Excretory Flashcards
- paired, reddish brown, retroperitoneal
Kidney
Kidney coverings:
- Renal capsule
- perirenal fat (perinephric fat)
- renal fascia (gerota’s fascia)
- continuous with transversalis fascia - Pararenal (paranephric fat)
Which kidney is lower?
Right
Kidney 2 parts:
2 parts:
1. cortex
- outer
2. medulla - inner
- union of major calyces
Pelvis
- union of minor calyces
Major calyx
- Structural and functional unit of the kidney
- 1 million nephron each kidney
Nephron
Nephron Consist of the ff:
- glomerulus
- bowman’s capsule
- Proximal convoluted tubule
- Loop of henle
- Distal convoluted tubule
Bowman’s capsule
1.Inner visceral layer
2. Parietal layer
- composed of podocytes, octopus like that terminates in branching pedicles (Bowman’s capsule)
Inner visceral layer
simple squamous epithelium (Bowman’s capsule)
Parietal layer
Glomerulus plus bowman’s capsule
Juxtaglomerular apparatus- consist of the ff:
1. JG cells
2. Macula densa
3. Mesangial cell
Renal(Malphigian) corpuscle
Juxtaglomerular apparatus- consist of the ff:
- JG cells
- Macula densa
- Mesangial cell
Mechanism of urine formation
- Glomerular filtration
- Tubular reabsorption
- Tubular secretion
- Acts as a filter
- 1/5 ofblood flowing through the kidneys is filtered from the glomeruli
- Through filtration membrane
Glomerular filtration
Pressures acting on the Glomerulus
- Glomerular hydrostatic pressure
- Glomerular osmotic pressure
- Capsular hydrostatic pressure
- a force that push the water and solutes across the filtration membrane (Pressures acting on the Glomerulus)
Glomerular hydrostatic pressure
- opposes filtration, hold the fluid inside the glomerulus exerted by plasma protein (Pressures acting on the Glomerulus)
Glomerular osmotic pressure
- opposes filtration, force exerted by the fluid inside the bowman’s capsule (Pressures acting on the Glomerulus)
Capsular hydrostatic pressure
- Force responsible for filtrate formation
Net Filtration Pressure
NFP=
glomerular hydrostatic pressure- (glomerular oncotic pressure + capsular hydrostatic pressure)
- Refers to the amount of filtrate formed per minute time
- Equal to 125ml/min
- Directly proportional to the net filtration pressure
Glomerular Filtration Rate
- The process of returning needed subts from the filtrate to the capillary blood
- Active or passivedepending on a particular substance
- PCT is the most active 80% of filtrate, nutrients water and Na, the bulk actively transported ions are reabsorbed here
- Reabsoption in DCT tubule and collecting duct is controlled by Aldosterone and antidiuretic hormone
Tubular reabsortion
- 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
Urine osmolarity ranges from ____________
50-1200mosm
In the absence of ADH, urine becomes _____________
diluted
When Blood ADH increases the permeability of DCT and collecting duct to water _____________
increases
_____________of the medullary fluid ensures that the urine reaching the DCT is hypo-osmolar
Hyperosmolarity
- 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
- 3 anatomical constrictions of ureter
- at the uretero-pelvic junction
- where iliac vessels cross the ureter
- where it joins the urinary bladder
- Hollow muscular organ
- Wall consist of detrussor muscle
- Inner- trigone occupied by ureteral orifices and urethral orifice
Urinary bladder
Male urethra
a. prostatic
b. membranous
c. penile
- widest, most dilatable (Male urethra)
prostatic
- traverses urogenital diaphragm, shortest and least dilatable (Male urethra)
membranous
- longest, traverses corpus spongiosum (Male urethra)
penile
- 4 cm
- opens into vestibule
Female urethra
