Renal System Flashcards
Define excretion
The removal of toxic materials and metabolic waste products from the body
Define blood osmolarity
The concentration of solutes in the blood plasma
Define osmoregulation
The maintenance of a relatively constant blood osmolarity
What is the renal corpuscle made of?
Bowman’s capsule and glomerulus
Parts of the nephron
Proximal convoluted tubule
Loop of henle
Distal convoluted tubule
Pathway of blood in renal system
Renal artery
Afferent arteriole
Glomerulus
Efferent arteriole
Peritubular capillaries and bass recta
Renal vein
Adaptations of renal corpuscle
- Filtration barrier: filtration slits, slot membrane, fenestrated walls, basal lamina
- Afferent arteriole is larger in diameter to efferent arteriole
- High hydrostatic pressure
Adaptations of proximal convoluted tubule (nephron)
The epithelial cells have
1. numerous microvilli : more SA for absorption
and 2. mitochondria : provide energy for active transport
Adaptations of loop of henle
Descending limb:
1. Permeable to water, aquaporins
2. Water transformed into vasa recta
Ascending limb:
1. No aquaporins
2. Solutes transported out into interstitial fluid by
- facilitated diffusion
- active transport
- cotransport
Homeostatic reaction during overhydration
DECREASE in blood osmolarity
DECREASE in antidiuretic hormone (ADH) from posterior pituitary
DECREASE in no of aquaporins in collecting ducts = DECREASE water reabsorption
Large volume of dilute urine
Blood osmolarity returns through neg feedback
Homeostatic reaction during dehydration
INCREASE in blood osmolarity
INCREASE in antidiuretic hormone (ADH) from posterior pituitary
INCREASE in no of aquaporins in collecting ducts = INCREASE water reabsorption
Small volume of concentrated urine
Blood osmolarity returns through neg feedback
What is type 1 diabetes mellitus
Not enough insulin produced
What is type 2 diabetes mellitus
Tissues do not respond properly to insulin
Process of hemodialysis
Blood is drawn from an artery and pumped through a selectively permeable membrane. The tube is bathed in dialysis fluid that contains essential substances such as glucose, but not waste like urea. the filtered blood then returns to a vein.
Features of haemodialysis
- Fluid contains same concentration of useful substances
- Tubing prevents large molecules and blood cells from passing
- Tubing is long narrow and coiled for SA
- Direction of blood flow is opp to fluid
