Define the term 'chemical element'. Four most common chemical elements in the body are: Oxygen (O), Carbon (C), Hydrogen (H), and Nitrogen (N). Define the term 'atom' and describe... Define the term 'chemical element'. Four most common chemical elements in the body are: Oxygen (O), Carbon (C), Hydrogen (H), and Nitrogen (N). Define the term 'atom' and describe the structure of an atom. Define the terms 'molecule' and 'compound'. Describe the formation of an ion and an ionic bond. Distinguish between organic and inorganic molecules. Composition of organic molecules. Chemical properties of water. Characteristics associated with life and why the cell is the basic unit of life. Levels of structural organization in the body. Structure and functions of major cell components. Define metabolism, anabolism, and catabolism. Cell specialization and its importance. General characteristics of specific cell types. Fluid mosaic model of membrane structure. Define tissue and the importance of tissue-level organization. Structure and function of major tissue types. Define organ, organ system, and organism. The eleven organ systems. Anatomical position and body surfaces. Directional terms in human anatomy. Planes of the body. Body cavities. Define homeostasis and its importance to physiology. Conditions maintained by homeostasis. Define stressor. Define feedback loop. Organization of the nervous system. Structures and functions of neuron-related components. Main areas of the brain. Spinal cord structure and function. Autonomic Nervous System. Resting membrane potential. Process of Neurotransmission. Components and function of a reflex arc. Main categories of sense receptors. Structure and functions of the ear. Physiology of hearing. Main components of the human eye. Read more

A chemical element is a pure substance of one type of atom. Four common elements in the body are oxygen, carbon, hydrogen, and nitrogen. Essential concepts include atom structure, molecule/compound distinctions, ion formation, organic vs. inorganic molecules, and the role of cells in life.

A chemical element is a pure substance consisting of one type of atom distinguished by its atomic number. The four most common chemical elements in the human body are oxygen, carbon, hydrogen, and nitrogen. An atom is the smallest unit of matter with properties of an element, composed of protons, neutrons, and electrons. Molecules are two or more atoms bonded together. Compounds are substances composed of two or more different elements bonded together. Ions are formed when atoms gain or lose electrons, creating a charge. An ionic bond is the attraction between oppositely charged ions. Organic molecules contain carbon and hydrogen, while inorganic molecules do not. Water, essential for life, has properties like cohesion, adhesion, and high specific heat. Cells are life’s basic unit due to their role in structure and function, influenced by cellular organization from atoms to organisms. Metabolism encompasses all chemical reactions in an organism; anabolism builds molecules, while catabolism breaks them down. Cell specialization allows for diverse functionalities. Biological membranes follow the fluid mosaic model. Tissues, collections of cells with similar function, are essential for complex organisms. Organs and organ systems represent higher organizational levels, with eleven main human organ systems. Anatomical position refers to standard body orientation, with directional terms providing relative positions. Homeostasis maintains internal stability, controlled via feedback loops. The nervous system is structured into central and peripheral parts, with specialized components like neurons controlling reflex arcs. Sensory systems, including sight and hearing, involve complex structures and processes.