Excretion Flashcards Preview

Biology (Mona) > Excretion > Flashcards

Flashcards in Excretion Deck (46)
Loading flashcards...
1
Q

Excretion

A

the removal of waste products of metabolism from the body

2
Q

3 organs of excretion

A

lungs
skin
kidneys

3
Q

2 things the lungs excrete

A

CO2 H2O

4
Q

2 things the skin excretes

A

H2O, NaCl

5
Q

4 things the kidneys excrete

A

H2O, excess salts, urea, uric acid

6
Q

where are the kidneys located

A

in the abdominal cavity in the small of the back

7
Q

2 functions of the kidneys

A

excretion

osmoregulation

8
Q

excretory function of the kidneys

A

removal pf urea, uric acid, salts and water

9
Q

osmoregulatory function of the kidney

A

maintenance of water and salt balance in body fluids

10
Q

urine path

A

formed in kidneys, ureter to bladder, released from urethra

11
Q

each kidney consists of

A

many tiny tubes called nephrons and blood capillaries

12
Q

function of nephrons

A

provide a large surface area for exchange of materials with blood

13
Q

blood through kindey

A

renal artery - afferent arteriole - glomerulus - efferent arteriole - capillaries - venule - renal vein

14
Q

function of kidney

A

to remove unwanted substances from the blood, this results in the formation of urine

15
Q

3 processes involved in urine formation

A

filtration of blood
selective reabsorption
secretion

16
Q

filtration

A

small molecules are filtered out of the blood

17
Q

location in kidney of filtration

A

cortex

18
Q

selective reabsorption

A

as the filtrate flows along the tubules, useful substances are removed from it and taken back to blood

19
Q

location in kidney of selective reabsorption

A

cortex and medulla

20
Q

secretion

A

some substances e.g K+ and H+ not needed by the body are actively transported by the cells of the nephron from the blood into the filtrate

21
Q

location in kidney of secretion

A

cortex

22
Q

filtration is under

A

high pressure

23
Q

3 ways that the blood in the glomerulus is put under pressure

A

arterial blood pumped from heart
arterioles present at both ends
afferent arteriole has a wider lumen than efferent arteriole

24
Q

what comes out of glomerulus

A

glomerular filtrate

25
Q

3 things not in glomerular filtrate

A

red and white blood cells, platelets and blood proteins

26
Q

glomerular filtrate

A

part of the blood plasma that passes through the glomerulus into the lumen of Bowman’s Capsule

27
Q

Selective reabsorption

A

useful substances are taken back from the glomerular filtrate by osmosis and active transport and returned to the blood

28
Q

4 locations of reabsorption in the nephron

A

proximal convoluted tubule
loop of Henle
Distal convoluted tubule
Collecting duct

29
Q

3 things reabsorbed in proximal convoluted tubule

A

water (osmosis)
glucose and amino acids (active transport)
salt (active transport)

30
Q

2 things reabsorbed in loop of Henle

A

H2O (osmosis)

salts (active transport)

31
Q

1 thing reabsorbed in distal convoluted tubule

A

H2O (osmosis)

controlled by ADH

32
Q

1 thing reabsorbed in collecting duct

A

H2O (osmosis)

controlled by ADH

33
Q

what is the filtrate called after selective reabsorption

A

urine

34
Q

why is the concentration of urea and uric acid much higher in urine than in plasma/glomerular filtrate

A

a lot of H2O is reabsorbed from filtrate as it moves along the tubule

35
Q

the bladder

A

a sac with an elastic muscular wall that stores urine

36
Q

composition of urine

A
urea
uric acid
salts
water 
(hormones, vitamins, drugs etc)
37
Q

ADH 2 names

A

anti-diuretic hormone

vassopressin

38
Q

what secretes ADH

A

pituitary gland

39
Q

function of ADH

A

makes the cells in the distal convoluted tubule and collecting duct more permeable to water

40
Q

what is amount of ADH secreted controlled by?

A

water concentration of the blood

41
Q

homeostasis

A

the maintenance of a constant internal environment in the body

42
Q

why is homeostasis necessary

A

to ensure that cells have optimum conditions to carry out their metabolism

43
Q

role of kidney in homeostasis

A

osmoregulation

44
Q

osmoregulation in kidney

A

excretion/reabsorption of water

excretion/reabsorption of salts

45
Q

1 disorder of the urinary system

A

kidney failure

46
Q

treatment for kidney failure

A

dialysis / kidney transplant