1 Gray matter located on the surface of the brain is called cortex (e.g., cortex of the cerebral hemispheres, cortex of the cerebellum). 2  Masses of gray matter located deeper in the brain are called nuclei .(e.g., brainstem nuclei, nuclei of the thalamus).yramidal cells are the efferent (long-axon) cells of the cerebral cortex. The name refers to the shape of the cell body as seen in standard sections perpendicular to the cortical surface. The apex of the pyramid points toward the cortical surface.
Panic attacks are periods of intense fear or apprehension of sudden onset accompanied by at least four or more bodily or cognitive symptoms (such as heart palpitations, dizziness, shortness of breath, or feelings of unreality) and of variable duration from minutes to hours.anic attacks are periods of intense fear or apprehension of sudden onset accompanied by at least four or more bodily or cognitive symptoms (such as heart palpitations, dizziness, shortness of breath, or feelings of unreality) and of variable duration from minutes to hours.
It's well known that anxiety can cause heart palpitations, and it's believed that the main cause may be an over-awareness of one's own heart, combined with surges of adrenaline that may occur at random in those with anxiety. These types of palpitations often trigger panic attacks. Panic attacks themselves can also cause palpitations. During a panic attack, two things occur that lead to rapid heartbeat: First, the sympathetic nervous system is on high alert, which may lead to a rapid increase in heart rate. Second, during panic attacks, people often have a tendency to hyperventilate.