Chapter 4 Flashcards
(107 cards)
Brain & spinal cord
Central Nervous System (CNS)
Nerves outside the brain & spinal cord
Peripheral Nervous System (PNS)
consists of axons conveying msgs from sense organs to the CNS & from CNS to the muscles.
Part of PNS is Somatic Nervous System
controls the heart, intestines, & other organs
autonomic nervous system
Toward the back
Dorsal
Toward the stomach
Ventral
Part of the CNS w/in the spinal column; communicates w/all the sense organs & muscles except those in the head
Spinal Cord
Entering dorsal roots (axon bundles) carry sensory info & exiting ventral roots carry motor info
Bell-Magendie Law
Clusters of neurons outside spinal cord (contain cell bodies of sensory neurons)
Dorsal root ganglia
in center of spinal cord-densely packed w/cell bodies & dendrites
Gray Matter
Consists mostly of myelinated axons
White Matter
Network of nerves that prepare organs for vigorous activity
sympathetic nervous system
increased breathing & heart rate, & decreased digestive activity
“fight or flight”
facilitates vegetative, nonemergency responses
Parasympathetic nervous system
Extend from spinal cord to parasympathetic ganglia close to each internal organ
Preganglionic axons
Shorter fibers that extend from parasympathetic ganglia into organs themselves
Postganglionic fibers
Cluster outside the Nervous system
Ganglion
Cluster inside nervous system
Nucleus
AKA known as craniosacral system; consists of cranial nerves & nerves from sacral spinal cord
Parasympathetic system
Brain has 3 major divisions
the hindbrain, midbrain, & the forebrain
consists of medulla, & pons, midbrain, & certain central structures of the forebrain
brainstem
consists of medulla, pons & cerebellum; located @ posterior; AKA rhombencephaion
hindbrain
enlarged extension of spinal cord-controls some vital reflexes thru cranial nerves; located just above the spinal cord & could be regarded as an enlarged extension of the spine.
Medulla; AKA Medulla Oblongata
allow the medulla to control sensations from the head muscle movements in the head & many parasympathetic outputs to the organs.
cranial nerves