A&P Chapter 23 Renal System Flashcards
What is the primary function of the Renal System?
To maintain homeostasis by regulating concentrations of WATER and SOLUTES in the blood.
It DISPOSES of metabolic wastes, excess water, excess ions and toxins while RETAINING the proper amount of H2O, the proper concentrations of ions (especially Na+ and K+), the proper nutrients and anything else needed in the blood.
What is the secondary function of the Renal System?
It regulates the blood pressure to keep it within normal ranges.
What are the organs of the Renal System?
The Right and Left Kidneys which sit in the RETROPERITENEAL space at about the 12th rib.
The Ureters which deliver urine to the bladder.
The Urinary Bladder which stores urine until it is excreted.
Describe the Kidneys
They are located high in the abdominal cavity posterior to the PERITONEUM. The RIGHT kidney is slightly inferior to the left.
They are approx. 150g and ~12X6X3cm.
The lateral surface is convex and the medial surface is concave with a HILUS/HILUM where the blood vessels, nerves, ureters and lymphatic vessels enter/exit.
Describe the internal structure of the Kidneys
The outer surface is the CAPSULE which is a dense irregular connective tissue covering.
Directly deep to that is the CORTEX which is a solid region.
Deep to the cortex is the MEDULLA which contains 8-12 cone shaped masses called RENAL PYRAMIDS. The pyramids are separated by RENAL COLUMNS.
The PELVIS of the kidneys is the hollow medial region with extensions called Calyses. They connect to the ureters to deliver urine to the bladder.
Trace the blood flow through the Kidney, name all ARTERIES AND VEINS IN ORDER.
Renal Arteries, Lobar Arteries, Interlobar Arteries, Arcuate Arteries (reside BETWEEN the Cortex and Medulla), Interlobular Arteries (which travel into both the cortex and medulla), Afferent Arterioles, Glomerulus, Efferent Arterioles, Peritubular Capillaries, —-> Interlobular Veins, Interlobar Veins, Lobar Veins, to the Renal Vein.
Which blood vessels in the Kidneys are Elastic? Which are Muscular? What vessels run between the Pyramids in the Renal Columns? Which vessels run between the cortex and medulla? Which vessels run into the cortex and the medulla?
The Renal Arteries are Elastic.
The Lobar and Interlobar Arteries are Muscular arteries.
The Interlobar Arteries and Veins run through the renal columns between the pyramids.
The Arcuate Arteries and Veins run between the renal cortex and medulla.
The Interlobular Arteries and Veins run into the cortex and medulla.
Where is the only PORTAL ARTERIOLE?
Between the capillaries in the Glomerulus and the Peritubular capillaries, this is the only place where an artery runs between the two capillary beds rather than a vein.
Where do ALL the Glomeruli reside?
In the RENAL CORTEX.
What is the series of tubes that filters out plasma from blood passing through the Glomerulus?
A Nephron
What type of Epithelia makes up the Nephron?
A Simple Squamous Epithelium
Trace the flow of the fluid that eventually becomes urine through the parts of a Nephron.
The Afferent arteriole delivers blood into the Glomerulus, the plasma filters into the GLOMERULAR CAPSULE, then into the PROXIMAL CONVOLUTED TUBULE then to the LOOP OF HENLE then to the DISTAL CONVOLUTED TUBULE and then to the COLLECTING DUCT.
How many nephrons does a kidney contain?
About 1 Million.
The Proximal Convoluted Tubule of a Nephron ALWAYS exists in which part of the kidney?
The RENAL CORTEX.
What parts of a Kidney make a single Lobe?
A Renal Pyramind, the Cortex above it and the Capsule above it.
What parts of a nephron make up the Renal Cortex? Which parts make up the Renal Medulla/Pyramid? What is found in the Renal Columns?
The cortex consists primarily of convoluted tubules and the Medulla/Pyramid is primarily the Loops of Henle and the Collecting ducts.
Blood vessels and connective tissues are found in the Renal Columns.
Describe the Functional Steps of filtration/reabsorption in a nephron.
- Glomerular filtration creates a plasmalike filtrate from the blood.
- Tubular reabsorption (occurring in the proximal convoluted tubule, loop of henle and distal convoluted tubule via the peritubular capillaries) removes useful solutes from the plasmalike filtrate and returns them to the blood.
- Tubular secretion removes additional wastes from the blood and adds them to the filtrate.
- Concentration occurs, water is removed from the urine/put back into the blood and wastes are concentrated.
What are the types of pressure involved in filtration and reabsorption?
Hydrostatic Pressure and Osmotic Pressure