Anatomy Laboratory Writeups
Essay by emmck4 • May 27, 2015 • Study Guide • 1,121 Words (5 Pages) • 1,273 Views
BMS2011 Practical Class Activities - Weeks 1-5
Week 1
Part 1.
Part 2.
Part 3. Based on your observations from Parts 1 and 2, in the section below compare and contrast the skeletal anatomy of humans with the other vertebrates:
A) Axial Skeleton: what similarities or differences do you see in how the axial skeleton is organised in humans relative to the other vertebrates?
Similarities | Differences |
5 vertebral segments - cervical, thoracic, lumbar, sacral and coccyx | Inferior Foramen Magnum as opposed to Posterior Foramen Magnum in other vertebrates |
All have seven cervical vertebra | Human orbits at front, above nasal aperture as opposed to at the sides and being posterior to nasal aperture |
Scapulae | Humans have minimal nasal and mid-face projection whereas other vertebra have significant nasal and mid-face projection |
Humans have a “U”-shaped mandible (no midline separation) whereas other vertebrates have “V”-shaped mandible (separates at midline) | |
The human pelvis is more broad and short as opposed to the longer, narrower pelvis of other vertebrates. | |
Humans have a different number of vertebral numbers as opposed to other vertebrates. | |
Humans have an upright sternum as opposed to the downward sternum of other vertebrates. |
Consider the range of activities these animals engage in. How does the anatomy of the axial skeleton relate to function?
The Foramen Magnum in humans is anteriorly positioned and is inferiorly orientated (opening directly downward), whereas in other vertebrates such as the dog, the Foramen Magnum is posteriorly positioned and projects more backward and downward as opposed to just downward. The difference in position and orientation of the foramen magnum reflects differences in habitual body posture and mode of locomotion. Because humans are bipedal with a cranium that rests directly atop the vertebral column the anterior positioning of the foramen magnum is necessary to balance the mass of the head and the inferior orientation is required to allow for the upright sternum of humans. In contrast to this, the quadrupedal vertebrates such as the dog have a cranium that projects anterior of the vertebral column, therefore the positioning and orientation of the foramen magnum must be posterior.
Difference in flexibility and strength of spine *****
B. Appendicular Skeleton: In what ways are the limbs proportioned or adapted in humans relative to other vertebrates?
Humans have longer hindlimbs than forelimbs whereas vertebrates that are non-human primates such as apes and gorilla have longer forelimbs than hindlimbs.
Week 4:
Part 1: Masticatory Muscles
Which masticatory muscles are not visible in this lateral view?
Medial pterygoid and lateral pterygoid. They would be covered by the temporalis and masseter.
What cranial nerve (CN) innervates all these muscles of mastication?
The trigeminal nerve which is the fifth cranial nerve (CN V).
Describe the origin, insertion and pathway of the temporalis and masseter muscles.
Temporalis:
The temporalis muscle originates from the temporal fossa and the deep surfaces of the temporal fascia and its insertion point is onto the coronoid process of the mandible. This pathway it follows is passing medially to the zygomatic arch.
Masseter:
The masseter consists of two heads, the superficial and deep head. the superficial head originates from the zygomatic process of the maxilla and the anterior two-thirds of the inferior border of the zygomatic arch. This head is inserted into the angle of the mandible and inferior half of the lateral surface of the ramus of the mandible. The fibres pass inferiorly and posteriorly from its origination point to its insertion point.
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