Midterm COPY Flashcards
What is Necrosis?
Premature cell death where cells rupture, spilling their contents into the exracellular space
Which type of cell death results in an inflammatory response, which can lead to further distress?
Necrosis
What is Apoptosis?
Programmed cell death, cells are dismantled into membrane-bound vesicles
‘Cell Suicide’
What is Acquired Brain Injury (ABI)?
Any brain injury that occurs after birth and is not hereditary, congenital, or degenerative
What are three possible causes of ABI?
- Lack of Oxygen
- Drug toxicity
- Poisoning
What is Tramautic Brain Injury (TBI)?
A sub-category of ABI which includes only damage to brain caused by an external mechanical force
What are three possible causes of TBI?
- Concussion (blow to head)
- Blast Injury
- Penetrating Trauma
What is a major cause of death and disability across the world and the number one cause of death in children in youth?
Traumatic Brain Injury
How does a TBI occur?
When a blow to the head is sufficiently forceful the CSF is unable to protect the brain resulting in a collision of the brain with the skull
What is a Contrecoup TBI?
When the brain collides with the skull on the opposite side of impact
What is a Coup TBI?
When the brain collides with the skull on the same side of impact
TBI severity depends mostly on degree of _______ force.
How does this occur and what can result from it?
Rotational Force
Skull rotates and brain is too slow to catch up
Can result in sheared corpus callosum or torn bridging veins
What happens at the site of contact with skull in a TBI? (The Primary Phase)
Swelling (Edema) and Bleeding (Hematoma) which can lead to Inceased Intracranial Pressure (ICP)
Necrotic Death - result of direct impact leading to rupturing of cells
What is Generalized Damage in TBI?
Diffuse injury throughout the brain as a result of white and grey matter having different densities and shifting during impact
How does Diffuse Axonal Injury (DAI) occur?
Twisting and shearing forces cause axons to be torn from cell bodies (axotomy)
What is the Energy Crisis faced in TBI?
Disrupted blood flow leads to:
Lack of Oxygen (Hypoxia)
Lack of Glucose (Hypoglicemia)
What is Excitotoxicity and how does it happen in TBI?
Excess Glutamate Release due to rupturing cells (necrosis)
How does Excitotoxicty effect neurons?
Glu continously binds to and activates post-synaptic receptors which causes neurons to depolarize and fire leading to influx of Ca2+ and K+
Ca2+ (Calcium) ends up sequestered in mitochondira which disrupts production of ATP and increased production of Reactive Oxygen Species (ROS)
ATP is required to make and use _______
_______ is required to make ATP
Glucose
Glucose
In TBI there is a lack of glucose as a result of decreased _______ flow and _______ production
Blood
ATP
Hypoglycemia in TBI leads to _______ deficits as neuronal activity _______ after over-excitation
Cognitive
Decreases
Lack of Oxygen (Hypoxia) in TBI as a result of decreased blood flow causes a switch to _______ glucose metabolism which can lead to overproduction of _______ _______ (acidosis) which damages BBB
Anaerobic
Lactic Acid
What type of cytokines do microglial secrete?
Pro-inflammatory Cytokines
What is ROS and what causes it?
Reactive Oxygen Species which can lead to DNA damage, protein admage and lipid abnormalities
ROS levels increase during times of environmental stress