excretory system

Question 1

what is excretion

Answer 1

the removal of waste products of metabolism from the body

Question 2

what are the exctretory organs nd what are their functions

Answer 2

Lungs-CO2 water and heat
Colon/gut- faeces
Kidney- nitrogenous waste
Skin- sweat

Question 3

what are the nitrogenous waste products

Answer 3

uric acid
urea
creatinine
ammonia

Question 4

what other useful substances are exctreted out of the body

Answer 4

water
amino acids
hormones
vitamins
salts
ions
glucose

Question 5

what is the glomerulus

Answer 5

a cluster of capilaries

Question 6

what is found in the renal corpusle

Answer 6

-bowmans capsule
-glomerulus

Question 7

what is found in the renal tubule

Answer 7

proximal convulated tubule
loop of henle
distal convulated tubule

Question 8

what is the microscopic structure that is vital for excretion in the kidney called

Answer 8

nephron

Question 9

how many nephrons share the same collecting duct

Answer 9

12

Question 10

how do the kidneys maintain homeostasis

Answer 10

removing unwanted substances from the blood

Question 11

what is glomerular filtration

Answer 11

when the fluid part of the blood is filtered through a glomerular membrane into the cavity of the bowmans capsule

Question 12

what is tubular reabsorbtion

Answer 12

when useful substances are reabsorbed back into the bloodstream in the mounts that are needed by the body

Question 13

what is tubular excretion

Answer 13

when the waste products from the blood are excreted into the tubules

Question 14

where does glomerular filtration take place

Answer 14

in the renal corpuscle

Question 15

what is the difference between an efferent arteriole and an afferent arteriole

Answer 15

an efferent arteriole carries blood towards the nephron and the afferent arteriole carries blood away fron the nephron

Question 16

how does the size of the 2 arterioles influence glomerular filtration

Answer 16

blood enerts through the wider afferent arteriole and and pressure is created because the efferent areriole is more narrow, which means more blood is entering the glomerulus that what can leave

this causes pressure to buld up forcing blood to filter thrugh the glomerular membrane

Question 17

what is ultrafiltration

Answer 17

filtration of blood in the capilries into the bhowmans capsule while under pressure through the glomerular membrane

Question 18

what are some non-nitrogenous wastes

Answer 18

toxins and drugs (painkillers, tranquillisers, and nicotine)
alcohol

Question 19

what is defaecation or egestion

Answer 19

removal of undigested and unabsorbed food material from the gut

Question 20

is the bladder an excretory organ

Answer 20

no, its only function is to store urine

Question 21

what type of glands are adrenal glands

Answer 21

endocrine glands

Question 22

where are the kidneys found

Answer 22

in the abdominal cavity below the diaphragm

Question 23

where is the nephron in the kidney found

Answer 23

in the cortex and the medulla

Question 24

what does the renal artery carry

Answer 24

blood that is rich in nitrogenous waste

Question 25

what does the renal vein carry

Answer 25

purified, deoxygenated blood from the kidney to the inferior vena cava

Question 26

how much blood is filtered in 1 minute

Answer 26

120ml

Question 27

how is the glomerular membrane adapted for filtration

Answer 27

it is made up of 2 layers of cells: endothelial cells- make the wall of glomerular capillaries and they are porous which allows plasma through the pores but not blood cells flattened podocyte cells - make up the podocyte layer and it has spaces between them called filtration slits that only allow plasma protein through

Question 28

what makes up glomerular filtrate

Answer 28

Blood plasma without the blood cells or plasma protein with useful substances (water, glucose, amino acids, vitamins, hormones and ions) as well as waste substances such as nitrogenous waste (urea, uric acid & cratinine)

Question 29

what is the function of the shape of the Bowman's capsule

Answer 29

large surface area, so that the max amount of filtration can take place

Question 30

what is glomerular filtration

Answer 30

passive process in which fluids and solutes are forced through the glomerular membrane by means of hydrostatic pressure

Question 31

what happens to the filtrate as it moves along the renal tubule

Answer 31

the useful substances that are needed by the body are reabsorbed into the blood in the surrounding capillaries

Question 32

where does the reabsorbtion of useful substances take place

Answer 32

proximal convoluted tubule

Question 34

what cells are the walls of the PCT made up of

Answer 34

cuboidal epithelial cells

Question 35

what adaptations are made with the walls of the PCT

Answer 35

microvilli along the border of the tubule= increases surface area for max reabsorption Outer surface of tubule is folded to increase surface area A lot of mitochondria for active transport

Question 36

What is active reabsorption in the PCT

Answer 36

molecules combine carrier molecules and are then able to move against the concentration gradient

Question 37

what is needed for active reabsorption to take place

Answer 37

ATP- adenosine triphosphate

Question 38

what is the concentration gradient

Answer 38

the gradual difference in the concentration of solutes in a solution between 2 regions

Question 39

what substances are reabsorbed

Answer 39

-glucose -protein -water soluble vitamins(Vitamin C) -amino acids -salts

Question 40

are there any glucose or protein molecules in normal urine?

Answer 40

No

Question 41

how is water reabsorbed into the blood

Answer 41

by means of osmosis. 65% of the water is passively reabsorbed

Question 42

what is the role of the loop of Henle

Answer 42

to create a high concentration of salt in the medulla of the kidney in order to actively transport sodium ions out of the filtrate

Question 43

what is a sodium pump

Answer 43

salt(nacl) is transported to the surrounding tissue fluid, causing water to move out fo the loop by means of osmosis

Question 44

what is the final oucome of the loop of henle

Answer 44

water is actively conserved & passed into blood rather than urine less urine is formed=conservation of water

Question 45

what does it mean is an organism has a longer loop of henle

Answer 45

encourages more water to be reabsorbed= highly concentrated urine

Question 46

what is the pH range for urine

Answer 46

6 (weak acid)

Question 47

what is the pH of blood

Answer 47

7.35- 7.45 (slightly alkaline)

Question 48

what is a buffer

Answer 48

chemical substance that prevents a great change in pH by binding with H+ when pH drops and releasing H+ when pH rises

Question 49

what is urine

Answer 49

filtrate containing all substances that the body does not want that flows through the collecting ducts

Question 50

what can affect the composition, amount and colour of urine

Answer 50

diet exercise volume of liquids drunk health

Question 51

how much urine is produced daily

Answer 51

1l - 1.5l

Question 52

what is the process of urine moving out of the kidneys

Answer 52

- passes into the calyx then into the renal pelvis - moves through the 2 ureters into the bladder -stored in bladder until it is able to be expelled by the urethra

Question 53

what is osmoregulation

Answer 53

maintains the correct balance between the water and solute contents of body fluid

Question 54

what happens is there is too much water in the cell

Answer 54

the cell will burst

Question 55

what happens when there is too little water in the cell

Answer 55

dehydration of cells

Question 56

what is osmolarity

Answer 56

the number of solute particles dissolved in 1 litre of water *the greater the concentration of solutes the greater the osmolarity