Structure and function of the human body
Transcript
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The human body has many different parts. The science that studies the structures and arrangement of those parts is called anatomy, while the study of how they function is called physiology.
To understand how the human body works, let’s start at a microscopic level and look at cells. Cells are the smallest structural and functional unit of the body.
Now, cells, with similar structures, join together to form tissues, which are specialized to carry out specific functions. There are four types of tissues.
We have epithelial tissues that cover external body surfaces and line our internal body cavities; muscle tissues that contract and help carry out some functions, like movement; nerve tissue, which transports electric signals between various body parts and the brain; and the connective tissue, which supports and connects all other tissues.
Now, when different tissues come together, they form an organ. Organs can carry out tasks that are actually too big to be fulfilled by a single type of tissue.
One example of an organ is the heart, which is made of different tissues, such as the cardiac muscle tissue that helps the heart pump blood and the nervous tissue that helps regulate its rhythm.
Okay, now, different organs work together in a systematic way to form organ systems. Organ systems carry out the much more extended functions that an isolated organ couldn’t be able to handle.
A good example of this is the digestive system that consists of the mouth, esophagus, stomach, small and large intestines, the pancreas, liver, and gallbladder; all of which take part in digestion.
Okay, let’s shift gears a little bit and take a closer look at the cell. All of the body’s functions start at the cellular level. Cells have structures called organelles that act like very simple organs.
One of these organelles is the cell’s outer layer, called the cell membrane, or plasma membrane. This plays a role in regulating what enters and leaves the cell.
Inside the cell is a jelly-like medium, called the cytoplasm, in which other cell organelles float and operate. The cytoskeleton helps the cell keep its shape and offers structural support.
Next, the nucleus is an important organelle that contains all of the genetic information a cell needs to do its job, grow, and reproduce.
Key Takeaways
The human body has many different parts. The science that studies the structures and arrangement of those parts is called anatomy, while the study of how they function is called physiology. The structural organization of the body starts at the cellular level. Cells with similar structures and functions form tissues.
Tissues grouped to perform specific functions form organs, and when organs work together to carry out certain common tasks, they form an organ system. Cells have organelles that help them carry out their functions. Cell organelles include the cell membrane, cytoskeleton, nucleus, ribosomes, mitochondria, and others floating in the cytoplasm. For cells to work properly, homeostasis must be kept, meaning certain factors in their environment, such as pH and oxygen, body temperature, and concentration of substances like sodium and potassium, are kept constant to create an optimal state for the cells to perform their function.