Exploding Cells & Acid Trouble

Question 1

Is ATP energy required for apoptosis or necrosis?

Answer 1

ATP energy required for apoptosis (not necrosis).

Question 2

What is necrosis?

Answer 2

Premature death of cells as a result of cell injury. Cytoplasm swells, cell bursts.

Question 3

What is the cause of the swelling of a cell during necrosis?

Answer 3

The failure of the Na/K ATPase pump

Question 4

Does apoptosis or necrosis cause an immune response?

Answer 4

Necrosis does (apoptosis does not)

Question 5

What is osmosis?

Answer 5

Movement of water molecules from a region of high concentration of free water molecules to a region of low concentration of free water molecules across a selectively permeable membrane

Question 6

What is oncotic pressure?

Answer 6

A form of osmotic pressure - exerted by proteins in the blood notably albumin

Question 7

Where is albumin produced?

Answer 7

Liver

Question 8

Why do cirrhosis of the liver result in fluid build-up in the stomach?

Answer 8

Less albumin produced, water not attracted out of stomach into the blood

Question 9

What is osmolarity/osmolality?

Answer 9

Refers to the concentration of solutes (proteins etc.) in the blood (a solution)

So… high osmolarity = high [solutes]

Question 10

Does water move to areas of higher or lower osmolarity?

Answer 10

Water moves wherever there is a higher osmolarity.

Question 11

Generally increased osmolarity = increased/decreased oncotic pressure?

Answer 11

Increased oncotic pressure

Question 12

What is tonicity?

Answer 12

RELATIVE concentration of solutes in solution separated by a semi-permeable membrane

Question 13

What is the normal plasma osmolality?

Answer 13

290 mOsmol/kg

285-295 mOsmol/kg

Question 14

How is serum/urine osmolality measured?

Answer 14

Using freezing point depression technique

Question 15

Which 4 solutes does the CALCULATED osmolality take into account?

Answer 15

Sodium, Potassium, Urea and Glucose

Question 16

Why is 0.9% saline called normal saline?

Answer 16

Has an osmolality similar to that of blood

Question 17

What is the capillary (plasma) concentration of albumin compared to the interstitial concentration of albumin.

Answer 17

4x greater in the capillaries/plasma.

Question 18

What would you expect to happen with regards to water movement from the interstitial fluid to cells and why? The action of what prevents this?

Answer 18

You would expect water to move into cells due to the higher osmolarity and result in cells swelling and bursting.

Na/K ATPase pump

Question 19

What ions does the Na/K ATPase pump move in one cycle?

Answer 19

3 Na+ out and 2 K+ in - requires ATP energy

Question 20

Why does the action of the Na/K ATPase pump prevent cell swelling/bursting?

Answer 20

More Na pumped out than K in - a net loss of osmotically active ions

Question 21

What is the typical gastric pH?

Answer 21

1.5-3.5

Question 22

What can result from gastric acid getting into the oesophagus?

Answer 22

Oesophagitis (acid reflux), inflammation of the oesophagus.

Stricture - narrowing of the oesophagus.

Question 23

What can result from the stomach losing its mucus protection?

Answer 23

Gastric ulceration/perforation

Question 24

What is the formula for pH?

Answer 24

PH = -log[H+]

Question 25

A one unit change in the pH scale results in a X-fold change in the H+ concentration relative to pure water?

Answer 25

A ten-fold change per one unit change in the pH scale.

Question 26

What is the normal plasma pH? What are the pH limits for survival?

Answer 26

7. 4

6. 8-7.8

Question 27

A 2 fold change in [H+] results in a pH scale change of what?

Answer 27

A pH change of 0.3

Question 28

What is the [H+] at 7.0 and 7.4 respectively?

Answer 28

100nm/l

40nm/l

Question 29

What two things can result in abnormal plasma pH?

Answer 29

Major organ dysfunction (lungs, kidneys and liver)

Shock

Question 30

What is shock?

Answer 30

Poor tissue perfusion resulting in hypoxia in cells and tissues

Question 31

What are the most common types of shock?

Answer 31

Cardiogenic
Hypovolaemic
Septic

Question 32

Why do poorly perfused tissues result in a lower pH?

Answer 32

Low oxygen —-> Anaerobic glycolysis —-> increased lactic acid —–> lactic acidosis —-> lower pH —-> impaired cardiac function

Question 33

What is normal plasma lactate levels?

Answer 33

Less than 1.6 mMol/L