Secretory structures and Intracellular Flashcards
sacs or pouches surrounded by a secretory
epithelium consist of two types: (a) gum cavity; & (b)resin cavity
Intercellular cavities
Types of Intercellular cavity
(a) gum cavity; & (b)
resin cavity
more or less elongated spaces, surrounded by a secretory epithelium, and being either axial or vertical, radial or horizontal in disposition
Intercellular canals
structures containing and producing
latex
Laticifers
chains of cells in which the walls separating the cells remain intact, are perforated, or completely dissolved.
Articulated laticiferous tube
These structures are often called latex vessels
Articulated laticiferous tube
These are originated from single cell, (simple in origin), which through continued growth develop into tube-like often much branched, but typically they undergo no fusion with other similar cells.
Non-articulated laticiferous tube
These
types of laticifers are called laticiferous cell
Non-articulated laticiferous tube
this term is applied to cells of nearly
normal size, or only somewhat
enlarged, containing oil, resin, or
mucilage
Secretory Cells
longitudinally and/or horizontally oriented
openings that are surrounded by cells
secreting resinous, gummy or oily
substance.
Resin ducts; gum and oil ducts
may occur as a normal characteristic feature or may arise due to injury.
Resin and gum canals
sometimes referred to as resin ducts, are unique to conifers;they are technically not individual cells, but are actually open,
Resin canals,
tube-like spaces bordered by special cells that have the ability to secrete pitch or resin into the neighboring opening (canal).
Resin canals,
Most Dipterocarp timber species will exhibit resin ducts in ____________ except those seen in Apitong group which are either diffused or in short tangetial series
long tangetial series
Resin canals very obvious in __________
Late wood
tubular, intercellular spaces of indeterminate length, which serve as repositories for gums or resins, secreted by the epithelium.
Gum canals
breakdown or degeneration of cells
Gummosis
Normal gum canals are either _______, i.e., longitudinal or horizontal, i.e., _____ in disposition.
axial, radial
are a constant feature in all local dipterocarp woods under a trade name “Philippine mahogany.”
Axial gum canals
occur as a result of injury or wounding in
woods.
traumatic or pathologic gum canals in
hardwoods
are restricted to the longitudinal kind only. They may be formed in three ways: schizogenously, lysigenously, or schizolysigenously.
Traumatic canals,
arise in the same manner as normal gum
canals which result from the separation of the cells at the middle lamella.
Schizogenous canals
They are provided with excreting parenchymatous tissue surrounding the cavity, known as the epithelium.
Schizogenous canals
result from the actual disintegration of cells, are much larger than the schizogenous canals and are devoid of epithelium. An example of this type of canal is the pith fleck, caused by insect damage.
Lysigenous canals
the result of both processes. The cavities are formed through cell fission and cell separation at the middle lamella, followed by the enlargement of the cavities through actual disintegration of the cells surrounding them.
Schizolysigenous canals
Like the lysigenous canals, they are larger than schizogenous canals.
Schizolysigenous canals
This refers to the presence of phloem
(bark) in the xylem (wood). This is a
characteristic feature of the species
Api-api (Avicennia officinalis L.)
included phloem
The frequency of pore contents contents, if
present, are described using the relative terms:
sparse, common, and abundant.
foam-like or sac-like deposits found in vessels
Tyloses
are found in axial parenchyma and ray cells and less frequently in septate fibers in tyloses
Crystals
Druce, Raphides Elongated and rod-like
Acicular, Crystal sand Rhomboidal
Types of
crystals
globular or star- like in shape; in calcium oxalate they as appear needle- or spear-shaped
DRUSE
needle-shaped crystals of calcium
oxalate monohydrate or calcium carbonate as
aragonite, found in more than 200 families of plants
RHAPIDES
