Problem 9

Question 1

Alzheimer

Answer 1

Most common form of dementia in the elderly. Likelihood increase with age, about 10% of people over 65 suffer from Alzheimer

Question 2

Three defining characteristics of Alzheimer

Answer 2

1. Neurofibrillary tangles: are threadlike tangles of protein in the neural cytoplasm
2. Amyloid plaques: are clumps of scar tissues composed of degenerating neurons and aggregates of a protein called beta-amyloid which is normally only present in small amounts.
3. Neuron loss:

Question 3

Microbleeds (Alzheimer)

Answer 3

recently discovered (in the brain of Alzheimer patients) dot like lesions which are a result of microhemorrhages

Question 4

Where does Alzheimer cause damage?

Answer 4

o Although neurofibrillary tangles, amyloid plaques and neuron loss tend to occur throughout the whole brain they are more prevalent in the medial temporal lobe structures such as the entorhinal cortex, amygdala, and hippocampus which are all involved in various memory
o They are also prevalent in the inferior temporal cortex, posterior parietal cortex and prefrontal cortex – all areas that mediate complex cognitive functions

Question 5

Alzheimer Genetic component

Answer 5

People with an Alzheimer’s victim in their immediate family are twice as likely to be stricken by the disease if they survive to old age
o Gene involved in Alzheimer: chromosome 21 that codes for the protein apolipoprotein E (APOE), increases probability for Alzheimer by approximately 50%. APOE leads to development of amyloid plaques

Question 6

Misfolding of proteins (possible alternative cause for Alzheimer)

Answer 6

o Could also be caused by a misfolding of the beta amyloid protein which leads to a chain reaction of more misfolding of beta amyloid proteins what leads to aggregation of amyloid plaques that are characteristic of Alzheimer disease

Question 7

Parkinson disease

Answer 7

o is a movement disorder of middle and old age that affects 1 percent of the population of the age over 55
o Causes of Parkinson: faulty DNA, brain infections, strokes, tumors, traumatic brain injury, and neurotoxins have all been implicated in specific cases

Question 8

Symptoms of Alzheimer

Answer 8

1. Early stage: selective decline in memory deficits in attention, and personality changes
2. Intermediate stage: confusion, irritability, anxiety and deterioration of speech
3. Advanced stage: the patient deteriorates to the point that even simple responses such as swallowing and bladder control are difficult

Question 9

Symptoms of Parkinson

Answer 9

o Initial symptoms: no more than slight stiffness or tremor of the fingers, but the increase with age.
o Full blown symptoms: heavy tremor that occurs during inactivity but not during voluntary movement or sleep, muscular rigidity, difficulty initiating movement and mask like face, pain and depression often develop before the motor symptoms occur can also cause Parkinson dementia
o Problems with initiating, changing and stopping behaviour (walking)
o “thinking people trapped in a body they can’t control

Question 10

Where does Parkinson causes damage?

Answer 10

o Is associated with widespread degeneration but is particular severe in the substantia nigra, which is the midbrain nucleus whose neurons project via the nigrostriatal pathway to the striatum of the basal ganglia. So, patients with long term Parkinson have less dopamine in their substantia nigra and striatum
ewy bodies: clumps of proteins in the surviving substantia nigra

Question 11

Dementia

Answer 11

o Brain degenerative disease which damages especially the memory brain functions

Question 12

Infarct

Answer 12

the area of dead or dying tissues produced by a stroke

Question 13

Penumbra

Answer 13

the tissue around the infarct which will die or recover in the following days

Question 14

Cerebral Hemorrhage (Stroke)

Answer 14

(bleeding in the brain) occurs when a cerebral blood vessel ruptures and blood seeps into the surrounding neural tissue and putting pressure on it what leads to damage in the tissue
 Aneurysm: a balloon like dilation that forms in the wall of an artery at a point where the elasticity of the artery wall is defective (causes Hemmorrhage) can be congenital (present at birth)

Question 15

Cerebral Ischemia

Answer 15

 Thrombosis: a plug called thrombus if formed and blocks blood flow at the site of its formation (composed of blood clot, fat, oil, an air bubble, tumor cells or any combination thereof)
 Embolism: Same principle as Thrombosis just that the so-called plug embolus is carried by blood from a larger vessel where it was produced to a smaller whet it block the small vessel
 Arteriosclerosis: the walls of the blood vessels thicken and the channels narrow, usually as a result of fat deposits, this narrowing can eventually lead to a complete closure of the vessel

Question 16

Damage (Stroke)

Answer 16

Damage is mostly in the hippocampus

General damage can very from little to large

Question 17

excitotoxic lesion

Answer 17

Blood deprived neurons become overactive and release a lot of glutamate, which overactivates glutamate receptors in the membranes of postsynaptic neurons (NMDA receptors). That leads to large number of Ca2+ and Na+ ions in the postsynaptic cell which leads to an excessive release of new glutamate and they trigger a sequence of internal reactions that ultimately kill the postsynaptic neuron

Question 18

free radicals

Answer 18

damaged mitochondria produce free radicals. They are extremely toxic and destroy nuclei acids, proteins and fatty acids

Question 19

Symptoms of a Stroke

Answer 19

amnesia, aphasia (language difficulties), paralysis and coma

Question 20

Contusions (Closed head injuries)

Answer 20

Closed-head injuries that involve damage to cerebral circulatory system.

• Damage produces internal hemorrhaging, which results in hematoma (= bruise).
• It occurs when brain slams against inside of the skull.
• Countercoup injuries – Contusions occur on side of brain opposite to side struck because blow causes brain to strike inside of skull on other side of head.

Question 21

Concussion (Closed head injuries)

Answer 21

Diagnosis when there is disturbance of consciousness after blow to head without evidence of contusion or other damage.

• Cognitive, motor and neurological effects last many years.
• Punch-drunk syndrome – Dementia (= intellectual deterioration) and cerebral scarring seen in individuals who experience repeated concussions (boxers).

Question 22

Meningiomas (20%) (Tumor)

Answer 22

– Tumors that grow between the meninges (= membranes covering CNS). It originates mostly in dura mater which is found between two cerebral hemispheres.

• Most begining of all brain tumors – It can be removed surgically with little risk of further growth.
• Since these are often multiple and disturb brain function because of the pressure they put on it (seizures).
• Encapsulated tumor – It grows within its own membrane.

Question 23

Metastatic tumor

Answer 23

One that grow from infiltrating cells and are carried to brain by bloodstream from some other region of the body. - Metastasis – Transfer of disease from one organ to another not directly connected to it. - Usually multiple so the treatment is hard.

Question 24

Apotosis

Answer 24

Apoptosis of a neuron proceeds gradually, starting with shrinkage of the cell body. Then, as parts of the neuron die, the resulting debris is packaged in vesicles. No inflammation so no damage to other cells

Question 25

Necrosis

Answer 25

the damaged neuron swells and breaks apart, beginning in the axons and dendrites and ending in the cell body. This fragmentation leads to inflammation, which can damage other cells in the vicinity