Lecture 34 Flashcards
What does normal urine consist of and what can the colour tell us?
Normal urine is 95-98% water (1.5L per day), this helps to keep blood pressure constant by removing excess water, there are also creatinine, urea, uric acid, H+, NH3, Na+, K+, drugs (anti-viral and diuretics) and toxins. The level of hydration in a person can be seen based on the lightness of the urine, tests can also be done to measure the osmolarity of the urine.
What can pathologic urine contain?
Pathologic urine may have glucose (glucosuria or diabetes), protein (proteinuria), blood (erythrocytes, haematuria), haemoglobin (haemoglobinuria), leukocytes etc.
What do normal urine and pathologic urine look, taste and smell like?
Normal urine is clear, light or a dark amber look, it will be acidic, more acidic if high meat in diet, more basic (up to pH7.2) for veggie diet and unremarkable smell. It could be pathologic if it is golden, red, brown, blue. If it tastes sweet or smells like fruits (ketosis, diabetes, chronic alcohol abuse) or rotten if there is an infection or a tumour.
What are the general functions of the kidney?
The kidney functions for: water homeostasis (hydration and blood pressure), filters blood, produces erythropoietin, metabolism, gluconeogenesis, pH-regulation, excretion of drugs, endogenous metabolites and toxins, reabsorption of nutriesnt, salt/ion homeostatis.
What are the two hormones produced by the kidney and what do they do?
Erythropoietin is secreted by the kidney in response to low oxygen levels, it will stimulate the bone marrow to produce more red blood cells and hence if a chronic renal failure occurs anaemia can result. It also secretes vitamin D, which is essential for calcium balance and bone mineralisation, this can lead to bone problems with chronic renal failure.
What molecule does the kidneys secrete for energy and pH balance?
Gluconeogenesis is synthesis of glucose from amino acids, the precursors occur in the kidney and the liver (never secretes glucose). Ammonia is also synthesised and secreted in the kidney (a role in nitrogen and pH balance).
How do the kidneys regulate pH?
The kidney’s secrete bicarbonate and H+ as well as also secrete NH3. This can be used to regulate pH.
What are the three steps in basic nephron processes?
The three steps in basic nephron processes are 1. filtration (creates plasma-like filtrate of the blood, at the glomeruli not much selection occurs and this process goes through 180L/day, for some substances they are filtered and reabsorbed, the degree of which varies, for others part is filtered and the rest is expelled), 2. secretion (adds additional wastes from the blood to the filtrate), 3. re-absorption (removes useful solutes from the filtrate and returns them to the blood).
What are the glomerulus, proximal tubule, distal tubule and collecting duct for?
The glomerulus is for filtration, the proximal tubule for bulk reabsorption, the distal tubule for fine-tuning of electrolytes, and the collecting duct for fine tuning of water reabsorption.
