Answer to Question 1
Postmortem studies and brain dissections have been done for centuries. Even in the twenty-first century, researchers often use dissection to study the relation between the brain and behavior. In the ideal case, studies start during the lifetime of a person. Researchers observe and document the behavior of people who show signs of brain damage while they are alive. Later, after the patients die, the researchers examine the patients' brains for lesionsareas where body tissue has been damaged, such as from injury or disease. Then the researchers infer that the lesioned locations may be related to the behavior that was affected. The case of Phineas Gage was explored through these methods.
Answer to Question 2
An ischemic stroke usually occurs when a buildup of fatty tissue occurs in blood vessels over a period of years, and a piece of this tissue breaks off and gets lodged in arteries of the brain. Ischemic strokes can be treated by clot-busting drugs. The second kind of stroke, a hemorrhagic stroke, occurs when a blood vessel in the brain suddenly breaks. Blood then spills into sur- rounding tissue. As the blood spills over, brain cells in the affected areas begin to die. This death is either from the lack of oxygen and nutrients or from the rupture of the vessel and the sudden spilling of blood. The prognosis for stroke victims depends on the type and severity of damage. Symptoms of stroke appear immediately on the occurrence of stroke.
The image formed on the retina is inverted. The brain rights the image as part of the interpretation
Sheep Brain Dissection
Contact dermatitis resulting from poison ivy.
Summary of major brain structures.
Brain Areas Involved in Memory
An example of nucleotide excision repair. UVR proteins remove UV-induced damage from DNA strands