FINALS: URINARY SYSTEM Flashcards
Blood pH must remain between _______ to maintain homeostasis
7.35 & 7.45
pH above 7.45
ALKALOSIS
pH below 7.35
ACIDOSIS
arterial pH between 7.35 & 7.0
PHYSIOLOGICAL ACIDOSIS
Most ions originate as byproducts of cellular metabolism
MAINTAINING ACID-BASE BALANCE IN BLOOD
Most acid-base balance is maintained by the
kidneys
Other acid-base controlling systems
Blood buffers
Respiration
Systems of 1 or 2 molecules that act to prevent dramatic changes in H+ concentrations when acids/bases are added
BLOOD BUFFERS
Bind to H+ when pH ____
drops
Release H+ when pH _____
rises
1st line of defense in resisting pH changes
BLOOD BUFFERS
3 MAJOR CHEMICAL BUFFER SYSTEMS:
Bicarbonate buffer system
Phosphate buffer system
Protein buffer system
Mixture of carbonic acid (H2CO3) & sodium bicarbonate (NaHCO3)
BICARBONATE BUFFER SYSTEM
______ react with strong acids to change them to weak acids
Bicarbonate ions (HCO3‾)
______ dissociates in the presence of a strong base to form a weak base and water.
Carbonic acid
prevents excessive water loss in urine
ADH
regulates Na+ content of ECF
ALDOSTERONE
Triggered by the renin-angiotensin mechanism
REGULATION OF WATER & ELECTROLYTE REABSORPTION
This general role of the kidneys involves a complex combination of renal functions:
-Secretion of renin
-Secretion of erythropoietin
-Conversion of the steroid prohormone vitamin D
-Gluconeogenesis
a protease important for the regulation of blood pressure by cleaving circulating angiotensinogen to angiotensin I;
renin
a glycoprotein growth factor that stimulates erythrocyte production in red marrow when the blood O2 level is low;
erythropoietin
to the active form (1,25-dihydroxyvitamin D3 or calcitriol);
Conversion of the steroid prohormone vitamin D, initially produced in the skin
during starvation or periods of prolonged fasting, making glucose from amino acids to supplement this process in the liver.
Gluconeogenesis
ORGANS & FUNCTION OF THE URINARY SYSTEM
KIDNEYS
URETERS
URINARY BLADDER
URETHRA
Regulate aspects of homeostasis: water balance, electrolytes, acid-base balance in blood, BP (renin) , RBC production (EPO), activation of vitamin D
Excretes wastes in urine
KIDNEYS
Transport urine from kidneys to urinary bladder
URETERS
Stores urine & expels it into urethra
URINARY BLADDER
Discharges urine from body
URETHRA
Lie against the dorsal body wall in a retroperitoneal position in the superior lumbar region
KIDNEYS
At the level of T12 to L3
KIDNEYS
_____ is slightly lower than the left
Right kidney
Attached to ureters, renal blood vessels, & nerves at renal hilum
KIDNEYS
Atop each is an adrenal gland
KIDNEYS
Adult: 12 cm (5in) long, 6 cm (2.5in) wide, & 3 cm (1in) thick
KIDNEYS
COVERINGS OF KIDNEY
FIBROUS CAPSULE
PERIRENAL FAT CAPSULE
RENAL FASCIA
Smooth, transparent sheet of dense irregular connective tissue that is continuous with the outer coat of the ureter
FIBROUS CAPSULE
Barrier against trauma & helps maintain the shape of kidney
FIBROUS CAPSULE
Mass of fatty tissue surrounding the fibrous capsule
PERIRENAL FAT CAPSULE
Protects the kidney from trauma & holds it firmly in place within the abdominal cavity
PERIRENAL FAT CAPSULE
Thin layer of dense irregular connective tissue
RENAL FASCIA
Anchors the kidney to the surrounding structures & to the abdominal wall
RENAL FASCIA
outer region
RENAL CORTEX
inside the cortex
RENAL MEDULLA
Triangular regions with a striped appearance
Renal/medullary pyramids
portions of the renal cortex that extend between renal pyramids
Renal columns
inner collecting tube
RENAL PELVIS
cup-shaped structures that funnel urine towards the renal pelvis
Calyces
The structural and functional units of the kidneys
Responsible for forming urine
NEPHRONS
MAIN STRUCTURES OF NEPHRON
RENAL CORPUSCLE
RENAL TUBULE
blood plasma is filtered
RENAL CORPUSCLE
capillary network
Glomerulus