Ch.25: Urinary System Part 2:

Question 1

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

Answer 1

Glomerular filtration
Tubular Reabsorption
Tubular Secretion

Question 2

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

Answer 2

Urine

Question 3

_______ contains everything found in blood plasma except protiens

Answer 3

Filtrate

Question 4

__________ __________, 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

Answer 4

Glomerular filtration

Question 5

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

Answer 5

Filtration membrane

Question 6

Filtration membrane has 3 layers:

Answer 6

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

Question 7

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

Answer 7

Podocytes

Question 8

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

Answer 8

water, glucose, amino acids, and nitrogenous waste

Question 9

_________ 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

Answer 9

Larger

Question 10

_________ _______ promote filtrate formation

Answer 10

Outward pressure

Question 11

________ ________ 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.

Answer 11

Hydrostatic pressure

Question 12

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

Answer 12

Colloid osmotic pressure

Question 13

______ _______ inhibit filtrate formation by opposing HP

Answer 13

inward pressure

Question 14

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

Answer 14

net filtration pressure

Question 15

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

Answer 15

Glomerular filtration rate

Question 16

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

Answer 16

NFP

Question 17

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

Answer 17

Glomerular mesengial cells

Question 18

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

Answer 18

Glomerular capillaries

Question 19

The 3 Mechanisms for GFR regulation:

Answer 19

Myogenic Mechanism
Tubular feedback Mechanism
Neural and Hormonal Mechanism

Question 20

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

Answer 20

renal autoregulation

Question 21

________ ________ 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

Answer 21

Mygoenic Mechanism

Question 22

_________ _______ __________: 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

Answer 22

Tubuloglomerular feedback mechanism

Question 23

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.

Answer 23

dilate

Question 24

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

Answer 24

Norepinephrine and epinephrin

Question 25

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

Answer 25

Renin-angiotensin-aldosterone

Question 26

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

Answer 26

Rennin

Question 27

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

Answer 27

Tubular Reabsorption

Question 28

Reabsorbed items include:

Answer 28

glucose, amino acids, water, sodium

Question 29

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

Answer 29

PCT

Question 30

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

Answer 30

Descending/ Ascending

Question 31

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

Answer 31

Solute

Question 32

______ 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.

Answer 32

ADH (Antidiuretic hormone)

Question 33

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

Answer 33

Aldosterone

Question 34

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

Answer 34

ANP (atrial natriuretic peptide)

Question 35

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

Answer 35

Tubular secretion

Question 36

4 Importance of Tubular Secretion:

Answer 36

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

Question 37

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

Answer 37

Diuretics