Lab 8 - Nervous system

Question 1

What is chronaxie?

Answer 1

Min. duration necessary to elicit an AP if the stimulus strenght twise rheobase

Question 2

What factor determines if we have a monophasic or biphasic CAP?

Answer 2

Distance between electrodes

Question 3

Define local response

Answer 3

Decreasing magnitude of potential change due to physical processes

Question 4

What is resting membrane potential

Answer 4

Difference between intra and extracellular space potential

Question 5

Name of fibres leading impulse from organ to spinal chord?

Answer 5

Neuron fibres type Ia and type II

Question 6

Explain exteroceptive reflex?

Answer 6

Receptors outside muscle pick up signal, and trough an arch, it reach an muscle

Question 7

Explain all- or none-law concerning the action potential?

Answer 7

Must have certain polarization to get reaction, either or not

Question 8

Explain repolarization

Answer 8

Positive charges decrease inside the cell

Question 9

Define treshold?

Answer 9

When the depolarization reaches a certain level

Question 10

Main component of reflex arch?

Answer 10

Receptor, afferent nerve, synapse, efferent nevre and the target organ

Question 11

How to check an normal reaction of Achilles reflex?

Answer 11

Hit just above the insertion of achilles tendon on an freehanging leg

Question 12

In which phase do you have absolute refractory period?

Answer 12

Period before repolarization where the CAP will disappear

Question 13

What is proprioceptive?

Answer 13

Receptors in the organ

Question 14

4 stages of action potential.

Answer 14

Depolarisation, overshoot, repolarization and post-hyperpolarization

Question 15

Frequency coding?

Answer 15

Stronger stimulus, more frequent action potential

Question 16

Describe CAP?

Answer 16

Compound action potentials, a summation of different fibers that make up a nerve

Question 17

Receptors in intrafusal muscle

Answer 17

Nuclear chain receptors and bag receptors

Question 18

In which phase of action potential is the total refractory period?

Answer 18

Supernormal phase

Question 19

Describe the normal reaction of ankle jerk reflex?

Answer 19

Streching the ankle, plantar flexion

Question 20

Where do you tap to get the knee jerk reflex?

Answer 20

Patellar ligament

Question 21

Which channel opens during re-polarization?

Answer 21

Potassium

Question 22

What is rheobase?

Answer 22

Minimal stimulus intensity that just generates an AP after long time application

Question 23

Give the most characteristic features of non-myelinated impulse transmission?

Answer 23

AP propagates step by step, a channel activates immediately adjacent one