Lesson 4: Animal and Plant Tissues Flashcards
individual cells arranged into groups that function collectively
tissues
composed of similar cells performing the same funcions
Tissues in turn are combined into?
organs
organs are combined into?
organ systems
Animal tissues are generally classified into four types:
- epithelial
- connective
- muscular
- nervous
- consist of sheets of cells that cover organisms and their organs
- also form glands that synthesize secretory products for discharge into their environment
epithelial tissues
examples of glands formed by epithelial tissues:
- sebaceous glands
- salivary glands
all epithelial tissue usualy adhere tightly to the similar cells on either side of them througj cell-to-cell juntions called
tight junctions
seals off a tissue from adjacent open spaces and prevent the entrance of disease-causing microorganisms
tight junctions
epithelial tissues can be classified according to :
- number of cell layers (simple or stratified)
- cell shape (squamous, cuboidal, columnar)
- surface specialization (cilia, keratin, goblet, or brush border
Types of Epithelial Tissues in Terms of their Structure:
- Simple epithelium
- Stratified epithelium
is made up of only one layer of cells, and according to cell shape, can be squamous, cuboidal or columnar
Simple epithelium
is made of more than one layer of cells. According to the shape of its top-most layer, this can be classified as squamous, cuboidal, columnar, transitional, or pseudostratified
stratified epithelium
they connect and bind parts together just like the Achillles tendons found in your legs
Connective Tissues
examples of connective tissues that we often encounter while eating chicken are
ligaments and tendons
tissue that usually bind a muscle to a bone
tendons
tissues that connect a bone to another bone
ligaments
its most common types are the areolar tissue, fibrous tissue, adipose tissue, bone, cartilage and blood
connective tissue
is considered a supportive tissue since its primary function is to supply the body with nutrients and gases it needs
Blood
types of connective tissues:
- collagenous
- reticular
- elastic
is predominantly made up of type I collagen
collagenous connective tissue
e.g. dense regular connective tissues in the tendons, and dense irregular connective tssues in periosteum
- primarily formed by type III collagen, a protein found in bones and cartilage,
- is commonly found as a supportive framework of hematopoietic and lymphold organs
reticular connective tissue
e.g. adipose tissue, baal lamina, animal stroma of glandular organs
primarily formed by type II collagen, a component of joint cartilage, contains retractile fibers with elastin
elastic connective tissue
not easily visualized unless it is stained. Found in the bronchi, trachea, blood vessels, and hollow organs
Forms the body and also helps the bones in body movement
Muscle or muscular tissue
different kinds of muscular tissues:
- skeletal
- smooth
- cardiac
Muscles can be grouped into two:
voluntary and involuntary
are muscles that can be controlled by the nervous system
voluntary muscles
skeletal muscles attached to the bones are voluntary muscles. They only move at our will.
muscles that are beyond the control of the nervous system
involuntary muscles
e.g. muscles of the digestive tube and the heart
type of muscular tissues
are made up of very long, cylindrical, multi-nucleated cells capable of quick and forceful contractions that are usually voluntary
Skeletal muscles
interactions of the thin and thick fillaments make it possible for them to slide through each other during contraction
type of muscular tissues
- are composed of elongated branched individual cells that are configured parallel to each other
- capable of involuntary, vigorous, and rhythmic contractions
cardiac muscles
tyoe of muscular tissues
- are collections of cells that do not show cross-striations
- largest at their midpoints and taper toward their ends
- contraction process is slow and involuntary
smooth muscle
e.g. digestive tube
comprised of cells that are specialized for the reception and conduction of impulses
nervous tissues
usually found in the brain & spinal cord except for cytoplasmic extensions like axons
individual cells of the brain and the spinal cord
neurons or nerve cells
types of neurons according to functions:
- sensory
- motor
- interneurons
carry information obtained from the interior of the body and the environment to the CNS (central nervous system)
sensory neurons
carry impulses from the CNS to the effector organs commanded by these centers
motor neurons
are found only in the CNS, connect one neuron to another.
Interneurons
Plant tissues can be classified based on origin:
- meristematic or embryonic
- non-merismatic or permanent
- these tissues are mostly located at the tips of roots and shoots of plants – where cells actively divide
- they are responsible for the production of more cells
merismatic or embryonic tissiue
new cells formed are typically small, each with a proportionately large nucleus at the center and tiny vacuoles or no vacuoles at all
found at the tips of shoots and roots which increase in length and produce new cells
apical meristems
found at the vicinity of nodes which occurs at intervals along stems
intercalary meristems
they also increase the length of stems
increase the girth or diameter of plants. they are also found along the sides of some roots and stems.
lateral meristems
these are tissues formerly derived from meristems but have already assumed various shapes and sizes related to their specific functions as they develop and mature.
non-meristematic or permanent tissues
usuaally non-dividing with few exceptions
kinds of non-meristematic tissues:
- surface
- fundamental
- vascular
serve as the outermost covering in plants
surface tissues
two types of surface tissues:
- epidermis
- periderm
- the outermost layer of cells of all young plant organs
- one-celled, thick, and may have several layers in some.
epidermis
- functions for added protection and usually found in mature plants
- consists of sevral layers of dead cells impregnated with suberin or waxy substance when mature found in bark of trees.
periderm
are designed to give support and strength to the plant
fundamental tissues
the most abundant of all the cell types and found in almost major parts of higher plants
parenchyma
- cells are more or less spherical in shape when newly produced
- they push against each other when they mature and their thin pliable cells are flattened at points of contact
composed of uneven thick-walled cells. they often occur just beneath the epidermis.
collenchyma
- characterized by cells with thick and tough cell wall.
- these are normally impreganated with lignin
- dead at maturity and function for support
sclerenchyma
commonly found in pears and chicos (also known as “stone cells”)
are involved in the transport of substances in the body of the plants
vascular tissues
types of vascular tissues:
- xylem
- phloem
functions for conducting water and
minerals in the plant upward
xylem
which function for translocating food materials to all the growing parts of the plants and roots
phloem
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sample tissues or cells from plants are isolated and grown aritificially in specific culture media
plant tissue culture (micropropagation)