A normal, healthy animal never contracts the flexor muscles and the extensor muscles of the same leg at the same time. Why not?
a. When the interneuron sends excitatory messages to one, inhibitory messages go to the other.
b. Both muscles are mechanically connected in a way that makes it impossible for both to contract at the same time.
c. Such coordination is learned through prenatal movement.
d. Both muscles are controlled by branches of the same axon.
Question 2
What is one reason why animals with a lesion in the lateral hypothalamus eat so little?
a. They are constantly active and over-responsive to sensory stimuli.
b. All the food they eat is immediately converted into fat storage.
c. They experience a decreased cortical response to the smell and sight of food.
d. They have low levels of blood sugar.
Traditional animal phylogeny based on body plans.
Muscles of the Body, Posterior View
A normal pregnancy.
The Major Cleavage Patterns of Animal Embryos
Muscles of the posterior lower leg.
Major muscles of the human musculoskeletal system