The Urinary System

Question 1

the urinary system

Answer 1

eliminates organic waste products; helps regulate blood volume; helps regulate ion concentrations in the blood; involved in regulating blood pH (more than any other system)

Question 2

kidneys

Answer 2

located outside the parietal peritoneum (retroperitoneal); have a certain amount of adipose on the outside of the surface for protection; goal is to filter the blood and produce urine that is excreted from the body

Question 3

filtration

Answer 3

takes place in the cortex and the pyramids (renal medulla); urine is produced drop by drop and collected in the funnels that are at the base of each renal pyramid; urine runs down the ureter and to the bladder

Question 4

the renal nephron

Answer 4

the basic functioning unit of the kidney; each nephron produces urine; contain renal corpuscle, glomerular capsule, glomerulus, proximal convoluted tubule, nephron loop, distal convoluted tubule, and collecting duct

Question 5

renal corpuscle

Answer 5

start of the nephron; composed of the two sub-components listed next, the Bowman’s capsule and the glomerulus

Question 6

glomerular capsule

Answer 6

this capsule forms the beginning of the tubule; fluid that enters the glomerular capsule will run directly into the tubule

Question 7

glomerulus

Answer 7

a blood capillary packaged within the glomerular capsule; it is fenestrated (has pores that make it very permeable); an arteriole brings blood to the glomerulus; after the blood travels through the glomerulus, the blood continues to travel into a capillary bed surrounding the rest of the tubule

Question 8

proximal convoluted tubule

Answer 8

after leaving the glomerular capsule, the renal tubule has several sections; the first known as the proximal convoluted tubule; contained within the area of the renal cortex

Question 9

nephron loop

Answer 9

the middle portion of the tubule; extends down into the renal pyramid

Question 10

distal convoluted tubule

Answer 10

the last segment of the tubule; located in the renal cortex

Question 11

collecting duct

Answer 11

not technically part of the nephron; where the nephron dumps the urine

Question 12

filtration

Answer 12

first stage of the entire process of producing urine; blood plasma is forced from the glomerulus capillaries into the glomerular capsule; fluid from the blood enters the nephron tubule

Question 13

filtrate

Answer 13

the fluid moving through the tubule

Question 14

what forms filtrate?

Answer 14

water, all but the largest molecules dissolved in the water (ions, organic wastes, nutrient molecules, and many other substances)

Question 15

what doesn’t leave the capillary?

Answer 15

formed elements (RBCs, WBCs, and platelets are too big to fit), almost all proteins

Question 16

reabsorption

Answer 16

desirable substances are reabsorbed into the bloodstream

Question 17

water

Answer 17

the most important substance reclaimed; done through osmosis; junk is removed before its reabsorbed; most occurs in the proximal convoluted tubule

Question 18

nutrients

Answer 18

all valuable nutrients are reabsorbed, including: glucose, fructose, amino acids, vitamins, proteins, carious ions; pumped back via active transport

Question 19

secretion

Answer 19

certain substances are pumped out of the bloodstream and into the filtrate; involves active transport

Question 20

examples of what is pumped out

Answer 20

ammonia, hydrogen ions, histamines, and penicillin

Question 21

urine

Answer 21

officially urine when the filtrate leaves the end of the tubule; travels down the collecting duct to the tip of the renal pyramid, then drips into the collecting funnel of the ureter

Question 22

characteristics of urine

Answer 22

yellowish color, slightly acidic pH (6.0), mostly water, most common waste product is urea - also creatinine, uric acid, and excess ions

Question 23

path of urine

Answer 23

after it leaves the kidneys, it is carried to the urinary bladder by the ureter; both the ureter and the urinary bladder are lined with transitional epithelium, which provides a watertight barrier and can stretch and require; also the bladder has a thin layer of smooth muscle around the outside wall, which contracts during urination; urine is carried by the urethra to the outside of the body

Question 24

kidney function

Answer 24

innervated by a sympathetic branch of the nervous system; no parasympathetic innervation to the kidneys the nerve endings innervate the muscular arteries that arise from the renal artery; the nerve endings release a chemical that stimulates the smooth muscle in the arterial walls to contract harder

Question 25

less active kidney rate

Answer 25

low sympathetic stimulation, relaxed walls of arteries in kidneys, maximum blood flow to glomerulus, maximum filtrate production

Question 26

more active kidney rate

Answer 26

high sympathetic stimulation, constricted walls of arteries in kidneys, blood flow to the glomerulus will decrease, less filtrate will be produced

Question 27

regulation of water balance

Answer 27

regulated by hormonal control

Question 28

antidiuretic hormone (aka vasopressin)

Answer 28

secreted by the pituitary gland; stimulates the kidneys to retain water; when stimulated by the hormone. cells become more permeable to water and more water moves from the tubules back to the capillaries, and less goes into the urine

Question 29

regulation of ion balance

Answer 29

kidneys regulate how much of each ion is excreted

Question 30

aldosterone

Answer 30

secreted by the adrenal gland; increases when sodium levels get low; target the cells in the tubule wall that are involved in the reabsorption of sodium, aldosterone stimulates an increase in the reabsorption rates of sodium, more sodium is reabsorbed, raising the sodium levels back up

Question 31

intracellular fluid

Answer 31

the cytoplasm of all the body cells

Question 32

extracellular fluid

Answer 32

all of the fluid outside of the cells; includes: interstitial fluid, blood plasma, lymph fluid, cerebrospinal fluid, synovial fluid

Question 33

hyponatremia

Answer 33

too much water in the body; decreases sodium concentration, can be called water intoxification

Question 34

hypernatremia

Answer 34

not enough water in the body; increases sodium concentration

Question 35

electrolyte

Answer 35

an ion that is released by the dissociation of a salt or similar molecule; important electrolytes include: sodium, potassium, calcium, chloride, magnesium, and phosphate

Question 36

electrolyte functions

Answer 36

help maintain osmotic balance, necessary for the normal function of muscle and nerve cells, required for several metabolic activities, provide ground substance

Question 37

acid/base balance

Answer 37

pH is critical; can be affected by: carbonic acid dissociating to form a hydrogen ion and a bicarbonate ion, ammonia picking up a hydrogen ion, and lactic acid will give up a hydrogen ion in solution, and as a result lowers the pH

Question 38

chemical buffer systems

Answer 38

buffers - chemicals that resist change in pH

Question 39

respiratory system

Answer 39

an increase in carbon dioxide in the blood lead to an increase in the carbonic acid, which lowers pH; also works in reverse

Question 40

renal regulation

Answer 40

the kidneys have the ability to change blood pH by either eliminating more hydrogen ions, or less hydrogen ions

Question 41

acidosis

Answer 41

blood pH below 7.35

Question 42

alkalosis

Answer 42

blood pH above 7.45