Difference between revisions of "Organisation of cells animal tissues"

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In cells lining blood vessels or lung alveoli, where transportation of substances occurs through a selectively permeable surface, there is a simple flat kind of epithelium. This is called the '''simple squamous epithelium'''. Simple squamous epithelial cells are extremely thin and flat and form a delicate lining.The oesophagus and the lining of the mouth are also covered with squamous epithelium. The skin, which protects the body, is also made of squamous epithelium. Skin epithelial cells are arranged in many layers to prevent wear and tear. Since they are arranged in a pattern of layers,the epithelium is called '''stratified squamous epithelium'''.<br>
 
In cells lining blood vessels or lung alveoli, where transportation of substances occurs through a selectively permeable surface, there is a simple flat kind of epithelium. This is called the '''simple squamous epithelium'''. Simple squamous epithelial cells are extremely thin and flat and form a delicate lining.The oesophagus and the lining of the mouth are also covered with squamous epithelium. The skin, which protects the body, is also made of squamous epithelium. Skin epithelial cells are arranged in many layers to prevent wear and tear. Since they are arranged in a pattern of layers,the epithelium is called '''stratified squamous epithelium'''.<br>
  
[Image:http://science.tjc.edu/Course/BIOLOGY/1409/squamoushigh.jpg|150px]
+
http://science.tjc.edu/Course/BIOLOGY/1409/squamoushigh.jpg
 
'''Simple squamous epithelium'''
 
'''Simple squamous epithelium'''
  

Revision as of 15:51, 5 August 2014

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NCERT Textbook Chapter Tissues

Teaching Outlines

Concept #1 Animal tissues-Epithelial tissue

Learning objectives

  1. Epithelial tissue perform the function of protection.
  2. Epithelium covers most organs and cavities within the body.

Notes for teachers

Blood and muscles are both examples of tissues found in our body. On the basis of the functions they perform we can think of four different types of animal tissues, such as epithelial tissue, connective tissue, muscular tissue and nervous tissue. Blood is a type of connective tissue, and muscle forms muscular tissue.
EPITHELIAL TISSUE The skin, the lining of the mouth, the lining of blood vessels, lung alveoli and kidney tubules are all made ofepithelial tissue. Epithelial tissue cells are tightly packed without intercellular spaces and form a continuous sheet.
Epithelial tissue is classified into 3types-Squamous epithelium, Columnar epithelium and Cuboidal epithelium.
Squamous epithelium In cells lining blood vessels or lung alveoli, where transportation of substances occurs through a selectively permeable surface, there is a simple flat kind of epithelium. This is called the simple squamous epithelium. Simple squamous epithelial cells are extremely thin and flat and form a delicate lining.The oesophagus and the lining of the mouth are also covered with squamous epithelium. The skin, which protects the body, is also made of squamous epithelium. Skin epithelial cells are arranged in many layers to prevent wear and tear. Since they are arranged in a pattern of layers,the epithelium is called stratified squamous epithelium.

squamoushigh.jpg Simple squamous epithelium

Where absorption and secretion occur, as in the inner lining of the intestine, tall epithelial cells are present called columnar epithelium. This columnar (meaning ‘pillar-like’) epithelium facilitates movement across the epithelial barrier. In the respiratory tract, the columnar epithelial tissue also has cilia, which are hair-like projections on the outer surfaces of epithelial cells. These cilia can move, and their movement pushes the mucus forward to clear it. This type of epithelium is thus ciliated columnar epithelium.

goblet1.gif Simple columnar cells

digestivesimplecolumnar.jpg Simple columnar cells in the digestive tract

PseudoCilia4.jpg ciliated columnar epithelium

Epithelium consisting of cube shaped cells is known as cuboidal epithelium.They form the lining for many ducts such as pancreatic duct, salivary duct and sweat ducts. Epithelial cells often acquire additional specialisation as gland cells, which can secrete substances at the epithelial surface. Sometimes a portion of the epithelial tissue folds inward, and a multicellular gland is formed. This is glandular epithelium.

simple_cuboidal.jpg

simple-cuboidal-epithelium-high-power-640x480.jpg Cuboidal epithelium

Activities

  1. Activity No #1Epithelial_tissue_1
  2. Activity No #2Epithelial_tissue_2

Concept #2 Muscular tissue

Learning objectives

  1. Muscular tissue is responsible for the movements of the body.
  2. The movement of the internal organs like heart,stomach are also caused by muscles.

Notes for teachers

Muscular tissue consists of elongated cells, also called muscle fibres.Muscles contain special proteins called contractile proteins, which contract and relax to cause movement.This property is responsible for movement of limbs and bending of body.The movement of internal organs like heart, stomach and alimentary canal are also caused by muscles.
Muscles are of three types, based on structure,function and location.They are;

  1. Striped muscles
  2. Unstriped muscles
  3. Cardiac muscles

Striped muscles
Muscles present in our limbs can be moved or stopped by our conscious will. Such muscles are called voluntary muscles. These muscles are also called skeletal muscles as they are mostly attached to bones and help in body movement. Under the microscope, these muscles show alternatelight and dark bands or striations when stained appropriately. As a result, they are also called striated muscles. The cells of this tissue are long, cylindrical, unbranched and multinucleate.These muscles fatigue easily.
Plate66.jpg Longitudinal section of Striped muscles

Skeletal+muscle+01a.jpg T.S of Striped muscles

Unstriped muscles
Unstriped muscles are made up of spindle shaped, elongated muscle fibres without striations. They are called smooth muscles.The movement of food in the alimentary canal or the contraction and relaxation of blood vessels are involuntary movements. We cannot control these movements on our own will. Smooth muscles or involuntary muscles control such movements. They are also found in the iris of the eye, in ureters and in the bronchi of the lungs.

SMOOTH%20MUSCLE%20COMPOSITE.jpg Unstriped muscles

40_05Muscle-smooth.jpg Unstriped muscles

Cardiac muscles
The muscles of the heart show rhythmic contraction and relaxation throughout life. These involuntary muscles are called cardiac muscles. Heart muscle cells are cylindrical,elongated, branched and uninucleate. They do not fatigue easily.

MuscleCardiacCells.gif Cardiac muscles

cardiac-muscle-tissue-structure.jpg Cardiac muscles

3D4M000006783.jpg Cardiac muscles

Activities

  1. Activity No #1Muscular_tissue
  2. Activity No #2 page_name_concept_name_activity2

Concept #3

Learning objectives

Notes for teachers

Activities

  1. Activity No #1 page_name_concept_name_activity1
  2. Activity No #2 page_name_concept_name_activity2

Concept #4

Learning objectives

Notes for teachers

Activities

  1. Activity No #1 page_name_concept_name_activity1
  2. Activity No #2 page_name_concept_name_activity2


Assessment Activities for CCE

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