Cell and Muscle Physiology

Question 1

What is the formula in measuring the flow of molecule in simple diffusion

Answer 1

J = PA x (C1 - C2)

Question 2

The permeability of the cell membrane is increased by the following factors ____. Cite 3

Answer 2

1. Increased oil/water partition coefficient of solute
2. Decreased radius of solute
3. Decreased membrane thickness

Question 3

____ factor which governs diffusability

Answer 3

Lipid Solubility

The more lipid soluble, the more diffusable!

Question 4

Cite 3 characteristics of a carrier mediated transport system.

Answer 4

1. Stereospecificity - accommodates specific shape
2. Saturation - finite number of carriers
3. Competition - different solutes compete for the same transporter

Question 5

____ is a substance that has 0 osmlolarity/osmolality

Answer 5

water

Question 6

The normal resting membrane potential is caused by (cite 3)

Answer 6

1. Nerst potential for Na and K
2. K leaks channel
3. Na/K ATPase

Question 7

Cite the characteristics of a True Action potential

Answer 7

1. Stereotypical size and shape
2. Propagating
3. All-or-none

Question 8

In depolarization, the m gate ____ (opens, closes) leading to Na inward current making the membrane potential more ____ (positive, negative).

Answer 8

1. Opens
2. More positive

In hyperpolarization, membrane potential is more negative, outward current (like in K).

Remember, lalabas si positive, walang AP

Question 9

____ occurs during an action potential when no new AP can be elicited no matter how large the stimulus

Answer 9

Absolute Refractory Period

Question 10

___ occurs during an AP after ARP due to prolonged opening of K+ channels

Answer 10

Relative Refractory Period

Question 11

Conduction velocity is increased by?

Answer 11

1. Fiber size - larger fiber size, the faster it is (dependent on nerve diameter)
2. Myelination - the more you insulate it, the faster it is
3. Nodes of Ranvier that contains the highest [Na channels] per square micrometer of cell membrane

Question 12

This supporting cell acts as a tissue scavenger and removes debris (like a macrophage but in the brain)

Answer 12

Microglia

Question 13

This supporting cell envelopes synapses and forms the BBB

Answer 13

Astrocytes

Question 14

Synaptic transmission happens via ____(orthodromic, antidromic)

Answer 14

Orthodromic (synapse to axon)

Antidromic (axon to synapse)

Question 15

EPSPs: Na influx :: IPSPs : ____

Answer 15

Cl- influx

EPSPs - depolarizes
IPSPs - hyperpolarizes

Question 16

Fast EPSP is caused by ___ influx and ___ influx

Answer 16

Na Influx, Ca influx

Question 17

IPSP is caused by ___ influx, ___ efflux or closure of Na or Ca channels

Answer 17

Cl influx, K efflux

Question 18

Presynaptic inhibition is caused by ____ efflux

Answer 18

K+ efflux

Question 19

Action potential can be inhibited by (goal is to make the cell less positive)

Answer 19

1. Cl influx
2. K efflux
3. Inhibit Na or Ca influx

Question 20

[outer leaflet/inner leaflet of the cell membrane]

phosphatidylcholine/ phosphatidylinostol

Answer 20

inner leaflet

Question 21

[outer leaflet/inner leaflet of the cell membrane]

phosphatidylcholine, Sphingomyelin, Phosphatidylethanolamine

Answer 21

outer leaflet