Chapter 10.3 Flashcards
When does glomerular filtration occur?
When whole blood enters the glomerulus by way of the afferent arteriole
Due to glomerular blood pressure, water and small molecules move from?
The glomerulus to the inside of the glomerular capsule
The nonfilterable components leave the glomerulus by way of?
Efferent arteriole
Once the nonfilterable components leave, the glomerular filtrate inside the glomerular capsule now contains?
The filterable blood components in approximately the same concentration as plasma
Nephrons in the kidneys filter how much water per day?
180 liters, along with a considerable amount of small molecules (such as glucose) and ions (such as sodium)
If the composition of urine were the same as that of the glomerular filtrate, the body would?
Continually lose water, salts, and nutrients
Tubular reabsorption occurs as
molecules and ions are passively and actively reabsorbed from the nephron into the blood of the peritubular capillary network
The osmolarity of the blood is maintained by the presence of?
Plasma proteins and salt
When sodium ions are actively reabsorbed what follows passively?
Chloride ions (CI-)
The reabsorption of salt (NaCI) increases the osmolarity of?
The blood compared with the filtrate
Water moves passively from?
The tubule into the blood
About how much of Na+ is reabsorbed at the proximal convoluted tubule?
65%
What returns to the peritubular capillaries almost exclusively at the proximal convoluted tubule?
Nutrients such as glucose and amino acids
Only molecules recognized by carrier proteins are?
Actively reabsorbed
What happens is diabetes mellitus
The liver and muscles fail to store glucose as glycogen, so the blood glucose level is above normal and glucose appears in the urine
The presence of excess glucose in the filtrate raises its
Osmolarity
Frequent urination and increased thirst experienced by people with untreated diabetes are due to
Less water being reabsorbed from the filtrate into the blood
The filtrate that enters the proximal convoluted tubule is divided into two portions:
- Components reabsorbed from the tubule into blood
2. Components not reabsorbed that continue to pass through the nephron to be further processed into urine
Reabsorbed filtrate components are
- Most water
- Nutrients
- Required salts (ions)
Nonreabsorbed filtrate components
- Some water
- Much nitrogenous waste
- Excess salts (ions)
Substances not reabsorbed become
The tubular fluid, which enters the loop of the nephron
A second way in which substances are removed from blood and added to the tubular fluid
Tubular secretion
What are some of the substances moved by active transport from blood into the kidney tubule?
- Hydrogen ions (H+)
- Creatinine
- Drugs such as penicillin
Urine contains substances that have undergone glomerular filtration but have not?
Been reabsorbed and substances that have undergone tubular secretion
Tubular secretion is now known to occur?
Along the length of the kidney tubule
