8b Renal system

Question 1

renal system:

Mammals in general require a means to:

Answer 1

1. Regulate the composition of body fluids
2. Regulate fluid volume
3. Excrete wastes from the body

Question 2

Which structure produces urine?

Answer 2

kidney

Question 3

What structure propels urine from kidneys to bladder?

Answer 3

ureter

Question 4

What is function of bladder?

Answer 4

hold urine

Question 5

What structure connects bladder to external environment?

Answer 5

urethra

Question 6

The kidney is organized into 2 layers – name them and describe their location:

Answer 6

1. cortex (outer layer)

2. medulla (inner region)

Question 7

1. collecting ducts are found in what layer of the kidney and converge to what structure?
2. The region this is found is known as ??

Answer 7

inner medulla
renal papilla

2. renal pelvis

Question 8

Monocalyceal kidney

Answer 8

one single renal pelvis and set of papillae (together called a calyx)
i.e.: mouse kidney

Question 9

Multicalyceal kidney

Answer 9

divided into multiple calcies

i.e.: humans, mammals

Question 10

Multireniculated kidney

Answer 10

separated into distinct lobes each individual lobe called reniculum acts as a serape little kidney having its own cortex and medulla
i.e.: marine mammals, few terrestrial males that need to conserve water

Question 11

What is unique about Sirenia kidneys?

Answer 11

DO NOT have TRUE reniculated kidneys; cortex is continuous

Question 12

What is the name given to the kidney found in pinniped and cetaceans?

Answer 12

multireniculated kidney

Question 13

Describe the structural anatomy of this style of kidney

Answer 13

A. hilus
renal arter energy; renal vein exits; ureter exists

b. renal capsule
CT and peritoneum

c. renicule
= single until of kidney has own cortex, medulla and pelvis

Question 14

hilus

Answer 14

renal arter energy; renal vein exits; ureter exists

Question 15

Renal capsule

Answer 15

CT and peritoneum

Question 16

Gross overview in marine mammals

Answer 16

A: renicule
medulla = pink lighter aarea
cortex is the redder area
b. capsule of the kidney

Question 17

Harbor seal bladder opened to expose inside

Answer 17

A. bladder inside view
muscular wall capable of significant expansion
b. urethra opening bladder side

Question 18

1. What forms the basic functional filtration unit of the kidney?
2. Are there few or many of these per kidney?
3. What exactly do they do? What is their end product?
4. What, if anything, can these structures resorb?

Answer 18

1. nephrons
2. hundred of thousands
   filter the blood to removes metabolic waste and excess minerals and excrete it as urine
3. filter out everything that is smaller than 68 kda
4. selectively reabsorb what the body requires.

Question 19

What is the nephron function and urine concentration dependent on? What happens here to allow urine to be produced?

Answer 19

the cortico-medullary acts as the kidney

establishes a counter current concentrator to produce urine

Question 20

Thin segment of ascending limb

Answer 20

passive transport of cl-

Question 21

descending limb

Answer 21

water reabsorbed, urine concentration

Question 22

thick LOH

Answer 22

active transport of Na+, K+

Question 23

collecting duct

Answer 23

selectively permeable to h20 reabsorption

Question 24

Describe 2 structural differences that the kidney can increase ability to concentrate urine ?

Answer 24

deep the medulla is relative toe the cortex

the longer the LOH (marine mammals do not have long loops though)

Question 25

The urine that mammals excrete is dependant upon what 3 processes?

Answer 25

1. what is filtered out 2. what is reabsorebed 3. what is actively secreted

Question 26

Describe 2 unique strategies that marine mammals have developed to minimize water loss

Answer 26

1. increased reabsorption of water | 2. increased filtration nada secretion of salts and waste products

Question 27

Marine mammals are presented with unique challenges: - list 3 key ones relevant to the renal system.

Answer 27

1. coping with increased salt intake 2. coping with long fasting periods 3. finding fresh water

Question 28

Marine mammals have to adapt their renal system to:

Answer 28

1. extreme the large amounts of minerals injected | control the amount info water loss to prevent dehydration

Question 29

number of reticule correlates to...

Answer 29

The number of reticule correaltes with the salinity of the diet and is associate with an increased capacity to excrete urine

Question 30

Describe the 3 basic sources of water that mammals obtain water from to use for osmoregulation?

Answer 30

1. drinking fresh water directly 2. h2o in food; most fish and invertebrates consists of 60-80% water 3. metabolic water: synthesis of fat or metabolism of protein

Question 31

Do marine mammals that live in freshwater lakes or rivers have to worry about removing huge amounts of minerals from their bodies ? Give 2 examples of such species?

Answer 31

NO | ir; manatees, amazing river dolphins

Question 32

What do some pinnipeds do to directly access fresh water either in the wild or in captivity?

Answer 32

chew on ice or snow | captive: drink water from hose or trough

Question 33

What was the outcome with respect to urine output, of a study wherein West Indian Manatee maintained in salt water, deprived of fresh water but fed a diet of leafy green vegetables (~70% fresh water)?

Answer 33

produced normal urine output

Question 34

What are the 2 main compounds that are broken down by the body and how much water can each provide? What is the implication of this for a marine mammal? During fasting are these sources available and why?

Answer 34

fatty acid catabolism i gram of palmitate -->beta oxidation) -->1.07grams of h20 proteolysis 1 gram of protein --> 0.4 g h20 eat more fatty fish yes because of storage of fat and protein

Question 35

A sea lion is deprived of both salt and fresh water for 45 days. Describe what will happen

Answer 35

along with fasting, the marine mammal will also decrease its urine output for further conservation of water

Question 36

What is one consequence of protein breakdown relevant for the kidney?

Answer 36

urea

Question 37

what is the impact of urea on water retention

Answer 37

urea must be excreted in the ruin resulting water loss

Question 38

What do marine mammals with high protein diet do to deal with this situation? Give the scientific name for this and describe it

Answer 38

Mariposa = intentional ingestion of sea water beneficial to marine mammals who have high protein diets, as the sea water an pride urinary osmotic space for urea, minimizing water loss

Question 39

Give one example of this from otariids, phocids and dolphins and the relative magnitude (daily) with mariposa

Answer 39

northern fur seal = 1.8 mL.kg per BW harbour seal= 4.8mL/kg BW common dolphin 12-13mL/kG per BW

Question 40

Discuss sea otters, their diet, eating habits and how relevant this issue is for them and what they do to cope.

Answer 40

Sea otters freely swallow sea water (avg. 62 ml'kg per body weight of saw water per day) to help extreme the high amount of urea it forms.

Question 41

Reducing Water Loss | What are 3 other key non-renal adaptations to conserve water in marine mammals:

Answer 41

- skin of pinnipeds have FEW sweat glands - cetaceans have NO sweat glands - water loss from breathing is reduced by conserving breaths and cooling expressed air (countercurrent exchanges)