Which of the following statements about exercise is NOT correct? More Content. Inside the Torso. Was This Page Helpful? Yes No. Organ Systems. Overview of Autoimmune Disorders of Connective Tissue. Figure 1. Four Types of Tissue: Body. The four types of tissues are exemplified in nervous tissue, stratified squamous epithelial tissue, cardiac muscle tissue, and connective tissue in small intestine. The next level of organization is the organ, where several types of tissues come together to form a working unit.
Just as knowing the structure and function of cells helps you in your study of tissues, knowledge of tissues will help you understand how organs function. The epithelial and connective tissues are discussed in detail in this chapter. Muscle and nervous tissues will be discussed only briefly in this chapter. The zygote, or fertilized egg, is a single cell formed by the fusion of an egg and sperm. After fertilization the zygote gives rise to rapid mitotic cycles, generating many cells to form the embryo.
The first embryonic cells generated have the ability to differentiate into any type of cell in the body and, as such, are called totipotent , meaning each has the capacity to divide, differentiate, and develop into a new organism. As cell proliferation progresses, three major cell lineages are established within the embryo.
Each of these lineages of embryonic cells forms the distinct germ layers from which all the tissues and organs of the human body eventually form. Figure 2 shows the types of tissues and organs associated with the each of the three germ layers. Note that epithelial tissue originates in all three layers, whereas nervous tissue derives primarily from the ectoderm and muscle tissue from mesoderm.
A tissue membrane is a thin layer or sheet of cells that covers the outside of the body for example, skin , the organs for example, pericardium , internal passageways that lead to the exterior of the body for example, abdominal mesenteries , and the lining of the moveable joint cavities.
For example, the heart and the blood vessels of the cardiovascular system circulate blood and transport oxygen and nutrients to all the body cells. Levels of Organization : Molecules form cells. Cells form tissues, and tissues form organs. Organs that fulfill related functions are called organ systems. An organism is made up of interconnected organ systems. Privacy Policy. Skip to main content. The primary tissue types work together to contribute to the overall health and maintenance of the human body.
Thus, any disruption in the structure of a tissue can lead to injury or disease. Epithelial tissue refers to groups of cells that cover the exterior surfaces of the body, line internal cavities and passageways, and form certain glands.
Connective tissue , as its name implies, binds the cells and organs of the body together. Muscle tissue contracts forcefully when excited, providing movement. Nervous tissue is also excitable, allowing for the generation and propagation of electrochemical signals in the form of nerve impulses that communicate between different regions of the body Figure 4.
An understanding of the various primary tissue types present in the human body is essential for understanding the structure and function of organs which are composed of two or more primary tissue types. This chapter will focus on examining epithelial and connective tissues. Muscle and nervous tissue will be discussed in detail in future chapters.
The cells composing a tissue share a common embryonic origin. The zygote , or fertilized egg, is a single cell formed by the fusion of an egg and sperm cell. After fertilization, the zygote gives rise many cells to form the embryo. The first embryonic cells generated have the ability to differentiate into any type of cell in the body and, as such, are called omnipotent , meaning each has the capacity to divide, differentiate, and develop into a new organism.
As cell proliferation progresses, three major cell lines are established within the embryo. Each of these lines of embryonic cells forms the distinct germ layers from which all the tissues and organs of the human body eventually form. Figure 4. Note that epithelial tissue originates in all three layers, whereas nervous tissue derives primarily from the ectoderm and muscle tissue derives from the mesoderm. View this slideshow to learn more about stem cells.
How do somatic stem cells differ from embryonic stem cells?
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