Neurons & synapses

Question 1

what is a neuron?

Answer 1

nervecell that carries out nerve impulses?

Question 2

which part of a neuron is responsible for the transmission?

Answer 2

axons terminals

Question 3

what is a synapse?

Answer 3

a specialized area of contact between two cells where transmission of information takes place

Question 4

Synapsis basic structure

Answer 4

• Presynaptic membrane - the membrane portion of the neuron that sends information
• Postsynaptic membrane - the membrane portion of the cells receiving the information
• synaptic cleft - the space between the two membranes

Question 5

Wich are the types of synapses?

Answer 5

Electrical - the element that the two cells communicate is the propagation of electric current

Chemical - the element that the two cells communicate is a molecule (neurotransmitter)

Question 6

what are the characteristics of an electrical synapse?

Answer 6

two cells communicate trough the propagation of electrical impulses
There are special junctions between neurons that serve as a bridge between their cytoplasm: gap junctions (3.5nm)

Question 7

What are the characteristics of a chemical synapse?

Answer 7

• Two cells communicate through a molecule called neurotransmitter.
• There is no communication between the cytoplasm of the two cells
• synaptic cleft (20-40nm)
• more abundant
• unidirectional
• synaptic delay (0.5nm) have to travel and bonds

Question 8

What are dendrites?

Answer 8

The connections to the synapses of past cells (it receives AP

Question 9

which are the two types of postsynaptic potentialls and response?

Answer 9

EPSP - excitatory postsynaptic potencial

IPSP - inhibitory postsynaptic potential

Question 10

Name the Three types of neurons

Answer 10

• multipolar interneurons
• motorneurons
• sensoryneurons

Question 11

Steps in a chemical synapse

Answer 11

• Diffusion away from the postsynaptic membrane
• degradation (proteolysis neuropeptide)
• reuptake the presynaptic nerve terminal by active transport (non peptide NT)The presynaptic membrane take the neurotransmitter back into the membrane

Question 12

AP

Answer 12

Resting membrane -70, threshold-55 mv.

1 stimuli

2. Depolazition Na+ v.g.c opens entering the cell

3 Repolaryzation na+ channels inactiveded, K+ v.g.c opens Ka+ enters the cell

4 Hypolarization Ka+ channels closes slow - Refactoryperiod K+ channels close slow causes hypolorazition.

Refractory period

5 RESTING MEMBRANE

Question 13

AP

Answer 13

Resting membrane -70, threshold-55 mv.

1 stimuli

2. Depolazition Na+ v.g.c opens entering the cell

3 Repolaryzation na+ channels inactiveded, K+ v.g.c opens Ka+ enters the cell

4 Hypolarization Ka+ channels closes slow - Refactoryperiod K+ channels close slow causes hypolorazition.

Refractory period

5 RESTING MEMBRANE

Question 14

What is neuromuscular junction?

Answer 14

Is a chemical synapse formed by the contact between a motor neuron and a musclefiber.
the neuromuscular junction makes it possible to transmit the signal that causing the musclefiber to contract

Question 15

What’s the characteristics of a preganglionoc neuron in Autonomic N.S (sympatich and paradympatethic)?

Answer 15

Cholignergic,myelated, uses ACh

Question 16

Name two Type of nicotinic receptors

Answer 16

NN Nicotinic receptors 》 present on neurons

NM Nicotinic muscle ,》 present on neuromuscular junction of the muscle cells (skeletonmuscle

Question 17

Were can NN be found?

Answer 17

Autonomic N.S, ganglia, and C.N.S

Question 18

How many motor neurons in somatic N.S

Answer 18

One motor neuron to reach the effector area