Main Points 1

fenestrated glomerular endothelium, the intervening basement membrane, and the podocyte-containing visceral layer

The filtration membrane consists of the ____?

Filtration membrane

permits free passage of substances smaller than (most) plasma proteins.

the glomeruli are fed and drained by arterioles, and the afferent arterioles are larger in diameter than the efferent arterioles.

The glomeruli function as filters. High glomerular blood pressure (55 mm Hg) occurs because ______?

one-fifth , glomerular capsule.

About ____ of the plasma flowing through the kidneys is filtered from the glomeruli into the ____?

10 , net filtration pressure (NFP) ,

Usually about ___ mm Hg, the ______ is determined by the relationship between forces favoring filtration and forces that oppose it

forces that oppose it

The net filtration pressure is determined by the relationship between forces favoring filtration and _____?

net filtration pressure , 125

The glomerular filtration rate (GFR) is directly proportional to the _____ and is about ___ ml/min

Intrinsic renal contro , renal autoregulation

______ , or ______ , enables the kidneys to maintain a relatively constant renal blood flow and glomerular filtration rate.

myogenic mechanism , tubuloglomerular feedback mechanism , macula densa

Intrinsic control involves a _______ and a _______ mediated by the _____.

nerves and hormones, maintains blood pressure

Extrinsic control of glomerular filtration rate via _______?

afferent arterioles , filtrate formation

Strong sympathetic nervous system activation causes constriction of the _____, which decreases _____.

angiotensin II

The renin-angiotensin-aldosterone mechanism raises systemic blood pressure by generating _____.

direct sympathetic nervous system stimulation, paracrines released by the macula densa, and reduced stretch of granular cell membranes.

Renin is released from granular cells in response to ____?

reabsorption , proximal convoluted tubules

The proximal tubule cells are most active in _____. Most of the nutrients, 65% of the water and sodium ions, and the bulk of actively transported ions are reabsorbed in the ______.

distal tubules , collecting ducts

Reabsorption of additional sodium ions and water occurs in the _____ and ____ and is hormonally controlled.

sodium , water reabsorption

Aldosterone increases the reabsorption of _____.

Antidiuretic hormone (ADH) enhances _____ by the collecting ducts.

tubule cells , peritubular capillary blood

During tubular reabsorption, needed substances are removed from the filtrate by the ____ and returned to the _____.

apical , facilitated diffusion

Na+ enters at the ___ surface of the tubule cell via _____ through channels or as part of a cotransport mechanism.

electrochemical gradients

Passive tubular reabsorption is driven by ______ established by active reabsorption of sodium ions.

transcellular , paracellular

In tubular reabsorption, Water, many ions, and various other substances are reabsorbed passively by diffusion via ______ or ______ pathways.

Na+ , transport proteins

Secondary active tubular reabsorption occurs by cotransport with ___ via ____.

glucose , amino acids , and some ions.

Actively reabsorbed substances include _____?

filtrate , drugs, certain wastes, excess ions , acid-base

Tubular secretion adds substances to the ____. It is an active process that is important in eliminating ____ , _____ and ___ and in maintaining the ____ balance of the blood.

graduated hyperosmolality , dilute

The _____ of the medullary fluids ensures that the filtrate reaching the distal convoluted tubule is _____.

permeable , medullary interstitial space.

The descending limb of the nephron loop is ____ to water, which leaves the filtrate and enters the ________.

hyperosmolar

The filtrate and medullary fluid at the bend of the nephron loop are ______.

impermeable , interstitial space , passively , actively

The ascending limb is _____ to water. Na+ and Cl- move out of the filtrate into the _____, _____ in the thin portion and _____ in the thick portion. The filtrate becomes more dilute.

interstitial space , recycled

As filtrate flows through the collecting ducts in the inner medulla, some urea diffuses into the ____. From here, urea reenters the ascending thin limb and is ____.

sluggish , equilibrates , isotonic

The blood flow in the vasa recta is ____, and the contained blood ____ with the medullary interstitial fluid. Hence, blood exiting the medulla in the vasa recta is nearly ____ to blood plasma and the high solute concentration of the medulla is maintained.

dilute urine

In the absence of antidiuretic hormone, ____ is formed because the dilute filtrate reaching the collecting duct is simply allowed to pass from the kidneys.

rise , more

When extracellular fluid osmolality rises, blood levels of antidiuretic hormone ___, and the collecting ducts become ___ permeable to water.