AC 2.1 Explain Typical Features Of Neruones Flashcards Preview

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Flashcards in AC 2.1 Explain Typical Features Of Neruones Deck (20):

What is knee-jerk response?

1. Stimulus: hammer hits tendon, causing stretch receptors to lengthen

2. Response: muscle contracts, causing foot to jerk upward (muscle in front of thigh stretches, stimulating stretch receptors)

- stretch receptors stimulated, send message to muscles of thigh
- muscles in front of thigh contract
- muscles in back of thigh relax
- foot jerks


Explain reflex arc in form of muscle dropping into someone’s hand

1. Stimulus: Weight dropping into hand, stretching the muscle

2. Response: muscle contracts, jerking arm upward


What do dendrites do

Receive the AP


What does the cell body do?

Produce neurotransmitter


What is the axon?

The conducting fibre


What are Schwann cells?

Produce myelin


What are axon terminals?

Transmit the AP


What is the myelin sheath?

Insulating fatty layer that speeds transmission in form of saltatory conduction and insulates against ions


What are the nodes of ranvier for?

They allow the AP to jump across the nodes in a process called saltatory conduction which speeds up transmission along the axon


What does the axon hillock do?

Contains many Na+ channels


What is the initial segment?

Trigger zone


Why is the axon long?

To get to far away places in the body (long distances)


Purpose of multiple dendrites?

Impulses can come from multiple sources and is useful in summation by using multiple small stimuli to produce an AP


Explain the concept of dermatomes

- An area of skin mainly supplied by a single spinal nerve

- Each of these nerves relays sensation (pain) from a region of skin to the brain

- Example is the sciatic nerve (pain from sciatica radiates from buttock down leg to the feet


Explain typical sensory neurones

1. Sensory/afferent neurons convert a specific type of stimulus, via their receptors, into action potentials or graded potentials (sensory transduction)

2. The cell bodies of the sensory neurons are located in the dorsal ganglia of the spinal cord.


Explain typical motor neurones

Motor/efferent neurones

1. cell body is located in spinal cord, whose axon (fiber) projects to control effector organs, mainly muscles and glands.


Explain interneurones

Interneurons create neural circuits, enabling communication between sensory or motor neurons and the central nervous system (CNS).


Explain relationship of neurones to nerves

1. Nerves are found in the peripheral nervous system, while neurons are found in the brain, spinal cord and the peripheral nerves.

2. neuron can also be called a neurone or a nerve cell.

3. Neurons conduct nerve impulses, while nerves transmit information to various parts of the body.


What is white matter

Made of axons with their myelin sheaths


What is grey matter

Made of cell bodies and their dendrites