Topic: Connective tissues and nervous tissue

Author: Elżbieta Szedzianis

Target group

7th‑grade student of the elementary school.

Core curriculum

III. The human body.

1. Hierarchical structure of the human body. The student presents the hierarchy of the structure of the human body (cells, tissues, organs, organ systems, organism).

Lesson objectives

Students describe the structure and properties of cartilage tissue, bone tissue and blood.

The criteria for success

• you will recognise cartilage tissue, bone tissue, nervous tissue and blood in a diagram as well as during microscopic observation;

• on the example of bone tissue, cartilage tissue, nervous tissue and blood you will specify the relationship between structure and function;

• you will explain the term - connective tissue and nervous tissue.

Key competences

• communication in the mother tongue;

• communication in foreign languages;

• mathematical competence and basic competences in science and technology; 

• digital competence;

• learning to learn;

• social and civic competences.

Methods/forms of work

„Eenie, meeny” educational game, „Old maid” educational game, microscopic observation, alternative observation, talk.

Individual activity, activity in pairs and activity in groups.

Teaching aids:

• abstract;

• interactive whiteboard or traditional blackboard;

• tablets/computers;

• microscopic imaging equipment;

• ready‑made microscope slides of bone tissue, cartilage tissue and blood;

• “Old maid” game cards.

Lesson plan overview

Introduction

1. The teacher invites students to play “Eenie, meenie” game. The teacher divides the students into two groups. Each group writes down concepts learnt during the previous lesson. Their lists should include concepts which are difficult to define, but which they are able to explain themselves. Students count out one by one within each group, each student memorises his/her number. The teacher draws two numbers. Students with these numbers from the first group ask opponents (with the same numbers) to explain the selected concepts. Students from the second group score one point for the correct answer. When answering, the students may only consult with each other in case of doubts. The correctness of their answer is judged by the students from the first group. If they asses the answer as being incorrect, the group loses one point. The game lasts five rounds.

2. The teacher specifies the lesson topic and objective in a language the student understands, and the criteria for success.

Realization

1. The teacher displays a slideshow entitled “Connective tissues” and discusses individual types of presented tissues.

2. Students, working in pairs, conduct microscopic observations of tissues and document them. They compare the observed tissue slides with the illustrations found in the abstract.

3. Students define the concept of connective tissue and nervous tissue, discuss the structure and function of bone tissue, cartilage tissue and blood.

4. The students review the knowledge gained during the lesson playing „Old maid”.

Summary

The teacher asks the students to finish the following sentence: “In today's lesson I have learned...”

Homework for the interested students

Students do interactive exercise no. 1.

Attachment

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Nervous tissue and connective tissues

Nervous tissue is responsible for receiving, analyzing and transferring information. It is composed of neural cells called neurones, which have a specific shape and which create thick networks or long strands. A neuron usually has a star‑shaped body in which there are cell organelle and 2 types of neural protrusions – dendrites and axons. Dendrites are short, branched structures which receive the neural impulses and conduct them to the body of the neurones. Axons are single, long protrusions which conduct the neural impulses from the body of the cell to other neural cells, called effectors. Effectors are cells or organs of the body that realize the answer to a received stimulus, e.g. skeletal muscles (stimulus – hot iron, effector – muscle that contracts to withdraw the burnt finger).

Between the neurones there are glial cells. These are 90% of the brain cells. They create a cover for the neurones and provide them with nutrients. Last research shows that, besides those functions, at least some part of the glial cells is able to modify the work of neurones. It has also been observed that there is a positive relation between the number of glial cells (called astrocytes) and the plasticity of behaviour of mammals, and, in the case of humans, the imagination and creativity.

Neural cells create the brain and nerves, are found in sensory organs and in skin, and their protrusions reach nearly to all the cells of the body.

Connective tissues are a group of tissues with the greatest diversity. Depending on the structure, they fill free spaces between other tissues and organs, form the core of internal organs and framework of the body, participate in thermoregulation processes, perform reserve function, transport oxygen and nutrients. Depending on the functions performed, the connective tissue cells have different shapes and structures. They are characterised by the ability to produce large amounts of intercellular substance in which they are loosely distributed. The intercellular substance may be hard (mineralised), gelatinous or liquid. It consists of an amorphous basal substance and protein fibres. Due to the structure and function of the connective tissues in the body, we distinguish, among others, adipose tissue, supportive tissue (bone and cartilage) and liquid tissues – blood and lymph.

Adipose tissue is made up of spherical cells, filled with fat which pushes cytoplasm and cell nucleus to the edge of the cell. In addition to being a storage of energy compounds in the form of fat, this tissue protects the body and internal organs against injuries and constitutes a  thermal insulation.

Bone tissue is part of the bones that form the framework of the body, support the muscles and protect the internal organs. It is made of a hard, mineralised intercellular substance in which mainly inorganic compounds, such as calcium, phosphorus and magnesium salts, are deposited. Together with the protein fibres, they form bone lamellae that can lay around the blood vessel and nerves running in the canals inside the bones. Bone cells are found between the lamellae.

Cartilage tissue is composed of a jelly‑like, elastic extracellular substance. There are scattered recesses in it – cartilicular cavities in which there are 1, 2 or 3 cartilage cells. Protein fibres occur in the intercellular substance as well, thanks to which the cartilage is elastic (e.g. the cartilage of the ear) and tensile (cartilages of ligaments and tendons). Cartilage tissue often accompanies bones, forming joint surfaces, which facilitates bone movement in the joints. It constitutes a large percentage of the skeleton of young individuals, as well as the framework of organs which must maintain elasticity and flexibility, such as respiratory tract, nose, rib bases.

The connective tissues that are in motion are blood and lymph. here, the intercellular substance is liquid and consists mainly of water as well as organic and inorganic compounds contained in water. In case of blood, it is called plasma. It contains such cells as: erythrocytes – red cells transporting oxygen from lungs to cells and leucocytes – white cells fighting foreign bodies (among others, bacteria and viruses). Apart from them, plasma contains fragments of cells, called thrombocytes or blood platelets, participating in blood coagulation processes.

• The human body has got a hierarchical structure, which can be illustrated as follows: cell – tissue – organ – organ system – organism.

• Individual structures of the body cooperate with each other, performing vital functions.

• There are 4 types of tissues in the human body: epithelial, muscular, nervous, connective.

• The structure of the tissue shows adaptations to the function performed.

• Connective tissue fills the spaces between other tissues, has a very diverse structure and function.