Cheatography
https://cheatography.com
histology unit histology unit histology unit
This is a draft cheat sheet. It is a work in progress and is not finished yet.
Histology
Histology |
the study of tissue |
Tissue |
a group structurally and functionally related cells and their external environment that together perform common functions |
| |
tissues share 2 basic components: all tissues consist of discrete population of cells that are related in structure and function |
| |
all tissues have a surrounding material called extracellular matrix (ECM) |
Types of Tissues |
are defined by the kind and number of cells, the amount and composition of ECM and their specific functions |
| |
Epithelial tissues |
•tightly packed sheets |
| |
|
•no visible ECM |
| |
|
•cover and line all body surfaces and cavities |
| |
|
•forms secretory glands |
| |
Connective Tissues |
•connect all the other tissues in the body to one another |
| |
|
•ECM is a prominent feature for most connective tissues types with cells scattered throughout |
| |
|
•bind, support, protect, and allow for transportation of substances |
| |
|
•fill internal spaces |
| |
|
•provide structural support and energy |
| |
Muscle Tissue |
•contracts to produce movement and force |
| |
|
•skeletal muscle, cardiac muscle, and smooth muscle |
| |
|
little ECM between cells |
| |
Nervous Tissue |
consist of cells capable of generating, sending, receiving messages, and cells that support this activity all within a unique ECM |
| |
|
conduct electrical impulses |
| |
|
carries information |
Cell Junctions
Cell Junctions |
another way cells bind to one another where neighboring cell's plasma membranes are linked by integral proteins |
3 Major Types of Cell Junctions |
tight junctions ( occluding junctions ) |
hold cells closely together such that the space between is impermeable to the movement of macromolecules |
| |
desmosomes |
allow for materials in the ECF to pass through the space between cells |
| |
gap junctions |
small pores formed by protein channels between adjacent cells that allow small substances to flow freely between each cells cytoplasm |
|
|
The Extracellular Matrix (ECM)
Extracellular matrix (ECM) |
composed of substances in a liquid, thick gel, or solid that surround the cells of a tissues |
| |
2 Components |
Ground Substance |
| |
|
Protein Fibers |
ECM Functions |
provides the tissue with strength to resist tensile (stretching) and compressive forces |
| |
directs cells to their proper positions within a tissue and holds those cells in place |
| |
regulates the development, mitotic activity, and survival of cells in a tissue |
Ground Substance |
Makes up most of ECM and consists of extracellular fluid (ECF) and their components: water, nutrients, and ions |
| |
also found: three families of macromolecules, glycosamingoglycans (GAGs), proteoglycans, and cell-adhesion molecules (CAMs) |
Protein Fibers |
long molecules composed of multiple fibrous subunits with a ropelike structure with enormous tensile strength |
| |
embedded within the ground substance |
j |
| |
3 Types of Protein Fibers |
| |
Collagen Fibers |
composed of multiple repeating subunits that form a white fibrous protein that is resistant to tension ( pulling and stretching forces) and pressure |
| |
Elastic Fibers |
composed of the protein elastin surrounded by glycoproteins |
| |
f |
has the property of extensibility that allows the fiber to stretch up to one and a half times its resting length without breaking |
| |
|
give elasticity |
| |
Reticular Fibers |
a thin short collagen fiber, form a meshwork that support the cells and ground substance of many tissues |
| |
|
form web-like structure in organs like the spleen that help trap foreign cells |
|
|
The Extracellular Matrix (ECM)
Ground Substance and Protein Fibers
|
.jpg)
