Ch.25: Urinary System Part 2: Flashcards Preview

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Flashcards in Ch.25: Urinary System Part 2: Deck (37)
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1
Q

Urine formation and the adjustment of blood composition involves three processes:

A

Glomerular filtration
Tubular Reabsorption
Tubular Secretion

2
Q

_______ contains unneeded substances such as excess salts, and metabolic waste.

A

Urine

3
Q

_______ contains everything found in blood plasma except protiens

A

Filtrate

4
Q

__________ __________, is a passive process in which hydrostatic pressure forces fluids and solutes through a membrane. Viewed as a simple mechanical filters because filtrate formation does not directly consume metabolic energy. NONSELECTIVE

A

Glomerular filtration

5
Q

The _________ _______, lies between the blood and interior of the glomerular capsule. It’s porous membrane allows free passage of water and solutes smaller than plasma proteins

A

Filtration membrane

6
Q

Filtration membrane has 3 layers:

A
  1. Fenestrated endothelium of the glomerular capillaries
  2. Basement membrane (negative charge)
  3. Foot processes of podocytes of the glomerular capsule
7
Q

The visceral layer of the glomerular capsule is made of ___________ that have filtration slits between their foot processes.

A

Podocytes

8
Q

Molecules such as _____, ______, ______ _____, _________ _______ pass freely from the blood into the glomerular capsule.

A

water, glucose, amino acids, and nitrogenous waste

9
Q

_________ molecules pass with greater difficulty, barred from entering the tubule. Keeping the plasma proteins in the capillaries maintains the colloid osmotic pressure of the glomerular blood, preventing the loss of all its water to the capsular space

A

Larger

10
Q

_________ _______ promote filtrate formation

A

Outward pressure

11
Q

________ ________ in the glomerular capillaries is essentially glomerular blood pressure. It is the chief force pushing water and solutes out of the blood and across the filtration membrane. The BP in the glomerulus is extremely high. 55 mm Hg . Due to the high resistance of the efferent arteriole that feeds them.

A

Hydrostatic pressure

12
Q

________ ______ _______ in the capsular space of the glomerular capsule would “pull” filtrate into the tubule. Pressure is essentially zero because no proteins enter the capsule.

A

Colloid osmotic pressure

13
Q

______ _______ inhibit filtrate formation by opposing HP

A

inward pressure

14
Q

The hydrostatic pressure in the capsular space and colloid osmotic pressure in the glomerular capsule determine the ____ ________ ______

A

net filtration pressure

15
Q

The _________ ______ ______ is the volume of filtrate formed each minute by the combined activity of all 2 million glomeruli of the kidneys.

A

Glomerular filtration rate

16
Q

______ is the main controllable factor. Controlled by the changing diameter of the afferent arteriole

A

NFP

17
Q

________ ______ ___ surrounding these glomerulus capillaries can fine tune the GFR by contracting to adjust the total surface area available for filtration

A

Glomerular mesengial cells

18
Q

_________ ________ are thousands of times more permeable than other capillaries because of their fenestrations

A

Glomerular capillaries

19
Q

The 3 Mechanisms for GFR regulation:

A

Myogenic Mechanism
Tubular feedback Mechanism
Neural and Hormonal Mechanism

20
Q

By adjusting its own resistance to blood flow, a process called _____ _________

A

renal autoregulation

21
Q

________ ________ reflects a property of the smooth muscle, it contracts when stretched and relaxes. Rising Bp causes the afferent arteriole to constrict. This constriction restricts blood flow into the glomerulus and prevents glomerular blood flow into the glomerular blood pressure from rising to damaging levels. Vice versa

A

Mygoenic Mechanism

22
Q

_________ _______ __________: is directed by the macula densa cells of the juxtaglomerular complex. Located in the ascending walls of the loop of henle. Responds to filtrate NaCl concentration. When GFR increases,leads to not enough time for re-absorption to occur, as well as the NaCl concentration remains high. The macula densa cells respond by releasing vasoconstrictors chemicals (ATP and others) that cause intense constriction of the afferent arteriole and reducing blood flow into the glomurulus. This drop in blood flow decreases NFP and GFR slowing the flow and allowing time. Vice versa

A

Tubuloglomerular feedback mechanism

23
Q

When the volume of the extracellular fluid is normal and the sympathetic nervous system is at rest, the renal blood vessels are ______ and renal autoregulation mechanisms prevail.

A

dilate

24
Q

When blood pressure falls, ___________ released by sympathetic nerve fibers and __________ released by the adrenal medulla causes vascular smooth muscle to constrict, increasing peripheral resistance and bringing blood pressure back up toward normal

A

Norepinephrine and epinephrin

25
Q

The ______ ______ _______ mechanism is the body’s main mechanism for increasing the blood pressure. Regulates GFR indirectly

A

Renin-angiotensin-aldosterone

26
Q

Low blood pressure causes the granular cells of the JGC to release ________.

A

Rennin

27
Q

_________ __________ is SELECTIVE transepithelial process that begins as soon as the filtrate enters the proximal tubules.

A

Tubular Reabsorption

28
Q

Reabsorbed items include:

A

glucose, amino acids, water, sodium

29
Q

Normally, the _____ reabsorbes all of the glucose and amino acids in the filtrate and 65% of the Na+ and water

A

PCT

30
Q

Water can leave the ___________ limb of the nephron loop but not the ________ limb, where aquaporins are scarce or absent in the tubule cell membrane

A

Descending/ Ascending

31
Q

Virtually no ________ reabsorption occurs in the descending limb of the nephron loop, but they are reabsorbed both actively and passively in the ascending limb,

A

Solute

32
Q

______ inhibits diuresis or urine output. Makes the principle cells of the collecting ducts more permeable to water by causing aquaporins to be inserted into their apical membranes.

A

ADH (Antidiuretic hormone)

33
Q

__________ fine tunes reabsorptions of the remaining Na+, increases blood volume or pressure. Conserve Na+

A

Aldosterone

34
Q

_________, reduces blood Na+ thereby decreasing blood volume and pressure. Released by cardiac atrial cells when blood volume/ pressure is elevated.

A

ANP (atrial natriuretic peptide)

35
Q

___________ ___________: moves selected substances from the peritubular capillaries through the tubule cells into the filtrate.

A

Tubular secretion

36
Q

4 Importance of Tubular Secretion:

A
  1. Disposing of substances (drugs and toxins)
  2. Eliminating undesirable substances or end products
  3. Ridding the body of excess K+
  4. Controlling blood pH
37
Q

_________, chemicals that enhance urinary output, Alcohol inhibits ADH. Most ??? inhibit Na+ associated symporters

A

Diuretics