Chapter 17 Urinary System Flashcards
Where are the kidneys located.
retroperitoneally - behind the parietal peritoneum and against the deep muscles of the back. On either side of the vertebral column.
Describe kidney structure.
bean shaped
two distinct regions, inner medulla and outer cortex.
Name the kidney’s functional unit.
Nephrons
List the general functions of the kidneys.
Maintains homeostasis
secretes erythropoietin, which helps control the rate of red blood cell production.
Helps in activation of vitamin D
maintains blood volume and blood pressure by secreting the enzyme renin.
Trace the blood supply to the nephron.
abdominal aorta flow to the renal arteries, which enter through the hilum and branch into the interlobar arteries, which then pass between the renal pyramids. At the medulla/ cortex junction, the interloper arteries branch into the arcuate arteries, which branch to cortical radiate arteries, then they become afferent arterioles that lead to the nephrons.
Abdominal aorta - renal arteries - interloper arteries - arcuate arteries, cortical radiate arteries, afferent arterioles, nephrons.
Name the parts of the nephron.
renal corpuscle which is mad of a tangled cluster of blood capillaries called a glomerulus surrounded by a glomerular capsule.
and a renal tubule, which receives fluid from the glomerular capsule. Fluid flows through the tubule on its way out of the body.
Describe the system of blood vessels associated with a nephron.
complex and freely interconnecting network with low pressure.
Which structures form the juxtaglomerular apparatus?
smooth muscle cells called juxtaglomerular cells and cells of the macula dense.
What determines the amount of substances in urine?
amount filtered at glomerulus - amount reabsorbed by tubules + amount secreted by tubules. = amount excreted in urine.
Which processes form urine?
Glomerular filtration, tubular reabsorption, and tubular secretion.
Which forces affect net filtration pressure?
hydrostatic pressure of blood, colloid osmotic pressure of plasma in the glomerulus.
Which factors influence the rate of glomerular filtration?
glomerular hydrostatic pressure, glomerular plasma osmotic pressure, or hydrostatic pressure int the glomerular capsule.
What is the function of the macula densa?
Its main function is to regulate blood pressure and the filtration rate of the glomerulus.
How does renin help regulate filtration rate?
When the sodium chloride concentration in the tubular fluid decreases,the macula densa senses these changes and causes the juxtaglomerular cells to secrete renin. Secretion of renin triggers a series of reactions leading to the production of angiotensin II, which acts as a vasoconstrictor; this may, in turn, affect filtration rate. Presence of angiotensin II also increases the secretion of aldosterone, which stimulates reabsorption of sodium.
Which chemicals are normally present in the glomerular filtrate but not in urine?
Glucose and proteins.
