Week 7 - Spinal Cord: Reflexes

Question 1

What are reflexes?

Answer 1

• rapid, predictable, and involuntary responses to stimuli

- occur over neural pathways called “reflex arcs”

Question 2

What are the two types of reflexes?

Answer 2

1) Somatic reflexes

2) Autonomic reflexes

Question 3

What are somatic reflexes?

Answer 3

• reflexes that stimulate the skeletal muscles
• involuntary, although skeletal muscle is normally under voluntary control
• EXAMPLE: pulling your hand away from a hot object

Question 4

What are autonomic reflexes?

Answer 4

• regulate the activity of smooth muscles, the hearts, and glands
• EXAMPLE: regulation of smooth muscles, heart and blood pressure, glands, digestive system

Question 5

What are the 5 elements of a reflex arc?

Answer 5

1. Sensory receptor — reacts to a stimulus
2. Sensory neuron — carries message to the integration center
3. Integration center (CNS) — processes information and directs motor output
4. Motor neuron — carries message to an effector
5. Effector organ — is the muscle of gland to be stimulated

Question 6

What are two (2)-neuron reflex arcs?

Answer 6

• simplest type

- EXAMPLE: patellar (knee-jerk) reflex

Question 7

What are three (3)-neuron reflex arcs?

Answer 7

• consists of five elements: receptor, sensory neuron, interneuron, motor neuron, and effector
• EXAMPLE: flexor (withdrawal) reflex