Unit 12 - Nervous System Key Terms 1 Flashcards
Divisions of the nervous system
Central Nervous System (CNS) and Peripheral Nervous System (PNS)
Central Nervous System contains…
brain and spinal cord
Peripheral Nervous System contains…
cranial nerves and spinal nerves
Four majjor structures of the brain
cerebrum, cerebellum, diencephalon, brain stem
spinal cord
extends from the brain stem to the lumbar vertebra in the spinal column, protected and nourished by the meninges, relay station for sending and receiving electrical signals between the brain and body
meninges
Three layers of protective membrane covering the brain and spinal cord
Dura mater (outermost layer)
Arachnoid (middle layer)
Pia mater (innermost layer)
cranial nerves
12 pairs that come from the brainstem
spinal nerves
31 pairs that emerge from the spinal cord
sensory (afferent) neurons
neurons—to the CNS
Motor (different) neurons
neurons—away from the CNS
Divisions of PNS
somatic nerous system and autonomic nervous system
Somatic nervous system (SNS)
Regulates skeletal (striated) muscles (voluntary actions) such as walking and talking
Autonomic nervous system (ANS)
Regulates visceral (smooth) muscles (involuntary actions) such as heart rate and peristalsis, and glandular and secretory activity
Divisions of ANS
sympathethic nervous system and parasympathetic nervous system
Sympathetic Nervous System
(fight or flight) increases heart rate, constricts blood vessels, and raises blood pressure to deal with a crisis