Chapter 7 - Kidneys Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Why are fluctuations in homoeostasis dangerous?

A

They can disrupt biochemical activities and large fluctuations can kill the cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is homoeostasis?

A

The maintenance of a constant internal environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What four internal features must be kept constant?

A

Chemical composition – blood pH ranging from 7.35 to 7. 45 – osmotic pressure, Osmo regulation – temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are effectors?

A

Things that change in response to stimuli in order to correct and achieve homoeostasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Name some of the response mechanisms that change in the body to correct temperature?

A

Blood vessels constrict or dilate – sweat produced – piloerection – shepherding thermogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does it mean if one solution is hyperosmotic to another?

A

Hyper osmotic – means the solution contains more solutes than other solution it therefore contains less water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does it mean if one solution is hypoosmotic to another?

A

It means it contains less solutes than the other solution therefore contains more water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define osmolarity

A

The number of osmoles solute per litre of solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Name the three important regulatory functions of the kidney

A

Removal of nitrogenous waste –
regulation of water content of the body – regulation of salt balance, sodium, potassium, chlorine, magnesium, calcium this is known as ionic regulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What three ways can ammonia be excreted?

A

As ammonium, urea and you uric acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the toxicity levels from high to low for ammonia, Urea and uric acid

A

Ammonia high - urea low - uric acid very low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the solubility for ammonia, urea, Uric acid

A

Ammonia has high solubility levels, urea has a low solubility levels, uric acid is almost not soluble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the metabolic cost for ammonia, urea, uric acid – from high to low

A

Ammonia has no metabolic cost
Urea has some metabolic cost
Eurich acid has a high metabolic cost

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What animals would have ammonia in the form of nitrogenous waste?

A

Fish or aquatic animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What animals with have urea in the form of nitrogenous waste?

A

Mammals, adult terrestrial amphibians

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What animals would have uric acid in the form of the nitrogenous waste,

A

birds and insects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What percentage of the bodyweight are the kidneys?

A

1%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What did juxtamedullary nephrons mean

A

Urine is very concentrated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the two types of nephrons?

A

Cortical and juxtamedullary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does cortical nephrons mean?

A

Less concentrated urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What percentage of nephrons are cortical and juxtamedullary and humans?

A

85% are cortical and 15% of juxtamedullary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What animals have both juxtamedullary and cortical nephrons?

A

Birds and mammals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What animals contain only cortical nephrons?

A

Reptiles and amphibians

24
Q

How does fluid escape Bowmans capsule?

A

It moves by the process of ultrafiltration – the hydrostatic pressure of the blood plasma a.k.a. blood pressure forces fluid and solutes through the glomerular capillaries into Bowmans capsule

25
Q

What type of energy process as the movement of fluid out of the Bowmans capsule?

A

It is a passive process therefore no energy is required

26
Q

What can pass freely into Bowmans space?

A

Anything less than 1.8 nm filter freely – water, glucose, urea, amino acids

27
Q

What is able to filter list file into Bowman space?

A

Anything between 1.8 to 4. 2 nm

28
Q

What molecules do not filter through Bowman space?

A

Anything larger than 4. 2 nm

29
Q

What prevents the movement of large molecules through the capillaries?

A

The pores in endothelium range between 50 to 200 nm wide – podocyte split pores size are also 4 nanometres wide

30
Q

What Are podocyte split pores?

A

They determine what can pass into bowmans space

31
Q

Define glomerular filtration rate

A

the amount of fluid filtered into the kidney tubules per minute

32
Q

How many litres of blood passed through the kidneys every minute

A

1.25 L

33
Q

How many litres of blood passes through the nephrons of the kidney daily?

A

180 L

34
Q

How much water did the kidneys reabsorb from the blood?

A

98 to 99%

35
Q

How many litres of urine is actually excreted a day?

A

1 to 2.5 L

36
Q

What is energy process for forming urine?

A

Both Mechanisms involve active transport

37
Q

What are the two mechanisms of forming urine?

A

One requires the tubular reabsorption of water and solites back into the body and the other is the secretion of salts into the tubules to be lost in the urine

38
Q

What percentage of water and solUtes Are reabsorbed into the proximal and distal tubules?

A

70 to 75% although it is mostly reabsorbed into the proximal tubes

39
Q

What is the maximum renal threshold mechanism for glucose?

A

180 mg/ 100 ml

40
Q

What is the renal threshold mechanism?

A

The limit as substance can be absorbed or filtered

41
Q

What does it mean if glucose is secreted in

urine?

A

This as a sign of diabetes mellitus

42
Q

Where is the highest grading of NaCl in the loop of Henley?

A

At the top of the hairpin

43
Q

How is NaCl filtered out of the thick ascending limb?

A

Via facilitated diffusion as the wall is not permeable to water it is actively transported out of the thick segment in the outer medulla

44
Q

Where does water leave by osmosis in the loop of Henley?

A

In the descending limb as the wall was not permeable to NaCl

45
Q

What happens in the collecting duct?

A

More NaCl leaves, some uvea also leaves, water leaves by osmosis,

46
Q

What animals have only juxtamedullary nephrons?

A

Desert mammals

47
Q

Why do desert mammals have very long Loops of Henley?

A

This is due to their lots of NaCl pumps that produce minute quantities are very concentrated urine hyperosmotic to the blood

48
Q

Describe the kidney function of freshwater fish

A

Freshwater fish are hyperosmotic to their surroundings so suffer a loss of salts and a large intake of water

49
Q

What is unique about the nephron structure and freshwater fish?

A

Freshwater fish have no loops of Henley

50
Q

Describe the kidney physiology in marine salt water fish

A

They are bony fish hypoosmotic to their surroundings so in danger of getting lots of salt and dehydrating

51
Q

What is unique about the nephron structure in salt water marine fish?

A

The lack of glomeruli and Bowmans capsule

52
Q

What is unique about the role of gills in Osmo regulation in fish?

A

Gills perform more osmoregulatory functions than the kidneys

53
Q

What hormones released from the posterior pituitary gland in response to dehydration?

A

The anti-diuretic hormone a.k.a. ADH

54
Q

What does a DH trigger in the kidney?

A

The release and insertion of Aquaporins a.k.a. proteins that allow water to be reabsorbed into the kidneys – the service water channels and lead to the formation of hyperosmotic urine

55
Q

What is diabetes insipidus?

A

Lack of the ability to produce ADH or kidneys do not react to ADH