Chapter 3: page 107-108

Chapter 3: page 107-108

Critical Thinking
(1) Which process- diffusion ,osmosis , or filtration- accounts for the following situations
(A) Injection of a drug that is hypertonic to the tissues stimulates pain
(B) A person with extremely low blood pressure stops producing urine.
(C) The concentration of urea in the dialyzing fluid of an artificial kidney is kept low.
I think that the process of diffusion accounts for the following situations.

Review questions

(2)Describe how the shapes of nerve, epithelial, and muscle cells are well suited to their functions? These functions are well suited because the genes controlling neurotransmitter synthesis are activated
(3)Name the major components of a cell and describe how they interact? T-cell receptors and coreceptor molecules are both large proteins displayed on the surface of T cells, and they play an essential role during the beginning of an immune response. T cells become activated after their T-cell receptor recognizes antigen -- small pieces of foreign pathogens -- on the surface of other cells. Coreceptors, while they do not recognize foreign antigen, also bind to molecules on neighboring cells and help in T cell activation.
(12)
(13)Describe the structure of the nucleus and the functions of its contents? The neutron is an electrically neutral particle slightly heavier than the proton. They are present in numbers greater than or equal to the number of protons in every element except Hydrogen (whose nucleus is a single proton), and variations in the number of neutrons of elements account for isotopes.
(14)Distinguish between diffusion and facilitated diffusion. Facilitated diffusion is the substances moving through the membranes from a region of higher of concentration while diffusion is random movement from reg