Unit 5: Urinary system

Organs in the urinary system

Kidney, ureter, urinary bladder, urethra

Function of the urinary system

• Filters cellular waste products from the blood

• Regulates ion levels in the blood

• Helps regulate blood pH

• Helps conserve valuable nutrients

• Helps regulate fluid volumes in the body by regulating the volume of blood

• Regulates the production of erythrocytes

• Stores and then excretes (eliminates) urine from the body

Location of the kidneys

Retroperitoneal and in the costal region. The right kidney is slightly inferior to the left kidney

Regions of the kidney

Cortex, medulla, hilum

Hilum

indentation on one side, where vessels enter and exit kidneys

Sinus

Fibrous capsule

Adipose tissue

Fibrous outer layer

Renal cortex

The outermost layer of the kidneys. It is lighter in color

Renal medulla

The innermost layer of the kidneys. It is darker in color

Renal pyramid

Triangular shaped structures of the medulla

Renal papilla

The apex of the renal pyramid

Minor calyces

Sits at the apex of each pyramid and collects urine

Major calyces

Collects urine from 4-5 minor calyces

Renal pelvis

Collects urine from major calyces

Nephron

Structural and functional unit of the kidney. There are about 1 million nephrons per kidney

Major regions of the nephrons

Renal corpuscle (Glomerulus and glomerular capsule) and Renal tubule (proximal convoluted tubule, loop of Henle, distal convoluted tubule)

Structures of the collecting system

Collecting duct, papillary duct, minor calyces

Pathway of urine

Glomerular capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule

Collecting duct, papillary duct, renal papilla, minor calyx, major calyx, renal pelvis, ureter, bladder, urethra

Glomerulus

Knot of fenestrated capillaries

Study filtration, reabsorption, and secretion

Blood flow through the kidneys

Glomerular filtration rate

The amount of filtrate produced per minute by all of the nephrons

Ureters

Connect kidneys to bladder; transports urine

Bladder

Stores urine. In males it is located posterior to the pubic symphysis and anterior to the rectum. In females it is located posterior to the pubic symphysis and inferior to the uterus

Urethra

Transports urine (in males it transports urine and sperm)