1. Chapter 11 Nervous System II
Meninges
protect CNS
three layers
11-2

2. Meninges of the Spinal Cord
11-3

3. Cerebrospinal Fluid
circulates in ventricles, central canal of spinal cord, and subarachnoid space
completely surrounds brain and spinal cord
clear liquid
nutritive and protective
helps maintain stable ion concentrations in CNS
11-5

4. Spinal Cord Structure extends foramen magnum to 2nd lumbar vertebra
11-6

5. Cross Section of Spinal Cord
11-7

6. Spinal Cord Functions center for spinal reflexes
conduit for nerve impulses to and from the brain
11-8

7. Reflex Arcs
Reflexes –
Reflex Ark.mov
11-9

8. Knee-jerk Reflex
11-10

9. Withdrawal Reflex
protective
11-11

10. Crossed-Extensor Reflex
flexor muscles contract
flexor muscles on opposite side inhibited
extensor muscles on opposite side contract for balance
11-12

11. Tracts of the Spinal Cord
Ascending
Descending
11-13

12. Brain Functions determines perception stores memory makes decisions
regulates visceral activities
determines personality
Major Parts
cerebrum
two cerebellar hemispheres
diencephalon
brain stem
cerebellum
11-16

13. Brain Development Three Major Vesicles Forebrain Midbrain Hindbrain
11-17

14. Structure of Cerebrum corpus callosum convolutions bumps or gyri sulci
longitudinal fissure
separates hemispheres
transverse fissure
separates cerebrum from cerebellum
11-19

15. Lobes of Cerebrum
Frontal
Parietal
Temporal
Occipital
Insula
11-20

16. Functions of Cerebrum interpretation initiating voluntary movements
storing memory
retrieving memory
reasoning
center for intelligence and personality
11-21

17. Functional Regions of Cerebral Cortex
11-22

18. Motor Areas Primary Motor Areas Broca’s Area Frontal Eye Field
frontal lobes
control voluntary muscles
Broca’s Area
anterior to primary motor cortex
usually in one hemisphere
controls muscles needed for speech
Frontal Eye Field
above Broca’s area
controls voluntary movements of eyes and eyelids
11-23

19. Motor Areas
11-24

20. Sensory Areas Cutaneous Sensory Area Visual Area Auditory Area
parietal lobe
interprets sensations on skin
Visual Area
occipital lobe
interprets vision
Auditory Area
temporal lobe
interprets hearing
11-25

21. Sensory Areas
11-26

22. Association Areas Frontal Lobe Association Areas concentrating
planning
problem solving
judging
Temporal Lobe Association Areas
remember visual scenes
remember music
remember complex patterns
Parietal Lobe Association Areas
understanding speech
using words to express thought
Occipital Lobe Association Areas
combine visual images with other sensory experiences
11-28

23. Hemisphere Dominance Nondominant hemisphere controls
nonverbal tasks
motor tasks
understanding and interpreting musical and visual patterns
provides emotional and intuitive thought processes
Dominant hemisphere controls
speech
writing
reading
verbal skills
analytical skills
computational skills
11-29

24. Memory Short Term working memory closed circuit
circuit is stimulated over and over
when impulse flow stops, memory disappears
Long Term
changes structure and function of neurons
enhanced synaptic transmission
11-30

25. Limbic System Consists of portions of frontal lobe
portions of temporal lobe
hypothalamus
thalamus
basal nuclei
other deep nuclei
Functions
controls emotions
produces feelings
interpret sensory impulses
11-34

26. Brain Stem
Three Parts
Midbrain
Pons
Medulla Oblongata
11-35

27. Types of Sleep Slow Wave person is tired
decreasing activity of reticular system
restful
dreamless
reduced blood pressure and respiratory rate
ranges from light to heavy
alternates with REM sleep
Rapid Eye Movement (REM)
some areas of brain active
heart and respiratory rates irregular
dreaming occurs
11-40

28. Peripheral Nervous System
Cranial nerves
Somatic fibers connecting to the skin and skeletal muscles
Autonomic fibers connecting to viscera
Spinal nerves
Somatic fibers connecting to the skin and skeletal muscles
Autonomic fibers connecting to viscera
11-42

29. Nerve Fiber Classification
Sensory Nerves –
Motor Nerves –
Mixed Nerves – contain both sensory nerve fibers and motor nerve fibers; most nerves
11-44

30. Cranial Nerves
11-46

31. Spinal Nerves mixed nerves 31 pairs 8 cervical (C1 to C8)
12 thoracic (T1 to T12)
5 lumbar (L1 to L5)
5 sacral (S1 to S5)
1 coccygeal (Co)
11-54

32. Dermatome
an area of skin that the sensory nerve fibers of a particular spinal nerve innervate
11-56

33. Autonomic Nervous System
functions without conscious effort
controls visceral activities
regulates smooth muscle, cardiac muscle, and glands
efferent fibers typically lead to ganglia outside CNS
Two Divisions
sympathetic – prepares body for fight or flight situations
parasympathetic – prepares body for resting and digesting activities
11-60

34. Sympathetic Division
11-64

35. Parasympathetic Division
11-66

36. Life-Span Changes Brain cells begin to die before birth
Over average lifetime, brain shrinks 10%
Most cell death occurs in temporal lobes
By age 90, frontal lobe has lost half its neurons
Number of dendritic branches decreases
Decreased levels of neurotransmitters
Fading memory
Slowed responses and reflexes
Changes increase risk of falling
Sleep problems common
11-71

37. Clinical Application Cerebral Injuries and Abnormalities Concussion
brain jarred against cranium
loss of consciousness
temporary loss of memory
mental cloudiness
headache
recovery usually complete
Cerebral Palsy
motor impairment at birth
caused by blocked cerebral blood vessels during development
seizues
learning disabilities
Cerebrovascular Accident
stroke
sudden interruption in blood flow
brain tissues die
11-72