Physiology 4

Question 1

What is GFR in litres per day

Answer 1

180litres per day

Question 2

What substance does the kidney reabsorb

Answer 2

Fluid 
Salt 
Glycose 
Amino acids 
50% of urea 
0% creatinine

Question 3

Reabsorption is specific/ non specific and filtration is specific / non-specific

Answer 3

Reabsorption os specific

Filtration is non-specific

Question 4

How often is plasma filtered per day

Answer 4

Around 65 times

Question 5

What is the initial tubular fluid

Answer 5

a modified filtrate of the blood

Question 6

What does the blood have that the initial tubular fluid doesn’t have

Answer 6

RBC

Plasma proteins

Question 7

How much fluid is reabsorbed in the proximal tubule

Answer 7

80ml/min of filtered fluid

Question 8

What does iso-osmotic mean

Answer 8

There is no change in the osmolarity between one area and an other

Question 9

What is the osmolarity of the proximal tubular fluid

Answer 9

300 (same as plasma)

Question 10

Why is there no change in the concentration of things in the proximal tubule

Answer 10

we reabsorb salt and water in equal portions

Question 11

Fluid reabsorbed in the proximal tubule is said to be:
a) Hypo-osmotic 
b) Iso-osmotic 
c) Hyper-osmotic 
with the filtrate 
Why

Answer 11

Iso-osmotic
We reabsorb salt and water in equal portions so there is not change in the concentration of things in the proximal tubule

Question 12

What are some substances that are reabsorbed in the Proximal tubule

Answer 12

sugars 
amino acids 
phosphate
sulphate 
lactate

Question 13

What are some substances that are secreted i the proximal tubule

Answer 13

H+
Hippurates
Neurotransmitters
Bile pigments
Uric acid 
Drugs 
Toxins

Question 14

What is transcellular reabsorption

Answer 14

Substances that are to be reabsorbed into the blood via a number

Question 15

What are the tight junctions and what do they do

Answer 15

Protein junctions

Help to separate the apical luminal membrane and the basement membrane

Question 16

What determines the amount of the substance that is reabsorbed back into the blood

Answer 16

Whether a cell junction is tight or leaky

Question 17

What are the 3 ways in which substances can be moved across the membrane

Answer 17

Primary active transport
Secondary Active Transport
Facilitated division

Question 18

Describe what happens in primary active transport

Answer 18

Energy is directly required to operate the carrier and move the substrate against its concentration gradient - hydrolysis of ATP is required

Question 19

Describe what happens in secondary active transport

Answer 19

The carrier molecule is transported coupled to the concentration gradient of an ion (usually Na+)
Sodium comes from outside to inside the cell and with this moves another molecule either in the same direction (symporter) or second

Question 20

What happens in facilitated diffusion

Answer 20

Passive carrier-mediated transport of a substance down its concentration gradient to get a molecule to move a substance from one side of the membrane to the other. The concentration gradient already exists

Question 21

Give an example of primary active transport

Answer 21

Na/ K pump

Question 22

Give an example of secondary active transport

Answer 22

Na/ glucose

Question 23

What are some other ways in which molecules can move in or out of a cell

Answer 23

Diffusion through the lipid layer (O2 and CO2)

Diffusion through channels (ions)

Question 24

Where is the sodium potassium pump found

Answer 24

lateral membrane of the epithelial cells

Question 25

For every 1 ATP molecule used in the K/Na transporter, how many of each ion would be moved

Answer 25

3Na out of the cell

2K in of the cell

Question 26

What does the K/Na pump do

Answer 26

helps to keep the concentration the same