Chapter 4 Part II

What are the five key causes of brain damage

Tumors

Infections

Exposure to toxic substances and radiation

Degenerative diseases

Close head injuries

Exposure to toxic substances and radiation

Degenerative diseases

Close head injuries

Lead poisoning

Alzeimers

A brain injury caused by impact to the head that does not crack the skull or puncture the brain

Three facts about plasticity after brain damage

Almost all survivors of brain damage show behavioural recovery to some degree.

Some recovery relies on the growth of new branches of axons and dendrites.

Babies and young children recover the quickest 

What are the two key types of strokes 

Ischemia 

Hemorrhages 

Ischemia

Hemmorage

An obstruction. The most common type of stroke, where neurons lose their glucose and oxygen supply

A rupture. Neurons are flooded with excess blood, calcium, oxygen, and other chemicals

Two negative after-effects of strokes 

Edema: fluid build-up—if someone has a stroke early on, that can increase the risk of a future stroke.

Disruption of the sodium–potassium pump leading to the accumulation of potassium ions inside neurons, causing excessive depolorization

Five-central immediate post-stroke treatments

Tissue plasminogen activator (tPA)

Blocking glutamine synapses

Blocking calcium entry

Cooling the brain

Cannabinoids

Acronym for spotting a stroke

BEFAST

B - Balance

E - Eyes

F - Face

A - Arms

S - Speech

T - Time

Three reasons tissue doesn’t grown back in the CNS

Scar tissue makes a mechanical barrier to axon growth

Neurons on the two sides of the cut pull apart.

Glia cells that react to CNS damage release chemicals that inhibit axon growth

Axon collateral sprouts

New branches formed by other non-damaged axons that attach to vacant receptors.

Neurotrophins

Proteins that attract collateral sprouts to the desired area

Cortical reorganization

The brain's ability to adapt by changing the functional role of its neural pathways

EX. If you touch the face of someone who has lost an arm, they may feel that arm, because the cortex face area is close to the hand area, and parts of the face area move into the area of the former arm