1. THE NERVOUS SYSTEM
Chapter 7

2. Processes and interprets input-________________________________
Monitors changes-__________________________--inside and outside the body
Processes and interprets input-________________________________
Effects a response by activating muscles or glands(effector)via_____________________________________
Stimuli and gathered info is sensory input
integration
Motor output

4. Organization of the Nervous System

5. Peripheral nervous system
Divided by structure and activities
Structural classification
_____________________________________-consists of brain and spinal cord and is integrating command center
__________________________________-part of system outside CNS-nerves extending beyond the brain and SC
_______________________________-carry messages to and from SC and
______________________________-carry impulses to and from brain
CNS
Spinal nerves
Cranial nerves
Peripheral nervous system

6. Functional classification
Divides peripheral nervous sytem into 2 divisions
__________________or afferent division consists of nerves conveying info to CNS via sensory receptors in the body
__________________________-bring in impulses from skin,skeletal muscles and joints
________________________________bring in messages from inside and outside the body
Visceral or sensory fibers or afferents
sensory
Somatic sensory fibers

7. effect Voluntary nervous sysyem Involuntary NS
Somatic nervous system
Voluntary nervous sysyem
Motor or efferent division carry impulses from CNS to effector organs-muscles and glands-They _________a motor response
a)______________________allows us to consciously,or voluntarily control skeletal musces-so this sytem is also called ______________________________/some skeletal responses are initially involuntary
b) __________________ regulates autonomic or involuntary-like smooth muscle ,cardiac muscle and glands…..commonly called ______________________,which has 2 parts :1)sympathetic-opposes parasympathetic-associated w/ flight or fight 2)parasympathetic division-opposes sympathetic and craniosacral division
Involuntary NS
Autonomic nervous system

8. Nervous Tissue:Structure and Function
Either supporting cells or neurons
Supporting Cells-limped together as neuroglia and includes cells that generally support,insulate and protect delicate neurons---glial cells have special functions:

9. ______________________________-abundant star shaped cells-swollen ends that cling to neurons,bracing them and anchoring to nutrient supply:________________________/They form a living barrier between capillaries and neurons and help make exchange between the 2-help protect neurons from harmful substances in the blood and also help control brain chemical environment by “mopping”up leaked K ions and recapturing released neurotransmitters
_____________________________-spider like phagocytes to dispose of debris-like dead brain cells and bacteria
astrocytes
microglia
capillaries

10. ependymal
oligiodendrocytes
_____________________________-glial cells that line the central cavities of the brain and SC …..beating of cilia to distribute cerebrospinal fluid for those cavities and provide a cushion
_________________________________-glia that wrap flat extensions tightly around nerve fibers-producing fatty myelin sheath(an insulation)
2 major varieties in PNS:______________________form myelin sheath and ______________________________-positive cushioning cells
Schwann cells
Satellite cells

15. Neurons-- anatomy-all have cell body,which contains nucleus and is metabolic center and one or slender extending processes
Neurons-- anatomy-all have cell body,which contains nucleus and is metabolic center and one or slender extending processes
Cell Body-metabolic center
Transparent ________________ w/ a conspicuous nucleolus
Cytoplasm has usual organelles except centrioles
Rough ER is called______________________________and _____________________________(intermediate filaments used in maintaining cell shape)
Nissal substance
nucleus
neurofibrils

16. Processes-or fibers- vary greatly in length from microscopic - ~3-4 ft
Processes-or fibers- vary greatly in length from microscopic - ~3-4 ft.Our longest reach from lumbar to large toe
________________________-convey incoming messages(electrical signals) towards cell body-may be many of these for one nerve cell
_____________________- carry messages AWAY from cell body-only 1 axon,but branch much 2 end w/hundreds of axon _____________________________.-they contain 100’s of tiny vesicles,or membranous sacs w/___________________________chemicals-released into extracellular space
Axon terminals
axons
dendrites
neurotransmitters

17. _____________________________tiny gap that separates axon terminal from next neuron(synapse)
_____________________________-whitish ,fatty material w/waxy appearance.It functions by insulating or protecting fibers and Increases transmission rate
Myelin sheath
Synaptic cleft

18. External to Schwann cell is neurilemma-
Axons outside CNS are myelinated by ____________________________,which is gradually squeezed tightly enclosing axon
External to Schwann cell is neurilemma-
Schwann cells

20. Nodes of Ranvier oligodendrites
Gaps between Schwann cells are called __________________________
Myelinated fibers also in CNS as ___________________________-around small segment of 1 nerve fiber-coiling around as many as 60 fibers at one time…Since they lack neurilemma that contributes to non –regeneration property
Nodes of Ranvier
oligodendrites

21. __________________________________is a neurological disorder causing visual or speech problems as wel as increasingle degenerating muscle …This is all due to an autoimmune response that destroys a protein in the myelin and cause nerves to short ciruit----Interferon is used
Multiple sclerosis

22. Terminology- nerves Gray matter nuclei ganglia -
cell bodies in CNS are usually called ______________--carrying out metabolic functions/not regenerated
__________________small collections of cell bodies outside CNS-in PNS
________________________ are bundles of nerve fibers running through CNS
_____________________________________ are bundles of nerve fibers running through PNS
_________________________-collections of myelinated fibers in CNS
________________________CNS unmyelinated fibers
nerves
tracts
Gray matter
White matter

23. Classification Sensory or afferent
Functionally groups neurons according to direction of nerve transmission relative to CNS…if carrying impulse from receptor to CNS-____________________________neurons-found in a ganglion outside CNS;dendrite endings of sensory neurons are usually associated with specialized recptors activated by specific nearby changes-cutaneous sense organs and_____________________________in muscle and tendons
proprioreceptors

24. _________________(efferent)neurons carry impulses from CNS to visceraan/or muscles or glands-cell bodies in CNS
________________________or association neurons connect motor and sensory neurons in neural pathways-cell bodies always in CNS
Structurally based on # of processes extending from cell body---if several:____________________________-inc. all motor and association neurons/__________________neurons have 2 processes-rare in adults/_____________________neurons have single process –sensory neurons in PNS
motor
interneurons
multipolarneuron
bipolar
Unipolar neurons

25. 6-Physiology

26. NERVE INPULSES:Neurons have 2 major properties-___________________________________________
__________________________refers to inactive or resting plasma membrane(fewer + ions on inner face(K+ions)-outside are Na+ ions …if the inside is more - ,it is inactive
Irritability and conductivity
polarized

27. depolarization
Action potential
repolarization
Action Potential and generation:…many different stimuli excite neurons—eg.light,sound,pressure-most excited by neurotransmitters released by other neurons….changes permeability of membrane changes briefly-gates of Na channels open---changing polarity-_________________________-inside now more +--graded potential
If this strong enough it initiates an_________________________(nerve impulse)-all-or none response
An outflow now of K+ ions will restore resting state-__________________________________

28. UNTIL REPOLARIZATION HAPPENS<A NEURON CANNOT CARRY ANOTHER IMPULSE !
NA-K pump uses ATP
The above describes unmyelinated impulses –Myeinated sheaths conducts impulses faster-__________________________________-leaps from node to node
Conductivity can be impaired by sedatives and anesthetics by altering permeability
Salatory conduction

29. Synapse Transmission-impulse does not traverse- synapse neurotransmitter do and they cause Na+ entry ,depolarization,etc.-brief transmission-electrochemical

30. Reflexes-rapid and predictable and involuntary response to stimuli
Somatic reflexes-stimulate skeletal muscles
_____________________regulate smooth muscles,heart and glands
Autonomic reflexes

31. _____________________________is a neural pathway and has at least 5 elements:____________________________________________________________________________________________________
Sensory receptor,effector organ,sensory or motor neurons and synapse-CNS integration center
Relex arcs

33. gyri
III. CNS
sulci
Functional Anatomy of the Brain
Brain is ~ 3 lbs.
4 regions-cerebral,diencephalons,brain stem,cerebellum
Cerebral hemispheres
Paired
Largest and most superior
____________-elevated regions of tissue separated by shallow _______
______________________are less numerous grooves and separate larger regions of brain
fissures

34. ______________-separates 2 hemispheres by deep fissure
Longitudinal fissure
______________-separates 2 hemispheres by deep fissure
Other fissures or sulci divide into lobes,named for corresponding cranial bone
3 basic regions to ea hemisphere:_______________________
Superficial cortex of gray matter,internal white matter,and basal ganglia(Gray)

35. Cerebral Cortex:-includes speech,memory,logical and emotional response, consciousness , interpretation of sensation,and voluntary movement
________________________-posterior to central sulcus-primary somatic sensory area-interprets impulses traveling from body sensory receptors(except for special senses)/allows you to perceive pain,coldness or light touch….as shown in 7-14,p.245…body is represented in an upside down manner in sensory area-such a spatial map is a ___________________-crossed pathways-left primary somatic sensory area receives impulse from right and vice verse
Primary somatic sensory area in parietal lobe
Sensory homunculus

40. __________________________visual area in posterior
___________________________has auditory area and has olafactory area
_________________________is primary motor area/the axons of these motor neurons make ________-major voluntary motor tract and it descends to cord-pathways again crossed
_________is map on motor cortex
Temporal lobe
Occipital lobe
Corticospinal or pyramidal tract
Motor homunculus
Frontal lobe

41. ______________________at base of precentral gyrus-involved in speech-usually only in left hemisphere-damage here can cause inability to say words properly
In anterior frontal lobes is believed to be intellectual reasoning and socially acceptable behavior region
The main _____________________is located at junction of temporal,parietal,and occipital lobes-usually only in 1 hemisphere also
__________________is involved w/word meanings
Cell bodies of neurons involved in cerebral hemisphere are in outermost gray matter
Speech area
Broca’s area
Frontal lobes

45. Cerebral White Matter-deeper,remaining cerebrum-composed of fiber tracts carrying impulses to and from or within cortex
__________________________________-large fiber tract that connects cerebral hemispheres(an example of a commisure)-allows hemispheres to communicate with each other….Association fiber tracts connects areas w/in hemisphere and projection fiber tract connects cerebrum
Corpus callosum

48. _______________________________-islands of gray matter buried in white matter of cerebral hemispheres-help regulate voluntary motor activities by modifying instructions-esp. starting or stopping
basal ganglia
Basal nuclei

50. ______________________________- genetic disease, middle-age and leads to massive degeneration of basal nuclei and then cerebral cortex-includes jerky movements and an eventual vegetative state w/in 15 years fatal-overdrive in motor stimulation
______________-has basal nuclei problems-strikes in 50’s-60’s and comes from a degeneration of dopamine releasing neurons-dopamine deprived basal nuclei become overactive-tremors,head nodding etc.
Huntington’s disease or Chorea
Parkinson’s disease

51. *Diencephalon-interbrain-atop brain stem and enclosed by cerebral hemispheres
____________________________-encloses shallow 3rd ventricle of brain and is relay station for sensory impulses passing upward to sensory cortex-interpret sensation
____________________________________-is under the thalamus makes up floor of diencephalons-helps regulate body temp.,water balance and,metabolism-also centers for many drives and emotions-part of ___________________________-“emotional visceral brain”-thirst,appetite and sex drive
Thalamus
hypothalamus
Limbic System

52. Contains pituitary gland and mammillary bodies that is involved in olafaction

53. ___________________-roof of 3rd ventricle/contains ____________________-an endocrine organ,choroid plexus-form cerebrospinal fluid
Pineal body
epithalamus

55. midbrain Brain stem Cerebral aqueduct
____________________________________-about the size of a thumb in diameter and about 3’’ long…includes midbrain,pons and medulla oblongata/provides a pathway for ascending and descending tracts and has small gray matter areas
1)____________________________-small/____________________________________ travels through midbrain and anteriorly midbrain has cerebral peduncles that convey ascending and descending impulses/dorsally are 4 rounded corpora quadrigemina-reflex centers for vision and hearing
midbrain
Brain stem
Cerebral aqueduct

56. 2)___________________----rounded just below midbrain and has bridge of fiber tracts and involves in control of breathing
3)___________________________-most inferior part and merges into SC…fiber tract area and helps regulate visceral activity
pons
Medulla oblongata

58. ***Cerebellum-dorsally under occipital lobe and has 2 hemispheres-has outer cortex of gray matter and inner cortex of white matter
Provides timing factor for skeletal and controls muscle activity
________________________-cerebellum damage causing clumsiness and disorganization
ataxia

61. Protection of CNS
A.__________-3 connective tissue membranes protecting CNS
1)______________________-outermost layer and leathery(“tough or hard mother”),double layered where surrounds brain
Dura mater
meninges

63. _____________________-attached to inner surface of skull
___________________-Outermost covering of brain and continues as dura mater of spinal cord
Dural layers fused except in 3 areas where they separate to enclose dural venous sinuses that collect _________________________.
Periosteal layer
Meningeal layer
Venous blood

64. Inner dural membrane extends inward to form a fold that attaches brain to cranial cavity

65. ______________________________-middle meningeal layer,weblike;spans
subarachnoid space to attach TO innermost membrane.
Arachnoid mater

66. 3)_____________________________-innermost membrane(“gentle mother”)-clings tightly to surface of brain and spinal cord,following every fold
Subarachnoid space is filled w/ cerebrospinal fluid and ______________________________protrude through dura mater
Cerebrospinal fluid is absorbed into venous blood in dural sinuses through arachnoid villi
Projections of arachnoid membrane called arachnoid villi
Pia mater

68. encephalitis
______________________________-inflammation of meninges,serious threat to brain(bacterial or viral) because may spread to the nervous tissue of the CNS/spinal diagnostic taps derived from subarachnoid space
___________________________-brain inflammation
meningitis

69. Cerebrospinal Fluid(CSF)-somewhat watery and similar to blood plasma,but contains less protein and more vitamin C and a different ion composition
CSF continually formed from blood by choroids plexus(clusters of capillaries hanging from roof of each of brain’s ventricles)
Forms a watery cushion to protect fragile nervous tissue
Continually moves in brain,circulating from 2 _________________________into 3rd ventricle and then through cerebral aquaduct of midbrain into 4th ventricle….some of this continues down SC,but most circulates into subarachnoid space
Lateral ventricles

71. Test w/ lumbar puncture
CSF returns to blood in dural venous sinuses through _____________________________
Normal means CSF forms and drains at a constant rate maintaining about ½ cup fluid.Any significant changes-like blood cells or general composition may mean ____________________
Test w/ lumbar puncture
________________________________--if drainage of CSF is obstructed-maybe by tumor or born that way
Sign of miningitisor certain brain pathologies such as tumor or MS
Arachnoid villi
hydrocephalis

77. Blood-Brain Barrier
Brain is very sensitive to pressure and chemical changes
Thus,the least permeable capillaries in body—almost seamlessly bound by tight junctions all around-passing only water ,glucose and amino acids pass easily through—preventing _________________________
Barrier useless against ____________________________(thus explains entrance of alcohol,nicotine and anesthetics
Preventing urea, toxins,proteins and many drugs from entering
Fats,respiratory gases and other fat-soluble molecules

79. Brain Dysfunctions
_______________________________-progressive degenerative disease of brain resulting,eventually, in dementia;associated w/shortage of Ach and structural changes in brain;gyri shrink and brain atrophies
_______________________-minor and not permanent brain damage
__________________________-marked tissue destruction-severe forms always result in comas
concussion
Alzheimer’s disorder
contusion

80. ____________________________-after a blow to the head-bleed from ruptured vessels
________________________-swelling of brain from inflammatory response to injury
______________________________-3rd leading cause of death in US-when blood circulation is blocked and vital tissue dies
____________________one sided paralysis
_________________damage to left cerebrum and affects speech
__________________-temporary restriction of blood flow
Cerebral edema
Cerebrovascular accidents-CVA-ie.stroke
Intracranial hemorrhage
hemiplegia
aphasias
Transient ischemic attack -TIA

81. 1st or 2nd lumbar vertebra
SPINAL CORD-cylindrical and appx.17” long,glistening white;2 way conduction pathway to and from brain and reflex center
Extends from foramen magnum to _________________________________,ending below the ribs(thus L3 good for spinal tap)
Protected by CSF and meningeal coverings
31 prs spinal nerves-arise from cord and exit from vertebral column to serve nearby area of body
____________________collection of spinal nerves at end of vertebral canal
Cauda equina
1st or 2nd lumbar vertebra

85. A)Gray matter of SC and spinal roots
Looks like butterfly in crosssection
Contains dorsal horns(has interneurons) ,ventral horns(contain cell bodies of motor somatic{voluntary} nervous sytem and surrounds central canal of SC ,containing CSF)
Cell bodies of sensory neurons enter cord by dorsal root and are called ___________________________________-If severed ,sensation at that point is lost
Ventral horn sends its axons out ______________________
Dorsal and ventral roots fuse to form ________________________________
____________________________-damage to ventral root/affecting muscles served;muscles will atrophy
Flaccid paralysis
Spinal nerves
Dorsal root ganglion
Ventral root of cord

87. B-White matter of SC
Myelinated fiber tracts-serving higher centers,some travel brain to SC and some innervate one or the other side of the SC
Dorsal,lateral and ventral columns-3 regions of white matter
Tracts conducting Sensory impulse to brain by _________________or afferent tracts
Motor(efferent tracts) carry from __________________________________
__________________________________-if SC is cut crosswise or crushed-afferent stay intact and involuntary movement of those muscles results and sensation loss below cut-compare quadriplegic to paraplegic
Brain to skeletal muscles
sensory