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Flashcards in Problem 9 Deck (38)
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1

Tumor

a mass of cells whose growth is uncontrolled and serves no useful function

--> damages by infiltration + compression

2

Malignant tumor

harmful tumor / cancerous

--> no distinct border between mass of tumor cells + surrounding tissue (hard to remove)

3

Benign tumor

harmless tumor / encapsulated

--> distinct border between the mass of tumor cells + surrounding tissue (easy to remove)

4

Metastases

shed cells which then travel through the blood stream

--> serve as seeds for the growth of new tumors in different locations of the body

=> form of malignant tumor

5

Glioma

Brain tumors that arise from glial cells and infiltrate brain substance

--> originate from transformations of neural stem cells

6

Seizure

period of sudden excessive activity of cerebral neurons

--> nearly all genes that play a role in seizures control ion channels

--> cause damage to the hippocampus due to an excessive loss of glutamate

7

Convulsion

uncontrollable activity of the muscles

8

Generalized seizures

widespread, involve most of the brain

9

Absence seizure
(Petit mal)

type of generalized seizure, very brief seizures - hard to detect

ex.: kind das in die ferne starrt

10

Grand mal

type of generalized seizure that occurs in 2 stages

1. Tonic phase: all muscles contract forcefully which leads to unconsciousness of the person

2. Clonic phase: muscles begin trembling, jerk convulsively --> after some time they relax

11

Partial seizures

source of irritation is a specific brain region

12

Simple partial seizures

cause a change in consciousness

13

Complex partial Seizures

cause a loss of consciousness

14

Stroke

derives from a variety of vascular disorders

15

Hemorrhagic stroke
(Cerebral Hemorrhage)

caused by bleeding within the brain

--> blood seeps in surrounding blood tissue, damaging it

16

Ischemic Stroke

- block a blood vessel and obstruct the blood flow

--> caused by thrombi and emboli

17

Thrombus

blood clot that forms in blood vessels

18

Embolus

formed in one part of the vascular system,

--> carried through blood stream + passes through too small arteries

=> obstructs blood flow

19

Ischemic Stroke
(Process)

1. Interruption of the blood supply to a specific brain region leads to a depletion of oxygen and glucose

2. Sodium potassium pump stops functioning

3. Neural membranes become depolarized
--> excessive release of glutamate

4. Activation of glutamate receptors leads to
--> increase of Na+ ions
--> absorption of huge amounts of Ca+

=> presence of Na+ and Ca+ = toxic

5. Intracellular Na+ causes cell to absorb water (cells swell)

6. Swell --> activates microglia which become phagocytic (Fresszelle)

7. microglia destroys injured cells

8. Damaged mitochondria produces free radicals

20

Penetrating Brain Injury/Open Head Injury

Dura mater + skull is breached/injured

21

Closed head injury

Skull + dura mater remain intact

22

Coup

"Blow"

The injury to the brain that occurs in the area of direct impact

23

Contrecoup

"Counterblow"

The pressure of the blow might push the brain against the opposite side, causing an additional bruise

24

Parkinsons disease

- Degenerative disorder

-->deficiency of automatic, habitual responses due to damage to basal ganglia

--> patients have almost no nigrostriatal dopaminergic neurons (surviving neurons contain lewy bodies)


25

Symptoms of Parkinson's

- resting tremor
- postural instability
- muscular rigidity

26

Akinesa

difficulty in initiating movement

--> decreased activity of the supplementary Motor area

27

Where do tremors come from ?

result from abnormalities in

--> pons
--> cerebellum
--> midbrain
--> thalamus

28

Causes of Parkinsons

--> mutation of a gene on chromosome 6 that produces a gene called parkin

this mutation permits a high level of defective proteins to accumulate in dopaminergic system + damage its neurons

--> mutation of a gene that produces a-synuclein

this mutation produces a toxic gain of function

29

Parkin

gene, transfers defective proteins to proteasomes which in turn destroy these defective proteins

30

Dementia

acquired and persistent syndrome of intellectual impairment