Chapter 25 Urinary System Flashcards
What are the functions of kidneys?
- regulates water vol and solute concentration in water
- regulates ion concentration in ECF
- gluconeogenesis
- exerts metabolic waste, toxins and drugs
- activates vit D
Kidney produce erythropoietin. What does erythropoietin do?
regulates blood pressure and renin (RBC production)
What region is the kidney located?
Retroperitoneal (superior lumbar region)
What gland is above the kidney?
adrenal (suprarenal)
Surface of kidney
convex (outward) lateral surface, concave (inward) medial surface
3 Layers of supportive tissue surrounding kidney
- Renal fascia (OUTER): dense fibrous connective tissue
- Perirenal Fat Capsule: fatty cushion
- Fibrous capsule (INNER): protection
What does the third layer of the kidney do?
Fibrous capsule: biological protection from infection and virus
How much cardiac output does the renal arteries deliver?
one fourth, 1200 ML per Min
What does the glomeruli do?
filters blood and forms filtrate
How do kidneys get nerve supply?
via sympathetic fibers from renal plexus
What does the nerve supply in kidneys do?
regulates blood flow to renal arterioles and influence urine production in nephron
Increase blood pressure increases…
urine production
Blood vessel flow
aorta —>renal art.—> segmental art.—-> Interlobar art.—>arcuate art. —-> cortical radiate art —> afferent arteriole—> glomerulus —> efferent arteriole —> peritubular capillaries/ vasa recta —> cortical radiate v. —>arcuate v. —>interlobar v. —->renal v. —-> inferior vena cava
What are nephrons?
structural and functional units that create urine
What are themain parts of nephrons?
Renal corpuscle and renal tibule
- PCT (proximal convoluted tubule) - directly attached to corpuscle
- Loop of henle (descending and ascending limb)
- DCT (distal convoluted tubule)
Thick segment of ascending limb: type of cell
simple cubodial or short columnar
Thin segment of descending limb: type of cell
simple squamous epithelium
Types of cells in nephrons?
(Parietal) Glomerular capsule: simple sqamous epitherlium
(Visceral): Podocytes
Proximal convulated tublule cells: microvilli and cubodial cells
Proximal convulated tublule cells: similar to proximal, no/few microvilli
Nephron Loop (thin segement) cells
Collecting duct cells:
Glomerular capsule visceral layer: podocytes functions
Modified epithelium cells with filtration slits that capture molecules are filtrate is forming and surround the glomerulus.
Foot like extensions.
Glomerular Capsule (parietal layer)
Podocytes: epithelial cells
have foot processes that cling to the basement membrane of the glomerulus. The clefts or openings between the foot processes are called filtration slits. Through these slits, filtrate enters the capsular space inside the glomerular capsule.
Proximal Convulated tubule cells
microvilli increases surface area and increases absorption
cubodial cells - uniform appearance and very controlled
reabsorb h20 and solutes back INTO blood
secrete substances into filtrate OUT of blood and end up in urine
Distal convulated tubule cells
a few or no microvilli, very similar to PCT but shorter
Collecting duct cells
Principal cells= more numerous
short microvilli
Maintains the water and sodium balance
Intercalated cells = less numerous (type A and type B cells) They maintain Acid/ base balance of blood
Two major classes of nephron
cortical and juxtamedullary
What percentage of nephrons is cortical?
85%
Juxtamedullary nephron ascending limbs are..
both thick and thin and invade the medulla
Why are juxtamedullary nephrons important?
important in production of concentrated urine
What is consisted in the Renal Corpuscle?
Squamous epithelium (Parietal layer of glomerular corpuscle)
Glomerular capsular space
Glomerulus
What does the capsular space of renal corpuscle do?
captures filtrate that is forced from glomerulus
What is consisted in the juxtaglomerular complex?
Macula Densa cells
Extraglomerular mesangial cells
Granular cells
What does the juxtaglomerular complex do?
Checks Blood Pressure and salinity and modifies it
Communicates to release hormones
What does the afferent arteriole do for the glomerulus?
Supplies the glomerulus
What does the efferent arteriole do for the glomerulus?
drains it
How much fluid and urine is formed?
180 L fluid processed
1.5 urine formed DAILY
How much blood passes the glomeruli each min?
1200 ml
650ml plasma
20% 125 ml of plasma becomes filtrate
