Tubular

Question 1

Tubular () quickly reclaims most of tubular contents and returns them to blood
Selective process
Almost all organic nutrients are reabsorbed
Water and ion reabsorption is hormonally regulated and adjusted

Answer 1

reabsorption

Question 2

Tubular reabsorption of sodium
() transport across the membrane
()+ is most abundant cation in filtrate
()+-K+ ATPase pumps ()+ into interstitial space
()+ is then swept by bulk flow into () capillaries

Answer 2

Sodium
Na,Na
peritubular

Question 3

Transport () (Tm) exists for almost every reabsorbed substance
When carriers for a solute are saturated, excess is excreted in ()
Example: () leads to high blood glucose levels that exceed Tm, and glucose spills over into urine

Answer 3

maximum
urine
hyperglycemia

Question 4

(/) tubule
Site of most ()
All nutrients, such as glucose and amino acids, are reabsorbed
65% of Na+ and water reabsorbed
Many ions
Almost all uric acid
About half of urea (later secreted back into filtrate)

Answer 4

Proximal convoluted
reabsorption

Question 5

(/)
() limb: H2O can return to blood, () cannot
() limb: H2O stays, solutes diffuse out and () to blood

Answer 5

Nephron loop
Descending, solutes
Ascending,return

Question 6

(/)tubule and collecting duct
() is hormonally regulated in these areas
(/) (ADH)
-Released by () pituitary gland
-Causes collecting ducts to insert () in membranes, increasing water ()
Increased ADH levels cause an increase in water reabsorption

Answer 6

Distal convoluted
Reabsorption
Antidiuretic hormone,posterior
aquaporins
reabsorption

Question 7

()
Targets collecting ducts and DCT
Promotes synthesis of Na+ and K+ channels, and Na+−K+ ATPases for Na+ reabsorption (water follows)
As a result, little Na+ leaves body
Without aldosterone, daily loss of filtered Na+ would be 2%, which is incompatible with life
Functions: increase (/)and decrease K+ levels

Answer 7

Aldosterone
blood pressure

Question 8

(/)peptide
Reduces blood ()+, resulting in decreased blood volume and blood pressure
Released by cardiac atrial cells if blood volume or pressure elevated

() hormone
Acts on () to increase ()+ reabsorption

Answer 8

Atrial natriuretic
Na
Parathyroid
DCT
Ca2

Question 9

-Tubular () is reabsorption in ()
-Occurs almost completely in ()
Selected substances are moved from () capillaries into filtrate
K+, H+, (), (), organic acids and bases

Answer 9

secretion,reverse
PCT
peritublar
NH4+
creatinine

Question 10

Tubular secretion is important for:
-Disposing of substances, such as () or (), that are bound to plasma proteins
-Eliminating undesirable substances that were passively reabsorbed (example: () and () acid)
-Ridding body of excess ()+ (aldosterone effect)
Controlling blood pH by altering amounts of H+ or HCO3– in urine

Answer 10

drugs
metabolites
urea,uric
K