Lecture 14 Flashcards
which structures increase the absorptive area of proximal convoluted tubule cells?
Microvilli
In the kidney, the process by which fluid and solutes from the tubular fluid are reclaimed and returned to the blood is called tubular ______.
reabsorption
Sodium is transported into the cells of the PCT by a protein that simultaneously moves it and another solute in the same direction. This type of transport protein is called a(n) ______.
symport
The PCT reabsorbs water at a constant rate known as what?
Obligatory water reabsorption
The accumulation of reabsorbed fluid on the basal side of the epithelial cells creates a high tissue fluid pressure that drives water ______ the peritubular capillaries.
into
Which region of the nephron is adapted for reabsorption, as seen in its length and prominent microvilli?
Proximal convoluted tubule
When the transporters within the proximal convoluted tubule are saturated and no additional solute can be reabsorbed,which of the following has been reached?
Transport maximum
Where does most tubular reabsorption take place?
In the proximal convoluted tubule
what is tubular secretion? (explain)
renal tubule extracts chemicals from capillary blood and secretes them into tubular fluid
What is tubular secretion?
The movement of water and solutes from the blood into the tubular fluid
An antiport transports sodium into the cells of the PCT while pumping hydrogen ions out. What hormone activates this transport?
Angiotensin II
Choose all the solutes that are reabsorbed from the nephron loop.
- potassium ions
- sodium ions
- glucose and amino acids
- water
- chloride
Na+, K+, Cl-
Potassium ions
Sodium ions
Chloride
Water is reabsorbed through specialized water channels called ______.
aquaporins
Choose all the hormones that regulate the amount of water and salt reabsorbed by the DCT and collecting duct.
- epinephrine
- antidiuretic hormone
- aldosterone
- natriuretic peptides
- angiotensin converting enzyme
aldosterone
natriuretic peptides
antidiuretic hormone (ADH)
parathyroid hormone (PTH)
What are the mechanisms of peritubular capillary absorption?
Osmosis and solvent drag
Which defines the transport maximum?
It is the upper limit of the rate solute can be reabsorbed
the hormone ___ causes increased reabsorption of sodium (and the water that follows) and secretion of potassium from the later segments of the renal tubule.
aldosterone
Aspirin, penicillin, and other drugs are cleared from the blood via the kidneys by which of the following processes?
tubular secretion
why does the heart secrete natriuretic peptides?
heart secretes natriuretic peptides in response to high BP
natriuretic peptides lower BP
excrete more salt and water in urine –> reduce blood volume and pressure
what are the effects of atrial natriuretic peptides?
1) dilate afferent arteriole and constrict efferent arteriole –> increase GFR
2) antagonize the renin-angiotensin-aldosterone mechanism by inhibiting renin and aldosterone secretion
3) inhibit the secretion of antidiuretic hormone and its action on the kidney
4) inhibit NaCl reabsorption by the collecting duct
Which leads to an increased secretion of natriuretic peptides?
increased blood pressure
The primary function of the nephron loop is to generate a medullary extracellular fluid (ECF) osmotic gradient that allows for what?
The concentration of urine
Antidiuretic hormone is secreted in response to _____.
dehydration
loss of blood volume
rising blood osmolarity
What is the primary function of the distal convoluted tubule and collecting duct?
The reabsorption of water and salts
