Urinary Sys
System
tem
Known as body’s “filtration and removal plant”.
Organs:
o Kidneys: Extracts waste from the blood, precisely regulate and adjusts electrolytes levels, body fluid levels, PH
levels in blood and body tissues and forms urine
▪ Located in retroperitoneal space, adrenal gland located on top, extremely vascular.
▪ Hilum: notch where blood vessels, nerves, ureter enter.
o Ureters: Conducts urine from kidneys to urinary bladder, contains narrow tubes from renal pelvis to bladder,
carry urine from kidneys to balder for storage via peristalsis (mucosa, muscularis, fibrous coat)
o Urinary bladder: Serves as a reservoir for urine.
▪ Hollow, muscular sac, normally sterile; stores urine
▪ Urinary retention-inability to void, internal sphincter (involuntary), external sphincter
(voluntary), detrusor muscle.
o Urethra: Conducts urine from the bladder to the outside of the body for elimination.
▪ Tube leading to outside body.
▪ Men: 8 in long, passes through prostate gland, two ducts from male sex glands, join it through
the length of penis.
▪ Women: 1.5 in opens to outside at urinary meatus or urinary canal, passageway for urine only.
(women are more prone to urinary infections due to length of urethra)
Functions:
o Maintains homeostasis: maintains blood pressure, regulates electrolytes (reabsorbs some electrolytes), ph
balance, acid/base balance, activates vitamin D for bone calcification.
▪ Blood pressure regulation: maintained/partially controlled by specialized kidney mechanisms.
o Manufacture: renin and erythropoietin
o Processing of waste: filters blood, forms urine, stores urine and expels urine.
o Elimination: protein wastes, excess salts and toxic materials
▪ 750-2000 Ml of urine daily, formed in nephron by glomerular filtrations, tubular reabsorption,
tubular secretion.
▪ ADH: another method using hormonal control (integral part)
, Kidneys: Afferent arteriole-→Glomerulus and Bowman capsule→PCT→Loop of Henie→(Descending Loop=Ascending
Loop→DCT→Collecting Duct→Renal Pyramid→Renal Pelvis→Ureter→Bladder
Nephrons:
o Nephrons: (functional units of the kidney) form urine, 1 million (include
)
▪ ADH allows tubule to become partially permeable to water. ATP produced by mitochondria.
▪ Glomerulus and Bowman Capsule: filter water, wastes, glucose, salts out of blood
▪ Proximal Convoluted Tubule: reabsorbs some needed electrolytes, water, glucose and some
amino acids & bicarbonate.
▪ Loop of Henie: reabsorbs water and additional electrolytes.
▪ Distal convoluted tubule: reabsorbs sodium, water and remainder of glucose.
Hormones:
o Renin and RAA Mechanism
▪ Renin-regulates blood pressure, if bp or circulating blood is low, cells of JGA secrete renin:
activates RAA(angiotensin-aldosterone) mechanism to raise bp.
▪ Stimulates formation of angiotensin I, converted to angiotensin II-causes blood vessel
constriction, raise bp, stimulates adrenal cortex to secrete aldosterone (stimulates thirst center)
▪ Aldosterone-promotes sodium/water retention, increase blood volume and elevates bp.
▪ Antidiuretic Hormone (ADH): secreted by posterior pituitary gland, increases reabsorption of
water by kidney tubules, maintains homeostasis.
▪ Atrial natriuretic peptide (ANP): secreted by cells in atria of heart; increases kidney filtration and
blood flow when blood volume increases, causes kidneys to excrete water/sodium; suppresses
ADH and aldosterone secretion. (reduces strain on heart).
System
tem
Known as body’s “filtration and removal plant”.
Organs:
o Kidneys: Extracts waste from the blood, precisely regulate and adjusts electrolytes levels, body fluid levels, PH
levels in blood and body tissues and forms urine
▪ Located in retroperitoneal space, adrenal gland located on top, extremely vascular.
▪ Hilum: notch where blood vessels, nerves, ureter enter.
o Ureters: Conducts urine from kidneys to urinary bladder, contains narrow tubes from renal pelvis to bladder,
carry urine from kidneys to balder for storage via peristalsis (mucosa, muscularis, fibrous coat)
o Urinary bladder: Serves as a reservoir for urine.
▪ Hollow, muscular sac, normally sterile; stores urine
▪ Urinary retention-inability to void, internal sphincter (involuntary), external sphincter
(voluntary), detrusor muscle.
o Urethra: Conducts urine from the bladder to the outside of the body for elimination.
▪ Tube leading to outside body.
▪ Men: 8 in long, passes through prostate gland, two ducts from male sex glands, join it through
the length of penis.
▪ Women: 1.5 in opens to outside at urinary meatus or urinary canal, passageway for urine only.
(women are more prone to urinary infections due to length of urethra)
Functions:
o Maintains homeostasis: maintains blood pressure, regulates electrolytes (reabsorbs some electrolytes), ph
balance, acid/base balance, activates vitamin D for bone calcification.
▪ Blood pressure regulation: maintained/partially controlled by specialized kidney mechanisms.
o Manufacture: renin and erythropoietin
o Processing of waste: filters blood, forms urine, stores urine and expels urine.
o Elimination: protein wastes, excess salts and toxic materials
▪ 750-2000 Ml of urine daily, formed in nephron by glomerular filtrations, tubular reabsorption,
tubular secretion.
▪ ADH: another method using hormonal control (integral part)
, Kidneys: Afferent arteriole-→Glomerulus and Bowman capsule→PCT→Loop of Henie→(Descending Loop=Ascending
Loop→DCT→Collecting Duct→Renal Pyramid→Renal Pelvis→Ureter→Bladder
Nephrons:
o Nephrons: (functional units of the kidney) form urine, 1 million (include
)
▪ ADH allows tubule to become partially permeable to water. ATP produced by mitochondria.
▪ Glomerulus and Bowman Capsule: filter water, wastes, glucose, salts out of blood
▪ Proximal Convoluted Tubule: reabsorbs some needed electrolytes, water, glucose and some
amino acids & bicarbonate.
▪ Loop of Henie: reabsorbs water and additional electrolytes.
▪ Distal convoluted tubule: reabsorbs sodium, water and remainder of glucose.
Hormones:
o Renin and RAA Mechanism
▪ Renin-regulates blood pressure, if bp or circulating blood is low, cells of JGA secrete renin:
activates RAA(angiotensin-aldosterone) mechanism to raise bp.
▪ Stimulates formation of angiotensin I, converted to angiotensin II-causes blood vessel
constriction, raise bp, stimulates adrenal cortex to secrete aldosterone (stimulates thirst center)
▪ Aldosterone-promotes sodium/water retention, increase blood volume and elevates bp.
▪ Antidiuretic Hormone (ADH): secreted by posterior pituitary gland, increases reabsorption of
water by kidney tubules, maintains homeostasis.
▪ Atrial natriuretic peptide (ANP): secreted by cells in atria of heart; increases kidney filtration and
blood flow when blood volume increases, causes kidneys to excrete water/sodium; suppresses
ADH and aldosterone secretion. (reduces strain on heart).
