21 - The Nervous System Flashcards Preview

Survey Final Ch. 20-22 > 21 - The Nervous System > Flashcards

Flashcards in 21 - The Nervous System Deck (41)
Loading flashcards...
1

CNS, central nervous system consists of...

the brain and spinal cord

2

afferent nerve

sensory nerve
-transmits impulses to the nervous system

3

efferent nerve

motor nerve
-transmits impulses from brain or spinal cord to muscle

4

-destruction of motor neurons by disease
-interruption of reflex arc responsible for muscle tone
-muscle deprived of innervation
-low muscle tone
-peripheral nerve destruction

Flaccid paralysis

5

-reflex arc not disturbed
-injury to cortical neurons stops voluntary control
-muscle retains innervation
-increased muscle tone

spastic paralysis

6

anencephaly

-failure of normal development of brain and cranial cavity
-multifactorial inheritance

7

-alpha-fetoprotein leaks from fetal blood into amniotic fluid through open neural tube defect; high levels found in amniotic fluid

spina bifida

8

voluntary motor activity is controlled by the _____________ system and the ______________ system.

pyramidal system and extrapyramidal system

9

-controls voluntary motor functions

pyramidal system

10

-regulates muscle groups concerned primarily with balance, posture, and coordination

extrapyramidal system

11

-from congenital obstruction of aqueduct or absence of openings in roof of 4th ventricle
-head enlarges as ventricles dilate because cranial structures have not fused

congenital hydrocephalus

12

protein produced by fetal liver early in gestation. sometimes produced by tumor cells. level is elevated in amniotic fluid when fetus has neural tube defect.

alpha fetoprotein (AFP)

13

-obstruction of cerebral spinal fluid (CSF) by tumor or adhesions blocking opening in 4th ventricle
-ventricles dilate but head does not enlarge because cranial structures are fused

acquired hydrocephalus

14

treatment of hydrocephalus

-inserting a plastic tube into a dilated ventricle and rerouting (shunting) the fluid into another part of the body where it can be absorbed.

15

any injury to brain tissue from disturbance of blood supply to brain

stroke, or cardiovascular accident

16

most common; thrombosis of cerebral artery narrowed by arteriosclerosis

cerebral thrombosis

17

occurs less frequently; blockage of cerebral artery by fragment of blood clot from an arteriosclerotic plaque or from heart

cerebral embolus

18

most serious type of stroke; usually from rupture of a cerebral artery in person with hypertension

cerebral hemorrhage

19

ischemic infarct

no blood leaks into brain

20

hemorrhagic infarct

blood leaks into damaged brain tissue

21

-sclerosis of major artery from aorta that supplies brain
-common affected site: carotid artery in neck; arteriosclerotic plaque may narrow lumen and reduce cerebral blood flow

arteriosclerosis of extracranial arteries

22

cerebral angiogram

-dye is injected into the carotid and vertebral arteries that arise from the arch of the aorta to the brain
-the course of the dye is followed by serial x ray studies

23

temporary cerebral dysfunction as a result of transient obstruction of a cerebral vessel by a bit of atheromatous debris or blood clot usually embolized from an arteriosclerotic plaque in the carotid artery

transient ischemic attack (TIA)

24

About 1/# of patients with TIAs eventually suffer a major stroke.

1/3.

25

-most common type of cerebral aneurysm
-results from a congenital defect in the elastic and muscular tissue of the vessel wall, usually at the point where the artery branches

congenital cerebral aneurysm

26

infection affecting meninges

meningitis

27

infection of brain tissue

encephalitis

28

affects both meninges and brain tissue

meningoencephalitis

29

an inflammation of the grey matter of the spinal cord caused by a virus

poliomyelitis

30

responsible for cases of meningitis and encephalitis

arboviruses