Slide 1 : Mast Cells
Large, spherical or oval cells
Mostly gathered along small blood vessels, lymphatics and nerves.
They secrete three chemicals
Heparin (anticoagulant)
Histamine (vasodilator)
Serotonin (vasoconstrictor)
Slide 2 : Lymphoid or Lymphocyte cells
Form antibodies and are seen at the sites of inflammation.
Plasma cells
They are mature B lymphocytes.
Eosinoplils
Play phagocytic role in inflammatory and allergic reactions.
Fibres of loose Connective Tissue : Fibres of loose Connective Tissue Secreted by fibroblast cells.
They are three kinds
Slide 5 : Collagen
Long wavy fibres of a soluble collagen or tropocollagen protein
Toughest fibrous protein
When boiled in water changes into gelatin.
Used in Tanning and Leather industry
Elastin
Made of Elastin protein
Branched and elastic
Reticular fibres
Made of reticulin protein (modified collagen)
Extensively branched forming network
MUSCULAR TISSUE : MUSCULAR TISSUE These are responsible for movements of organs and locomotion of body in response to stimuli.
These develop from embryonic mesoderm
Iris and cililary body of eyes are
exceptional being ectodermal
Kinds of Muscles : Kinds of Muscles
STRIATEDMUSCLES : STRIATEDMUSCLES
SMOOTH MUSCLES : SMOOTH MUSCLES
CARDIAC MUSCLES : CARDIAC MUSCLES
Nervous Tissue : Nervous Tissue Highly cellular
How does this compare to the other 3 tissue types? 1.
2 cell types : 2 cell types Neurons
Functional, signal
conducting cells
Neuroglia
Supporting cells
Slide 13 : The structural and functional unit of neural system
Typical post mitotic cell of nervous system
That is, fully formed neurons do not divide.
They are specialized ectodermal cells
Capable of conducting electrochemical nerve impulses.
The human body consists of over 100 billion neurons
Mostly located in the brain. Neuron
Properties of neurons : Properties of neurons Excitability
The ability to respond to stimuli and
Conductivity
The ability to conduct a signal
Neurons (Nerve Cells) : Neurons (Nerve Cells)
Neurons (Nerve Cells) : Neurons (Nerve Cells)
What is Myelination ? : What is Myelination ?
Slide 18 : Plant tissues
Slide 20 : Plant tissues
Permanent tissues : Permanent tissues Simple tissues = permanent tissue
Composed of only one cell type.
Parenchyma tissue
Made of living thin walled cells with large vacuoles and flattened sides.
Parenchyma cells retain the ability to become meristematic and can heal wounds and regenerate other types of tissues.
Simple tissues : Simple tissues Collenchyma tissue
Gives support to young petioles, stems and veins of leaves.
Cell walls are thickened made up of cellulose.
A living tissue
Sclerenchyma tissue
Composed of thick walled cells
Found throughout the plant as fibers and sclerids.
he protoplasts in these cells die eventually.
Common in bark, stems and nut shells.
SCLEREIDS : SCLEREIDS Short sclerenchyma cells
Isodiametric or irregular in shape.
Walls are hard
Greatly thickened with lignin
The lumen is greatly reduced.
Show simple pits. Sclerenchyma
Types of Sclerieds : Types of Sclerieds
Slide 26 : Fibers
Thick walled cells
Provide support to plants.
Most xylem tissue is missing in one or two of these cell types.
Fiber crops : Fiber crops Field crops grown for their fibres
Traditionally used to make paper, cloth or rope.
Fibres can be extracted from phloem (Bast)
Slide 28 : Bast = Stem-skin fibres
Jute
(widely used, cheapest fibre after cotton)
Flax
(which produces linen)
Ramie
Slide 29 : Hemp
Kenaf
Abaca
Nettles
Important fibres : Important fibres Musa textilis Manila hemp is used to make ropes and cords.
Agave sisalana Sisal hemp is used to make coarse ropes and twines.
Cannabis sativa True hemp or marijuana hemp is used to make twine and ropes.
Slide 31 : Linum usitatissimum
Flax is used to make linen.
Linen is flexible, soft and lustrous
But not as elastic and flexible as cotton.
Boehmeria nivea
Ramie is used to make fine oriental textiles and more recently, the Western clothing.
Corchorus capsularis
Jute is used to make coarse fabrics, bags and sacks. After cotton, jute is the most important textile fibre in world of commerce.
Other fibers (Trichomes, Leaf, fruit and other fibers) : Other fibers (Trichomes, Leaf, fruit and other fibers) Cotton
Bamboo
Esparto
Slide 33 : Papaya
Coir
Sisal