31 Excretory

Question 1

Kidneys location and links

Answer 1

Lie at the back of the abdominal cavity. Each kidney is connected to a structure called the ureter. It is responsible for carrying the urine back to the urinary bladder. Sphincter muscles regulate micturition.

Question 2

The kidneys receive blood from the

Answer 2

Renal artery and blood leaves through renal vein

Question 3

The urinary system general function

Answer 3

Removes toxic by products of metabolism from the bloodstream, thus the kidneys are essential. Salts, glucose, proteins, ions, and water must be conserved or reabsorbed back into the body.

Question 4

Glomerular filtrate

Answer 4

Preurine. Contains urea, aa, water, salts, glucose, and ions.
It contains the same substances as blood plasma, except larger proteins.

Question 5

What many L of urine are produced each day?

Answer 5

1.5L

Question 6

Kidney hormones

Answer 6

EPO (erythropoietin): stims RBC production

Renin: Regs BP

Question 7

All the blood in our body passes through the kidneys every _ minutes

Answer 7

5

Question 8

Functional unit of kidneys

Answer 8

Nephron, each kidney contains about 1 mil.

Each nephron originates in the cortex.

Question 9

Filtration path

Answer 9

Glomerulus -> Bowman’s Capsule -> Proximal T -> Loop of Henle -> Distance T - > Collecting Duct - > Renal Pelvis - > Ureter

Question 10

Afferent arterioles

Answer 10

Supply blood to the glomerulus. Efferent arterioles path to leave for blood.

Question 11

Excretory System 4 processes micuriation

Answer 11

1) Filtration - Glom, BC
2) Reabsorption - PCT
3) Secretion- DCT
4) Excretion

Hydrostatic pressure(BP) drives filtration in the glomerulus. Ions, glucose, aa, small solutes, Urea, Vitamins, is filtered

Question 12

Glomerulus

Answer 12

Large surface area due to great number of capillaries. These capillary walls are more permeable that most capillaries to H20, small solutes, ions.
Large molecules are held back and put back into blood. Then proceeds to glomerular filtration.

Question 13

Bowman’s capsule cells

Answer 13

Podocytes involved with filtering. Podocytes have long tentacle like extensions.

Question 14

Proximal Convoluted T

Answer 14

PCT- most reabsorption takes place here, packed with mitochodria. 75% of Na+ goes out by active transport by ATPase pump, CL- follows through charge attraction, and H2O goes by osmosis.
Glucose, aa, drugs, nutrients, and other ions are transported out of the PCT by active transport to the interstitial fluid and to the peritubluar capillaries.
Reabsorb 65% of H2O, all small plasma proteins and vitamins.
H+ + NH3 -> NH4+.
Urea is only partly reabsorbed, but at a slower rate than H3O+.

Question 15

Loop of Henle

Answer 15

Descending : Aquaporins are very permeable to water. Low salt permeability, as filtrate descends the loop, urine becomes more concentrated.
Ascending : NaCl moves outward, but no H2O moves since here is impermeable to H2O. The fluid goes hypertonic in the descending limb to hypotonic in the ascending limb.

Question 16

Distal convoluted tubule

Answer 16

The fluid is hypoomsotic compared to normal body fluid. K+, H+, and NH4+ are secreted. Which also helps reg the pH. Many mitochondria but not as much as PCT.

Question 17

Aldosterone ions

Answer 17

Rate of Na+ absorption and K secretion by Na+ pumps are reg’d.

Question 18

Juxtaglomerular apparatus

Answer 18

Involved with regulating blood pressure and filtration rate of the glomerulus. If BP drops, the blood volume drops. Some juxtaglomerular cells produce renin (myoendocrine cells).

Question 19

Renin

Answer 19

converts angiotensinogen to angiotensin I. I goes to II. Angiotension II constricts blood vessels, increasing BP. Angiotension II also stim. increased aldosterone secretion, allowing more Na+ and H2O reabsorption.

Question 20

Macula Densa

Answer 20

Senses changes in Na+, relays info to the juxtaglomerular apparatus to release Renin.

Question 21

Collecting duct

Answer 21

When the kidneys need to conserve more water, water can move out by osmosis concentrating the solutes including urea left in the filtrate. In the presence of ADH, water can leave the collecting ducts and be conserved for use. Urine becomes hypertonic in the presence of ADH.

Question 22

Alcohol and ADH levels

Answer 22

Alcohol decreases the ADH levels, water is not returned but you end up urinating more.

Question 23

ADH

Answer 23

Regs water balance. Increases the permeability of collecting duct to water and some urea. Gives more conc. urine and reduced water loss from the body.

Question 24

After collecting ducts urine goes

Answer 24

to the Renal pelvis through the ureter to the Urinary bladder, Urethra.

Question 25

Desert animals and water

Answer 25

Those animals eats dry seeds high in carbohydrates and low in protein. Oxidation of fatty seeds produces metabolic water.
Long loops of Henle are displayed. The longer the loop, the more urine can be concentrated. Most of the water is reabsorbed.

Question 26

Diuretic makes you increase urination by

Answer 26

a) Decreasing permeability of collecting ducts
b) Decreasing ADH production
Coffee, tea, and alcohol are all diuretics.

Question 27

Urine composition

Answer 27

95% water, Urea (aa), uric acid (nucleic acid metabolism), creatine (metaboilsm of creatine)

Question 28

Rate of glomerular filtration is directly proportional to

Answer 28

Filtration pressure

Question 29

Afferent arteriole is under which NS control?

Answer 29

Sympathetic NS. If the afferent arteriole becomes constricted:

a) Glomerular hydrostatic pressure decreases
b) Filtration rate decreases
c) Volume of urine flow decreases thus urine output decreases

Question 30

Efferent arteriole is constricted blood cannot flow out

Answer 30

Glomerulus is backe up.

a) Glomerular hydrostatic pressure now increases
b) Filtration rate increase
c) Urine output increases
d) Potential urine output increases

Question 31

As the bladder fills with urine, stretch receptors are stim.

Answer 31

And the need to urinate occurs. The micturition reflex center is located in the spinal cord.

Question 32

Counter current mechanism

Answer 32

Recycling of NaCl that permits the kidney to maintain a salty environment in the interstitial fluid at the bottom of the loop of Henle. The Na+ and Cl- ions from the ascending loop return to the descending loop.

Question 33

Malphigian tubulue

Answer 33

Main excretory structure of insects.

Question 34

Uric acid other species

Answer 34

Birds, Reptiles, Insects, and land snails

Question 35

Mammals and mature amphibians nitrogenous wastes

Answer 35

Urea

Question 36

Aquatic animals nitrogenous waste

Answer 36

ammonia

Question 37

Uric acid compared to ammonia or urea

Answer 37

Uric acid is water soluble and less toxic. Uric acid is in the form of crystals.

Question 38

Contractile vacuoles

Answer 38

Organelle used for osmoregulation and waste removal.

Paramecium, amoeba, some algae, some fungi, and hydra.

Question 39

Flame cells

Answer 39

Function like a kidney, waste removal.

Excretory cells in flatworms (platyhelminthes) and rotifers.

Question 40

Freshwater fish

Answer 40

Large amounts of urine are made and urine is less conc that fluids of the body. Dilute urine

Question 41

Marine Fish

Answer 41

Small amount of urine, urine fairly conc.

Question 42

UTI in female more common

Answer 42

Urethra is shorter in females than males.
Painful urination, burning sensation, feeling urge to urinate but cannot, malaise. Cloudy dark urine which smells bad and might contain blood.