Tissues Flashcards
What are tissues
Tissues are defined as a groups of cells have a common structure and/or function.
What are tissues made of
Cells and extra cellular matrix (ecm)
How many cells types are there?
4 - connective, epithelial, muscle and nervous tissue
How are cells classified?
By their tissue type
What is ECM?
ECM Is the material around the tissues cells that is largely produced by themselves
Extracelluar Matrix (ECM) composition :
Ecm - is the non living material that surrounds the cell that themselves have synthesized. They are called ECM. They are made up of:
Ground substance - made up of mostly glycoproteins & water. Surrounds the cell and makes up most of the ECM.
Protein fibers found in ground substance - collagen is the most common, making up large parts of the connective tissue, like bone and tendon. They’re is also elastin.
Basement membranes - at interfaces between epithelium and connective tissues.
What are the primary tissues
Epithelium - lining, protective and secrotory
Connective - supportive, structural. Holds us together. Defined by presence of extra cellular.
Muscle - contractile. Defined by function .gut and heart.
Nerve - irritable, responsive. Defined by function
Skin is a tissue
Cell junctions :
Tight junctions - literally saw cells together, holding them tightly together and prevent diffusion between them. (Zip locks)
Desmosomes and hemidesmosomes (half a of a desmosomes) Less restrictive than tight junctions but also good cells together, especially epithelial lining cells.
Gap junctions- which allows the transfer of contents between two adjacent cells without having to pass through the cell membrane.
Epithelium tissue
It is defined by morphology - it functions in two ways
Inner Lining of body (mouth and anus) and pro receive. The skin and mucosa are both this type. It had a tough barrier to outside organisms keeping the body aseptic.. Piercing this leads to infection. Skin is this type of tissue too.
Secretion and transport - they form glans, (saliva gland. Digestive glands, and pancreas, liver - all of this type of tissue(
It is a an active transmembrane metabolism, being exclusive responsible for bringing nutrients in the almond tart can also and removing metabolic wastes in the kidney.
Glands —-
Exocrine glands have ducts that transport the glandular secretions (sweat glands, oil glands, salivary glands)
Endocrine glands- ductless and secrete into the blood steam. Making them far more powerful, since the bloodstream goes everywhere. Their secretions are hormones.
How do exocrine glands secrete?
Medicine (eccrine) glands - form secretary vesicles in their cells that are released through exocystos (through plasma membrane through cell) -
Holocrine glands - form their secretions intracellulRy and then rupture to release their contents.
Apocrine glands - activate in puberty. Form secretion by pinching off a portion of plasma membrane. .. a signal or something like sexually mature.
How are epithelial tissue classified and describe their classification.
Epithelial tissue are classified by he number of layers they have:
- simple one layer of cells
- stratified two or more layer of cells
And by the cell cell shape :
- Squamous - cells are flat
- Cubodial cells are as tall and they are wide (like a cube)
- Columnar : taller than wide ( like a column)
Simple epithelia - have only one layer of cells
- simple squamous epithelium - single layer of cells with a centrally located flattened nucleus - found in places where substances have to cross quickly - like air sacs
Simple cubodial epithelium - short and have spherical, central nucleus. Found lining glands as thyroid gland and certain respiratory passages and in the kidneys.
Simple columnar epithelium spherical nuclei, generally near the base of the cell. Line digestive tract
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Stratified epithelia - have two or more cells of layers.
All tissues share two basic components what are the components?
Cells and ECM
The ECm is composed of substances in liquid thick gel or a solid that surrounds the cells of a tissue. What are the two main components?
Ground substance and protein fibers
What is ground substance made up of?
It’s mostly made up of water and glycoproteins.
