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
Parasympathetic Nervous System
(rest and digest) slows heart rate, increases glandular secretions, relaxes sphincters
neuron
individual nerve cell, Interconnecting to form complicated networks called nerves that transmit electrical impulses throughout the body
neuroglia
Glial cells that provide a supportive framework for neurons, Responsible for protecting against infection by performing phagocytosis (engulfing and digesting unwanted substances), Unable to transmit electrical impulses
Four types of neurogial cells
astrocyte, microglia, oligodendrocyte, ependyma
NTD
Neural Tube Defect
Neural Tube Defect
Congenital deformity of the neural tube (embryonic structure that becomes the fetal brain and spinal cord)
Anencephaly
Brain fails to form during fetal development, baby is usually stillborn or dies shortly after birth
Spina Bifida
Abnormal opening in the vertebral column
Spinal cord and nerves may protrude
Defect covered only by the meninges
Types of Spina Bifida
occulta, meningocele, meningomyelocele
Spina Bifida - occulta
small gap or malformation in one or more of the spinal vertebrae, asymptomatic and no treatment required
Spina Bifida - meningocele
protrusion of meninges through an opening in the spine
Spina Bifida - myelomeningocele
protrusion of spinal cord and meninges through an opening in the spine
Preventative treatment for Spina Bifida
addition of folic acid to the diet of women of childbearing age
Spinal Cord Injury
Spinal injury or disease resulting in a lack of or decrease in function or feeling
Degree of dysfunction related to site of injury on the spinal cord (higher site associated with greater dysfunction
Halo brace
used to immobilize the head and neck vertebrae