The Urinary System

Kidney Functions (1)

• Your kidneys filters your blood daily, allowing urinary excretion of toxins, metabolic wastes, and excess ions

• Kidneys also regulate the volume and chemical makeup of the blood

• Kidneys maintain homeostatic balance between water and salts, and acids and bases

Associated excretory organs & functions (2)

• Urinary bladder – urine reservoir

• 2 ureters – urine transportation to bladder from kidneys

• Urethra – urine transport from bladder to outside world

Tissue layers supporting the kidney (3)

• Renal capsule – fibrous capsule that prevents kidney infection

• Adipose capsule – fatty mass that cushions the kidney and attaches it to the body wall

• Renal fascia – outer layer of dense fibrous tissue that anchors the kidney

Major parts of the kidney and their function (4)

• Cortex - the light colored, granular superficial region

• Medulla - exhibits cone-shaped medullary (renal) pyramids

Major parts of the kidney and their function (4) continued

• Renal pelvis - flat, funnel-shaped tube lateral to the hilum within the renal sinus

– A hilum is part of an organ where structures such as blood vessels and nerves enter.

– The hilum of kidney is the medial depression for blood vessels and ureter to enter the kidney chamber

• (admits the renal artery, vein, ureter, and nerves)

Urinary infections (5) UTIs

• Pyelitis - Acute inflammation of the pelvis of the kidney, caused by bacterial infection.– the renal pelvis, the central part of the kidney

is where urine accumulates before discharge.

– It is more common in women than in men.

Pyelonephritis• pyelonephritis is when a urinary tract infection

has reached the pyelum (pelvis) of the kidney

• Symptoms include:

• Loin pain, often severe

• Fever and shivers

• Blood-stained urine

• Foul-smelling and cloudy urine

• Painful and frequent urination

• Nausea and vomiting

Volume of blood filtered daily (6)

• 200 liters!

• The kidneys filter the body’s entire plasma volume 60 times each day

Parts of the nephronParts of the nephron (7) A normal kidney contains 800,000 to one million nephrons

• Renal corpuscle consists of

• Glomerulus – a tuft of capillaries associated with a renal tubule

• Bowman’s capsule – a cup-like sac that houses the glomerulus

Glomerulus inside Bowman’s capsule together called Renal Renal CorpuscleCorpuscle

Renal Tubule

• PCT - Proximal convoluted tubule – reabsorbs water and solutes from filtrate & secretes substances into it

• Loop of Henle – part of the PCT that is hairpin shaped

• DCT - Distal convoluted tubule – functions more for secretion than reabsorption

Renal Tubule continuedCollecting tubule and collecting Collecting tubule and collecting ductduct

• Receive filtrate from many tubules giving a striped appearance

• As collecting ducts reach renal pelvis, fuse to form large papillary ducts

• Ducts deliver urine into minor calyces via papillae of pyramids