Introduction Show
As can be seen, anatomy can be studies in multiple ways, and at various levels. Understanding the hierarchy of these levels, provides context to the complexity of the human organism. The simplest level of organization (although first year chemistry students would disagree) is the chemical level of organization. At this level, simple atoms combine to form relatively simple molecules. For example, carbon dioxide (CO2) is made up of one carbon atom, and two oxygen atoms, and water (H2O) is made up of two hydrogen atoms and one oxygen atom. Macromolecules (macro: big) are larger and more complex, and include four key types in the human body; carbohydrates (sugars), lipids (fats), proteins and nucleic acids (DNA). These four macromolecules form the building blocks of the next level of organization: the cellular level. Cells are the smallest units of life and are responsible for regulating their own environment. The four macromolecules, interact to complete complex tasks for the cell, like generating energy (ATP) or producing muscle contractions (through the interactions of two protein complexes: actin and myosin).  The tissue level of organization consists of a group of cells that work together to accomplish one or more specific functions. There are only four distinct types of tissue in an adult human. Muscle tissue is specialized for contraction to generate movement; neural tissue is specialized for generating action potentials for rapid communication within the body; epithelial tissue provides a physical barrier for entry into the body and produces specialized secretions via glands; and connective tissue shows the greatest variability of all of the tissues, and forms much of the structure of the body (among many other things). The organ level of organization is when two or more tissues work together for a specific function. For example, the bladder consists of an inner lining of epithelial tissue, bound by various connective tissues to (smooth) muscle. Throughout the bladder, there are also neurons that control the muscle tissue directing it to contract or relax during the urination reflex. The organ system level of organization is when two or more organs work together for a specific function. The bladder mentioned, when combined with the kidneys (another organ), and the ureters (“tubes” connecting the kidneys to the bladder, form the urinary system (or urinary tract). The kidneys filter the blood, and the waist products drain through the ureters to be stored in the bladder. The waist is eliminated from the body when we urinate.The urinary system is one of the eleven body systems that can be examined using systemic anatomy. The most complex level of organization is the organismal level, where all eleven organ systems function in the human organism, the whole living person. The correct option is A Organ systemLiving organisms can be unicellular or multicellular based on the number of cells in an organism. In muticellular organisms, several cells come together to form tissues. For example, epithelial tissue, connective tissue, etc. Tissues come together to form organs. For example, lungs, trachea, etc. Several organs in the body come together to perform a common body function and it is known as organ system. For example lungs, bronchi, pharynx, trachea, etc. come together to form the respiratory system in human body. All these organs facilitate and perform the common function of exchange of gases.Living organisms are made up of four levels of organization: cells, tissues, organs, and organ systems. Learning Objectives Key Points
Key Terms
EXAMPLESUsing the circulatory system as an example, a cell in this system is a red blood cell, the heart’s cardiac muscle is a tissue, an organ is the heart itself, and the organ system is the circulatory system. An organism is made up of four levels of organization: cells, tissues, organs, and organ systems. These levels reduce complex anatomical structures into groups; this organization makes the components easier to understand. Level 1: CellsThe first and most basic level of organization is the cellular level. A cell is the basic unit of life and the smallest unit capable of reproduction. While cells vary greatly in their structure and function based on the type of organism, all cells have a few things in common. Cells are made up of organic molecules, contain nucleic acids (such as DNA and RNA), are filled with fluid called cytoplasm, and have a membrane made out of lipids. Cells also contain many structures within the cytoplasm called organelles, which perform various cellular functions. Cells may be prokaryotic (without a nucleus) in bacteria and archaea (single-celled organisms), or eukaryotic (with nucleus-enclosing DNA) in plants, animals, protists, and fungi. In humans, most cells combine to form tissues, but some cells are found independent of solid tissues and have their own functions. A red blood cell found circulating in the bloodstream carrying oxygen throughout the human body is an example of an independent cell. Level 2: TissuesTissues are a group of similar cells of the same origin that carry out a specific function together. Humans have four different types of basic tissues. Connective tissues such as bone tissue are made up of fibrous cells and give shape and structure to organs. Muscle tissue is made up of cells that can contract together and allow animals to move. Epithelial tissues make up the outer layers of organs, such as the skin or the outer layer of the stomach. Nervous tissue is made of specialized cells that transmit information through electrochemical impulses, such as the tissue of nerves, the spinal cord, and the brain. Level 3: OrgansAn organ is a structure made up of different tissues that perform specific bodily functions. Most organs contain tissues such as parenchyma (used to perform the organ functions), stroma (connective tissue specific to organs) and epithelial. Organs may be solid or hollow, and vary considerably in size and complexity. The heart, lungs, and brain are all examples of organs. Level 4: Organ SystemsAn organ system is a collection of organs that that work together to perform a similar function. There are eleven different organ systems in the human body, each with its own specific functions. One example is digestive system, which is made up of many organs that work together to digest and absorb nutrients from food. While most organ systems control a few specific physiological processes, some processes are more complex and require multiple organ systems to work together. For example, blood pressure is controlled by a combination of the renal system (kidneys), the circulatory system, and the nervous system. Levels of Organization in Animals: An organism contains organ systems made up of organs that consist of tissues, which are in turn made up of cells. LICENSES AND ATTRIBUTIONS CC LICENSED CONTENT, SHARED PREVIOUSLY
CC LICENSED CONTENT, SPECIFIC ATTRIBUTION
What are the 3 scientific theories?The Modern Atomic Theory. The Cell Theory. The Theory of Evolution by Natural Selection. These are all classic scientific theories.
What is the smallest unit of an organism that can carry out all the functions of life?Cells- the smallest unit that can perform all of life processes.
Which theory enables scientists to understand?The theory of evolution enables scientists to understand: history of life, anatomy, physiology, and the development of organisms, and a variety of organisms.
How is a theory in everyday language different than a scientific theory?In everyday language, a theory means an idea or speculation. This is not the case in science. In science, the word theory refers to a complete explanation of an important feature of nature supported by facts gathered over time. Theories also allow scientists to make predictions about unobserved phenomena.
|
An organ is a combination of different functioning together for a specific task
zusammenhängende Posts
Urheberrechte © © 2024 decemle Inc.
