Chapter 26 The urinary System Flashcards
(100 cards)
The urinary system contributes to homeostasis by
excreting wastes; altering blood composition, pH, volume, and pressure; maintaining blood osmolarity; and producing hormones. /.
As body cells carry out metabolic activities,
they consume oxygen and nutrients and produce waste products such as carbon dioxide, urea, and uric acid.
Wastes must be eliminated from the body because
they can be toxic to cells if they accumulate.
While the respiratory system rids the body of carbon dioxide, the urinary system
disposes of most other wastes.
The urinary system performs waste disposal by
removing wastes from the blood and excreting them into urine
The urinary system also
helps regulate blood composition, pH, volume, and pressure; maintains blood osmolarity; and produces hormones.
The urinary system consists of
two kidneys, two ureters, one urinary bladder, and one urethra
The kidneys
filter blood of wastes and excrete them into a fluid called urine
Once formed, urine
passes through the ureters and is stored in the urinary bladder until it is excreted from the body through the urethra.
Nephrology (nef-ROL-ō-jē; nephr- = kidney; -ology = study of) is
the scientific study of the anatomy, physiology, and pathology of the kidneys.
urology
The branch of medicine that deals with the male and female urinary systems and the male reproductive system
Urine formed by the kidneys
passes first into the ureters, then to the urinary bladder for storage, and finally through the urethra for elimination from the body
What is the function of the Kidneys
regulate blood volume and composition; help regulate blood pressure, pH, and glucose levels; produce two hormones (calcitriol and erythropoietin); and excrete wastes in urine.
What is the function of the ureters
transport urine from kidneys to urinary bladder.
What is the function of the urinary bladder
stores urine and expels it into urethra.
What is the function of the urethra
discharges urine from body.
What are ALL of the functions of the kidneys
Excretion of wastes
Regulation of blood ionic composition
Regulation of blood pH
Regulation of blood volume
Regulation of blood pressure
maintainance of blood osmolarity
Production of hormones
Regulation of blood glucose level
Some wastes excreted in urine result from metabolic reactions. These include
urea and ammonia from the deamination of amino acids; creatinine from the breakdown of creatine phosphate; uric acid from the catabolism of nucleic acids; and urobilin from the breakdown of hemoglobin.
Urea, ammonia, creatinine, uric acid, and urobilin are collectively known as
nitrogenous wastes because they are waste products that contain nitrogen.
non-nitrogenous wastes excreted in the urine are
foreign substances that have entered the body, such as drugs and environmental toxins
The kidneys help regulate the blood levels of several ions, most importantly
sodium ions (Na+), potassium ions (K+), calcium ions (Ca2+), chloride ions (Cl−), and phosphate ions (HPO42−).
The kidneys regulate blood ionic composition by
adjusting the amounts of these ions that are excreted into the urine.
The kidneys excrete
a variable amount of hydrogen ions (H+) into the urine
The kidneys
conserve bicarbonate ions (HCO3−), which are an important buffer of H+ in the blood