January 29, 2013
Chapter 29 “Do You Understand” Questions
1) The roles of the blood plasma and the interstitial fluid in serving the needs of the body are to exchange materials and nutrients with the cells it surrounds. These two extracellular fluids interrelate because the plasma is 20% of all extracellular fluid and the interstitial fluid is the remaining 80%. 2) A) Epithelial tissues are sheets of densely packed, interconnected epithelial cells that cover inner and outer body surfaces. They serve as selective barriers, transport functions, or movement of mucus and detritus over surfaces. Some epithelial tissues serve sensory functions as well. B) Connective tissues are dispersed populations of cells embedded in an extracellular matrix that the cells themselves secrete. A matrix of protein fibers (collagen and elastin) provides the structural strength and elasticity that characterizes cartilage (the substance that lines the joints between bones and gives structure to the nose and the external ears). C) Nervous tissues consist of neurons and glial cells. Neurons are individual cells that generate and conduct electrical signals, or nerve impulses, around the body. Nervous tissues support the information-processing functions of neurons in various ways. D) Muscle Tissues account for most of the body mass of vertebrates. They consist of elongated cells that contract to generate forces that result in movement. Skeletal muscle is responsible for locomotion and other body movement. 3) Organ systems contribute to the maintenance of the internal environment by maintaining the relatively constant composition and condition of the blood and tissue fluids in order to ensure that cells will function normally. One example is the cardiovascular system; without the system, no blood would be distributed throughout the body and we wouldn’t be able to live. Chapter 29.2:
1) The regulatory system would be the individual who...