Kidneys

Question 1

Excretion

Answer 1

the removal of body waste products and toxins

Question 2

Water potential

Answer 2

measure of potential energy of water, water always moves from high to low water potential

Question 3

Osmoconformers

Answer 3

marine animals that allow body fluid to mirror environmental osmotic pressure (need to be isotonic)
use active transport to maintain ion concentration

Question 4

Osmoregulators

Answer 4

animals (mostly mammals) that alter fluid levels by excreting water

Question 5

Malpighian tubes

Answer 5

system of water and solute regulation in insects

Question 6

Kidney

Answer 6

system of water and solute regulation in mammals

Question 7

Urea

Answer 7

toxin created by metabolic pathways that can break down proteins and weak covalent bonds, and must be removed from body through urine

Only about 50% is reabsorbed to keep medullary osmolarity gradient

Main toxin found in mammal waste

Question 8

Uric Acid

Answer 8

main toxin in insects and birds, excreted in solids and is the main waste product of metabolism

Question 9

Nephron

Answer 9

the base unit of the kidney

Question 10

Ultrafiltration

Answer 10

process that occurs in glomerulus of kidney, and occurs when hydrostatic pressure forced blood through the semi-permeable membrane to filter it

Question 11

What are the water potentials in the process of filtering out blood?

Answer 11

Total water potential- 10mmHg out from glomerulus to Bowman’s capsule

Glomerulus- 55 mmHg out
Capsule- 15 mmHg in
Colloid pressure (pressure of the solids in the capsule)- 30 mmHg

Question 12

Afferent arteriole

Answer 12

Entrance of the nephron, brings blood in to be filtered, contains following:
RBCs
Abs
Proteins
Hormones
WBCs
Vitamins
K+, Na+, Cl-, and glucose

Question 13

Glomerulus

Answer 13

place in the nephron where filtration occurs

Question 14

Bowman’s Capsule

Answer 14

(Ultrafiltration) capsule that covers the glomerulus, collects filtrate

Question 15

Basement Membrane

Answer 15

fine mesh that restricts passage of blood cells and proteins in between glomerulus and bowman’s capsule

Question 16

Efferent Arteriole

Answer 16

arteriole that removes blood from the nephron after being filtered

Question 17

Filtrate Components

Answer 17

1. Na+
2. K+
3. Cl-
4. Vitamins
5. Glucose

Question 18

Proximal Convoluted Tubules (PCT)

Answer 18

(Selective Reabsorption) Extends from Bowman’s Capsule, where most of selective reabsorption takes place (glucose, amino acids, vitamins & hormones all reabsorbed here and abt 80% of ions and water)

Question 19

Features of PCT cells

Answer 19

1. Has microvilli to increase SA
2. Contains lots of mitochondria

Question 20

Which components of the filtrate are actively absorbed?

Answer 20

Minerals, ions, vitamins, and glucose

Question 21

Which components of the filtrate are passively absorbed?

Answer 21

Water (follows salt passively through osmosis)

Question 22

Loop of Henle

Answer 22

(Osmoregulation) area that establishes salt gradient in medulla

Question 23

The loop of henle is long/short in desert conditions

Answer 23

long, because it allows for more water retention from a greater salt concentration

Question 24

The descending limb of the loop of henle is permeable/impermeable to H2O and permeable/impermeable to NaCl

Answer 24

permeable to H2O, impermeable to NaCl

Question 25

The ascending limb of the loop of henle is permeable/impermeable to H2O and permeable/impermeable to NaCl

Answer 25

impermeable to H2O, permeable to NaCl

Question 26

Where is the loop of henle the most salty?

Answer 26

in the deep medulla, because at that point it has lost most of the water but hasn’t yet lost the salt. Allows for water reabsorption in the collecting ducts

Question 27

What is in the cortex?

Answer 27

nephrons

Question 28

What is in the medulla?

Answer 28

the loop of henle

Question 29

Distal Convoluted Tubules

Answer 29

(Selective reabsorption) area right after loop of henle, mostly reabsorbs sodium and chloride

Question 30

Collecting Duct

Answer 30

(Osmoregulation, water retention) final step in the kidney, contains aquaporins where ADH acts upon it and increases permeability to water, so more or less water is retained by the body. Leads directly down to ureter

Question 31

Ureter

Answer 31

Tube that brings urine from the kidney to the bladder

Question 32

Process of filtration

Answer 32

1. Blood enters through Afferent Arteriole
   2a. Blood pushed through glomerulus and into Bowman’s Capsule, becoming filtrate
   2b. Blood parts not pushed into Bowman’s Capsule are moved out through Efferent Arteriole
2. Filtrate moves through PCT and most is reabsorbed except ions and water
3. Filtrate moves through loop of Henle, and creates salty gradient in the medulla
4. Filtrate moves through the DCT, where some Na+ and Cl- is reabsorbed
5. Filtrate goes through Collecting Duct, where water may be reabsorbed, depending on action of ADH
6. Urine moves out of collecting duct, into ureter, and down into bladder

Question 33

Vasa recta

Answer 33

the blood network that reabsorbs components from the filtrate (capillary network)– Made up of efferent arteriole

Question 34

What does the presence of glucose in urine indicate?

Answer 34

Diabetes, because all of the glucose is supposed to be reabsorbed in the PCT, but if there’s too much glucose in the blood, active transport can’t do everything

Question 35

What does the presence of protein in urine indicate?

Answer 35

diseases like PKU or hormonal conditions like pregnancy (from elevated hCG levels). Generally should not be in filtrate, because they are too big to pass through basement membrane

Question 36

PKU

Answer 36

disease where phenyl-alanine cannot be digested, and can create problems with cognitive abilities if not tested

Question 37

What does the presence of blood in urine indicate?

Answer 37

Infections, cancer, or kidney damage

Question 38

What does the presence of drugs/toxins in urine indicate?

Answer 38

usage of drugs, because drugs are not reabsorbed into the body

Question 39

Ammonia

Answer 39

nitrogenous excretory molecule created from the metabolism of proteins and nucleic acids, used by early animals.

highly toxic

eventually evolved mechanism to maintain water with urea instead of ammonia