RENAL SYSTEM Flashcards
What is the normal Total Body Water percentage in the average person (70 kg)?
50-70% of body weight
what are “Starling forces”?
the forces that drive the exchange of fluid through the capillary walls
does Intracellular fluid contain more or less phosphate ions than Extracellular fluid?
more
what term is used to describe the number of dissolved particles in a solution?
Osmolarity
which ions contribute to 80% of osmolarity in ECF?
sodium and chlorine ions
give 2 examples of isotonic solutions that are of importance in the medical scene?
- 0.9% saline solution
2. 5% glucose solution [dextrose]
Is a saline solution greater than 0.9% considered to be hypertonic or hypotonic?
hypertonic
what condition can occur due to the prevention of lymphatics from returning fluid from interstitial spaces back to the circulation?
Oedema
give 3 major functions of kidneys
- remove metabolic wastes
- aid in the control of blood pressure by maintaining salt and water balance in the body.
- Maintains pH in the body
where are the kidneys located in the body?
retroperitoneally at the level of the lower ribs
what is the outer and inner layers of the kidneys respectively?
inner= renal medulla outer= renal cortex
what is the basic functional unit of the kidneys?
the nephron
what are the two components of the nephron?
- vascular component
2. tubular component
what are the 6 cell types found in nephrons?
- parietal layer of glomerulus [Bowman’s Capsule]
- visceral layer of glomerulus [Bowman’s capsule]
- Proximal convoluted tubule cells
- Distal convoluted tubule cells
- thin segment cells [nephron loop cells]
- collecting duct cells
what is the intersection of the Macula Densa cells of distal tubule , afferent and efferent arterioles and JG cells called?
Juxtaglomerular Apparatus
what do the JG cells do?
secrete Renin into the afferent arterioles
what is the difference between afferent and efferent arterioles?
afferent: bring blood to the glomerular
efferent: take blood away from the glomerular
what are the 3 types of capillary beds found in kidneys?
- glomerular
- peritubal
- vasa recta
what are the 3 processes by which urine is formed?
- glomerular filtration
- reabsorption
- secretion
what is the osmolarity of extracellular fluid?
300 mOsm/l
what is the difference between obligatory and facultative reabsorption?
Obligatory= reabsorption of water in the tubules regardless of the state of hydration of the body.
Facultative= final reabsorption of water dependent on the body’s state of hydration.
what condition results from the inactivity or the absence of ADH?
Diabetes Insipidus
what are the 2 basic requirements for the formation of concentrated urine?
- high levels of ADH
- high osmolarity of medullary interstitial fluid in order to create an osmotic gradient for water to flow into the collecting ducts.
to which parts of the nephron are we referring to using the terms “counter multiplier” and “counter exchange” ,and what are the functions of these parts?
Counter multiplier= Loops of Henle= increases osmolarity gradients in interstitial fluid
Counter exchange= Vasa Recta= maintains the osmolarity gradient
