Comparison of epithelial and connective tissue. Fabrics. Types of fabrics, their properties. Connective tissue types and their functions

Comparison of the structure of tissues of multicellular organisms (for example: plants, fungi, animals and humans). Types of tissues and their functions

Laboratory work

Biology and genetics

Laboratory work No. 3 Topic: Comparison of the structure of tissues of multicellular organisms using the example of: plants, fungi, animals and humans. Types of tissues and their functions. Tissue is a group of cells and intercellular substance united by a common structure, function and origin...

Laboratory work No. 3

Subject: Comparison of the structure of tissues of multicellular organisms (for example: plants, fungi, animals and humans).Types of tissues and their functions.

Textile this is a group of cells and intercellular substance, united by a common structure, function and origin. There are four main types of tissue in the human body: epithelial (integumentary), connective, muscle and nervous.

Target : learn to find structural features of cells of different organisms, compare them with each other; study the structure of various types of tissue and determine their functions; master the terminology of the topic.

Equipment : microscopes, slides and cover glasses, glass rods, microscopic preparations of cells of multicellular animals, microscopic preparations of epithelial, muscle, connective, nervous tissue.WITH containers with water, Elodea leaf, yeast, Bacillus subculture.

Safety precautions: work carefully with a microscope; treat the rules of working with it responsibly; When turning the lens to high magnification, carefully work with the screw so as not to crush the microspecimen.

PROGRESS OF WORK

Work 1.

1. Prepare a preparation of Elodea leaf cells. To do this, separate the leaf from the stem, place it in a drop of water on a glass slide and cover with a coverslip.
2. Examine the preparation under a microscope. Find chloroplasts in the cells.
3. Draw the structure of an Elodea leaf cell. Write captions for your drawing.

1. membrane
2.chloroplasts
3.cytoplasm
4.core
5.vacuole

4. Look at Figure 1.

5.Draw a conclusion about the shape and size of the cellsdifferent plant organs

Rice. 1. Color, shape and size of cells of different plant organs

Watermelon cell structure

O - cell membrane; n - granular wall layer of protoplasm; T - strands of protoplasm; yak - nuclear pocket (accumulation of protoplasm in which the nucleus lies ( I ) with nucleolus and plastids); V - vacuoles (according to Rostovtsev and Komarnitsky).

A living cell made from a coconut shell with branched canals and a very thick lignified shell: 1 - pore canals filled with cytoplasm; 2 - core; 3 - layered cell membrane; 4 - cytoplasm.

Plant leaf pulp cell

Stinging nettle leaf hair:

1 - base of the hair, 2 - burning cell, 3 - nucleus, 4 - vacuole, 5 - cytoplasm, 6 - broken off tip of the burning cell.

Work 2.

1.Remove some mucus from the inside of your cheek with a teaspoon.

2. Place the mucus on a slide and tint with blue ink diluted in water. Cover the preparation with a coverslip.

3. Examine the preparation under a microscope.

Job 3

Consider a ready-made microslide of cells of a multicellular animal organism.

Compare what you saw in the lesson with the images of objects on the tables.

Compare these cells with each other.

Enter the comparison results in Table 1

Answer the questions:

What are the similarities and differences between cells?

All these cells have a cell membrane, cytoplasm, hereditary material in the form of chromosomes, ribosomes, and inclusions. Eukaryotes (all except bacteria) have mitochondria, EPS, Golgi complex, lysosomes, nucleus, and centrioles. Plant cells, unlike animal cells, have vacuoles, plastids and a cellulose membrane. Bacteria have the most primitive structure, consisting of a murein shell, capsule, and ribosome.

What are the reasons for the similarities and differences between cells of different organisms?

The fact is that any living organism consists of cells, but cells perform different functions.

Job 4

I. Epithelial tissue

1. Examine a microslide of epithelial tissue. Sketch.

2. Name the types of epithelial tissue.

Classification of epithelial tissues:

1. integumentary epithelia- forming external and internal covers;
2. glandular epithelia- making up most of the body's glands.
3. Ciliated epitheliumforming the internal coverings of the respiratory tract (retains dust and other foreign bodies with the help of movable cilia).

Morphological classification of integumentary epithelium:

• single-layer squamous epithelium, endothelium - lines all blood vessels;
• mesothelium - lines the natural human cavities: pleural, abdominal, pericardial;
• single-layer cuboidal epithelium - the epithelium of the renal tubules;
• single-layer single-row cylindrical epithelium - the nuclei are located at the same level;
• Single-layer multirow columnar epithelium - nuclei are located at different levels (pulmonary epithelium);
• stratified squamous keratinizing epithelium - skin;
• multilayered squamous non-keratinizing epithelium - oral cavity, esophagus, vagina;
• transitional epithelium - the shape of the cells of this epithelium depends on the functional state of the organ, for example, the bladder.

Glandular epithelium forms the vast majority of glands in the body. It consists of: glandular cells - glandulocytes; basement membrane.

Classification of glands according to the number of cells:

1. unicellular (goblet gland);
2. multicellular - the vast majority of glands.

According to the method of removing secretions from the gland and according to its structure:

• exocrine glands - have an excretory duct;
• endocrine glands - do not have an excretory duct and secrete hormones into the blood and lymph.

According to the method of secretion from a glandular cell:

• merocrine - sweat and salivary glands;
• apocrine - mammary gland, sweat glands of the armpits;
• Holocrine - sebaceous glands of the skin.

3. List the functions of epithelial tissue.

Functions of epithelial tissue:

• protective function against mechanical damage
• participates in metabolism, at the initial and final stages
• regulate the constancy of the internal environment of the body, metabolism, etc..

II. Connective tissue

1. Consider a connective tissue preparation. Sketch.

2. Name the types of connective tissue.

Most of the hard connective tissue is fibrous (from lat. fiber fiber): composed of fibers collagen and elastin . Connective tissue includes bone, cartilage, fat and others. Connective tissue also includes blood and lymph . Therefore, connective tissue is the only tissue that is present in the body in 4 types: fibrous (ligaments), solid (bones), gel-like (cartilage) and liquid (blood, lymph, as well as intercellular, spinal and synovial and other fluids).

3. List the functions of connective tissue.

Functions of connective tissue:

1) gives strength to organs, forming the basis of tendons and skin

2) performs a supporting function

3) Provides transportation of nutrients and oxygen throughout the body.

4) contains a supply of nutrients

III. Muscle tissue

1. Examine a microscopic specimen of muscle tissue. Sketch.

1. Name the types of muscle tissue.

Types of muscle tissue

• Smooth muscle tissueThe cells are mononuclear, located in layers in the walls of blood vessels, airways, bladder, digestive tract and other hollow internal organs.
• Transversely striated skeletal muscle tissueThe cells are multinucleated and form the muscles of the body, moving the human skeleton.
• Transversely striated cardiac muscle tissueforms the heart muscle, which contracts involuntarily.

3. List the functions of muscle tissue.

Functions of muscle tissue:

Motor. Protective. Heat exchange. You can also highlight one more function - facial (social). Facial muscles, controlling facial expressions, transmit information to others.

IV. Nervous tissue

1. Examine a microscopic specimen of nervous tissue. Sketch.

1. Name the types of nervous tissue.

Neurons - perform the main function.
Neuroglia - perform an auxiliary function (they surround neurons, protect them and provide them with support, protection and nutrition, there are 10 times more of them than neurons).

3. Function of nervous tissue.

Functions of nervous tissue:

• Excitability and conductivity. Excitation that appears under the influence of various environmental stimuli is transmitted to the central nervous system. It then ensures that the body responds to this irritation.

Questions

1. What tissue do the glands belong to?

Glands belong to epithelial tissue.

1. What is the peculiarity of the structure of connective tissue?

Feature: there is much more intercellular substance than cellular elements.

1. In the walls of which organs is smooth muscle tissue located?

They are located in layers in the walls of blood vessels, airways, bladder, digestive tract and other hollow internal organs.

4. Thanks to the contractions of which muscles does movement occur?

Due to the contraction of skeletal muscles.

5. What tissue is characterized by electrical signals?

For nervous tissue.

Problematic issues

1. What tissues are involved in wound healing?

Connective tissue, as well as epithelial

2. Which tissues lack blood vessels?

Epithelial tissues. Epithelium lines the surface of the human body, the inner surface of hollow organs and forms most of the body's glands. The epithelium can be keratinized or non-keratinized. Epithelium is a layer of cells that are located on the basement membrane. They are devoid of blood vessels and have a high ability to regenerate.Cartilage, lens, and cornea are devoid of blood and lymphatic vessels.

Conclusion:

We examined the structure of prokaryotic and eukaryotic cells. We learned to find differences between cells of different organisms and highlight their similarities, studied the structure and functions of cell organelles and the cell itself as a whole.

We examined the structure of various types of tissues of the animal body. We studied the structure and functions of nervous, epithelial, muscle and connective tissue and their location in the human body.

The human body is a certain integral system capable of regulating itself independently and periodically recovering if necessary. This system, in turn, is represented by a large set of cells.

At the cellular level, very important processes take place in the human body, which include metabolism, reproduction, and so on. In turn, all the cells of the human body and other non-cellular structures are grouped into organs, organ systems, tissues, and then into a full-fledged organism.

Tissue is the union of all cells found in the human body and non-cellular substances that are similar to each other in the functions they perform, appearance, and formation.

Epithelial tissue, better known as epithelium, is the tissue that forms the basis of the surface of the skin, serous membrane, cornea of ​​the eyeball, digestive, genitourinary and respiratory systems, genital organs, and also participates in the formation of glands.

This tissue is characterized by a regenerative feature. Numerous types of epithelium differ in their appearance. The fabric can be:

• Multilayer.
• Equipped with a stratum corneum.
• Single-layer, equipped with villi (renal, coelomic, intestinal epithelium).

Such tissue is a boundary substance, which implies its direct participation in a number of vital processes:

1. Gas exchange occurs through the epithelium in the alveoli of the lungs.
2. The process of urine secretion occurs from the renal epithelium.
3. Nutrients are absorbed into the lymph and blood from the intestinal lumen.

The epithelium in the human body performs the most important function - protection, it in turn is aimed at protecting the underlying tissues and organs from various types of damage. In the human body, a huge number of glands are created from a similar base.

Epithelial tissue is formed from:

• Ectoderm (covering the cornea of ​​the eye, oral cavity, esophagus, skin).
• Endoderm (gastrointestinal tract).
• Mesoderm (organs of the genitourinary system, mesothelium).

The formation of epithelial tissue occurs at the initial stage of embryo formation. The epithelium, which is part of the placenta, is directly involved in the exchange of necessary substances between the fetus and the pregnant woman.

Depending on the origin, epithelial tissue is divided into:

• Skin.
• Intestinal.
• Renal.
• Ependymoglial epithelium.
• Coelomic epithelium.

These types of epithelial tissue are characterized by the following features:

1. Epithelial cells are presented in the form of a continuous layer located on the basement membrane. Through this membrane, epithelial tissue is saturated, which does not contain blood vessels.
2. The epithelium is known for its restorative properties; the integrity of the damaged layer is fully regenerated after a certain period of time.
3. The cellular basis of tissues have their own polarity of structure. It is associated with the apical and basal parts of the cell body.

Within the whole layer between neighboring cells, communication is formed quite often with the help of desmos. Desmos are numerous structures of very small sizes, they consist of two halves, each of them in the form of a thickening is superimposed on the adjacent surface of neighboring cells.

Epithelial tissue has a coating in the form of a plasma membrane containing organelles in the cytoplasm.

Connective tissue is presented in the form of non-motile cells called:

• Fibrocytes.
• Fibroplasts.

Also, this type of tissue contains a large number of free cells (wandering, fat, fat, and so on). Connective tissue aims to provide shape to the human body, as well as stability and strength. This type of tissue also connects organs.

Connective tissue is divided into:

• Embryonic- is formed in the mother's womb. Blood cells, muscle structure, and so on are formed from this tissue.
• Reticular– consists of reticulocyte cells that accumulate water in the body. The tissue participates in the formation of antibodies; this is facilitated by its content in the organs of the lymphatic system.
• Interstitial- supporting tissue of organs, it fills the gaps between internal organs in the human body.
• Elastic– located in tendons and fascia, contains a huge amount of collagen fibers.
• Fatty– aimed at protecting the body from heat loss.

Connective tissue is present in the human body in the form of cartilage and bone tissue, which make up the human body.

Difference between epithelial tissue and connective tissue:

1. Epithelial tissue covers organs and protects them from external influences, while connective tissue connects organs, transports nutrients between them, and so on.
2. Connective tissue has a more pronounced intercellular substance.
3. Connective tissue is presented in 4 types: fibrous, gel-like, hard and liquid, epithelial in the 1st layer.
4. Epithelial cells resemble cells in appearance; in connective tissue they have an elongated shape.

Epithelium is a collection of cells covering the surfaces of the body and lining its cavities. Epithelial tissue plays a protective, receptor function. It ensures the absorption of substances and their release, and participates in gas exchange. There are cubic, flat and columnar epithelium. Flat is found in the vessels of the circulatory and lymphatic systems, pulmonary alveoli, and body cavities. Cuboidal epithelium is located in the retina of the eyes, columnar epithelium is located in the intestinal tract.

Connective tissue consists of fibers - well-developed intercellular structures (elastic, collagen and reticular), as well as the main structureless substance. The types of connective tissue are: loose, dense (cartilage, bone), reticular. It performs storage, protective and nutritional functions.

In cartilage tissue, chondrocytes are embedded in the ground substance. There are elastic, hyaline, fibrous cartilage. Hyaline cartilage lines the joint sockets and articular heads. Elastic cartilage is found in the auricles, fibrous cartilage is found in the intervertebral discs. The functions of cartilage are mechanical and connective.

Bone tissue is formed from connective tissue or by replacing cartilage. Its main substance consists of collagen fibers and protein-polysaccharide complexes. Fully formed bone tissue consists of bone plates, inside of which lie osteocytes.

Reticular connective tissue is associated with large, branched, reticular cells that can develop into phagocytes or blood elements. Reticular cells and fibers form a supporting network, within which free cells are present. Lymphatic organs and hematopoietic tissues have a similar structure.

Muscle and nerve tissue

Muscle tissue is divided into smooth and striated. Smooth muscle consists of spindle-shaped cells and is characterized by slow contraction and slow relaxation. Smooth muscles form the muscles of internal organs: blood vessels, uterus, intestines, respiratory tract, ureters. Muscle tissue is innervated by the autonomic nervous system.

Striated tissue is formed by multinucleated cells called muscle fibers. It consists of skeletal muscles, which are innervated by spinal nerves. Striated muscles can contract quickly and fatigue quickly.

Nerve tissue consists of nerve cells (neurons) and glial cells. Nerve cells receive signals from the environment and translate these signals into nerve impulses that are carried to nerve endings. Neurons exhibit secretory activity; they secrete mediators - physiologically active substances involved in contacts between cells. Neurons can also release hormones.

Glial cells are necessary for the transport of substances to nerve cells from the blood and back. They form myelin sheaths and perform supporting and protective functions.

Epithelial (integumentary) tissue, or epithelium, is a boundary layer of cells that lines the integument of the body, the mucous membranes of all internal organs and cavities, and also forms the basis of many glands.

The epithelium separates the organism (internal environment) from the external environment, but at the same time serves as an intermediary in the interaction of the organism with the environment.

Epithelial cells are tightly connected to each other and form a mechanical barrier that prevents the penetration of microorganisms and foreign substances into the body.

Epithelial tissue cells live for a short time and are quickly replaced by new ones (this process is called regeneration).

Epithelial tissue is also involved in many other functions: secretion (exocrine and endocrine glands), absorption (intestinal epithelium), gas exchange (lung epithelium).

The main feature of the epithelium is that it consists of a continuous layer of tightly adjacent cells. The epithelium can be in the form of a layer of cells lining all surfaces of the body, and in the form of large accumulations of cells - glands: liver, pancreas, thyroid, salivary glands, etc. In the first case, it lies on the basement membrane, which separates the epithelium from the underlying connective tissue . However, there are exceptions: epithelial cells in the lymphatic tissue alternate with connective tissue elements; such epithelium is called atypical.

Epithelial cells, arranged in a layer, can lie in many layers (stratified epithelium) or in one layer (single-layer epithelium). Based on the height of the cells, epithelia are divided into flat, cubic, prismatic, and cylindrical.

Consists of cells, intercellular substance and connective tissue fibers. It consists of bones, cartilage, tendons, ligaments, blood, fat, it is present in all organs (loose connective tissue) in the form of the so-called stroma (framework) of organs.

In contrast to epithelial tissue, in all types of connective tissue (except adipose tissue), the intercellular substance predominates over the cells in volume, i.e. the intercellular substance is very well expressed. The chemical composition and physical properties of the intercellular substance are very diverse in different types of connective tissue. For example, blood - the cells in it “float” and move freely, since the intercellular substance is well developed.

In general, connective tissue makes up what is called the internal environment of the body. It is very diverse and is represented by various types - from dense and loose forms to blood and lymph, the cells of which are in the liquid. The fundamental differences in the types of connective tissue are determined by the ratios of cellular components and the nature of the intercellular substance.

IN dense Fibrous connective tissue (muscle tendons, joint ligaments) is dominated by fibrous structures and experiences significant mechanical loads.

Loose fibrous connective tissue is extremely common in the body. It is very rich, on the contrary, in cellular forms of different types. Some of them are involved in the formation of tissue fibers (fibroblasts), others, which is especially important, provide primarily protective and regulatory processes, including through immune mechanisms (macrophages, lymphocytes, tissue basophils, plasma cells).

Nervous tissue consists of two types of cells: nerve (neurons) and glial. Glial cells are closely adjacent to the neuron, performing supporting, nutritional, secretory and protective functions.

Neuron is the basic structural and functional unit of nervous tissue. Its main feature is the ability to generate nerve impulses and transmit excitation to other neurons or muscle and glandular cells of working organs. Neurons can consist of a body and processes. Nerve cells are designed to conduct nerve impulses. Having received information on one part of the surface, the neuron very quickly transmits it to another part of its surface. Since the processes of a neuron are very long, information is transmitted over long distances. Most neurons have processes of two types: short, thick, branching near the body - dendrites and long (up to 1.5 m), thin and branching only at the very end - axons. Axons form nerve fibers.

A nerve impulse is an electrical wave traveling at high speed along a nerve fiber.

Depending on the functions performed and structural features, all nerve cells are divided into three types: sensory, motor (executive) and intercalary. Motor fibers running as part of nerves transmit signals to muscles and glands, sensory fibers transmit information about the state of organs to the central nervous system.

Municipal educational institution "Gymnasium" urban settlement Sabinsky municipal district of the Republic of Tatarstan

Regional seminar “Increasing creative initiative of students

in biology lessons through the use of information technology"

"Animal tissues: epithelial and connective"

Open biology lesson in 6th grade

according to the textbook N.I. Sonina "Living Organism"

2009/2010 academic year

Target: study the structural features of animal tissues

Tasks:

Educational:

To form an idea of ​​the structure of animal tissues: epithelial and connective;

To develop the ability to prove the correspondence of the structure of animal tissues to the functions performed;

Educational:

Develop the ability to compare, analyze, generalize, work with a microscope and micropreparations;

Development of self-control;

Develop a conscious attitude towards the result of your educational work;

Educational:

Foster a sense of cooperation and mutual assistance towards each other.

Lesson type: combined, laboratory work

Teaching methods: partially search, explanatory and illustrative

Equipment: textbook, microscope, microslides “Epithelial tissue”, “Bone tissue”, “Cartilage”, “Blood”, “Adipose tissue”, workbook for the textbook, computer, multimedia projector, multimedia presentation “Animal tissues”.

PROGRESS OF THE LESSON.

Organizational moment.

Updating knowledge and skills.

In the last lesson, we looked at the main types of plant tissues.

Frontal survey.

Define the term “fabric”?

What tissues are classified as plant tissues?

What functions do they perform in the body?

Test work on the topic “Plant tissues”.

Option 1.

1. Educational fabric provides:

A) the shape of the plant

B) plant growth

B) movement of substances

2. The pulp of the leaf is formed:

A) covering tissue

B) mechanical fabric

B) main fabric

D) conductive fabric

3. Function of integumentary tissue:

B) gives support to plants

D) gives strength and elasticity

4. Conductive tissues are located in

A) only in leaves

B) in the plant embryo, root tip

B) in leaves, stem and root

D) walnut shell

5. Mechanical fabric consists of:

A) living cells

B) thickened and lignified cells

B) dead cells

D) living and dead cells

Option 2.

1. Educational tissue consists of:

A) dead cells

B) small, constantly dividing cells

B) living and dead cells

D) thickened and lignified cells

2. Strength and elasticity are given by:

A) covering tissue

B) mechanical fabric

B) educational fabric

D) conductive fabric

3. Conductive fabric function

A) protection

B) supply of nutrients

C) movement of water, minerals and organic substances.

D) plant growth

4. Location of the main fabric

A) root tip, plant embryo

B) pulp of leaves and fruits, soft parts of flowers

B) leaf skin, cork layers of tree trunks

D) root, stem and leaf

5. What is the function of the leaf skin

A) protecting the plant from damage and adverse effects

B) gives support to plants

B) accumulates nutrients

D) gives strength and elasticity

Learning new material.

We continue to study the topic “Fabrics”. Let's consider the main tissues of the animal body. Lesson topic: “Animal tissues: epithelial and connective”

Teacher's story.

Textile - systems of cells similar in origin, structure and function. Included fabrics also includes intercellular substances and structures - products of cellular activity. There are 4 types of animal tissues - epithelial, connective, muscle and nervous.

Epithelial tissue (epithelium) covers the surface of the body, lining the walls of hollow internal organs, forming the mucous membrane, glandular (working) tissue of the exocrine and endocrine glands. The epithelium separates the body from the external environment and performs integumentary, protective and excretory functions. The epithelium is a layer of cells lying on the basal membrane; there is almost no intercellular substance. (Slide 2)

Connective tissue consists of a basic substance - cells and intercellular substance - collagen, elastic and reticular fibers. There are connective tissue itself (loose and dense fibrous) and its derivatives (cartilage, bone, fat, blood and lymph). Connective tissue and its derivatives develop from mesenchyme. It performs supporting, protective and nutritional (trophic) functions. Possessing regenerative (restorative) ability, connective tissue takes an active part in wound healing, forming a connective tissue scar.

Bonetextile- a type of connective tissue from which bones are built - the organs that make up the bony skeleton. Bone tissue consists of interacting structures: bone cells, intercellular organic matrix of bone (organic skeleton of bone) and the main mineralized intercellular substance. (slide 3)

Cartilage- one of the types of connective tissue, characterized by a dense elastic intercellular substance that forms special shells and capsules around chondrocyte cells and groups. (slide 4)

Blood- connective tissue that fills the cardiovascular system of vertebrates, including humans, and some invertebrates. Consists of plasma (interstitial fluid), cells: erythrocytes, leukocytes and platelets. (slide 5)

Adipose tissue- a type of connective tissue of animal organisms, formed from mesenchyme and consisting of fat cells - adipocytes. Almost the entire fat cell, the specific function of which is the accumulation and metabolism of fat, is filled by a fat drop, surrounded by a rim of cytoplasm with the cell nucleus pushed to the periphery. In vertebrates, adipose tissue is located mainly under the skin (subcutaneous tissue) and in the omentum, between organs, forming soft elastic pads. (slide 6)

Laboratory work “Study of the microscopic structure of tissues”

View finished microslides. Features of each type of fabric. Comparison of images under a microscope with figures 7-10 of the textbook, table “Animal Tissues”, illustrations in a multimedia presentation.

Modeviewing.

Bring the microscope into working condition: illuminate the object, adjust the sharpness. The most convenient viewing mode: eyepiece 15, lens 8.

As we watch, we formulate conclusions and fill out the table. (Slide 8)

Consolidation of the studied material.

Questions.

1. Are all living organisms formed by tissues?

2. How are cells in tissues connected?

3. How is epithelial tissue structured?

4. What functions does epithelial tissue perform?

5. What functions does connective tissue perform?

6. What tissues are connective?

7. What do connective tissues have in common?

Working with statements from the textbook “Which statements are true?”

Lesson summary. Reflection.

What discoveries did you make for yourself in today's lesson? Do you think the knowledge you gained in this lesson will be useful in the future?

Homework.