1. The Central Nervous System

2. The Cerebrum I. The Brain Function Thinking and consciousness
Willed movements
Memory
Vision
Hearing
Sensory perception
Emotions
Speech

3. A. The Cerebrum 2. General Comments 83% of total weight of brain
Paired cerebral hemispheres

4. A. The Cerebrum 3. Anatomy Lobes Named for bones over them Frontal
Temporal
Parietal
Occipital
Insula
(limbic) –inside lateral sulcus

5. Parietal Lobe - Responsible for the sensation of pain, touch, taste, temperature, pressure. It is also related with mathematics and logics.
Limbic Lobe - involved in the emotional and sexual aspects of behavior and in the processing of memory.
Temporal Lobe - involved with hearing, also a role in memory and emotion processing.
Frontal Lobe - Responsible for thinking, planning, programming individual needs and emotion.
Occipital Lobe - Responsible for vision. Damage to this area results in partial or complete blindness.

6. A. The Cerebrum 3. Anatomy Fissures c.Sulci (sulcus singular)
Deep grooves
Longitudinal (median, between cerebral hemispheres)
Transverse (between cerebrum and cerebellum)
c.Sulci (sulcus singular)
Shallow grooves
Central: between frontal/parietal
Parieto-occipital
Lateral: between temporal/frontal/ parietal

9. A. The Cerebrum 3. Anatomy Gyri (gyrus singular) c.Basic Regions
Elevated ridges of tissue
Precentral (anterior to central sulcus)
Postcentral (posterior to central sulcus)
c.Basic Regions
Cortex
Outer layer
Gray Matter
White Matter – internal
Basal Nuclei
Islands of gray matter inside white matter

10. A. The Cerebrum 4. Cortex Gyri (gyrus singular) c.Basic Regions
Elevated ridges of tissue
Precentral (anterior to central sulcus)
Postcentral (posterior to central sulcus)
c.Basic Regions
Cortex
Outer layer
Gray Matter
White Matter – internal
Basal Nuclei
Islands of gray matter inside white matter

11. The Diencephalon VI. The Brain Consists of Thalamus Hypothalamus
Epithalamus

12. The Diencephalon VI. The Brain Thalamus
“Gateway of the Cerebral Cortex” for afferent (sensory) fibers
Relay station for sensory and motor impulses

13. The Diencephalon VI. The Brain Hypothalamus Autonomic control center
Main visceral control center of the body
Involved in regulation of
Body temperature
Water balance and thirst
Food intake and metabolism
Sleep and wake cycles

14. The Diencephalon VI. The Brain Hypothalamus Involved in regulation of
Endocrine functions
Regulates pituitary
Produces releasing and inhibiting hormones
Produces hormones
Antidiuretic hormone (ADH)
Oxytocin

15. The Diencephalon Hypothalamus Involved in regulation of
Endocrine functions
Center for emotional response and behavior
Thirst center
Appetite center
Sex (sexual arousal) center
Pain center
Pleasure center
Fear
Anger

16. The Diencephalon Epithalamus Forms roof of 3rd ventricle
Pineal Gland or Body
Secretes melatonin
Regulates sleep-wake cycles and moods
Choroid Plexus
Forms cerebral spinal fluid

17. VI. The Brain
The Brain Stem
Midbrain
Pons
Medulla Oblongata

18. The Brain Stem VI. The Brain Midbrain
Conduction pathway between higher and lower brain centers
Cranial Nerves III & IV

19. The Brain Stem VI. The Brain Pons
Conduction pathway between higher and lower brain centers
Regulates breathing
Cranial Nerves V - VII

20. The Brain Stem Medulla Autonomic reflex center for body homeostasis
Centers
Cardiac
Vasomotor
Respiratory
Vomiting
Hiccupping
Swallowing
Coughing
Sneezing
Cranial Nerves VIII - XII

21. VI. The Brain Cerebellum Assists in maintaining Balance Posture
Equilibrium
Coordinates skeletal muscle

22. VI. The Brain Functional Brain Systems Limbic System
Our emotional or affective (feelings) brain
Includes hypothalamus and parts of the cerebrum

23. VI. The Brain Functional Brain Systems The Reticular Formation
Involved in arousal of the brain
Filters the flood of sensory input (99% filtered out)
Filters out repetitive, familiar or weak signals
Passes on unussual, strong, or significant signals

24. Functional Brain Systems
VI. The Brain
Functional Brain Systems
The Ventricles
Cavities within the brain through which cerebral-spinal fluid flows
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

25. Function – involved with
VII. The Spinal Cord
Function – involved with
Sensory pathways to brain
Motor pathways to body
Spinal cord reflexes
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

26. Gray Matter at center of cord
VII. The Spinal Cord
Gray Matter at center of cord
Dorsal (posterior) horns = cell bodies of the sensory neurons
Ventral (anterior) horns = cell bodies of the motor neurons
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

27. Gray Matter at center of cord
VII. The Spinal Cord
Gray Matter at center of cord
Lateral horns = cell bodies of preganglionic neurons of the autonomic nervous system
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

28. B. Gray Matter at center of cord
VII. The Spinal Cord
B. Gray Matter at center of cord
Gray commisure = connects the lateral halves of gray matter
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

29. VII. The Spinal Cord C. Spinal Cord Injuries Flaccid Paralysis
occurs when there is damage to lower motor neurons (i.e. anterior horns of gray matter)                    
results in a total loss of muscle tone and atrophy of the muscle tissue
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

30. VII. The Spinal Cord C. Spinal Cord Injuries Spastic Paralysis
occurs when there is damage to upper motor neurons    
results in increased muscle tone, due to reduced inhibition of, but no voluntary control over, skeletal muscle
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

31. VIII. CNS Protective Structures
Skull and Vertebral Column
Cranial Bones (8)
Vertebral Column (33) .

32. VIII. CNS Protective Structures
Meninges
three, thin membranes that completely cover the brain and the spinal cord.
Spinal fluid flows in the space between two of the membranes.
Include the dura, arachnoid, pia .

33. VIII. CNS Protective Structures
Meninges
Dura Matter
Outer layer    
In the skull,
a double
layered                     
outer layer = periosteal layer attached to periosteium of skull
inner layer = meningeal layer is outermost brain covering
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

34. VIII. CNS Protective Structures
Skull and Vertebral Column
Meninges
Dura Mater
In vertebral column             
no outer layer
Arachnoid mater- middle layer 
Pia mater - inner layer
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

35. VIII. CNS Protective Structures
Skull and Vertebral Column
Meninges
C.Spaces between the meninges
1.Epidural
Above the dura
Only in spinal column
2.Subdural
Between dura and arachanoid
3.Subarachnoid
Between dura and pia .

37. VIII. CNS Protective Structures
D. Ventricles
1.fluid filled cavities in the brain
2.Include
2 Lateral Ventricles: in the cerebral hemispheres
Third ventricle: in diencephalon
4th ventricle: between the Pons & Cerebellum
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

39. VIII. CNS Protective Structures
D. Ventricles
3. Contain tufts of vascular tissue called the choroid plexus
Produce cerebral spinal fluid
b.CSF flows flows from ventricles to surface of brain and then is returned to the blood. .

41. VIII. CNS Protective Structures
Cerebral Spinal Fluid
Nourishes brain and spinal cord
Gives buoyancy to brain
Prevents brain from being crushed by its own weight
Produced in choroid plexuses
volume = 150 mL (1/2 cup)
Replaced every 3-4 hrs
arachanoid            
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

42. Blood Brain Barrier
Is the relative impermeability of brain capillaries           
Due to tight junctions, and endothelial lining of blood vessels in brain .

43. Blood Brain Barrier
Prevents passage of proteins, blood borne metabolic wastes (urea, creatine), some toxins, most drugs .
Allows passage of nutrients: glucose, essential amino acids, some electrolytes

44. VIII. CNS Protective Structures
Blood Brain Barrier
Protects brain against fluctuations in
Hormones
Ions
Nutrients
Toxic substances
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

45. HIV

46. VIII. CNS Disorders Meningitis 1.Infection of the CSF
Viral: less dangerous
Bacterial: can lead to brain damage, hearing loss, learning disabilities, death          
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord
2.Infection of the CSF
Causes inflamation of the meninges

47. VIII. CNS Protective Structures
Meningitis
3.Symptoms
High fever
Stiff neck
Intolerance for light          
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

48. VIII. CNS Protective Structures
Encephalitis
Inflamation of brain tissue and surrounding meninges
Cause – viral infections
Outcome
Destruction of gray matter
Can be fatal         
Alzheimer Disease
Accumulation of plaque and tangles in brain
Cause – unknown
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

49. VIII. CNS Protective Structures
Parkinson
characterized by a decrease in spontaneous movements, gait difficulty, postural instability, rigidity and tremor
Cause the degeneration of the neurons producing dopamine
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

50. IX. CRANIAL AND SPINAL NERVES
Cranial Nerves
Visible on ventral surface
12 pair
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

51. IX. CRANIAL AND SPINAL NERVES
Cranial Nerves
12 Pair
Olfactory: smell
Optic: vision
Oculomotor: eye movement pupil dilation
Trochlear: eye movement
Trigeminal: chewing; somatosensory (pain touch) for head
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

52. A. Cranial Nerves 2. 12 pair Abducens: eye movement
Facial Nerve: taste, facial expressions, somatosensory from ear
Vestibulocochlear: hearing and balance
Glossopharyngeal: taste, swallowing, sematosensory from tongue
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

53. A. Cranial Nerves
pair
Vegas: sensory, motor, autonomic functions of viscera
Spinal Accessory: head movement
Hypoglossal: tongue muscles .
Here is a mnemonic:
On Old Olympus Towering Top A Famous Vocal German Viewed Some Hops.

54. IX. CRANIAL AND SPINAL NERVES
B. Spinal Nerves – 31 pair
(1) Cervical
Thoracic
Lumbar
Sacral
Coccygeal
Sciatic
Lumbar plexus
Intercostal
Brachial plexus
Cervical plexus
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

55. IX. CRANIAL AND SPINAL NERVES
B. Spinal Nerves – 31 pair
A nerve plexus is a network of interwoven nerves.
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

56. Recall Divisions of the N.S. Central N.S. Peripheral N.S. Efferent
Afferent
Spinal Cord
Brain
CNS: brain and spinal cord
PNS: all nerves coming from/to the CNS
Afferent: carries impulses towards CNS
Efferent: carries impulses away from CNS
Somatic: goes to skeletal muscles (voluntary; responds to external stimuli; one ganglia)
Autonomic: goes to viscera and glands (involuntary; responds to internal stimuli; two ganglia)
Parasympathetic: rest and digest
Sympathetic: fight or flight
Autonomic
Somatic
Parasympathetic
Sympathetic

57. X. THE PERIPHERAL NS
CNS PNS

58. X. THE PERIPHERAL NS
A. Afferent vs Efferent

59. X. THE PERIPHERAL NS A. Afferent vs Efferent Afferent NS
Sensory neurons.
Proprioceptors: sensitive to position and movement
Pick up stimulus and carry it toward the CNS
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

60. X. THE PERIPHERAL NS A. Afferent vs Efferent 2.Efferent NS
Motor neurons
Carry response impulses from the CNS to the effector
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

61. A. Afferent vs Efferent X. THE PERIPHERAL NS
3. Disorders of Afferent & Efferent systems
Myasthenia Gravis: immune system attacks Ach; leads to muscle weakness and fatigue
Multiple sclerosis: loss of myelin sheath of motor and sensory neurons; leads to limb weakness, tremors, vision disorders, vertigo
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

62. B. Somatic vs Autonomic NS
X. THE PERIPHERAL NS
B. Somatic vs Autonomic NS
Somatic
Controls skeletal muscles.
Can be conscious or subconscious
Has a single neuron between CNS and effector
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

63. B. Divisions of the Efferent NS
X. THE PERIPHERAL NS
B. Divisions of the Efferent NS
2. Autonomic
Controls smooth muscles of viscera and glands
Is subconscious
Has two neurons between CNS and effector
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

64. B. Divisions of the Efferent NS
X. THE PERIPHERAL NS
B. Divisions of the Efferent NS
2. Autonomic
c.Has two neurons between CNS and effector
Preganglionic neurons
Originate in spinal cord
Ganglion neurons
Nerve cell bodies
Neurons in effector
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

65. C. Sympathetic and Parasympathetic
X. THE PERIPHERAL NS
C. Sympathetic and Parasympathetic
1. Sympathetic
“Fight or Flight”
Consists of
Preganglionic neurons
2+ Ganglionic neurons
Specialized neurons in adrenal gland (secretes hormone controlling production of Ach)
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

67. A. Gate Control Theory XI. Pain Perception
Without any stimulation, both large and small nerve fibers are quiet and the inhibitory interneuron (I) blocks the signal in the projection neuron (P) that connects to the brain. The "gate is closed" and therefore NO PAIN
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

68. A. Gate Control Theory XI. Pain Perception
2.With non-painful stimulation, large nerve fibers are activated primarily. This activates the projection neuron (P), BUT it ALSO activates the inhibitory interneuron (I) which then BLOCKS the signal in the projection neuron (P) that connects to the brain. The "gate is closed" and therefore NO PAIN.
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

69. A. Gate Control Theory XI. Pain Perception
3.With pain stimulation, small nerve fibers become active. They activate the projection neurons (P) and BLOCK the inhibitory interneuron (I). Because activity of the inhibitory interneuron is blocked, it CANNOT block the output of the projection neuron that connects with the brain. The "gate is open", therefore, PAIN!!
. Ventricles
Lateral (1st & 2nd)                    
(1) Cerebrum            
b. Interventricular foramen (foramen of Monro)              
c. Third                    (1) Starts in Cerebrum                    (2) Diencephalon (Thalamus, etc.)            
d. Cerebral aqueduct        (1) Brain stem: midbrain              
e. Fourth                    
(1) Aperatures           (a) Lateral (2)          (b) Median (1)              
(2) Brain stem: pons                    
(3) Cerebellum                    
(4) Brain stem: medulla oblongata              
f. Central Canal                  
(1) Spinal cord

70. I = "Inhibitory Interneuron"; P = "Projection Neuron" - = inhibition (blocking); + = excitation (activation)

71. XI. Pain Perception B. Controlling Pain
1.Aspirin: acts mostly in PNS; reduces inflammation
2.Morphine: acts in CNS to block pain messages
3.Acupuncture:
stimulates large diameter fibers that inhibit pain (closes the gate)
. Other pain drugs act on a variety of neurotransmitter systems