Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Cell_Org
| Question | Answer |
|---|---|
| tissue | is a group of cells that usually have a common origin in an embryo and function together to carry out specialized activities. |
| Name the four basic types of tissues that make up the human body, and state the characteristics of each. | 1. Epithelial tissue 2. Connective tissues 3. Muscular tissues 4. Nervous tissue |
| Epithelial tissues | cover body surfaces and line hollow organs, body cavities, and ducts; they also forms glands. This tissue allows the body to interact with both its internal and external environments. |
| Connective tissues | protect and support the body and its organs. Various types of connective tissues bind organs together, store energy reserves as fat, and help provide the body with immunity to disease-causing organisms. |
| Muscular tissues | are composed of cells specialized for contraction and generation of force. In the process, muscular tissues generate heat that warms the body. |
| Nervous tissue | detects changes in a variety of conditiond inside and outside the body and responds by generating electtical signals called nerve action potentials (nerve impulses) that activate muscular contractions and glandular secretions. |
| biopsy | is the removal of a sample of living tissue for miscropic examination. |
| cell junctions | are contact points between the plasma membranes of tissue cells. |
| the five most important types of cell junctions: | tight junctions, adherens junctions, desmosomes, hemidesmosomes, and gap functions. |
| tight junctions | consist of weblike strands of transmembrane proteins that fuse together the outer surfaces of adjacent plasma membranes to seal off passageways between adjacent cells. (Located in stomach, intestines, and urinary bladder.) |
| adherens junctions | contains plague, a dense layer of proteins on the inside of the plasma membrane that attaches both to membrane proteins and to microfilaments of the cytoskeleton. |
| cadherins | transmembrane glycoproteins that joins the cells. |
| Each _______ inserts into the plaque from the opposite side of the plasma membrane, partially crosses the intercellular space (the space between the cells), and connects to _______ of an adjacent cell. | cadherins |
| adherin belt | In epithelial cells, adherens junctions often from extensive zones called _____ because they encircle the cell similar to the way a belt encircles your waist. |
| desmosomes | contain plaque and have transmembrane glysoproteins (cadherins) that extend into the intercellular shace between adjacent cell membranes and attach cells to one another. The plaque attaches to elements of the cytoskeleton known as intermediate filaments. |
| hemidesmosomes | resembles desmosomes, but they do not link adjacent cells. The name arises from the fact that they look like half of a desmosome. They anchor cells not to each other but to the basement membrane. |
| integrins | transmembrane glycoproteins in hemidesmosomes (rather than cadherins). Inside the plasma membrane, they attach to protein keratin intermediate filaments. Outside the plasma membrane, they attach to the protein laminin (present in the basement membrane). |
| connexons | tiny fluid-filled tunnels that connect neighboring cells. Through them, ions and small molecules can diffuse from the cytosol of one cell to another, but the passage of large molecules such as vital intracellular proteins is prevented. |
| The transfer of nutrients, and perhaps wastes | takes place through gap junctions in avascular tissues such as the lens and cornea of the eye. |
| ________ junctions allow the cells in a tissue to communicate with one another. | Gap |
| Which type of cell junction prevents the contents of organs from leaking into surrounding tissues? | tight junction |
| Which types of cell junctions are found in epithelial tissues? | adherens junction |
| State the main differences between epithelial and connective tissues. | Under a light microsocope: the number of cells in relation to the extracellular matrix (the substance between cells). And, that an epithelial tissue has no blood vessels, wheres connective tissues have significant networks of blood vessels. |
| the first obvious difference between epithelial and connective tissues. | An epithelial tissue many cells are tightly packed together with little or no extrcellular matrix, whereas the connective tissue large amount of extracellular material seperates cells that are usually widely scattered |
| the second obvious difference between epithelial and connective tissues. | is that an epithelial tissue has no blood vessels, wheres connective tissues have significant networks of blood vessels. |
| Another key difference between epithelial and connective tissues. | is that epithelial tissues almost always form surface layers and are not covered by another tissue. An exception is the epithelial lining of blood vessels where blood constanttly passes over the epithelium. |
| Why are epithelial and connective tissues found adjacent to each other? | Because epithelital tissues lack blood vessels and form surfaces, they're found immediately adjacent to blood-vessel-rich connective tissues enabling them to make the exchanges with blood necessary for the delivery of oxygen & nutrients & waste removal. |
| The ratio of cells to extracellular matrix | A major difference between epithelial tissues and connective tissues. |
| What relationship between epithelial tissues and connective tissues is important for the survival and function of epithelial tissues? | epithelital tissues are found adjacent to blood-vessel-rich connective tissues - enables exchanges with blood necessary for the delivery of oxygen & nutrients & the removal of wastes that're critical processes for their survival & function. |
| Epithelial tissues have three major functions. | selective barriers that limit or aid the transfer of substances into & out of the body; secretory surfaces that release products produced by the cells onto their free surfaces; and protective surfaces that resist the environment’s abrasive influences |
| apical (free) surface of an epithelial cell | faces the body surface, a body cavity, the lumen (interior space) of an internal organ, or a tubular duct that receives cell secretions. Apical surfaces may contain cilia or microvilli. |
| lateral surfaces of an epithelial cell | which face the adjacent cells on either side, may contain tight junctions, adherens junctions, desomosomes, and/or gap junctions. |
| basal surface of an epithelial cell | is opposite the apical surface. The basal surfaces of the deepest layer of epithelial cells adhere to extracellular materials such as the basement membrane. |
| hemidesmosomes in the basal surfaces of the deepest layer of epithelial cells | anchor the epithelium to the basement membrane. |
| apical layer | refers to the most superficial layer of cells (in epithelia with multiple layers) |
| basal layer | is the deepest layer of cells (in epithelia with multiple layers) |
| basement membrane | is a thin extracellular layer that commonly consists of two layers, the basal lamina and reticular lamina. It is found between epithelial tissues and connective tissues. |
| basal lamina | is closer to and secreted by the epithelial cells. It contains proteins such as laminin and collagen, as well as glycoproteins and proteoglycans. |
| laminin molecules in the basal lamina | adhere to integrins in hemidesmosomes and thus attach epithelial cells to the basment membrane |
| reticular lamina | is closer to the underlying connective tissue and contains proteins such as collagen produced by connective tissue cells called fibroblasts. |
| Other functions of basement membranes | They form a surface along which epithelial cells migrate during growth or wound healing, restrict passage of larger molecules between epithelium and connective tissue, and participate in filtration of blood in the kidneys. |
| avascular | without blood vessels |
| Epithelial tissues have their own _______. | nerve supply |
| exchange of substances between epithelial tissues and connective tissues occurs by ______. | diffusion |
| Covering and lining epithelium | forms the outer covering of the skin and some internal organs. It also forms the inner lining of blood vessels, ducts, and body cavities, and the interior of the respiratory, digestive, urinary, and reproductive systems. |
| Glandular epithelium | makes up the secreting portion of glands such as the thyroid gland, adrenal glands, and sweat glands. |
| Types of covering and lining epithelial tissues are classifieds according to two characteristics: | the arrangement of cells into layers and the shapes of the cells |
Created by:
rpkw0000