Chapter 15

Question 1

excretion

Answer 1

processes that remove wastes and excess material from the body

Question 2

urinary system

Answer 2

consists of the kidneys, the ureters, the bladder, and the urethra. transport and store urine untile it is eliminated from the body

Question 3

kidneys

Answer 3

theses 2 produce urine.

Question 4

medulla and cortex

Answer 4

contains long, thin, tubular structures called nephrons which share a common final section called the collecting duct, through which urine is delivered to the renal pelvis

Question 5

urinary bladder

Answer 5

stores urine. consists of 3 layers of smooth muscle lined on the insde by epithelial cells. can hold about 600-1000 ml of urin, though volumes that large may feel uncomfortable

Question 6

urethra

Answer 6

a single muscular tube that extends from the bladder to the body’s external opening.

Question 7

nephrons

Answer 7

kidney contains approximately a million small functional units called this. consists of a thin hollow tube of epithelial cells called tubule, plus blood vessels that supply the tubule. produce urine

Question 8

glomerular capsule

Answer 8

the nephron begins with a cup of tissue that looks like a deflated ball with one side pushed in called this.

Question 9

glomerulus

Answer 9

surrounded and encloses by glomerular. a network of capillaries which is part of the blood supply of the nephron

Question 10

proximal tubule

Answer 10

starts at the glomerular capsule and ends at the enal medulla

Question 11

loop of Henle

Answer 11

extends into the medulla as the descending limb and then loops back up to the vicinity of the glomerular capsule as the ascending limb

Question 12

distal tube

Answer 12

means distant from.

Question 13

collecting duct

Answer 13

extends from the cortex to the renal pelvis, where the urine is finally deposited

Question 14

afferent arteriole

Answer 14

is a single arteriole that supplys every nephron. enters a glomerular capsule and then divides many times to become the network of capillaries that constitutes the glomerulus

Question 15

efferent arteriole

Answer 15

carries filtered blood from the glomerulus. divides again into another capillary network that surrounds the proximal and distal tubules in the cortex called peritubular capillaries.

Question 16

peritubular capillaries

Answer 16

remove water, ions, and nutrients, which are reabsorbed by the proximal and distal tubules.

Question 17

formation of urine involves 3 processes

Answer 17

1. glomerular filtration - movement of a protein-free solution of fluid and solutes from the glomerulus inot the space within the glomerular capsule
2. tubular reabsorption - return of most of the fluid and solutes back into the peritubular capillaries or vasa recta
3. tubular secretion - the addition of certain solutes from the peritubular capillaries or vasa recta into the tubule

Question 18

glomerular filtration

Answer 18

process of filtering a large quantity of protein-free plasma fluid from the glomerular capillaries into the glomerular space.

Question 19

podcytes

Answer 19

cover and surround the outside surface of the capillaries and the capillary cells themselves

Question 20

tubular reabsorption

Answer 20

2nd step in urin formation, returns filtered water and solutes from the tubule into the blood of the peritubular capillaries or vasa recta

Question 21

tubular secretion

Answer 21

move from the capillaries (either peritubular capillaries or vasa recta) into the tubule to be excreted. may occur by either active transport or passive diffusion, depending on the substance being secreted

Question 22

antidiuretic hormone (ADH)

Answer 22

process of reabsorbing water i regulated by this from the posterior pituitary gland.

Question 23

countercurrent exchange mechanism

Answer 23

production of concentrated urine depends on this.

Question 24

micturition reflex

Answer 24

urination depends on the neural micturition reflex; bladder stretching initiates involuntary relaxation of the internal urethral spinchter. the brain can override the reflex by voluntary contraction of the external urethral sphincter

Question 25

aldosterone

Answer 25

steroid hormone from the adrenal gland increases the reabsorption of Na across the distal tubule and collecting duct.

Question 26

renin

Answer 26

an enzyme that functions like a hormone. secreted by a group of afferent arteriole cells that are part of a structure located very near the lomerulus called the juxtaglomerular apparatus.

Question 27

juxtaglomerular apparatus

Answer 27

region where the afferent and efferent arterioles are in close contact with the distal tubule

Question 28

kidneys help maintain acid-base balance and blood pH these 2 ways

Answer 28

1. reabsorption of filtered bicarbonate

2. renal excretion of acid as ammoniumes bone

Question 29

erythropoietin

Answer 29

stimulates the bone marrow to produce more red blood cells

Question 30

dialysis

Answer 30

attempts to duplicate the functions of healthy kidneys