Cell Physiology of Ions 2

Question 1

What is hypocalcaemia?

Answer 1

Insufficient free ionised calcium in the blood

Question 2

What can hypocalcaemia lead to?

Answer 2

paraesthesias

and over-reactive tendon reflexes

Question 3

What can severe hypocalcaemia cause?

Answer 3

ECG abnormalities –> arrhythmias and seizures

Question 4

In fertilisation what acts as a second messenger?

Answer 4

Ca2+, increase in intracellular concentration

Question 5

Which Ions are of higher concentration inside and outside of the cell?

Answer 5

Na+ high outside

K+ high inside

Question 6

What are excitable cells?

Answer 6

Those which can propagate an action potential

Question 7

What are examples of excitable cells?

Answer 7

Neurons

Muscle Cells

Question 8

What are non-excitable cells?

Answer 8

Cells without action potentials

Question 9

What are examples of non-excitable cells?

Answer 9

Epithelial cells such as the skin and liver

Question 10

Water tends to follow which Ion?

Answer 10

Cl-

Question 11

What Ion does plasma have in high concentration?

Answer 11

Na+

to balance the negative proteins

Question 12

Is plasma more or less negative in electrical potential than the Extracellular fluid?

Answer 12

more negative

ECF lacks proteins-

Question 13

What is extracellular space high in?

Answer 13

Cl-

lots of to make up for lack of negative proteins

Question 14

What is the composition of Intracellular fluid like?

Answer 14

High in cations
High in proteins
Highest electrolyte conc.
Most negative voltage -70mV

Question 15

What is free calcium?

Answer 15

Calcium ion which are ionised (Ca2+) and are in a solution = can activate enzymes

Question 16

When is Calcium insoluble?

Answer 16

When in bone or bound to proteins

Question 17

What does it mean if calcium is sequestered?

Answer 17

its hidden inside an organelle

Question 18

In the cytosol of a cell is free calcium of high or low concentration?

Answer 18

very low

Question 19

How low is the concentration of Ca (Free) in cytosol?

Answer 19

100 nanoM or less

Question 20

Outside of the cell free Calcium concentration is… compared to inside

Answer 20

1.2milliM

x10,000 more than inside cell

Question 21

Muscle cells can be activated when intracellular free Calcium is…….. in concentration

Answer 21

increased in concentration

Question 22

High cytosolic calcium is needed to for which step of muscle contraction?

Answer 22

attachment

Question 23

An increase in cystolic calcium concentration can leads too…..

Answer 23

synaptic transmission or muscle contraction

Question 24

pH is usually higher extracellularly or in the cytosol?

Answer 24

pH is higher extracellularly. (inside cell more acidic)

Question 25

Which 2 organs buffer our pH in blood?

Answer 25

kidneys and lungs

Question 26

How do RBC use Carbonic Anhydrase?

Answer 26

to remove H+ from muscles

Question 27

How do the lungs use carbonic anhydrase?

Answer 27

to remove CO2 from blood

Question 28

How do gastric parietal cells use carbonic anhydrase?

Answer 28

To secrete acid H2CO3 into the stomach

Question 29

How does the pancreases use carbonic anhydrase?

Answer 29

to secrete a base Bicarbonate HCO3-

Question 30

In the sodium/potassium pump what does what?

Answer 30

3 Na+ go out of the cell for 2 K+ going in

Question 31

State the Carbonic Anhydrase reaction?

Answer 31

Co2 + H20 H2CO3 H+ + HCO3-

Question 32

What form of Ion transport does the Bicarb + CL- transfer use?

Answer 32

co-transport

passive