1. Nervous System Dissection LIve

2. Learning Outcomes
Explain the difference between the central nervous system and the peripheral nervous system.
Describe the functions of the nervous system.
Describe the structure of a neuron.
Describe the function of a nerve impulse and how a nerve impulse is created.
Describe the structure and function of a synapse.
Describe the function of the blood-brain barrier.
Describe the structure and functions of meninges.
Describe the structure and functions of the spinal cord.

3. Learning Outcomes (cont.)
Describe the location and function of cerebrospinal fluid.
Define reflex and list the parts of a reflex arc.
List the major divisions of the brain and give the general functions of each.
Explain the functions of the cranial and spinal nerves.
Describe the differences between the somatic nervous system and autonomic nervous system.
Explain the two divisions of the autonomic nervous system.
Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the nervous system.

4. Learning Outcomes (cont.)
Describe the differences between the somatic nervous system and autonomic nervous system.
Explain the two divisions of the autonomic nervous system.
Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the nervous system.

5. Central Nervous System
Processing and organizing information.
Interesting Facts.
- 2% of the mass 20% of the O2
not till age 25 does the brain reach maturity
"The preponderance of young men engaging evil
and stupid acts may be a result of brains that
have yet to fully developed,” Psychiatry at Albert
Einstein College of Medicine
The CNS consists of two major structures:
The Brain
The Spinal Cord
Phineas Gage

6. None of these behaviors is mentioned
Phineas Gage
mistreatment of wife and children (though Gage actually had neither)
inappropriate sexual behavior
vagrancy, begging, drifting, drinking
lying, brawling, bullying.
None of these behaviors is mentioned
by anyone who had met Gage.  
Gage is "a great story for illustrating
the need to go back to original sources"

7. General Functions of the NS
PNS
Peripheral nerves
Two sections
Somatic nervous system (SNS)
Skeletal or voluntary muscles
Autonomic nervous system (ANS)
Automatic functions
CNS
Brain
Spinal cord

8. General Functions (cont.)
Three types of neurons
Afferent or sensory nerves
Sensory information from environment or inside body to CNS for interpretation
Efferent or motor nerves
Impulses from CNS to PNS to allow for movement or action
Interneurons
Interpretive neurons between afferent and efferent nerves in the CNS

9. Apply Your Knowledge Correct! ANSWER: Match the following:
___ Somatic nervous system A. Motor nerves
___ Autonomic nervous system B. Governs skeletal or voluntary muscles
___ Afferent nerves C. Governs respiratory and GI systems
___ Efferent nerves D. Go-betweens or interpreters
___ Interneurons E. Sensory nerves B C A E D
Correct!

10. Neuron Structure Functional cells of NS
Transmit electrochemical messages called nerve impulses to
Other neurons
Effectors (muscles or glands)
Factoid:
Neurons lose their ability to divide
If destroyed, not replaced

11. Neuron Structure (cont.)
Dendrites – short
Receive nerve impulses for the neuron
Axons – long
Send nerve impulses away from the cell body
Neurons have a cell body and processes called nerve fibers that extend from the cell body.

12. Neuron Structure (cont.)
White matter – axons with myelin sheath
Schwann cells
Wrap around some axons
Cell membranes contain myelin
Myelin insulates axons and enables axons to send nerve impulses more quickly
Gray matter – axons without myelin sheath
Schwann cells
Axon
Dendrites

13. Neurons and now Glial Cells
Neuralgia or Glial Cells (glue)
Support cells for neurons that can divide
Astrocytes – anchor blood vessels to nerves
Microglia – act as phagocytes
Oligodendrocytes – assist with production of myelin sheath

14. Apply Your Knowledge GOOD JOB! True or False:
___ Effectors are neurons.
___ Neurons can reproduce.
___ Astrocytes anchor blood vessels to nerve cells.
___ Microglia act as phagocytes.
___ Oligodendrocytes are reproductive cells.
___ Repolarization is the return to the resting state.
ANSWER: F
They are the muscles or glands. F
Neurons cannot reproduce. T T
They take part in myelin production. F T
GOOD JOB!

15. The Brain

16. Caudal Rostral is Tail nose

17. Sagittal Plane

18. Cerebrum Sulci – grooves on surface Gyri or convolutions – bumps of brain matter between sulci
Lobes
Frontal
Motor areas for voluntary body movements
Parietal
Somatosensory – interprets sensations
Temporal
Auditory – interprets sounds
Occipital
Interprets what a person sees
Parietal
Frontal
Temporal
Occipital

19. LOBES
Of The Cerebrum

20. Cerebrum – 80% of brain mass left and right hemispheres.
Responsible for
intellect
consciousness

21. Lobes of the Cerebrum

22. Frontal Lobe
voluntary motor muscle movement,
higher intellect like language.

23. Motor Cortex

24. Temporal Lobe – hearing
Occipital Lobe –vision

25. Parietal Lobe –Sensory Neurons collect here.
(touch, temperature, pressure, pain from the skin)

26. Sensory Cortex

28. Olfactory Lobe –smell
Before mummifying someone
ancient Egyptians would remove
the deceased's brain through the
nose. 
Today, during a surgery, we do the
same thing passing a through
the nose a thin bony partition
is removed to allow a endoscope
to enter the brain.

29. Nerves that connects the two halves of the brain.
Corpus Callosum
Nerves that connects the two
halves of the brain.
Not true but here goes….
Left brain – Logical
Right brain – Creative, artistic.
What is true (4minutes)…. nothing

30. BRAIN SECTION Diencephalon (After the Cerebrum) heading down

31. Diencephalon is the Thalamus and Hypothalamus
Between the cerebral hemispheres superior to the brain stem
Thalamus - Relay station for sensory information
going to the cerebral cortex for interpretation
Hypothalamus - regulates vital activities

32. Other parts of the brain
Functions
- Emotions
- Smell
Memory
(2 minutes)

33. BRAIN SECTION BRAIN STEM

34. Brain Stem Connects the cerebrum to the spinal cord Midbrain
Just beneath diencephalon
Controls both visual and auditory reflexes
Pons
Rounded bulge on underside of brain stem
Between midbrain and medulla oblongata
Regulates respiration
Medulla oblongata
Inferior portion of brain stem
Directly connected to spinal cord
Controls many vital activities, such as
Note, the cerebellum is NOT part of the brain stem heart rate, blood pressure, and breathing. It IS part of the hind brain, along with the Pons and Medulla, but NOT , of course, the mid-brain.

35. Cerebellum Coordinates Complex skeletal muscle contractions that are
needed for body movement
Fine movements , sports, driving…zombie

36. Hindbrain the Autopilot
Cerebellum – muscle co-ordination, posture.
Medulla oblongata – heartbeat, respiration.
Pons – connects the cerebrum to other brain parts
Note: Clearly, the MID brain cannot be part of
the Hind Brain.
Confusingly, the mid brain is found on the brainstem
Just a side note……The Brainstem is :
Medulla
Pons
Midbrain

37. Midbrain – 1)reflex center
for head movements
in response to visual
stimuli and…
2) connects cerebrum
to cerebellum

38. Review the lobes
7 minutes

39. Meninges – term encompassing ALL 3 protective CNS parts.
1. Dura mater - Latin for Hard Mother, thick and tough
2. Arachnoid mater- means spider, where the cerebrospinal fluid flows
Pia mater – kisses the brain
The REAL source of protection:
Cerebrospinal Fluid – circulates between
the inner and middle membranes
of the brain and spinal cord.
Provides protection
Nutrient / waste exchange.

40. Apply Your Knowledge Answer: Match the following:
SUPER!
Apply Your Knowledge
Answer:
Match the following:
___ Meninges A. Carry motor information from brain
___ Ascending tracts B. Stores memories and creates emotions
___ Descending tracts C. Grooves on the surface of the cerebrum
___ Cerebral cortex D. Carry sensory information to the brain
___ Hypothalamus E. Predictable, automatic response to stimuli
___ Sulci F. Maintains homeostasis
___ Cerebellum G. Coordinates skeletal muscle contractions
___ Reflexes H. Protects the brain and spinal cord H D A B F C G E

41. Pituitary Gland or Master Gland
Controlled by the hypothalamus.
 Anterior Lobe Hormones:
- Growth hormone (GH): 
- Prolactin: Prolactin stimulates breast milk production.
Thyroid-stimulating hormone (TSH): TSH
stimulates the thyroid gland to make hormones.
Posterior Lobe Hormones:
Anti-diuretic hormone (ADH): This hormone prompts
the kidneys to increase water absorption in the blood.
Oxytocin: Oxytocin causes contraction the uterus
during childbirth and stimulating breast milk production.

42. Blood-brain barrier
In 1885, Paul Ehrlich injected blue dye
into the blood of mice. The dye stained all of the
animals' organs blue — except their brains. 
Thus a barrier was found, only in the brain
Unlike other blood vessels in the body, these
endothelial cells in the brain are tightly wedged
together, creating a nearly impermeable boundary
between the brain and bloodstream. 
Yet, very small and/or fat-soluble, including alcohol, cocaine, and many hormones are able to slip through the endothelial cells. In contrast,
larger molecules, such as glucose or insulin, must
be ferried across by proteins. 
Unfortunately, this barrier is so effective at protecting against the passage of foreign substances that it often prevents life-saving drugs from being used.

43. Spinal Cord Functions center for reflex action provides a pathway for
communication between the
brain and peripheral nerves

44. Spinal Cord Central Cavity – contains cerebrospinal fluid
White Matter – myelinated nerve
cells
Grey Matter – un-myelinated cells
What is myelin?...click

45. Spinal Cord Dorsal Root Ganglion Entry at the back of a
gang of sensory neurons to
spinal cord.
Ventral Root
– exit of motor neurons

47. Peripheral Nervous System
Nerves that branch off the CNS
Peripheral nerves
Two types:
Cranial nerves
Spinal nerves

48. Spinal Nerves (cont.) Main portions of spinal nerves:
Cervical – supply skin and muscles of neck
Phrenic nerve originates from this plexus and controls the diaphragm
Brachial – control muscles in the arms
Lumbosacral – lower abdomen, external genitalia, buttocks, thighs, legs, and feet
Sciatic nerve originates from this plexus and controls muscles of legs

49. Spinal Nerves 8 pairs of cervical nerves (C1 through C8)
Peripheral nerves originating from the spinal cord
31 pairs of spinal nerves
8 pairs of cervical nerves (C1 through C8)
12 pairs of thoracic nerves (T1 through T12)
5 pairs of lumbar nerves (L1 through L5)
5 pairs of sacral nerves (S1 through S5)
1 pair of coccygeal nerves (C0)

50. Diagnostic Procedures
Computerized tomography (CT) scan
Electroencephalogram (EEG)
X-ray
Lumbar puncture
Magnetic resonance imaging (MRI)
Positron emission tomography (PET) scan
Cerebral angiography

51. Reflex Testing A reflexia Hyporeflexia Hyperreflexia
Absence of a reflex
Hyporeflexia
Decreased reflex
Hyperreflexia
Stronger-than-normal reflex

52. Reflex Testing (cont.) Biceps reflex Knee reflex Abdominal reflexes
Absence indicates spinal cord damage in the cervical region
Knee reflex
Absence may indicate damage to lumbar or femoral nerves
Abdominal reflexes
Used to evaluate damage to thoracic spinal nerves

53. Apply Your Knowledge Excellent! Match the following:
___ State of consciousness A. Determines the health of peripheral nerves
___ Reflex activity B. Loss of balance, abnormal posture
___ Speech patterns C. Stupor, delirium, vegetative
___ Motor patterns D. Loss of ability to form words
ANSWER: C A D B

54. In Summary
The central nervous system is composed of the brain and spinal cord. The peripheral nervous system consists of the peripheral nerves throughout the body. The PNS is further divided into 2 systems: the somatic and autonomic nervous systems. 3 separate types of neurons to carry out the functions: A) The afferent (sensory) nerves B) the efferent (motor) nerves C) interpretive interneurons “interpreters” between the afferent and efferent nerves.

55. In Summary (cont.)
- At rest, a neuron is said to be in a polarized state, and when it responds to stimuli, depolarization takes place. - Repolarization occurs after the electrical current (impulse) has passed. - A synapse is the space between the axon of one neuron and the dendrite of the next. - At the end of each axon contains vesicles that produce neurotransmitters. The blood-brain barrier is a layer of tightly woven cells in the brians capillaries that protects the delicate brain tissues This barrier prevents certain substances from crossing this barrier into the brain tissues.

56. In Summary (cont.)
The meninges, a triple-layered membrane protecting the brain and spinal cord, are:
The tough outer layer is the dura mater.
The middle layer is the arachnoid, and below it is the subarachnoid space, which contains cerebrospinal fluid (CSF).
The innermost layer is the pia mater.
A typical reflex flows as follows:
Sensory receptors send information (impulse) to
the interneurons, which in turn send the information on to
the effectors of the motor neurons, producing a response.

57. In Summary (cont.)
The cerebrum divided into 2 hemispheres subdivided into 4 lobes:
Frontal
Parietal
Temporal
Occipital.
The diencephalon contains the thalamus and hypothalamus.
The brain stem consists of three parts:
the midbrain B) pons C) medulla oblongata.
The cerebellum is the final area of the brain.