AP2 Practical 1: Nervous System Physiology

Questions and Answers

What is the difference between monosynaptic and polysynaptic reflex arcs?

Monosynaptic has one synapse between sensory neuron and motor neuron, while polysynaptic involves many synapses.

What is the difference between hyporeflexic and hyperreflexic?

Hyporeflexic shows less than average response, while hyperreflexic shows exaggerated response.

What is a reflex arc?

Receptor - Afferent Neuron - Integrating Center - Efferent Neuron - Effector.

Explain the patellar reflex.

It is a monosynaptic reflex that tests the femoral nerve by stimulating sensory neurons in the quadriceps muscle. Signup and view all the answers

Explain the triceps brachii reflex.

It tests the radial nerve and is a monosynaptic reflex where hitting the elbow causes movement. Signup and view all the answers

Explain the biceps brachii reflex.

It tests the musculocutaneous nerve by striking the antecubital fossa, causing upward movement. Signup and view all the answers

Explain the tendon reflex (calcaneus).

It is a polysynaptic reflex that tests the tibial nerve, leading to foot flexion. Signup and view all the answers

Explain the Babinski reflex.

Stroking the plantar surface typically results in flexion in adults, while extension indicates spinal damage. Signup and view all the answers

Study Notes

Reflex Arcs

Monosynaptic Reflex Arc: Involves a single synapse between a sensory neuron and motor neuron.
Polysynaptic Reflex Arc: Involves multiple synapses, typically including interneurons.

Reflex Responses

Hyporeflexic: Exhibits below-average reflex response, indicating potential neurological issues.
Hyperreflexic: Displays an exaggerated reflex response, possible indicator of increased neural sensitivity.

Structure of a Reflex Arc

Comprised of a sequence: Receptor, Afferent Neuron, Integrating Center, Efferent Neuron, Effector.

Patellar Reflex

Type: Monosynaptic reflex.
Function: Tests the femoral nerve.
Mechanism: Rapid muscle lengthening in the quadriceps activates sensory neurons that transmit impulses to the spinal cord, leading to motor neuron stimulation and muscle contraction to resist stretch.

Triceps Brachii Reflex

Type: Monosynaptic reflex.
Function: Tests the radial nerve.
Mechanism: Striking the olecranon (elbow) elicits a forward movement in the arm.

Biceps Brachii Reflex

Type: Monosynaptic reflex.
Function: Tests the musculocutaneous nerve.
Mechanism: A strike to the antecubital fossa results in upward movement of the arm.

Tendon Reflex (Calcaneus)

Type: Polysynaptic reflex.
Function: Tests the tibial nerve.
Response: Foot should flex when the tendon is stimulated.

Babinski Reflex

Normal Response: In adults, stroking the plantar surface leads to toe flexion.
Abnormal Response: Injury to pyramidal tracts causes extension of the big toe.
Significance: Useful for assessing spinal damage; a positive Babinski reflex is normal in infants but not in adults, indicating potential neurological development or injury.

Description

Test your knowledge of the nervous system with this set of flashcards covering crucial concepts like reflex arcs and reflex responses. Understand the distinctions between monosynaptic and polysynaptic pathways, as well as hyporeflexic and hyperreflexic conditions. Perfect for AP2 students seeking to reinforce their understanding of nervous system physiology.