kidney physiology

adipose capsule

Adipose surrounding the kidney protecting it from mechanical injuries.

What is the adipose capsule made of?

structural fat

what is structural fat used for?

Unlike typical adipose, structural fat is not used as an energy reserve for the body.

Fibrous Capsule

 this thin, membranous sheath is composed of tough fibers, chiefly collagen and elastin

What does the fibrous capsule do?

The fibrous capsule helps protect  vital kidney tissue from injury.

why can the fibrous capsule be hard to remove?

Kidney disease

Hilus

a depression or pit where blood vessels and nerves enter or leave an organ.

Renal Artery

The right and left renal arteries arise from the lateral aspects of the abdominal aorta. The right renal artery is longer than the left. The renal arteries carry blood to the kidneys, adrenal glands, and ureters.

Renal Vein

Renal veins are large and pass anterior to the renal arteries. The left renal vein is longer than the right. Both renal veins exit the kidney at the renal hilus and carry venous blood to the inferior vena cava.

Ureter

transports urine from the renal pelvis of one kidney to the urinary bladder.

How do Ureters transport urine?

Peristaltic contractions of the muscular walls of the ureters move urine toward the urinary bladder, but hydrostatic pressure and gravity also contribute.

How many peristaltic contractions happen per minute

one to five per minute

Urinary Bladder

a hollow, distensible muscular organ situated in the pelvic cavity posterior to the pubic symphysis. In males, it is directly anterior to the rectum. In females, it is anterior to the vagina and inferior to the uterus.

Urinary Bladder

a hollow, distensible muscular organ situated in the pelvic cavity posterior to the pubic symphysis. In males, it is directly anterior to the rectum. In females, it is inferior to the uterus.

What does the urinary bladder look like when empty?

collapsed

What does the urinary bladder look like when half full?

spherical

What does the urinary bladder look like when full?

pear-shaped

Urethra

a small tube leading from the internal urethral orifice in the floor of the urinary bladder to the exterior of the body.

Renal Sinus

The cavity that expands inward from the renal hilus. The Renal sinus contains part of the renal pelvis, the calyces, and branches of the renal blood vessels and nerves.

Renal Pelvis

The renal pelvis is the single, large cavity that urine from the major calyces drains into.  

Renal Cortex

The most peripheral zone of the kidney. Identified by its pale color and fine, granular appearance.

Renal Medulla

The more centrally located zone of the kidney. Identified by its darker color and striated appearance. 

Medullary Rays

Medullary rays are formed wherever medullary tissue extends up into the cortex

Renal Pyramid

In humans, the renal medulla consists of 8-18 cone-shaped renal pyramids. (In the cat, the entire medullary substance is arranged in such a manner that it forms a single renal pyramid.

Renal Papilla

the renal papilla is a conical structure located at the apex of each renal pyramid.

Calyx

The papillary ducts drain into cuplike structures called minor and major calyces

Renal Lobe

a renal lobe consists of a renal pyramid, its overlying area of renal cortex, and one-half of each adjacent renal column.

Parenchyma

the functional tissue of an organ or structure

How many nephrons reside in a single human kidney?

About 1-1.25 million microscopic structures called nephrons reside within the parenchyma

Interlobar Arteries

 the renal artery divides into several segmental arteries, which supply different segments (areas) of the kidney.

Arcuate Arteries

At the bases of the renal pyramids, the interlobar arteries arch between the renal medulla and cortex. Here, they are known as the arcuate arteries because they arch over the bases of the renal pyramids.