What type of animal would have the fastest conduction velocities?

Penaeid fibers of 120 mm diameter conduct impulses at the fastest speeds known: over 200 m s⁻¹, compared with ∼100 m s⁻¹ for the fastest recorded myelinated vertebrate axons [21]. Copepod myelin, too, is concentrically organized.

1. What types of animals would have the fastest conduction velocity?
2. What has the fastest conduction velocity?
3. Which nerve has the fastest conduction velocity?
4. What helps to determine conduction velocity?
5. What animal has the fastest nerves?
6. Do invertebrates have myelin?
7. Which part of the heart has the fastest conduction?
8. Which situation will see the fastest conduction rate across an axon?
9. Which fiber has the slowest conduction velocity?
10. Why is Saltatory conduction faster?
11. What influences conduction velocity?
12. Why is conduction velocity faster in myelinated axons?
13. What are the two main factors that determine conduction velocity in a neuron?
14. What is the conduction velocity of sciatic nerve frog?
15. What increases conduction velocity in an axon?

What types of animals would have the fastest conduction velocity?

Remarkably, shrimp giant nerve fibres have conduction speeds of more than 200 m s-1, making them among the fastest-conducting fibres recorded, even when compared with vertebrate myelinated fibres.

What has the fastest conduction velocity?

The fastest conduction velocity occurs in the largest diameter nerve fibres. This phenomenon has formed the basis for classifying mammalian nerve fibres into groups in order of decreasing diameter and decreasing conduction velocity. Another factor is the temperature of the nerve fibre.

Which nerve has the fastest conduction velocity?

Up until now, we have only activated fibres in the A-alpha group, the largest group of fibres in the nerve, containing fibres with the largest diameters and highest conduction velocity.

What helps to determine conduction velocity?

The conduction velocity of the action potential is determined by measuring the distance traveled (length of the nerve in m) and dividing by the time (sec) taken to complete the reflex arc, also called the latency. Conduction velocity = distance (m)/time (sec).

What animal has the fastest nerves?

1996, PMID 8807532 summary: "Giant nerve fibers of the shrimp family Penaeidae conduct impulses at the velocity highest among all animal species (~210m/s, highest in mammals=120m/s)." Although note, that for mammals, BNID 108973 Table - link top entry in table, gives value of 164m/sec for pyramidal tract in cat.

Do invertebrates have myelin?

Invertebrate axons are ensheathed by glial cells, but do not have a compact myelin. As a consequence, action potentials along invertebrate axons propagate at about 1 m/s, or less. This is sufficient, however, for the survival of small animals (between 0.1 and 30cm).

Which part of the heart has the fastest conduction?

Cardiac cells have the inherent property of spontaneous depolarization, which creates the cardiac impulse. Cells within the sinus node have the fastest rate of spontaneous depolarization, and, therefore, the sinus node is the main pacemaker region of the heart.

Which situation will see the fastest conduction rate across an axon?

Which situation will see the fastest conduction rate across an axon? During repolarization, more sodium ions are brought into the cell to reset the membrane potential. Myelination is created due to the wrapping of axons by Schwann cells.

Which fiber has the slowest conduction velocity?

Action potentials in C-nerve fibers travel only about 2.2 mph - slower than you can walk. A-delta nerve fibers can conduct action potentials as fast as a sprinter in the Olympics.

Why is Saltatory conduction faster?

Saltatory conduction occurs in myelinated axons from one node of Ranvier to the next node. Therefore, the action potential is only generated at the neurofibrils in myelinated axons. Hence, it is faster than continuous conduction.

What influences conduction velocity?

Conduction velocity is influenced by myelin sheath thickness and internode distance (i.e. the distance along the axon between the nodes of Ranvier) (Hursh, 1939), and both parameters are linearly related to axon diameter.

Why is conduction velocity faster in myelinated axons?

By acting as an electrical insulator, myelin greatly speeds up action potential conduction (Figure 3.14). ... For example, whereas unmyelinated axon conduction velocities range from about 0.5 to 10 m/s, myelinated axons can conduct at velocities up to 150 m/s.

What are the two main factors that determine conduction velocity in a neuron?

The speed of neuron transmission generally depends upon two factors: axon size and degree of myelination.

What is the conduction velocity of sciatic nerve frog?

A comparison of regenerated and normal frog sciatic nerves showed a marked reduction in conduction velocity from 37.5 to 15.2 m/s with little change in the absolute refractory period. Changes in conduction velocity corresponded to a reduced mean axon caliber (4.8 versus 6.6 micron).

What increases conduction velocity in an axon?

Conduction velocity (CV) is increased in axons with thicker myelin sheaths, and the length of the nodal gap and distribution of Na⁺ channels in the node of Ranvier have a strong influence on the action potential firing threshold, frequency of firing, and CV (1).