023 How Reflexes Work (Knee jerk and eye blink)

In this video, Leslie Samuel discusses reflexes, focusing on the knee jerk and eye blink reflexes. He demonstrates these reflexes with his wife, Marguerite, and explains the underlying mechanisms. The knee jerk reflex is a simple reflex arc with no interneurons, leading to automatic responses. The eye blink reflex involves an interneuron, allowing more control. The video concludes with an invitation for questions.

What is the primary purpose of demonstrating reflexes in the video?

• To discuss the history of reflexes

• To show off Leslie's wife

• To illustrate how reflexes work

• To entertain the audience

What happens when the patellar tendon is struck in the knee jerk reflex?

• The arm moves

• The leg kicks forward

• The head nods

• The leg remains still

Why is there less control over the knee jerk reflex?

• Because it involves many interneurons

• Because it lacks interneurons

• Because it is a voluntary action

• Because it is controlled by the brain

What additional element in the eye blink reflex allows for more control?

• A tendon hammer

• A second motor neuron

• A sensory neuron

• An interneuron

How does the presence of an interneuron affect the eye blink reflex?

• It causes the reflex to be delayed

• It makes the reflex faster

• It allows for more control

• It eliminates the reflex

What is the role of interneurons in complex movements like speech?

• They reduce control over movements

• They increase control over movements

• They have no role in speech

• They slow down the process

Why are reflex tests used by doctors?

• To entertain patients

• To assess nervous system function

• To measure muscle strength

• To diagnose heart conditions