SIXTH GRADE: TISSUE AND TISSUE TYPES

TISSUE AND TISSUE TYPES

Tissue is a cellular organizational level intermediate between cells and a complete organism.

ATOMS à MOLECULES à PRIMARY, SECONDARY TERTIARY AND QUATERNARY STRUCTURES à ORGANELLES à CELLS à TISSUES à ORGANS à SYSTEMS à ORGANISM

A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning. Organs are then formed by the functional grouping together of multiple tissues.

The study of tissue is known as histology or, in connection with disease, histopathology. 

ANIMAL TISSUES

Animal tissues can be grouped into four basic types: connective, muscle, nervous, and epithelial. Multiple tissue types comprise organs and body structures.

Connective tissue

Connective tissues are fibrous tissues. They are made up of cells separated by non-living material, which is called extracellular matrix. Connective tissue gives shape to organs and holds them in place. Both blood and bone are examples of connective tissue. As the name implies, connective tissue serves a "connecting" function.  It supports and binds other tissues. Unlike epithelial tissue, connective tissue typically has cells scattered throughout an extracellular matrix.

Types of Connective Tissue above

Muscle tissue

Muscle tissue functions to produce force and cause motion, either locomotion or movement within internal organs. Muscle tissue is separated into three distinct categories: visceral or smooth muscle, which is found in the inner linings of organs; skeletal muscle, in which is found attached to bone providing for gross movement; and cardiac muscle which is found in the heart, allowing it to contract and pump blood throughout an organism.

Types of muscle tissue in humans

Structure of muscles

Nervous tissue

Cells comprising the central nervous system and peripheral nervous system are classified as neural tissue. In the central nervous system, neural tissue forms the brain and spinal cord and, in the peripheral nervous system forms the cranial nerves and spinal nerves, inclusive of the motor neurons. The nervous tissue is important in communication.

Neuron cell

 

Epithelial tissue

The epithelial tissues are formed by cells that cover organ surfaces such as the surface of the skin, the airways, the reproductive tract, and the inner lining of the digestive tract. This tissue provides a barrier between the external environment and the organ it covers. In addition to this protective function, epithelial tissue may also be specialized to function in secretion and absorption. Epithelial tissue helps to protect organisms from microorganisms, injury, and fluid loss.

QUESTIONS ON TISSUES AND TISSUE TYPES

In your notes, copy and answer the following questions:

1.      Please describe the different levels of organization starting from atoms all the way to an organism.

2.      Define tissue.

3.      Define histology and histopathology.

4.      State the 4 different types of animal tissue.

5.       

a.       Define connective tissue.

b.      What is the function of connective tissue?

c.       Draw and label the different types of connective tissue.

6.      .

a.       What is the main function of muscle tissue?

b.      Draw the different types of muscle tissue and state where they can be found.

7.      .

a.       What are the 2 types of systems where you can find neural tissue?

b.      Draw a neuron cell and label all its different parts.

8.      .

a.       Where do you find epithelial tissue?

b.      What are the functions of epithelial tissue?

c.       Draw the different types of epithelial tissue.