neurobiology

Question 1

demyelination of axons in PNS is called

Answer 1

Gullian-Barre Syndrome (GBS) (due to prior infection / Inflammatory process )

Question 2

Main Symptoms of Gullian-Barre Syndrome (GBS)

Answer 2

● Progressive ascending motor weakness;
● Motor and sensory loss affecting the face,
limbs, trunk, and diaphragm;
● Areflexia due to damage of both reflex
arcs of the deep tendon reflex;
● Inflammatory cells (lymphocytes and
macrophages) found within peripheral
nerves.

Question 3

Disorders Associated With Defective Myelination

Answer 3

Charcot-Marie-Tooth Syndrome
Gullian-Barre Syndrome (GBS)
Multiple Sclerosis (MS)

Question 4

autoimmune demyelination of axons in CNS

Answer 4

Multiple Sclerosis (MS)

Question 5

Main symptoms of multiple sclerosis MS

Answer 5

● numbness in one or more limbs;
● tingling or pain in parts of the body;
● partial or complete loss of vision in one eye at a
time and double or blurred vision
● speech disturbances

Question 6

demyelination in PNS caused by gene mutations

Answer 6

Charcot-Marie-Tooth Syndrome

Question 7

Charcot-Marie-Tooth Syndrome is due to mutation of what gene ass. with schwann cells

Answer 7

Connexin ( therefore failure of gap junctions)

Question 8

main symptoms of
Charcot-Marie-Tooth Syndrome

Answer 8

● Demyelination affects both motor and
sensory nerves;
* weakness of the foot and lower leg
muscles is typical;
● patients have a high- stepped gait with
frequent tripping or falls;
* deformities in the foot and digits

Question 9

Disorders Associated With Defective Ion Channels:

Answer 9

Lambert-Eaton Syndrome
Cystic fibrosis

Question 10

Cystic fibrosis affects what channels

Answer 10

inherited disease with impaired functions of Cl- ion channels

Question 11

Organs commonly affected with recurrent infection ass. in cystic fibrosis is

Answer 11

Lungs and airway

CFTR (cystic fibrosis transmembrane conductance
regulator ) gene provides instructions for making
CFTR protein, which is located in the cell membrane

and functions as an ion channel through which Cl- ions and water are transported to maintain the

fluidity of mucus and secretions

Question 12

Function of the Cystic fibrosis transmembrane conductance regulator gene

Answer 12

Provides instructions for making
CFTR protein, which is located in the cell membrane

and functions as an ion channel through which Cl-
ions and water are transported to maintain the

fluidity of mucus and secretions;

Question 13

Lambert-Eaton Syndrome affects what channels

Answer 13

loss of voltage-gated Ca2+ channels in the presynaptic terminals
at the NMJ and other synapses;

Question 14

Lambert-Eaton Syndrome is ass. with

Answer 14

small-cell carcinoma of the lung :derived from neuroendocrine cells expressing voltage-gated Ca+ channels);

Question 15

Main symptons of lambert-eaton syndrome

Answer 15

dry mouth, constipation, reduced
sweating, orthostatic hypotension, and impotence
reduction in the release of the transmitter (Ach)
at the NMJ causing muscle weakness

Question 16

Diseases Affecting the Chemical Transmission at the NMJ

Answer 16

Myasthenia Gravis
Lambert-Eaton Syndrome

Question 17

Myasthenia Gravis involves

Answer 17

antibodies that reduce d number of nAchRs in the postsynaptic membrane

Question 18

In myasthenia Gravis muscle weakness is increased during _____ and reduced by ____

Answer 18

muscle weakness increased during exercise and
reduced by rest.

Question 19

Main symptoms of myasthenia gravis

Answer 19

● Muscular weakness due to a decrease in the
response of the muscle fiber to Ach;
● weakness of the eyelids, eye muscles,
oropharyngeal muscles, and limb muscles;

Question 20

Diseases Associated With Toxins:

Answer 20

Botulinum
Tetanus

Question 21

Disease Caused by anaerobic clostridium
bacteria in contaminated food

Answer 21

Botulism

Question 22

Main symptom in botulism

Answer 22

Neurotransmitter release at the NMJ abolished

● paralysis of the diaphragm causing respiratory fail-
ure and skeletal muscle weakness;

● visceral motor dysfunction occurs due to the
blockade of synapses in smooth muscles

Question 23

spinal interneurons affected in botulinum

spinal interneurons affected in tetanus

Answer 23

ACh
GABA & Glycine

Question 24

Ability of neurons to establish new and more stronger connections

Answer 24

Neuroplasticity