Tissue Flashcards
tissues are groups of cells of common ____ origin
embryonic
four basic tissues
(ECMN) Epithelial Connective Muscular Nervous
Epithelial
Connective
Muscular
Nervous
Epithelial – covering and lining; glands
Connective – connect, support, filling spaces
Muscle – generate forces that provide for movement Nervous – cell-to-cell communication
Tissues are formed by grouping cells together using a variety of
Intercellular Junctions
Intracellular Junctions connect adjacent cells ____ at the cell membranes or through _____ elements
within and between cells.
mechanically
cytoskeletal
What is the leakproof seal junction? ex’s
Tight Junctions; stomach and bladder
_____ make an adhesion belt (like the belt on your pants) that keeps tissues from separating as they stretch and contract.
Adherens Junctions
_______ attach to the plaque, partially cross the intercellular space, and connect to cadherins from an adjacent cells
Cadherin (transmembrane proteins)
plaque (from adhesion belt junction) attaches to ____, but also has ____ connecting it to ____ from adjacent cells
microfilaments (actin); cadherin (transmembrane glycoprotein)
Desmosomes are similar to an adherens
junction, in that desmosomes have plaque
and cadherins, BUT plaque attaches to
intermediate filaments
Has transmembrane glycoproteins called integrins (instead of cadherins)?
Hemidesmosomes
Gap junctions are made up of Connexons composed of connexins which allow continuity of the _____
cytosol
connexons (connexins)
gap junction
_____ tissues cover body surfaces
and form glands and line hollow organs,
body cavities, and ducts.
Epithelial
________ protect, support, and bind organs.
– Fat is a type of C.T. that stores energy.
– Red blood cells, white blood cells, and platelets are all C.T.
Connective tissues (C.T.)
_____ is used to line surfaces and form
protective barriers. Epithelium is also good
at secreting things like mucous, hormones,
and other substances . All epithelia have a
free apical surface and an attached
basal surface.
Epithelium
two surfaces of epithelia
free apical
attached basal
CT secretes
reticular lamina
Basal layer of epithelium secretes
basil lamina
basil + reticular
= basement membrane
FUNCTIONS OF EPITHELIAL TISSUE
Filtration Secretion Excretion Absorption Protection
Flat, wide “paving stone”
squamous
cells as tall as they are wide
cuboidal
Cells taller than they are cells
wide
columnar
One layer. All cells in contact with basement membrane
simple
simple squamous examples
air sacs/lungs
lining of blood vessels
capillaries
major part of serous membrane
simple cuboidal ex’s
tubules of the kidneys and many other glands
simple columnar examples
GI Tract with or without the following:
+/- cilia, +/- microvilli, +/- mucous (goblet cells)
name of cells comes from the shape of the cells at ____
the free surface
kertininized =
no nucleus
nonkeratinized =
nucleus present
is a specialized simple squamous epithelium that lines the entire circulatory system from the heart to the smallest capillary – it is extremely important in reducing turbulence of flow of blood.
Endothelium
found in serous membranes I.e. pericardium, pleura, peritoneum
mesothelium (simple squamous epithelium)
endocrine secrete to
Extracellular space
exocrine secrete to ______; typically are
secrete to surface or lumen;
multicellular (except goblet cells are unicellular)
Three types of exocrine glands
merocrine
apocrine
holocrine
Most common manner of secretion?
No part is damaged in exocytosis
merocrine secretion; common in salivary gland
think Golgi complex making secretory vesicles
Steps in formation of secretory product
- DNA instructions transcribed to mRNA in nucleus
- synthesized in rough ER
- packaged in Golgi complex
- formed into secretory vesicle
- Released by exocytosis
“Bud” their secretions off through the plasma membrane (membrane-bound vesicles) and breaks off by “decapitation”
example?
Apocrine glands; milk from mammory gland
are produced by rupture of
the plasma membrane, releasing the entire
cellular contents into the lumen and killing the cell
holocrine secretions I.e. sebaceous glands
Four basic types of tissue (CEMN)
connective, epithelial, muscle, nervous
connective tissue consists of…..
cells
extracellular matrix
Characteristics of connective tissue
Few cells
Abundant; ubiquitous; varied
Mainly extracellular matrix
Highly vascular (in general; cartilage is avascular, and tendons have sparse blood supply)
Does not usually occur on body surfaces
Is supplied with nerves (as is epithelial tissue)
Epithelium vs CT
Epithelium CT
cells lots few
ground sub few lots
fibers few lots
arteries none lots
Connective tissue cells arise from?
mesenchyme (embryonic connective tissue)
Progression cell types?
-immature cells end in -blast, and are derived from mesenchyme
mature cells, or differentiated cells, end in -cyte, derived from blast cells
mitotically competent, secrete the matrix
blast
Mature cells have reduced capacity for cell division and matrix formation, and are generally involved with maintaining the matrix
– Chondroblasts become chondrocytes
– Osteoblasts become osteocytes
connective tissue cells move between?
- compartments (mobile) I.e. WBCs
- throughout connective tissue I.e. fibroblasts, macrophages
- immobile or fixed (fixed macrophages in lungs or spleen or osteocytes and chondrocytes)
most common cell of connective tissue in general?
fibroblast: large, flat, migrate to secrete and maintain the matrix
matrix fibers
collagen, reticular, and elastic fibers
which cell type has filopodia (actin) and is irregularly shaped
macrophages
two types of macrophages
fixed macrophages wandering macrophages (monocytes in blood)
macrophage functions
phagocytose debris, foreign substances (assist mast), respond to leukocytes
form B lymphocytes, secrete antibody, reside in connective tissue, especially GI and respiratory tracts
***accumulate in infected connective tissue
plasma cells