1. ANATOMY Unit 2 Notes: Nerve Structure & Reflexes

2. (1) What is a Nerve? Nerve = Bundle of neurons. Nerves Are Made Of:
Fascicles
Neurons
Epineurium
Perineurium
Endoneurium

4. (2) Nerve Membranes
Endoneurium: The membrane which encases a single neuron.
Perineurium: The membrane which binds together a bundle of neurons (also called a fascicle).
Epineurium: The membrane which binds together a bundle of fascicles.

5. (3) Reflexes Automatically programmed response to a specific stimulus.
All reflexes are involuntary, however do not need to travel through the individual nervous system divisions.
Reflex Arc Path:
Stimulus triggers nerve impulse.
Impulse sent to CNS, but at spinal cord routes directly back out to effector organ.

8. (4) Types of Reflexes
Somatic: A reflex which stimulates a response in the skeletal muscle.
Example: Retracting your arm from a hot stove.
Autonomic: A reflex which stimulates a response in smooth muscle.
Example: Your stomach releasing gastric juice and churning once food is dropped in.