WEEK 10 CRANIAL VARIATION

Question 1

What is significant about fontanelles?

Answer 1

As the brain grows at much faster rate than bones, the fontanelles allow for plasticity of the brain growth

Question 2

What is plagiocephaly?

Answer 2

When baby spends too much time on back (flat head)

Question 3

What is anthropometry?

Answer 3

Measurements of the body and head (craniometry)

• they took measurements of the cranium and phenotipic traits (skin colour) and from this tried to class different races
• Thought white people were the perfect race and others were deformed versions (racist)

Question 4

What is the cephalic index?

Answer 4

Ratio of the maximum width of head multiplied by 100 and divided by the maximum length

Question 5

What could be found from cephalic index?

Answer 5

Classification of types of head shapes ; dolichocephaly , mesocephaly, brachcephaly (rounded head)

Question 6

Where is brachyocephaly more frequent?

Answer 6

In cold environments (Bergman and Allen rules), maintaining heat, larger body so larger head

Question 7

A. farensis anatomy (Australopithecus):

Answer 7

350-500cm3 cranial capacity, low forehead, projecting face (prognathism),sexual dimorphism

Question 8

What is prognathic face?

Answer 8

Projection of face well in front of braincase

Question 9

What is orthognathism?

Answer 9

Flat face (opposite of prognathism)

Question 10

Paranthropus anatomy:

Answer 10

Sagittal crest -only male feature (also found in male great apes and orangutang), crainial capacity 410cm3, large zgomatic arch, prominent brow ridges

Question 11

What is the sagittal crest for?

Answer 11

Attachment of masticatiory muscles; temporalis and masseter

Question 12

Homo errectus anatomy:

Answer 12

Large browridges, projecting nuchal turus, braincase long and low, wider at the base

Question 13

What is another name for the browridge?

Answer 13

Supraorbital torus

Question 14

What did the decrease of browridge help?

Answer 14

Human communication (possibly sexually)

Question 15

What function could browridge have?

Answer 15

Possible communication signals and also maybe genetic drift (no function, just there from random changes)

Question 16

Neanderthal morphology compared to modern humans:

Answer 16

• lack of chin
• larger cranial capacity than modern humans
• larger nose
• more prominent brow ridge

Question 17

Modern humans morphology compared to neanderthals:

Answer 17

• presence of chin
• smaller braincase
• smaller nose
• higher forehead

Question 18

What are the 3 possible reasons for presence of chin?

Answer 18

Possible change in diet, genetic drift (no function), importance in feeding-maintaining resistance to loads

Question 19

What is the neanderthal nose paradox?

Answer 19

They have a large nose(normally facilitates heat dissipation in hot environment) but come from a cold environment which goes against tradition

Question 20

Why do neanderthals have large nose?

Answer 20

Probably due to highly energetic lifestlye so increases of air needed by lungs, high food intake, and as a result, a large nose to allow for increased air capacity (greater volume of air for body) - not a special adaptation to cold

Question 21

Does the protruding face of neanderthal have a function?

Answer 21

NO

Question 22

Why did neanderthals have such a larger brain size than humans and does this relate to intelligence?

Answer 22

Their body was large and so was their brain so large brain and large body don’t correlate with intelligence. Our brain is much larger than our body. Also sutures (encephalisation determines intelligence but we can;t measure that in neanrerthals)

Question 23

Why does the head grow after birth?

Answer 23

Bc it wouln’t pass through the pelvic inlet of mother.