Animal Tissues

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Animal Tissues
Department of Zoology The Open University of Sri
Lanka
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• Content
• Learning Outcomes
• Introduction
• Epithelial tissues
• Connective tissue
• Muscular Tissue
• Nervous Tissue
• Classification of tissues

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Learning Outcomes

• By the end of this session you should be able to
• list the major functions of each of the four
  major animal
• tissue types
• give the functions carried out by epithelial
  tissue types
• and state their general location/s
• describe the basic features of connective
  tissue, and
• explain how the cells of this tissue type
  enable
• connective tissue to carry out its various
  tasks.
• distinguish among skeletal, cardiac, and smooth
• muscle tissues in terms of location,
  structure, and function

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Introduction

• Multicellular (large) organisms function more
• efficiently if cells become specialized for
  specific
• functions.
• A tissue is composed of cells that function
  together in a
• specialized activity.

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Introduction

• There are four types of tissues found in
• an animal.
• 1. Epithelial tissue
• 2. Connective tissue
• 3. Muscle tissue
• 4. Nervous tissue

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• 1. Epithelial tissue
• Forming tight covering and protecting
  layers below
• 2. Connective tissue
• Holding other tissues
• together and are surrounded by
• lots of nonliving material.

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• 3. Muscle tissue
• Shortening and lengthening to
• move other tissues.
• 4. Nervous tissue
• Allowing rapid flow of ions
• in and out to conduct
• signals

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1.Epithelial tissues

• Two types of epithelial tissues
• 1. Covering and lining epithelium ( outer
  layer of the
• skin and some organs)
• 2. Glandular epithelium
• ( constitute the secreting portion of
  glands)

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Epithelial tissues

• There are three types of cells in epithelial
  tissues
• Squamous thin flat cells
• Cuboidal cells are roughly square
• 3.Columnar - elongated cells.

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Epithelial tissues

• Three types of cell layers exist in epithelium
  tissues

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Glandular epithelium

• Glands are made up of single or a mass of
  epithelial
• cells.
• Two types of glands
• 1. Exocrine - Secrete their products in to
  ducts
• Eg . Salivary glands and mammary glands
• 2. Endocrine - Secrete their
  products into blood
• stream
• Eg. Pancreas

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Glandular epithelium

• Exocrine glands
• 
  
• 
  Endocrine glands

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• Functions of epithelial tissues
• Provides physical protection
• Controls permeability
• Detects sensations (sight, smell , taste,
  equilibrium)

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• 2. Connective tissue
• Most abundant and most widely distributed
  tissue in the body.
• These tissues provide support for organs and the
  
• body as a whole, protect and insulate
  internal
• organs and compartmentalize structures such
  as
• skeletal muscles, nerves.

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Connective tissue

• Connective tissue is made up of cells, ground
  
• substances and fibers. Ground substances
  together
• with fibers make matrix.

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Connective tissue

• Connective tissues can be classified as
• Loose connective tissue (fibers are loosely
  woven)
• B. Dense connective tissue
• (few cells among a dense network of fibers
  with
• little ground substances)
• C. Cartilage (tough but flexible)

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Connective tissue
Blood tissue - (composed of blood cells, cell
fragments and blood plasma)
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Connective tissue
D. Bone tissue (two types compact and
spongy) compact with osteons spongy -
no osteons
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• 3.Muscular Tissue
• Muscle cells are elongated and are called as
  muscle fibers
• These cells have main properties
• Excitability ( ability to respond to stimuli)

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Muscular Tissue

• Contractibility (ability to contract)
• Extensibility (ability to be stretched without
  tearing)
• Elasticity (ability to return to its normal
  shape)

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Muscular Tissue

• Muscle tissue is classified into three types
• (Cardiac, Skeletal and Smooth)

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Muscular Tissue

• Skeletal muscles are known as striated muscles or
  voluntary muscles.
• These muscles are attached to bones by tendons
  and are responsible for skeletal movements. Basic
  unit of a skeletal muscle is a muscle fiber.

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Muscular Tissue

• Cardiac muscle is unique and found only in
• the wall of the heart.
• Its fibers have cross striations .
• This muscle is involuntary.

Cardiac muscle
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Muscular Tissue

• Smooth muscle tissue is made up of thin
  elongated
• muscle cells called smooth muscle fibers.
• These fibers are pointed at their ends and each
  has a
• single , large oval nucleus.
• Each cell has many myofibrils which lie parallel
  to
• one another in striated pattern , as in
  skeletal muscles.

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• Nervous Tissue
• Nervous tissue is found in the brain , spinal
  cord and
• nerves and consists of only two principal
  kinds of cells ,
• neurons and neuroglia.

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Nervous Tissue

• Cells of nervous tissue have three principal
  parts
• Dendrites
• Cell body
• Axon

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Nervous Tissue

• Neuroglial cells that do not transmit impulses
  but
• instead support the activities of the
  neurons .
• Schwann cells, a type in the peripheral nervous
• system only in mammals.

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Tendon Ligament
Striated
Squamous
Areolar
Cuboidal
Smooth
Adipose
Columnar
Cardiac
Bone Cartilage
Cilliated
Skeletal
Glandular
Fluid
Blood
Lymph
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Author- Mrs. W.A.Y. Chandrani Web Content
Developer Chameera Kendaragama
Produced by The Open University of Sri Lanka
2014