URINARY SYSTEM Flashcards
URINARY SYSTEM Composed of:
- Kidney
- Ureter
- Urinary bladder
- Urethra
- Paired, reddish brown, retroperitoneal
Coverings
1.Renal capsule
2.Perirenal fat (perinephric fat)
3.Renal fascia (gerota’s fascia)
4.Pararenal (paranephric fat)
Kidney
– immediate covering of the kidney
Renal capsule
– around the renal capsule
Perirenal fat (perinephric fat)
– external to perirenal fat; continuous with transversalis fascia
Renal fascia (gerota’s fascia)
– outermost
Pararenal (paranephric fat)
2 parts of kidney
1.Cortex – outer
2.Medulla – inner
* Renal pyramids
* Renal column
* Renal Pelvis
* Major calyx
triangle in medulla of kidney
- Renal pyramids
extension of cortex towards the medulla; between the pyramids
Renal column
– union of major calyces
Renal Pelvis
– union of minor calyces
Major calyx
- Structural and functional unit of the kidney
- 1 million nephron each kidney
Consist of
1.Glomerulus – top of capillaries
2.Bowman’s capsule
3.Proximal convoluted tubule
4.Loop of henle
5.Distal convoluted tubule – yung kulot
Nephron
– papasok ng glomerulus
Afferent arteriole
– palabas ng glomerulus
Efferent arteriole
– this will be the collecting duct that will drain to your minor calyx
Collecting tubule
1.Inner visceral layer
* Composed of podocytes, octopus like
that terminates in branching pedicles
* Podocyte cell processes will be forming
filtration slits, together with the
endothelium of the capillary will form
the filtration membrane
2.Parietal layer
* Simple squamous epithelium
Bowman’s capsule
- Glomerulus plus bowman’s capsule
- Juxtaglomerular apparatus – consist of
a. JG cell (Juxtaglomerular cells)
b. Macula densa
c. Mesangial cell
Renal (Malphigian) corpuscle
o Secreting substance called Renin
JG cell (Juxtaglomerular cells)
o Extra glomerular mesangial cell/ Lacis cells
Mesangial cell
o Part of the distal convoluted tubule - Cuboidal cells
o Columnar cells – adjacent to the afferent arteriole
Macula densa
is the movement of materials across the filtration membrane into Bowman’s capsule to form filtrate
Filtration
solutes are reabsorbed (purple arrow) across the wall of the nephron into the interstitial fluid by transport process, such as active transport and cotransport.
Reabsorption
solutes are secreted (orange arrow) across the wall of the nephron into the capillaries.
Secretion
- Acts as a filter
- 1/5 of blood flowing through the kidneys is filtered from the glomeruli
- Through filtration membrane: podocyte cell processes, basement membrane & capillary endothelium
Glomerular filtration
o a force that push the water and solutes across the filtration membrane
Glomerular hydrostatic pressure
o opposes filtration, hold the fluid inside the glomerulus exerted by plasma protein
o plasma protein – like a magnet for the fluid
Glomerular osmotic pressure
o opposes filtration, force exerted by the fluid inside the bowman’s capsule
Capsular hydrostatic pressure
- Force responsible for filtrate formation
- NFP = glomerular hydrostatic pressure – (glomerular oncotic pressure + capsular hydrostatic pressure)
Net filtration pressure
- Urine osmolarity ranges from 50-1200mosm
- Hyperosmolarity of the medullary fluid ensures that the urine reaching the DCT is hypo-osmolar
- In the absence of Antidiuretic hormone (ADH), urine becomes diluted – If you don’t have ADH, your water will not be inhibited from going out of your system. Water will be joining the solutes therefore; the urine will become diluted.
- When Blood ADH increases the permeability of DCT and collecting duct to water increases (the water will not be going out, your ADH will hold the water in)
- Increased osmolality/ large decrease in BP – you have less water (decreased Fluid volume)
- Increased ADH release – the kidney will increase water reabsorption in decreased osmolality and increased BP(increased Fluid volume)
- When you have decreased BP, JG cells will secrete the renin
read the Regulation of Urine concentration and volume
- adding substance to the filtrate from blood or tubular cells
- Can be active or passive
- Important in eliminating urea, excess ions, drugs, and maintaining acid base balance
Tubular secretion
- The process of returning needed substance from the filtrate to the capillary blood
- Active or passive depending on a particular substance
- Proximal Convoluted Tubule (PCT) is the most active 80% of filtrate, nutrients water and Na, the bulk actively transported ions are reabsorbed here
- Reabsorption in Distal Convoluted Tubule (DCT) tubule and collecting duct is controlled by Aldosterone and antidiuretic hormone
Tubular reabsorption
- amount of filtrate formed per minute time
- Equal to 125ml/min
- Directly proportional to the net filtration pressure
Glomerular Filtration Rate
- will be circulating in the lungs
- angiotensin converting enzyme, this will be converted into Angiotensin II
Angiotensin I
- protein in your blood
- this will be converted by renin into Angiotensin I
Angiotensinogen
- vasoconstrictor, there will be an increased in BP
- it will stimulate the aldosterone secretion from your adrenal cortex
- aldosterone – will increased Na and water reabsorption results in increased BP
Angiotensin II
- The rate at which the kidneys clear the plasma for a particular solute
Renal clearance
- 10 inches long muscular tube
3 anatomical constrictions
1. at the uretero-pelvic junction
2. where iliac vessels cross the ureter
3. where it joins the urinary bladder
Ureter
- Prostatic
- Membranous
- Penile(spongy)
Urethra Male
- Hollow muscular organ
- Temporary storage of urine
- Wall consist of detrusor muscle
- Will contain folds called rugae; without rugae called trigone – smooth area
- Inner – trigone occupied by ureteral orifices and urethral orifice
Urinary Bladder
- widest, most dilatable, prostate gland
Prostatic
– traverses’ urogenital diaphragm, shortest and least dilatable
Membranous
- longest, traverses corpus spongiosum
Penile(spongy)
- 4cm
- Opens into vestibule
Urethra Female
