BrainstemThe brainstem (or brain stem) is the stalk-like part of the brain that interconnects the cerebrum and diencephalon with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is continuous with the thalamus of the diencephalon through the tentorial notch. The brainstem is very small, making up around only 2.6 percent of the brain's total weight. It has the critical roles of regulating cardiac, and respiratory function, helping to control heart rate and breathing rate.
Superior orbital fissureThe superior orbital fissure is a foramen or cleft of the skull between the lesser and greater wings of the sphenoid bone. It gives passage to multiple structures, including the oculomotor nerve, trochlear nerve, ophthalmic nerve, abducens nerve, ophthalmic veins, and sympathetic fibres from the cavernous plexus. The superior orbital fissure is usually 22 mm wide in adults, and is much larger medially. Its boundaries are formed by the (caudal surface of the) lesser wing of the sphenoid bone, and (medial border of the) greater wing of the sphenoid bone.
Ptosis (eyelid)Ptosis, also known as blepharoptosis, is a drooping or falling of the upper eyelid. This condition is sometimes called "lazy eye," but that term normally refers to the condition amblyopia. If severe enough and left untreated, the drooping eyelid can cause other conditions, such as amblyopia or astigmatism, so it is especially important to treat the disorder in children before it can interfere with vision development. The term is from Greek πτῶσις 'fall, falling'.
