1. CH 10- Objectives
1. Give the location and functions of the 4 main divisions of the brain
2. Name and locate the subdivisions of the brainstem
3. Name and describe the 3 meninges
4. Cite the function of CSF and describe where this fluid is formed
5. Cite one function of the cerebral cortex in each lobe of the cerebrum
6.Cite the names of the cranial nerves, #s 1,2,7,8,10
7. Describe several methods used to image the brain
List some disorders that involve the brain or the cranial nerves

2. The Brain & Spinal Cord
B&S CHAPTER 10

3. The Human Brain Is highly developed
Is an intricate mass of soft tissue
Weighs about 3 lbs

4. What does the brain look like?
Besides having the 3 meninges:
dura, arachnoid, pia…
There is another covering over the brain though, it’s called the cerebral cortex

5. What does the brain look like?
It appears to be gray in color due to it’s covering called cerebral cortex. This cortex is made up of:
1. Sulci (salsie)or grooves and folds throughout it
2. Gyri or elevations throughout it
(Sulci & Gyri A.K.A cerebral cortex)
These elevated and grooved areas give the brain surface area and bulk and are very important (will discuss it later)

6. Sulci & Gyri give the brain surface area which means it fills up the space
SULCI – grooves & folds
GYRI – elevations throughout

7. Gray matter versus white matter
Gray matter – nerve tissue composed mainly of cell bodies of neurons. Found in the CNS in the cerebral cortex, basal ganglia, and nuclei of the brain
White matter – the white substance of the spinal cord and brain consisting of nerve fibers being myelinated and unmyelinated

8. Basal Ganglia – Gray Matter
Basal ganglia is found in gray matter of the brain and looks like 4 masses of gray area
Basal ganglia are complex in function
Basal ganglia regulate body movement and facial expressions

9. Protection
The brain is protected by the:
Skull
Meninges
CSF

10. Skull Made of bones, provides protection
strong from calcium and phosphorus

11. Meninges
Are the 3 membranes that cover the brain and spinal cord, they are:
Dura mater
Arachnoid mater
Pia mater

12. Meninges
1. Dura mater is the external covering of the brain, contains tough, dense, fibrous , connective tissue with lots of blood vessels, dura mater is the thickest and toughest of all 3 membranes, found just under the skull bone
2. Arachnoid mater is the middle layer of the membrane. It looks like a fine cob-web of fluid filled spaces, it allows room for the CSF to move
3. Pia mater - internal layer, this layer covers the brain itself and is attached to the nervous tissue of the brain, has lots of blood vessels, and is held together by fine areolar connective tissue. The blood supply of the brain is carried by this pia mater

13. Spaces in between…
The space between the arachnoid and the pia mater is filled with CSF that is produced within the ventricles of the brain
This fluid acts as a shock absorber and a source of nutrients for the brain

14. Meninges

15. The Brain is divided into 3 parts:
1. Cerebrum
2. Cerebellum
3. Brainstem

16. Cerebrum The largest and highest part of the
brain, it holds the nerve center and
controls sensory & motor activities
It occupies the whole upper part of the skull
It weighs about 2 lbs
Gray matter covers the upper and lower surface of the cerebrum

17. The Cerebrum
The cerebrum controls conscious thought, judgment, memory, reasoning and will power
The awesome degree of development of the cerebrum makes the human the most intelligent of all animals

18. The Cerebrum Is divided into 2 hemispheres, RIGHT & LEFT
In the middle of the 2 hemispheres, down deep, is corpus callosum. This band of white matter bridges the 2 hemispheres together allowing communication between the centers of each hemisphere

19. Right & Left Hemispheres of the Cerebrum

20. Each of the Right & Left hemispheres are further divided into 4 uneven lobes
Each side of the cerebral hemisphere has 4 uneven lobes that controls different types of functions, the 4 lobes are :
1. Frontal
2. Parietal
3. Temporal
4. Occipital

22. Frontal Lobe 1. Controls the motor functions in humans
2. Motor area controls voluntary muscles
3. Cells in the R hemisphere control the L side of the body
4. Cells in the L hemisphere control the R side of the body
5. What happens in a R sided stroke pt= L side paralysis
6. Frontal lobe also includes 2 areas of speech control

23. Parietal Lobe
This part of the brain receives and interprets nerve impulses from the sensory receptors for pain, touch, heat and cold
It helps us in determination of distances, sizes and shapes (spatial ability)

24. Temporal Lobe
Contains the auditory area in the upper part of this lobe
The back of this lobe is where olfactory or smell center is

25. Occipital Lobe Is located over the cerebellum, controls eyesight
It’s the visual area of the brain

26. Covering of the Cerebral Hemisphere
As discussed earlier, the bulk, folds and grooves of the brain is known as the cerebral cortex
as stated earlier…
The outer nervous tissue of the cerebral hemisphere is gray matter known as cerebral cortex, this is the sulci and gyri

27. Cerebral Cortex
Is a thin layer of gray matter that is highly evolved and is responsible for conscious thought, reasoning and abstract mental functions
Specific functions are localized in the cortex of different lobes

28. Moving downward into the brain for a moment…
You’ll find the limbic system

29. The Limbic System
Lies along the border between the cerebrum and the diencephalon
This limbic system is involved in emotional states and behavior and governs wakefulness and sleep
The hippocampus is here (shaped like a sea-horse). Hippocampus is responsible for learning and long-term memory

30. Moving even deeper down into the brain…

31. Diencephalon
This is the area between the cerebral hemispheres and the brain stem
Di = 2, there are 2 major structures here:
1. Thalamus
2. Hypothalamus

32. Thalamus It’s located deep inside of the cerebral hemispheres
It acts as a relay for (sensory) incoming and outgoing nerve impulses and relays them to the appropriate area of the cerebral cortex
Damage to this area results in an increased ability to distinguish pain, or total LOC

33. Hypothalamus Lies below the thalamus hypo = below
Remember, the hypothalamus calls the pituitary and directs it to do things
Hypothalamus does 6 things:
1. Regulates the parasympathetic and sympathetic systems of the autonomic nervous system
2. Controls BP by constricting or dilating blood vessels and the beating of the heart

34. Hypothalamus Influences the following: 3. Temperature 4. Water balance
5. Sleep
6. appetite

35. Moving to the back lowest end of the brain…

36. The Cerebellum
Controls all body functions that have to do with skeletal muscles such as:
Balance
Muscle tone
Coordination
Removal of or injury to the cerebellum results in motor impairment

37. The Cerebellum
Is located below the cerebrum, towards the back of the brain, and is connected to the brain stem and spinal cord and to the underside of the cerebrum
It is composed of 2 hemispheres or wings R&L
The word cerebellum means “little brain”

38. The Cerebellum
The cerebellum communicates with the rest of the central nervous system
The cerebellum has gray matter on the outside and white matter on the inside
The cerebellum receives incoming messages regarding movement within joints, muscle tone, and tightness of ligaments and tendons

39. DID YOU KNOW…
Why does the Physician ask you to place your finger on the tip of your nose?
Placing a finger on your nose is a diagnostic test for cerebellar function. The cerebellum normally coordinates and smoothes out skeletal muscle activity. In attempting to touch an object, a pt with cerebellar dysfunction may overshoot, first to one side and then to the next

40. Moving slightly forward and underneath from the Cerebellum is the Brainstem
The stem-like part of the
brain that connects the
cerebral hemispheres with
the spinal cord
This is where the respiratory
center is located

41. Brainstem Is made up of 3 parts: 1. midbrain 2. pons 3. Medulla
The brainstem extends down from the medulla some refer to the whole extension (midbrain, pons, medulla) as the stem
This is where the respiratory center is located

42. Pons Contains myelinated nerve fibers
Helps connect the 2 halves of the cerebellum to the brainstem and connects the cerebrum with the spinal cord
Cranial nerves 5-8 originate in the pons

43. Medulla It appears white because it contains myelinated fibers
It regulates HR, breathing, BP and other reflexes such as coughing, sneezing, swallowing and vomiting

46. Ventricles of the brain
The brain contains 4 lined cavities called ventricles.
Each of the 4 ventricles contains a rich network of blood vessels
The 4 ventricles are filled with CSF
CSF is formed from the choroid plexus

47. Choroid Plexus Is a vascular network within the ventricles
When filtration of blood and cellular secretions occurs, CSF is formed

48. Problems with the ventricles:
These ventricles can overfill causing increased intercranial pressure. Pts have shunts placed in their ventricles to take the extra CSF on out of the brain to the peritoneal area to be dumped then reabsorbed Or
If a pt has a spinal leak, and the fluid “goes away”, the pt will have horrible headaches. Blood patch can be placed to stop the leak

49. CSF Cerebral spinal fluid
This fluid is usually clear and contains nutrients that the brain uses
CSF serves as a liquid shock absorber protecting the delicate brain and spinal cord

50. Hydrocephalus
Increased accumulation of CSF within the ventricles of the brain
Causes vary, can result in interference of normal circulation due to blockage or narrowing of the foramina. Fluid can’t flow freely
Other causes are developmental anomalies, infection, injury or brain tumors

52. Signs & Symptoms of Hydrocephalus in children
Head becomes globular shaped
The face becomes disproportionately small with eyes hidden in sockets and turned upward
In children, sutures of the skull become separated, fontanels bulge and cranial bone becomes thin from the pressure, there is some room for the brain to grow from the fluid

53. Signs & Symptoms of Hydrocephalus in adults
Headache
Vomiting
Choked vertebral discs
Atrophy of the optic nerve
Mental disturbances
In adults, there is no room for the brain to expand from too much fluid

55. Treatment
Placement of a shunt into the brain

56. Hydrocephalus

58. Other Problems that can occur in the brain
CVA
Hematoma
Neurological diseases such as Alzheimers or Parkinson’s disease
Cerebral Palsy
Epilepsy/seizures
Tumors known as gliomas

59. CVA – Cerebral Vascular Accident
Blood clot (Thrombus) blocks blood flow to the brain, depriving blood and O2 to the brain
Many impairments can occur
Remember, if the stroke started on the L, you’ll see R sided impairment

60. Treatment of Cerebral Vascular Accident
Treatment includes Thrombolytics (clot busters)
Streptokinase
Urokinase
Given IV
Side Effect-Bleeding, blood is too thin, can be dangerous

61. F.Y.I
Streptokinase – an enzyme produced by certain strains of hemolytic streptococci, used to dissolve clots
Urokinase – an enzyme obtained from human urine, used experimentally for dissolving venous thrombi and pulmonary emboli.
These meds are given IV

62. Other maintenance medication after a stroke
Plain old fashion Aspirin. Usually 80mg/day = 1 tiny aspirin is sufficient
Plavix – taken P.O.
CANNOT take aspirin and Plavix together, will make blood too thin, possible hemorrhage can occur

63. Epidural space Epi – means upon or over
Dura – that outer most covering of the brain
You have a large amount of blood in the outer most covering of the brain, if injured, this pushes on the skull = pain and lots of pressure

64. Epidural Hematoma

66. Dura Mater

67. Dura Mater Removed and Subdural Hematoma revealed

68. Parkinson’s Disease Progressive condition
Tremors, rigidity of limbs and joints, slow movement, impaired balance
Neurotransmitter – dopamine, cell death causes faulty production of dopamine
TREATMENT – dopamine replacement

69. Parkinsons Disease Rigidity Tremors Slowness
Meds include L-dopa/levadopa and Sinemet

70. Alzheimer’s
There is an unusual protein build up in and around neurons in the 2 parts of the brain that control memory which is also known as cerebral cortex degeneration
When neurons die, people loose their capacity to remember and their ability to do everyday tasks
Physical damage to brain and other parts of the CNS can also kill or disable neurons

71. Medication used to treat Alzheimer’s
Aricept

73. Cerebral Palsy (CP)
Is an “umbrella” term for a group of nonprogressive, but often changing, motor impairment syndromes secondary to lesions or abnormalities of the brain arising in the early stages of development
The primary cause of CP is not always trauma or stress at birth or hypoxia
Most people think CP always causes seizures or developmental delay, not true

74. Cerebral Palsy
CP is classified by the extremities involved and the type of neurological dysfunction. CP causes different things to be affected:
Spastic CP
Hypotonic CP – flaccid tone
Dystonic CP – stiff and rigid body with intermittent jerking
Athetotic CP – snake-like spasms in upper body

75. Epilepsy
A recurrent jerking and spasming periodic sudden attacks of the cerebrum, marked by sudden, brief attacks of altered consciousness, motor activity or sensory phenomena.
Convulsive seizures are the most common form of attack.
Not all recurrent seizure patterns are d/t epilepsy, can be d/t gliomas or other tumors or brain abnormalities or fever

76. Types of seizures Simple Partial Seizure Partial Seizure
Complex Partial Seizure
Tonic Clonic or Grand Mal or Generalized
Absence Seizure or Petit mal

77. Status Epilepticus
A series of Grand Mal seizures that may occur when the pt is awake and active or during sleep and consciousness is not completely regained between attacks
This means the brain is continually firing, this becomes a medical emergency
Pt may have to be put in a Phenobarbitol coma to make seizures stop

78. Maintenance Meds for Epilepsy
Depakote
Phenobarbitol
Trileptal
Tegretol
Neurontin
There are others but these are seen most

79. Tumors - Glioma
Tumors can arise from the tissues that surround and protect the brain, there are tumors called:
gliomas, astrocytomas, neuroblastomas
Some tumors are malignant and others are benign
Benign tumors can cause pressure in areas that can cause one’s death

80. Imaging of the brain CT Scan (computed tomography) -
Provides multiple 3-D x-rays and pictures from different angles simultaneously. Pt may need sedation. A mild “whirring” sound is heard

81. CT Scan
A computed tomography (CT) scan uses x-rays to make detailed pictures of structures inside of the body.
The CT scanner sends X-rays through the body area being studied. Each rotation of the scanner takes less than a second and provides a picture of a thin slice of the organ or area.
All of the pictures are saved as a group on a computer. They also can be printed.

82. CT Scan
An iodine dye (contrast) is often used to make structures and organs easier to see on the CT pictures. The dye may be used to check blood flow, find tumors, and look for other problems. For some types of CT scans you drink the dye. CT pictures may be taken before and after the dye is used.
A CT scan can be used to study all parts of your body, such as the chest, belly, pelvis, or an arm or leg. It can take pictures of body organs.
It also can study blood vessels, bones, and the spinal cord.

83. MRI structural.gif Magnetic resonance imaging.
MRI gives more views in 2 and 3-D of the brain without having to use dye or x-rays

84. PET Scan Positron Emission Tomography
Nuclear Medicine-type test which means radioactive particles known as “tracers” are used
Pt is given an injection of a sugar compound tagged to a tracer and the brain is scanned to detect areas of alteration

85. Cranial Nerves
12 pairs
These are numbered according to their connection with the brain
They are numbered using Roman Numerals

86. Cranial Nerves to know Nerve # #1 olfactory – smell
#2 optic nerve – see
#7 facial nerve – facial expression muscles
#8 auditory nerve – hearing
#10 Vagus nerve – longest cranial nerve, supplies most of the nerves in the thoracic and abdominal cavities and the larynx and pharynx, will make you faint if you bear down d/t a decrease in HR

87. # 10 – Vagus Nerve
Vagus nerve is a mixed nerve having sensory and motor affects
If a patient is having supraventricular tachycardia, they can bear down as in a bowel movement, and slow the heart rate down
Seizure activity can be stopped by stimulating the vagal nerve through a vagal nerve stimulator

88. Disorders involving the cranial nerves
Bell’s Palsy – a facial paralysis caused by damage to the 7th cranial nerve
It’s usually paralyzed on one side of the face
Distortion of the face d/t one-sided paralysis

89. Neuralgia (nu-RAL-je-ah)
Severe spasmodic, nerve pain
Affects the 5th cranial nerve
The pain involved comes faster and harder
Treatment includes microsurgery or high-frequency current

90. (EEG) Electroencephalogram
Instrument that detects brain waves

91. EEG Reading

92. Quadraplegic
Paralysis of all 4 extremities

93. Paraplegic
Paralysis of the lower portion of the body and lower legs

94. Aging of the nervous system
As we grow older, the brain begins to decrease in size and weight due to loss of cells
These losses cause a decrease in the synapses and neurotransmitters
The speed of processing information decreases, especially for recent events

95. The End