The initial change in heart rate at the onset of exercise is due to _________.
A) sympathetic stimulation.
B) the withdrawal of parasympathetic inhibition.
C) overfilling of the ventricles.
D) stretching of the cardiac muscle fibers in response to increased venous return.
B) the withdrawal of parasympathetic inhibition.
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Lymphocyte activation can occur in several ways. However, in all cases
A. helper T cells are activated first and they then stimulate other cells. B. antigen-presenting cells process the antigen and present it to the lymphocytes. C. antigens must be able to recognize the lymphocytes. D. lymphocytes must recognize an antigen. E. cytokines released by the antigen stimulate the lymphocyte response.
Define erythropoiesis
What will be an ideal response?
Hemophilia is a(n)
A) example of dominance. B) example of codominance. C) polygenic trait. D) recessive trait. E) sex-linked trait.
What mechanism causes the movement water and solutes through the filtration membrane in the nephron?
A) Simple diffusion B) Hydrostatic pressure C) Osmotic pressure D) Pinocytosis