Topic L (Excretion) Flashcards Preview

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Flashcards in Topic L (Excretion) Deck (46)
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1
Q

Excretion

A

The removal of waste products of metabolism

2
Q

Ureter

A

Transports urine from the kidney to the bladder

3
Q

Urethra

A

Transports urine out of the body

4
Q

Urea

A

Produced from the breakdown of excess amino acids in the liver

5
Q

Urine

A

A solution of urea + water + salts, stored in the bladder before being released from the body

6
Q

Nephron

A

Functional filtering unit of the kidney, also known as kidney tubules

7
Q

Bowmans capsule

A

Hollow cup of cells surrounding the glomerulus

8
Q

Glomerulus

A

A dense network of capillaries where water, ions, glucose and urea are filtered from the blood into the tubules

9
Q

Glomerular filtrate

A

The fluid forced out of the glomerulus under high pressure

10
Q

What does glomerular filtrate contain?

A

Glucose, urea, ions

11
Q

What glomerular filtrate does not contain?

A

Blood cells, proteins

12
Q

Proximal convoluted tubule

A

Site where the majority of glomerular filtrate is reabsorbed

13
Q

What is reabsorbed back into the blood stream? Which process?

A

Glicose, active transport

14
Q

Loop of Henle

A

A U-shaped loop that runs down into the medulla of the kidney

15
Q

What is Loop of Henle’s main role

A

Concentrating the fluid in the tubule to allow more water to be reabsorbed into the blood

16
Q

Collecting duct

A

The tubule that receives urine from numerous nephrons.

17
Q

What controls the permeability of the wall’s of the collecting duct?

A

ADH hormone

18
Q

Ultrafiltration

A

The process where fluid is forced out of the glomerulus under high pressure

19
Q

Selective reabsorption

A

The process where the substances we need are absorbed into the blood stream.

20
Q

Active transport

A

The transport of substance across a biological membrane against a concentration gradient, which requires energy

21
Q

Osmoregulation

A

The hormonal control of water level in the blood

22
Q

ADH - stands for?

A

Anti diuretic hormone

23
Q

ADH

A

The hormone which increases the permeability of the collecting ducts allowing more water to reabsorbed back into the blood

24
Q

Hypothalamus

A

A region of brain which are sensitive to the solute concentration of the blood

25
Q

Pituitary gland

A

A small gland in the brain that releases several hormones including ADH

26
Q

Negative feedback

A

Any mechanism which reverts a change in a system back to its normal value.

27
Q

Homeostasis

A

The maintenance of a constant internal environment

28
Q

Egestion

A

Removal of faeces

29
Q

How does a nephron begin?

A

With a glomerulus

30
Q

What follows glomerulus?

A

Bowman’s capsule

31
Q

What is the tubule before loop of Henlé called?

A

Proximal convoluted tubule

32
Q

What is the tubule after loop of Henlé called?

A

Distal convoluted tubule

33
Q

What substances are reabsorbed during selective reabsorption? (3)

A

1) ALL Glucose 2) SUFFICIENT salt 3) SUFFICIENT water

34
Q

What process helps selectively reabsorb water?

A

Osmosis

35
Q

How are mineral ions reabsorbed into the blood stream?

A

Active transport

36
Q

Where does the nephron finally get to?

A

Collecting duct

37
Q

Main roles of kidneys (3)

A

1) Removal or urea 2) Adjustment of salt levels in the water 3) Adjustment of water content of the blood

38
Q

Where does most of selective reabsorption happen?

A

Proximal convoluted tubule

39
Q

What will happen if there is not enough water in the cells?

A

Reactions in cytoplasm would not occur

40
Q

What will happen if there is too much water in the cells?

A

Cells may rapture

41
Q

What are the 3 main mays of water leaving the body?

A

1) Sweating 2) Breathing 3) Urinating

42
Q

What mechanism controlls the process of osmoregulation

A

Negative feedback

43
Q

Describe negative feedback in terms of osmoregulation

A

When water content gets too high or too low a mechanism will be triggered to bring the level back to normal

44
Q

How does ADH travel through the body?

A

Blood

45
Q

Under what conditions less water will be stored? (3)

A

1) Cold temp 2) No sweating 3) Well hydrated

46
Q

Under what conditions more water will be stored? (3)

A

1) Hot temp 2) A lot if sweating 3) Poor hydrated