Summary
Cells form tissues, tissues form organs and organs work together in systems.
In depth
Four tissue types: epithelial, connective, muscle and nervous. Organs combine tissues, such as the stomach with epithelium, smooth muscle, connective tissue and nerves. Organ systems cooperate.
Epithelium covers surfaces; connective tissue supports; muscle contracts; nervous tissue conducts. Organ systems cooperate: digestive, circulatory, respiratory and others.
Example: the skin is an organ system called the integumentary system.
Epithelial tissue covers surfaces and lines cavities, and may be simple or stratified, and squamous, cuboidal or columnar; it has a basement membrane and no blood vessels. Connective tissue includes loose and dense connective tissue, cartilage, bone, adipose tissue and blood, with cells in an extracellular matrix. Muscle tissue contracts, and nervous tissue conducts signals through neurons supported by glia.
Organs are grouped into organ systems (11 in humans) that cooperate. Histology, the study of tissues, uses stained thin sections, and cancers are classified by tissue of origin: carcinomas arise in epithelium, sarcomas in connective tissue.
Remember: an organ's function depends on how its tissues are arranged, as in the layers of the gut wall.
Frequently asked questions
What is Tissues and Organs?
Cells form tissues, tissues form organs and organs work together in systems.
Which area of biology covers Tissues and Organs, and how advanced is it?
Tissues and Organs is one of the 51 topics in Human Physiology. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Skeletal System, Skin, Muscular System.
Can you give an example of Tissues and Organs?
Blood is a connective tissue with a fluid matrix.
What should I learn before Tissues and Organs?
Tissues and Organs is a Beginner topic, so no earlier topic is required. Other Beginner topics in Human Physiology that pair well with it include Homeostasis, Skeletal System, Muscular System.
What topics are related to Tissues and Organs?
The closest topics to Tissues and Organs are Skeletal System, Skin, Muscular System, Digestive System. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Tissues and Organs?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Tissues and Organs. To practise the whole of Human Physiology, use the Human Physiology quiz.
How is Tissues and Organs different from Skeletal System?
Tissues and Organs: Cells form tissues, tissues form organs and organs work together in systems. Skeletal System: Bones, cartilage and joints that support the body, protect organs and allow movement. Read both side by side and note what each one explains.
How should I study Tissues and Organs step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Skeletal System and explain the difference aloud. Finally, take the Human Physiology quiz and come back to this page for any question you miss.