Functions of renal system
Outer Structure and Location of Kidney
Structure: paired organs in posterior region of abdominal cavity (retroperitoneum). Lie on either side of vertebral column, upper and lower poles go from T12 to L3.

Inner structure of kidney

Functional unit of the kidney is the ____________.
nephron
Structural composition of nephron

What are the three kinds of nephrons in the kidney?
1) superficial cortical nephrons: 85% of nephrons, extend partially into the medulla
2) midcortical nephons: has short or long loops
3) juxtamedullary nephrons: ~12% of nephrons which lie close to and extend deep into the medulla (~40mm); important for concentration of urine
Composition of the renal corpuscle
1) Glomerulus: tuft of capillaries that loop into the Bowman capsule (like fingers pushed into bread dough). Blood supply from afferent arteriole, drained by efferent arteriole.
2) Bowman capsule/space
3) Mesangial cells: shaped like smooth muscle cells; secrete mesangial matrix (type of connective tissue) and lie between and support capillaries. Also have phagocytic abilities simliar to monocyes, release inflammatory cytokines, and can contract to regulate glomerular capillary blood flow.

Glomerular Filtration Membrane - Structure and Function
Structure: 3 layers
Function: filters blood components through its three layers. Separates the blood of glomerulr capillaries from fluid in Bowman space to allow filtration to occur (with the exception of blood cells and plasma proteins with a high MW). Filtrates passes through and finally becomes primary urine.
Structure and function of the juxtaglomerular apparatus
Structure:
Function: control of renal blood flow, glomerular filtration, renin and secretion

Structure of proximal convoluted tubule

Structure of loop of Henle

Structure of distal tubule

What are the major blood vessels of the kidney?
1) Renal arteries
2) Interlobar artery
3) Arcuate arteries
4) Glomerular capillaries
5) Peritubular capillaries
6) Vasa recta
7) Renal veins

Where do renal arteries originate and end?
Originate: as 5th branches of abdominal aorta, dividing into anterior and posterior branches at renal hilum, subdivide into lobar arteries
End: lower, middle, and upper thirds of kidney
Structure of interlobar artery
subdivisions travel down renal colummns and between pyramids, form afferent glomerular arteries
Structure of arcuate arteries
made of branches of interlobar arteries at cortical-medullary junction and arches over the base of pyramids and run parallel to the surface
Structure of glomerular capillaries
Structure of peritubular capillaries
Structure of vasa recta
Structure of renal veins
Flow of urine
formed by nephrons & flows from distal tubules and collecting ducts through papillary ducts to the renal papillae (projections of the ducts) into the calyces, where it is collected in the renal pelvis and then funneled into the ureters
Describe the structure & innervation of the ureters, and flow of urine through the ureters
Structures:
Flow of urine mechanism:

Structure of bladder
Structure: bag of smooth muscle that forms the destrusor muscle and smooth uroepithelium lining. Uroepithelium forms the interface between urinary space and underlying vasculature and connective/nervous/muscle tissue.

Function of uroepithelium