The aortic arches start as five pairs of symmetrical arteries connecting the heart with the dorsal aorta, and then undergo a significant remodelling to form the final asymmetrical structure of the great arteries, with the 3rd pair of arteries contributing to the semilunar valves, possess smooth muscle of mesodermal origin.
42.
Somewhat semilunar in shape, its convex edge is continuous with the white substance of the cerebellum, while its thin concave margin is apparently free; in reality, however, it is continuous with the epithelium of the ventricle, which is prolonged downward from the posterior medullary velum to the taeniae.
43.
He picked up on Darwin s concept of rudimentary organs such as listed in the " The Descent of Man " : the muscles of the ear, wisdom teeth, the appendix, the coccyx ( tail bone ), body hair, and the semilunar fold in the corner of the eye.
44.
He gave his name to Hey's amputation ( a tarso-metatarsal amputation ), Hey's internal derangement ( dislocation of the semilunar cartilages of the knee joint ), Hey's ligament ( the semilunar lateral margin ( falciform margin ) of the fossa ovalis ), and Hey's saw, used in skull surgery.
45.
He gave his name to Hey's amputation ( a tarso-metatarsal amputation ), Hey's internal derangement ( dislocation of the semilunar cartilages of the knee joint ), Hey's ligament ( the semilunar lateral margin ( falciform margin ) of the fossa ovalis ), and Hey's saw, used in skull surgery.
46.
At this point, some blood of the " previous cycle's systole " is " still flowing out " of the ventricles through the semilunar valves, due to the inertia of the moving blood column, which overcomes the " higher pressure " in the aorta / pulmonary trunk with respect to the pressure in the ventricles.
47.
Vesalius describes the organs of the body in great detail by commenting " on the variable strength of the attachment of the pleura to the thoracic walls, the strong attachment of the pericardium to the diaphragm, the shape and orientation of the ventricles of the heart, and the description of the semilunar valves . " He closes each book with a chapter on the correct way to dissect the heart and the brain respectively.
48.
On the anterior surface of the petrous portion of the temporal bone are seen the eminence caused by the projection of the superior semicircular canal; in front of and a little lateral to this a depression corresponding to the roof of the tympanic cavity; the groove leading to the hiatus of the facial canal, for the transmission of the greater superficial petrosal nerve and the petrosal branch of the middle meningeal artery; beneath it, the smaller groove, for the passage of the lesser superficial petrosal nerve; and, near the apex of the bone, the depression for the semilunar ganglion and the orifice of the carotid canal.
