Introduction to Urinary System and Gross Anatomy of the Kidney

Left and Right Kidenys

Filter blood to produce urine

Left and RIght Ureters

Carry urine to the urinary bladder

Urinary bladder

Store urine until urination

Urethra

Expels urine from the body in males and females. Also expels semen during ejaculation for males

Basic function of the urinary system/Kidneys

Constantly filters blood to maintain blood composition and remove waste. Excess fluid, molecules, and wastes are collected in urine. Storage and elimination of urine from the body

By filtering blood Kidneys can regulate

Blood ion/electrolyte concentration

Blood/body fluid pH

Blood volume

Location of Kidneys

In abdominal cavity (retroperitoneal)

Left kidney: Between 10th and 12th rib

Right kidney: Slightly lower than left to make room for the liver

Hilum (gross anatomy of kidney)

Indentation of medial side of the kidney, where blood vessels, nerves, lymphatic, and renal pelvis are attched

Renal sinus (gross anatomy of kidney)

Space in the center of the Kidney containing adipose tissue and urine collection tubes

Fibrous capsule/Renal capsule

thin surrounding the kidney made up of dense CT

Three distinct regions of Kidney tissue

Renal cortex, renal medulla, Urine collection tubes

Renal cortex

An outer layer of kidney tissue that is lighter in color

Renal medulla

Inner, darker layer Contains cone shaped structures called renal pyramids; between each renal pyramid is a region of cortex tissue that dips down into the medulla called a renal column

Urine collection tubes

Tubes in the center of the kidney that drain urine from the renal papillae into the ureters. Minor and Major Calyces, and Renal pelvis

Minor calyces

Attached to renal papillae, drain urine from renal papillae, one or more merge to form Major calyces

Major calyces

Formed by merging one or more minor calyces, drain urine from minor calyces into renal pelvis, all the major calyces merge to form renal pelvis

Renal pelvis

Flat, funnel-shaped tube in the center of the kidney that bends inferiorly out of the hilum of the kidney into the ureter.

Blood vessels of the kidney

The kidney filters your entire blood volume about 6 times every day, so blood flow through the kidney is essential to understanding its function

Flow of blood from Renal artery to renal vein

Renal artery → Segmental artery → Interlobar artery → Cortical Radiate artery Afferent arteriole → Glomerulus → Efferent Arteriole Nephron capillaries → Venules → Cortical Radiate vein → Arcuate vein → Interlobar vein → Renal vein