organ. The renal medulla is the inner region of the kidney. Medullary means pertaining to the medulla. The term comes from the Latin medulla, meaning marrow (inner part).
Potassium (K+)
Electrolyte regulated by the kidney so that a proper concentration is maintained within the blood. Potassium is essential for allowing muscle contraction and conduction of nervous impulses.
Renal artery
Blood vessel that carries blood to the kidney.
Renal tubule
Microscopic tube in the kidney where urine is formed after filtration.
Renal vein
Blood vessel that carries blood away from the kidney and toward the heart.
Renin
Enzyme secreted by the kidney. It raises blood pressure by influencing vasoconstriction (narrowing of blood vessels).
Trigone
Triangular area in the urinary bladder.
Sodium (Na+)
Electrolyte regulated in the blood and urine by the kidneys. It is needed for proper transmission of nerve impulses, heart activity, and other metabolic functions. A common form of sodium is sodium chloride (table salt).
Urination (voiding)
Process of expelling urine; also called micturition.
Urinary bladder
Hollow, muscular sac that holds and stores urine.
