Urinary Flashcards
Trace the blood supply through the kidney.
Aorta – renal artery – afferent arteriole – glomerulus – efferent arteriole – renal vein – inferior vena cava
Name the tubular components of a nephron in the order that filtrate passes through them.
proximal convoluted tubule (found in the renal cortex)
loop of Henle (mostly in the medulla)
distal convoluted tubule (found in the renal cortex)
collecting tubule (in the medulla)
collecting duct (in the medulla)
What are the structural differences between juxtamedullary and cortical nephrons?
Cortical nephrons have a glomerulus located nearer to the outer parts of the cortex and their loops of Henle are shorter.
Juxtamedullary nephrons have a glomerulus near the junction of the cortex and medulla and their loops of Henle penetrate deep into the medulla.
What type of capillaries are glomerular capillaries? What is their function?
Fenestrated capillaries. Their function is to filter large amounts of plasma into the glomerular capsule.
Describe the Juxtaglomerular apparatus (JGA) and its cells involved.
JGA: Regulates filtrate formation & blood pressure
Cells involved:
- Granular cells (afferent arteriole): Secrete renin. They sense the blood pressure in the afferent arteriole.
- Macula Densa: chemoreceptors that monitor the NaCl content of the filtrate entering the distal convoluted tubule
Name the retroperitoneal organs in the urinary system.
Suprarenal (adrenal) glands
Aorta
Ureters
Kidneys
What is the trigone of the bladder, and which landmarks define its borders?
The trigone of the bladder is a smooth triangular region at the base of the bladder. Its borders are the openings of the two ureters and the urethra.
Name the 3 regions of the male urethra.
Prostatic urethra, membranous urethra, and spongy (or penile) urethra
What type of epithelium is the urethra?
Mostly pseudostratified columnar epithelium
Transitional epithelium near bladder
Stratified squamous epithelium near tip- at the external urethral orifice
Internal vs External sphincters
Internal:
Thickened part of detrusor (smooth) muscle
Involuntary
Located at bladder-urethral junction
External:
Skeletal muscle
Supplied by pudendal nerve
Provides voluntary control of micturition
Describe 3 renal processes.
Glomerular filtration: water and solutes smaller than proteins are forced through the capillary walls and pores of the glomerular capsule into the renal tubule
Tubular reabsorption: water, glucose, amino acids, and needed ions are transported out of the filtrate into the tubule cells and then enter the capillary blood
Tubular secretion: h+, K+, creatinine, and drugs are removed from the peritubular blood and secreted by the tubule cells into the filtrate
What are the factors affecting GFR?
- Changes in BP (↑ BP → GFR ↑ )
- Changes in Plasma OP (↑OP of blood → GFR ↓)
- Changes in size of afferent and efferent arterioles
Constriction of afferent arterioles→ blood flow into glomerulus ↓ → GFR ↓
Constriction of efferent arterioles→ blood spends more time in the glomerulus → GFR ↑ - Kidney diseases
- Glomerulonephritis (GN)
Glomerular capillaries become so permeable that plasma proteins pass into filtrate; water follows and GFR increases
- Kidney stone
May block the ureter or enlarged prostate gland
GFR ↓
Extrinsic & intrinsic controls of GFR serve 2 different purposes. What are they?
Intrinsic: acts locally within the kidney to maintain GFR
Extrinsic: controls by the nervous and endocrine systems maintain blood pressure
Extrinsic & intrinsic controls of GFR serve 2 different purposes. What are they?
Intrinsic: acts locally within the kidney to maintain GFR
Extrinsic: controls by the nervous and endocrine systems maintain blood pressure
In which part of the nephron does most reabsorption occur?
Reabsorption takes place mainly in the proximal convoluted tubule of the nephron . Nearly all of the water, glucose, potassium, and amino acids lost during glomerular filtration reenter the blood from the renal tubules.
