Lecture 14 : General intro to renal system Flashcards
(11 cards)
Volumes of water we intake and output
INTAKE
Drinking - 1500ml
Food - 500ml
Metabolism - 400ml
Total - 2400ml
OUTPUT
Lungs - 400ml
Skin - 400ml
Faeces - 100ml
Urine - 1500ml
Total - 2400ml
Water % across body : Interstitial, plasma, fat, intracellular, transcellular, extracellular
Plasma composition in blood, haematocrit
- 55% of blood, rest are cells
- Makes blood fluid
- Haematocrit is a measure of proportion of blood occupied by cells, usually 45%
Measuring volume of distribution of drugs in body equation
Osmotic Pressure
The force required to stop flow of water across a semi permeable membrane due to differences in solute concentration between 2 solutions.
More solute = higher osmotic pressure.
Drives water movement from low solute → high solute area.
Ie. Concentration of solute, water diffuses.
What happens if plasma albumin falls?
- Albumin is a protein in blood plasma
- It keeps fluid inside blood vessels
- If albumin concentration drops, there is a lower oncotic pressure
- Lower oncotic pressure inside blood vessels means water will leak out of vessels into tissues
- Leads to oedema
- Caused by liver failure, protein malnutrition, renal failure
Role of the kidney summarised
- Elimnation of endogenous and exogenous compounds
- Maintenance of pH (any chemical homeostasis)
- Maintaining volume of water in blood
- Endocrine signalling
Renal interactions with GI system
- Gut regulates input, kidney regulates output
- Gut can be a rapid source of water, K+, H+ or HCO3- loss, so kidney restores these levels back to equilibrium
Renal interactions with cardiovascular system
- Kidney maintains BP
- Regulates ionic composition for cardiac muscle function
Renal interactions with respiratory system
pH regulation, combating respiratory and metabolic acidosis / alkalosis
Renal interactions with endocrine system
- Vitamin D regulation
- Regulation of Ca2+
- Diabetes
