Notes #1: Levels of Organization,
All living things are organized at different levels. These levels of organization organism include cells, tissues, organs, and organ systems. Cells form tissue, tissues form organs, and organs make up organ systems. The lowest level is the cell. What this means is that anything less than a cell is not living. For example, we have skin cells that form skin tissues. Our skin is our largest organ. Our skin, hair and nails form an organ system called the integumentary system. A turtle’s integumentary system includes its shell and skin. And a lizard’s integumentary system includes scales and claws. However teeth are part of the skeletal system.
Nerve cells form nerve tissue, which forms organs like the brain. The brain is part of the nervous system. The function of a Nerve cell’s is to send an electronic message.
Heart cells form heart tissue, which forms organs like the heart. The heart is part of the circulatory system. The function of a heart cell is to beat with other cells.
Skin, nerve, and heart cells look different because they have different jobs.
The cell is lowest level of organization for all organism. Germs like bacteria never form tissue because they exist as a single cell. So a germ’s lowest level of organization is also its highest level of organization. Jellyfish do not form organs like a heart or brain and therefore are stuck at the tissue level of organization.
An organism (and each of its cells) must breathe, grow, reproduce, use energy and responds to stimuli. Like a plant bending toward the light, the cells of the stem tissue are responding to the light. The light is the stimulus. All organisms react to changes in their environment. A change in an organism’s surroundings that causes the organism to react is called a stimulus (plural stimuli).
Nerve cells form nerve tissue, which forms organs like the brain. The brain is part of the nervous system. The function of a Nerve cell’s is to send an electronic message.
Heart cells form heart tissue, which forms organs like the heart. The heart is part of the circulatory system. The function of a heart cell is to beat with other cells.
Skin, nerve, and heart cells look different because they have different jobs.
The cell is lowest level of organization for all organism. Germs like bacteria never form tissue because they exist as a single cell. So a germ’s lowest level of organization is also its highest level of organization. Jellyfish do not form organs like a heart or brain and therefore are stuck at the tissue level of organization.
An organism (and each of its cells) must breathe, grow, reproduce, use energy and responds to stimuli. Like a plant bending toward the light, the cells of the stem tissue are responding to the light. The light is the stimulus. All organisms react to changes in their environment. A change in an organism’s surroundings that causes the organism to react is called a stimulus (plural stimuli).
The levels of organization in the human body consist of cells, tissues, organs, and organ systems. The smallest unit of organization is the cell. The next largest unit is tissue; then, organs. Finally, the organ system is the largest unit of organization.Complex organisms are composed of many cells in the same way a brick building is composed of many bricks. The human body contains about 100 trillion cells. Cells are quite tiny, and most cannot be seen without a microscope.
The next largest unit of organization in your body is a tissue. A tissue is a group of similar cells that perform the same function. The human body contains four basic types of tissue: muscle tissue, nervous tissue, connective tissue, and epithelial tissue.
Like the muscle cells that form it, muscle tissue can contract, or shorten. By doing this, muscle tissue makes parts of your body move. While muscle tissue carries out movement, nervous tissue directs and controls the process. Nervous tissue carries electrical messages back and forth between the brain and other parts of the body. Another type of tissue, connective tissue, provides support for your body and connects all its parts. Bone tissue and fat are connective tissues.The surfaces of your body, inside and out, are covered by epithelial tissue (ep uh thee lee ul). Some epithelial tissue, such as your skin, protects the delicate structures that lie beneath it.
Your stomach, heart, brain, and lungs are all organs. An organ is a structure that is composed of different kinds of tissue. Like a tissue, an organ performs a specific job. The job of an organ, however, is generally more complex than that of a tissue. The heart, for example, pumps blood throughout your body, over and over again. Each type of tissue contributes to the organ’s overall job of pumping blood.
Each organ in your body is part of an organ system which is a group of organs that work together to perform a major function. Your heart is part of your circulatory system, which carries oxygen and other materials throughout the body.
The different organ systems work together and depend on one another. When you ride a bike, you use your muscular and skeletal systems to steer and push the pedals. But you also need your nervous system to direct your arms and legs to move. Your respiratory, digestive, and circulatory systems work together to fuel your muscles with the energy they need. All the systems of the body work together to maintain homeostasis (hoh mee oh stay sis).
What is the largest organ in on the human body?
The next largest unit of organization in your body is a tissue. A tissue is a group of similar cells that perform the same function. The human body contains four basic types of tissue: muscle tissue, nervous tissue, connective tissue, and epithelial tissue.
Like the muscle cells that form it, muscle tissue can contract, or shorten. By doing this, muscle tissue makes parts of your body move. While muscle tissue carries out movement, nervous tissue directs and controls the process. Nervous tissue carries electrical messages back and forth between the brain and other parts of the body. Another type of tissue, connective tissue, provides support for your body and connects all its parts. Bone tissue and fat are connective tissues.The surfaces of your body, inside and out, are covered by epithelial tissue (ep uh thee lee ul). Some epithelial tissue, such as your skin, protects the delicate structures that lie beneath it.
Your stomach, heart, brain, and lungs are all organs. An organ is a structure that is composed of different kinds of tissue. Like a tissue, an organ performs a specific job. The job of an organ, however, is generally more complex than that of a tissue. The heart, for example, pumps blood throughout your body, over and over again. Each type of tissue contributes to the organ’s overall job of pumping blood.
Each organ in your body is part of an organ system which is a group of organs that work together to perform a major function. Your heart is part of your circulatory system, which carries oxygen and other materials throughout the body.
The different organ systems work together and depend on one another. When you ride a bike, you use your muscular and skeletal systems to steer and push the pedals. But you also need your nervous system to direct your arms and legs to move. Your respiratory, digestive, and circulatory systems work together to fuel your muscles with the energy they need. All the systems of the body work together to maintain homeostasis (hoh mee oh stay sis).
What is the largest organ in on the human body?
