15 BIO 210 The Autonomic Nervous System (1).pptx - Chapter...

Chapter 15: The
Autonomic Nervous
System
Anatomy and Physiology 210

LEARNING OUTCOMES
1. Compare and contrast the components of the autonomic and
somatic nervous systems.
2. Compare and contrast the sympathetic and parasympathetic
divisions of the autonomic nervous system

EFFERENT SUBDIVISIONS
OF PNS
•
Two subdivisions (based on effectors)
•
SOMATIC MOTOR NERVOUS SYSTEM
•
Effectors are voluntary: skeletal muscles
•
THE AUTONOMIC NERVOUS SYSTEM (Sympathetic & Parasympathetic)
•
Effectors are involuntary: cardiac muscle, smooth muscle, and glands

AUTONOMIC NERVOUS SYSTEM
•
Regulates involuntary effectors
•
Two divisions
•
SYMPATHETIC DIVISION
•
THORACOLUMBAR
•
Nerves of the sympathetic division branch from thoracic spinal nerves
(T1‑T12) and from some lumbar spinal nerves (L1‑L4)
•
PARASYMPATHETIC DIVISION
•
CRANIOSACRAL
•
Nerves of the parasympathetic division branch from some cranial nerves (III,
VII, IX, X, XI) and from some sacral spinal nerves (S2‑S4)

FUNCTIONS OF THE ANS
•
ANS regulates autonomic effectors in ways that maintain homeostasis
•
Both divisions continually conduct nerve impulses to autonomic effectors
•
For example: heart is connected to both divisions- one will cause heart rate to
increase and the other will cause heart rate to decrease
•