Cells, Tissues, Organs and Organ Systems Notes
Introduces cells, tissues, organs, and organ systems in the human body. After tissues, organs are the next level of organization of the human. Human organ is a community of cells of different types. The cells which helps assembling different organs into organ system to perform complicated body functions. Figure 1: Overview of Human Tissue Pattern Genes. . datasets can yield a consensus topology of organ relationship (Supplementary Fig. These cells in various forms throughout your body are its basic building blocks. You can find out more about cells in Is this answer still relevant and up to date? What is the relation among the cell, tissue, organs, and the system? Views.
It's found throughout your body, and it supports organs and blood vessels and links epithelial tissues to the muscles underneath. Dense, or fibrous, connective tissue is found in tendons and ligaments, which connect muscles to bones and bones to each other, respectively. Loose connective tissue is composed of loosely woven collagen and elastic fibers.
The fibers and other components of the connective tissue matrix are secreted by fibroblasts. Specialized forms of connective tissue include adipose tissue—body fat—bone, cartilage, and bloodin which the extracellular matrix is a liquid called plasma. Muscle tissue Muscle tissue is essential for keeping the body upright, allowing it to move, and even pumping blood and pushing food through the digestive tract.
Muscle cells, often called muscle fibers, contain the proteins actin and myosin, which allow them to contract. There are three main types of muscle: From left to right.
Smooth muscle cells, skeletal muscle cells, and cardiac muscle cells. Smooth muscle cells do not have striations, while skeletal muscle cells do. Cardiac muscle cells have striations, but, unlike the multinucleate skeletal cells, they have only one nucleus. Cardiac muscle tissue also has intercalated discs, specialized regions running along the plasma membrane that join adjacent cardiac muscle cells and assist in passing an electrical impulse from cell to cell.
Competency Structure and Function of Living Things | BioEd Online
Skeletal muscle is attached to bones by tendons, and it allows you to consciously control your movements. For instance, the quads in your legs or biceps in your arms are skeletal muscle. Cardiac muscle is found only in the walls of the heart. Like skeletal muscle, cardiac muscle is striated, or striped. But it's not under voluntary control, so—thankfully!
The individual fibers are connected by structures called intercalated disks, which allow them to contract in sync. Smooth muscle is found in the walls of blood vessels, as well as in the walls of the digestive tract, the uterus, the urinary bladder, and various other internal structures.
Smooth muscle is not striped, striated, and it's involuntary, not under conscious control. That means you don't have to think about moving food through your digestive tract! Nervous tissue Nervous tissue is involved in sensing stimuli—external or internal cues—and processing and transmitting information. It consists of two main types of cells: The neurons are the basic functional unit of the nervous system.
Aging changes in organs, tissues, and cells: MedlinePlus Medical Encyclopedia
They generate electrical signals called conducted nerve impulses or action potentials that allow the neurons to convey information very rapidly across long distances. The glia mainly act to support neuronal function. The neuron has projections called dendrites that receive signals and projections called axons that send signals. Also shown are two types of glial cells: For example, the heart pumps blood, the lungs bring in oxygen and eliminate carbon dioxide, and the skin provides a barrier to protect internal structures from the external environment.
Most organs contain all four tissue types. The layered walls of the small intestine provide a good example of how tissues form an organ. Modern cell theory states that all organisms are composed of one or more cells; cells are the basic units of all organisms; and cells arise only through division of a previously existing cell.
All cells have three major features: Prokaryotes are the simplest organisms. There are two main types of prokaryotes: Most prokaryotes have a strong cell wall outside of the plasma membrane.
Aging changes in organs, tissues, and cells
The internal organization of prokaryotic cells is simple, with few internal compartments and no subunits organelles surrounded by a membrane. Prokaryotic cells do not have a true nucleus surrounded by a membrane. Instead, their genetic material is present as a simple circle of DNA.
Eukaryotes, which comprise the Domain, Eukarya, contain membrane-bounded organelles that carry out specialized functions and a nucleus that is surrounded by a double membrane nuclear envelope.
DNA inside the nucleus is organized into chromosomes. View the following videos to get a better understanding of size and shape of cells as it relates to their specific function. Cell Size Shape and Form. Tutorvista provides a simple explanation of different kinds of cells. Structure and Function of Nucleic Acids.
Rae Lynn Alford provides an introduction to the molecules import for heredity in living organisms in this presentation and annotated slide set. Biology4Kids reviews the different components of cells. Click on the side menu for information about different organelles and structures. Biology4Kids provides an easy-to-follow summary of the many jobs of cells.
How Structure Complements Function in Tissues, Organs, Organ Systems, and Organisms The beginning teacher analyzes how structure complements function in tissues, organs, organ systems, and organisms. The cell is the basic unit of all forms of life.
However, there are several levels of cell organization within many multicellular organisms. Cells are arranged in hierarchical levels of organization. The lowest form of organization is the cell followed by tissues, organs, and organ systems. A tissue is a group of similar cells in an organism working together to perform a particular function e.
An organ is a collection of different tissues that carries out a particular function e. An organ system is a collection of organs that functions to carry out a specific task in the organism e. At each level of organization, the structure helps determine the function. The highest level of organization in multicellular living forms is the whole organism.
Watch this video to understand organization of tissues, organs, and organ systems.
This video from Brightstorm describes how animal cells are arranged into tissues, organs and organ systems. Drugs are removed from the body by the kidneys and liver at a slower rate. Lower doses of medicines may be needed, and side effects become more common.
Side effects of medicine can mimic the symptoms of many diseases, so it is easy to mistake a drug reaction for an illness. Some medicines have entirely different side effects in the elderly than in younger people. Some theories claim that aging is caused by injuries from ultraviolet light over time, wear and tear on the body, or byproducts of metabolism. Other theories view aging as a predetermined process controlled by genes.
No single process can explain all the changes of aging.Cells, Tissue, and Organs
Aging is a complex process that varies as to how it affects different people and even different organs. Most gerontologists people who study aging feel that aging is due to the interaction of many lifelong influences. These influences include heredity, environment, culture, diet, exercise and leisure, past illnesses, and many other factors. Unlike the changes of adolescence, which are predictable to within a few years, each person ages at a unique rate.
Some systems begin aging as early as age Other aging processes are not common until much later in life. Although some changes always occur with aging, they occur at different rates and to different extents. There is no way to predict exactly how you will age. If enough cells decrease in size, the entire organ atrophies.
This is often a normal aging change and can occur in any tissue. It is most common in skeletal muscle, the heart, the brain, and the sex organs such as the breasts and ovaries. Bones become thinner and more likely to break with minor trauma. The cause of atrophy is unknown, but may include reduced use, decreased workload, decreased blood supply or nutrition to the cells, and reduced stimulation by nerves or hormones.
This is caused by an increase of proteins in the cell membrane and cell structures, not an increase in the cell's fluid. When some cells atrophy, others may hypertrophy to make up for the loss of cell mass. The number of cells increases. There is an increased rate of cell division. Hyperplasia usually occurs to compensate for a loss of cells.