Peripheral Nervous System Chapter 8. Peripheral Nervous System Nerves connecting the brain and...
-
Upload
alec-corless -
Category
Documents
-
view
215 -
download
0
Transcript of Peripheral Nervous System Chapter 8. Peripheral Nervous System Nerves connecting the brain and...
Peripheral Nervous SystemChapter 8
Peripheral Nervous System
Nerves connecting the brain and spinal cord to other parts of the body
Cranial Nerves
12 pairs
attach to the undersurface of the brain
Spinal Nerves
31 pairs 8 cervical
12 thoracic
5 lumbar
5 sacrospinal
1 coccygeal
Autonomic Nervous System
Consists of motor neurons that conduct impulses from the spinal cord or brainstem to cardiac, smooth, and glandular epithelial tissue (involuntary functions)
the heartbeat
contractions of the stomach and intestines
secretions by glands
Sympathetic Nervous System Controlled in the thoracic and upper lumbar segments of the spinal cord
Functions as an emergency system – takes control when we exercise strenuously and when strong emotions (anger, fear, hate, anxiety) are elicited.
ParasympatheticNervous System
Controlled in the brainstem and sacral segments of the spinal cord (craniosacral system).
Controls under normal, everyday conditions.
Tends to do the opposite of the sympathetic nervous system.
Together they help our bodies to maintain homeostasis.
ResponsesSympathetic
Heart beats faster
Most blood vessels constrict, causing blood pressure to increase.
Blood vessels in muscles dilate, supplying the muscles with more blood.
Sweat glands and adrenal glands secrete more abundantly.
Salivary and other digestive glands secrete more sparingly.
“fight or flight”
Parasympathetic
Slow heartbeat
Increase peristalsis
Increase secretion of digestive juices and insulin.