Structure of Nerve Cells Quiz

Which part of the nerve axon lacks the myelin sheath?

Nodes of Ranvier

What is the function of the Schwann sheath?

Regenerates nerve fiber and forms myelin sheath

Why are electrical stimuli preferred in practical experiments?

They are similar to the natural signals inside the human body

What is excitability in the context of living tissues?

The ability to respond to a stimulus Signup and view all the answers

What are the factors that affect the degree of response to a particular stimulus?

The Rate of application and Strength of the stimulus Signup and view all the answers

What is the function of dendrites in a neuron?

Increase the surface area of the cell body and conduct nerve impulse towards the cell body Signup and view all the answers

What is the role of the axon in a neuron?

Conducts the nerve impulse away from the cell body and dendritic zone Signup and view all the answers

What is the function of Nissel bodies in a neuron?

Large triangular masses with high RNA content Signup and view all the answers

What does severe activity and anoxia cause in relation to Nissel bodies in a neuron?

Disappearance of Nissel granules (i.e. Chromatolysis) Signup and view all the answers

Why can a neuron never divide?

It doesn't contain a centrosome Signup and view all the answers

What makes up the structural unit of the nervous system?

Neuron Signup and view all the answers

Which component of the nerve axon is responsible for regenerating nerve fibers and forming the myelin sheath?

Neurilemmal sheath Signup and view all the answers

What property of living tissue refers to its ability to respond to a stimulus?

Excitability Signup and view all the answers

Which type of stimulus is preferred in practical experiments due to its similarity to the natural signals inside the human body and the ease of controlling its intensity?

Electrical Signup and view all the answers

What is the minimal intensity of a current needed to stimulate excitation called?

Rheobase Signup and view all the answers

In the Strength-Duration curve, what is the time needed by a current of double the rheobase intensity to stimulate excitation?

Chronaxie Signup and view all the answers

What does the Strength-Duration curve illustrate about the relationship between stimulus intensity and time needed for excitation?

Increasing stimulus intensity decreases the time needed for excitation Signup and view all the answers

What is the minimal time needed for a stimulus to produce a response called?

Minimal Duration (t) Signup and view all the answers

In diathermy, what effect does the use of high voltage alternating currents for a very short period of time cause?

Heating of tissues without stimulation Signup and view all the answers