Arrange the following components according to the order in which they appear on/within the skin, starting with the first at the top. keratinocytes
fat
hair shaft
muscles
blood vessels

To avoid whiplash, the center of the headrest must be your ears.

[120 total points] (public health) in one of the largest human experiments ever conducted, in 1954 a randomized controlled trial was run to see whether a vaccine developed by a doctor named jonas salk was effective in preventing paralytic polio. a total of 401,974 children (ages 6–9), chosen to be representative of those who might be susceptible to the disease, were randomized to two groups: 200,745 children (the control group c) were injected with a harmless saline solution (a placebo) and the other 201,229 children (the treatment group t) were injected with salk’s vaccine. what was the point of giving saline solution to the children who didn’t get the vaccine? explain briefly.

What else happens in your cardiovascular system in response to your sympathetic nervous system? why might your blood vessels need to expand to accommodate this?