56. Functions of the kidneys in homeostasis. Physiological anatomy of the
kidneys - the nephron as a functional unit of the kidney. Renal blood supply.
Glomerular filtration - the first step in urine formation. Physiological control of
glomerular filtration.
Functions of the kidneys in homeostasis.
The functions of the kidney in the maintenance of homeostasis include the following:
● Excretion of metabolic waste products and foreign chemicals
● Regulation of water and electrolyte balances
● Regulation of body fluid osmolarity and electrolyte concentrations
● Regulation of arterial pressure through excretion of varying amounts of sodium
and water and secretion of substances such as renin that lead to formation of
vasoactive products such as angiotensin II
● Regulation of acid-base balance through excretion of acids and regulation of
body fluid buffer stores
● Regulation of erythrocyte production through secretion of erythropoietin, which
stimulates red blood cell production
● Regulation of 1,25-dihydroxyvitamin D3 production
● Synthesis of glucose from amino acids (gluconeogenesis) during prolonged
fasting
● Secretion, metabolism, and excretion of hormones.
Physiological anatomy of the kidneys - the nephron as a functional unit of the
kidney.
● The two kidneys lie on the posterior wall of the abdomen, outside the peritoneal
cavity.
● The medial side of each kidney contains an indented region called the hilum
through which pass the renal artery and vein, lymphatics, nerve supply, and
ureter, which carries the final urine from the kidney to the bladder, where it is
stored until emptied.
● If the kidney is bisected from top to bottom, the two major regions that can be
visualized are the outer cortex and the inner region referred to as the medulla.
● The medulla is divided into renal pyramids. The base of each pyramid originates
at the border between the cortex and medulla and terminates in the papilla,
which projects into the space of the renal pelvis, a continuation of the upper end
of the ureter.
● The outer border of the pelvis is divided into open-ended pouches called major
calyces that extend downward and divide into minor calyces, which collect urine
from the tubules of each papilla.
kidneys - the nephron as a functional unit of the kidney. Renal blood supply.
Glomerular filtration - the first step in urine formation. Physiological control of
glomerular filtration.
Functions of the kidneys in homeostasis.
The functions of the kidney in the maintenance of homeostasis include the following:
● Excretion of metabolic waste products and foreign chemicals
● Regulation of water and electrolyte balances
● Regulation of body fluid osmolarity and electrolyte concentrations
● Regulation of arterial pressure through excretion of varying amounts of sodium
and water and secretion of substances such as renin that lead to formation of
vasoactive products such as angiotensin II
● Regulation of acid-base balance through excretion of acids and regulation of
body fluid buffer stores
● Regulation of erythrocyte production through secretion of erythropoietin, which
stimulates red blood cell production
● Regulation of 1,25-dihydroxyvitamin D3 production
● Synthesis of glucose from amino acids (gluconeogenesis) during prolonged
fasting
● Secretion, metabolism, and excretion of hormones.
Physiological anatomy of the kidneys - the nephron as a functional unit of the
kidney.
● The two kidneys lie on the posterior wall of the abdomen, outside the peritoneal
cavity.
● The medial side of each kidney contains an indented region called the hilum
through which pass the renal artery and vein, lymphatics, nerve supply, and
ureter, which carries the final urine from the kidney to the bladder, where it is
stored until emptied.
● If the kidney is bisected from top to bottom, the two major regions that can be
visualized are the outer cortex and the inner region referred to as the medulla.
● The medulla is divided into renal pyramids. The base of each pyramid originates
at the border between the cortex and medulla and terminates in the papilla,
which projects into the space of the renal pelvis, a continuation of the upper end
of the ureter.
● The outer border of the pelvis is divided into open-ended pouches called major
calyces that extend downward and divide into minor calyces, which collect urine
from the tubules of each papilla.
