Head Trends Flashcards
What is the cranium?
The part of the skull that encloses the brain and protects it from injury.
What is the Brow Ridge?
Well developed bony ridges above and around the eyes, the protect the eyes from powerful forces developed during chewing and biting.
(Eyebrow Area)
What are the Canines?
Large pointed teeth used for holding and killing prey, or as aggressive display.
What is the Zygomatic arch?
Important muscles used for chewing and articulation of the mandible. They are attached to the mandible and skull.
What is the Nuchal Crest?
Extension of the skull to which the the neck muscles attach onto. These muscles position, move and stabilize the head and the cervical vertebrae.
What is the Sagittal Crest?
A ridge of bone running lengthwise along the top of the head. The jaw muscles are attached to it.
What are molars?
Large, flat teeth that shear and crush food during chewing.
What is the Foreman Magnum?
A large hole at the base of the skull through which the spinal cord and spinal cord arteries enter the skull.
What is the diastema?
Space between the teeth for large canine teeth to fir into so that the other teeth can come together.
What is the Prognathism?
When the lower part of the face projects forward.
Shape of Teeth Trend?
Chimps have a more robust (strong), rectangular shaped jaw. The post canine teeth are parallel. Modern humans have a parabolic, wider dental arcade with smaller teeth and less robust mandibles. This is because of the diet difference from tough vegetation to soft meat and cooked food.
Chin and Simian shelf trend?
Apes have a pronounced “shelf” behind the chin region (simian shelf) but lack any protuberance forward of the chin. Human mandibles are rounded and have a protruding chin but lack the shelf.
Prognathism Trend?
The lower facial skeleton projects forward in chimpanzees. Human faces are less prognathic or show none.
Sagittal Crest Trend?
Chimp: Present
Human: Absent
The substantial jaw muscles needed to move the large robust mandible are attached here. This is not necessary in humans due to the difference in diet.
Canines Trend?
Chimps: Larger with associated diastema
Humans: Reduced
Canines are used by chimpanzees to display dominance and aggression, while humans use less aggression displays. There is also less sexual dimorphism in humans.
