Reflex Lecture Chapter 7 Reflex Rapid predictable and

Reflex Lecture Chapter 7

Reflex • Rapid, predictable, and involuntary responses to stimuli • Once a reflex begins, it always follows the same path

Types of Reflexes 1. Autonomic – – Regulate the activity of the smooth muscles, heart and glands Examples: saliva, digestion, blood pressure, sweating

2. Somatic – – Stimulate skeletal muscles Example: reflex when you touch a hot surface

Reflex Arc • neural path of a reflex • Minimum of 5 parts – 1. sensory receptor (reacts to stimulus) – 2. afferent neuron (neuron going to CNS) – 3. integration center (CNSspinal cord) – 4. efferent neuron (neuron going away from CNS) – 5. effector organ (muscle or gland stimulated)

Steps to Patellar Reflex 1. Sensory receptor senses strike to patellar tendon 2. Afferent neuron sends stimulus to CNS 3. Integration center (spinal cord) responds to stimulus

4. Efferent neuron sends message to muscle 5. Muscle contracts causing knee to jerk

Flexor Withdrawal Reflex What would be the steps for the flexor withdrawal reflex if you were to accidentally touch a hot stove?

1. Pain receptors in hand sense heat 2. Afferent neuron sends message to CNS 3. Integration center (CNSspinal cord) responds 4. Efferent neuron sends response to muscle 5. Bicep muscle contracts and forces hand to be removed from stove