Question

Draw a flowchart showing the sequence of events which occur during sneezing..

Answer 1

The sneeze reflex is a type of the many reflex actions that occur in the body.

Reflex actions are instantaneous, involuntary actions in response to a stimulus made possible by reflex arcs.

Reflex arcs have the capability of acting upon impulses without reaching the brain. This is important when fast responses are required.

All reflex arcs have the following components:

1. Receptor - these are the structure that detect change in the environment (stimulus)
2. Sensory neuron - carries the afferent impulse.
3. Integration centre/ relay neuron - relay of sensory impulse to motor impulse.
4. Motor neuron - carries the efferent impulse
5. Effector - muscles and organs.

Here is the flow of  the sequence of events in the sneeze reflex:

Receptor - The olfactory receptors and the nasal mucosa detect an irritant ( stimulus) and generates a nerve impulse.

Sensory nerve/Afferent nerve - the trigeminal nerve carries the impulse to the integration center.

integration center - the integration center is the sneeze center in the medulla.

Motor nerve/ Efferent nerve -  The trigeminal nerve and the vagus nerve carry motor impulses from the sneeze center in the medulla to the effector organs.

Effectors - the effectors in the sneeze reflex are the pharyngeal, tracheal and respiratory muscles.

⇒ Find attached the image of the flow chat of the sequence of these events and the image on the components of a reflex arc.

Answer 2

1. Nerves endings located at the nasal passage identifies the dust

2. Receptors send the information to the brain.

3. Brain in return sends instructions to lungs.

4.Diaphragm moves abruptly, chest muscles contract in response to the instructions

5.air blows out from the nose and mouth

6. Sneezing occurs in response to the dust irritant

This is the most simple sequence that anyone can study without memorising ....