Homeostasis or the source of body heat
During the sympathetic reaction the blood flow is augmented
to the skeletal muscles and brain. Then the blood flow will diminished to the
bowel which may led to constipation. The person will perspire excessively and
may lead to dehydration which eventually may constrain bowel function.
Answer:
The binding of chemical messengers to receptors often results in a shape change, which affects receptor function.
Explanation:
Binding of specific chemical messengers to the corresponding receptors of target cells brings about change in the shape of the receptors. This structural change in the receptor results in the generation of the desired response. It reflects how the form and specific configuration of substances or biomolecules affect their functions.
For example, binding of neurotransmitters to the receptors present on neurons opens the associated ligand-gated ion channels to allow the movement of specific ions through it. In the absence of bound ligand, these channels are present in a closed conformation.
The nutrients get to the cells in a flatworms solid acoelomate body by diffusion process. Flatworms feed primarily on protozoa and bacteria, smaller worms and tiny organisms, dead or alive, that they come across. Based on the species of the flatworms , they also consume plant materials. They rely on diffusion to transport oxygen and nutrients to their internal tissues.