In a hypotonic solution, osmotic hemolysis
in hypertensive - plasmolysis.
Plasma oncotic pressure takes part in the exchange of water between blood and intercellular fluid. driving force filtration of fluid from the capillary into the intercellular space is the hydrostatic pressure of the blood (Pg). In the arterial part of the capillary, P g = 30-40 mm Hg, in the venous part - 10-15 mm Hg. Hydrostatic pressure is counteracted by the force of oncotic pressure (Р onc = 30 mm Hg), which tends to keep the liquid and substances dissolved in it in the lumen of the capillary. Thus, the filtration pressure (P f) in the arterial part of the capillary is:
R f = R g R onc or R f = 40 30 = 10 mm Hg.
In the venous part of the capillary, the relationship changes:
Р f = 15 30 = 15 mm Hg. Art.
This process is called resorption.
The figure shows the change in the ratios of hydrostatic (numerator) and oncotic (denominator) pressures (mm Hg) in the arterial and venous parts of the capillary.
Physiological features
internal environment in childhood
The internal environment of newborns is relatively stable. The mineral composition of plasma, its osmotic concentration and pH differ little from the blood of an adult.
The stability of homeostasis in children is achieved by integrating three factors: the composition of the plasma, the characteristics of the metabolism of a growing organism, and the activity of one of the main organs that regulates the constancy of the plasma composition (kidneys.
Any deviation from a well-balanced diet carries the risk of disturbing homeostasis. For example, if a child eats more food than corresponds to tissue absorption, then the concentration of urea in the blood rises sharply to 1 g / l or more (normally 0.4 g / l), since the kidney is not yet ready to excrete an increased amount of urea .
Nervous and humoral regulation of homeostasis in newborns due to the immaturity of its individual links (receptors, centers, etc.) is less perfect. In this regard, one of the features of homeostasis during this period is wider individual fluctuations in blood composition, its osmotic concentration, pH, salt composition, etc.
The second feature of homeostasis in newborns is that their ability to counteract shifts in the main indicators of the internal environment is several times less effective than in adults. For example, even normal feeding causes a decrease in plasma Rosm in a child, while in adults, even taking a large amount of liquid food (up to 2% of body weight) does not cause any deviations from this indicator. This is because the mechanisms that counteract shifts in the basic constants of the internal environment have not yet been formed in newborns, and therefore are several times less effective than in adults.
Words themes
homeostasis
Hemolysis
Alkaline reserve
Questions for self-control
What is meant by the internal environment of an organism?
What is homeostasis? Physiological mechanisms homeostasis.
Physiological role of blood.
What is the amount of blood in an adult human body?
Name the osmotically active substances.
What is osmol? What is the osmotic concentration of blood plasma?
Method for determining osmotic concentration.
What is osmotic pressure? Method for determining osmotic pressure. Units of measurement of osmotic pressure.
What happens to erythrocytes hypertonic solution? What is the name of this phenomenon?
What happens to red blood cells in a hypotonic solution? What is the name of this phenomenon?
What is called the minimum and maximum resistance of erythrocytes?
What is the normal value of osmotic resistance of human erythrocytes?
The principle of the method for determining the osmotic resistance of erythrocytes and what is the significance of determining this indicator in clinical practice?
What is called colloid osmotic (oncotic) pressure? What is its value and units of measurement?
Physiological role of oncotic pressure.
List the buffer systems of the blood.
The principle of operation of the buffer system.
What products (acidic, alkaline or neutral) are formed in the process of metabolism more?
How can one explain the fact that the blood is able to neutralize acids to a greater extent than alkalis?
What is the alkaline reserve of the blood?
How are the buffer properties of blood determined?
How many times more alkali must be added to plasma than to water in order to shift the pH to the alkaline side?
How many times more acid must be added to blood plasma than to water in order to shift the pH to the acid side?
Bicarbonate buffer system, its components. How does the bicarbonate buffer system react to the influx of organic acids?
List the features of bicarbonate buffer.
Phosphate buffer system. Her reaction to the intake of acid. Features of the phosphate buffer system.
Hemoglobin buffer system, its components.
The reaction of the hemoglobin buffer system in tissue capillaries and in the lungs.
Features of the hemoglobin buffer.
Protein buffer system, its properties.
The reaction of the protein buffer system when acids and alkalis enter the blood.
How are the lungs and kidneys involved in maintaining the pH of the internal environment?
What is the name of the state at pH 6.5 (8.5)?.
Classes
Exercise 1. The task includes 60 questions, each of which has 4 possible answers. For each question, choose only one answer that you think is the most complete and correct. Place a "+" sign next to the index of the selected answer. In case of correction, the "+" sign must be duplicated.
- Muscle formed:
a) only mononuclear cells;
b) only multinuclear muscle fibers;
c) binuclear fibers tightly adjacent to each other;
d) mononuclear cells or multinuclear muscle fibers. + - Cells of striated striation, which make up fibers and interact with each other at the points of contact, form muscle tissue:
a) smooth;
b) cardiac; +
c) skeletal;
d) smooth and skeletal. - Tendons, through which muscles are connected to bones, are formed by connective tissue:
a) bone;
b) cartilaginous;
c) loose fibrous;
d) dense fibrous. + - The anterior horns of the gray matter of the spinal cord (“butterfly wings”) are formed by:
a) intercalary neurons;
b) bodies of sensitive neurons;
c) axons of sensitive neurons;
d) bodies motor neurons. + - The anterior roots of the spinal cord are formed by the axons of neurons:
a) motor; +
b) sensitive;
c) only intercalary;
d) insertion and sensitive. - The centers of protective reflexes - coughing, sneezing, vomiting are located in:
a) cerebellum;
in) spinal cord;
c) intermediate part of the brain;
d) medulla oblongata. + - RBCs placed in saline table salt:
a) wrinkle;
b) swell and burst;
c) stick to each other
d) remain unchanged. + - Blood flows faster in vessels whose total lumen is:
a) the largest;
b) the smallest; +
c) average;
d) slightly above average. - Meaning pleural cavity is that she:
a) protect the lungs from mechanical damage;
b) prevents overheating of the lungs;
c) participates in the removal of a number of metabolic products from the lungs;
d) reduces the friction of the lungs against the walls chest cavity, is involved in the mechanism of lung stretching. + - The value of bile produced by the liver and entering the duodenum, is that it:
a) breaks down hard-to-digest proteins;
b) breaks down hard-to-digest carbohydrates;
c) breaks down proteins, carbohydrates and fats;
d) increases the activity of enzymes secreted by the pancreas and intestinal glands, facilitates the breakdown of fats. + - Light sensitivity of sticks:
a) not developed;
b) the same as in cones;
c) higher than that of cones; +
d) lower than that of cones. - Jellyfish breed:
a) only sexually;
b) only asexually;
c) sexually and asexually;
d) some species only sexually, others - sexually and asexually. + - Why do children have new signs that are not characteristic of parents:
a) since all the gametes of the parents are of different sorts;
b) since during fertilization, gametes merge by chance;
c) in children, parental genes combine in new combinations; +
d) since the child receives one half of the genes from the father, and the other half from the mother. - The flowering of some plants only during the day is an example:
a) apical dominance;
b) positive phototropism; +
c) negative phototropism;
d) photoperiodism. - The filtration of blood in the kidneys occurs in:
a) pyramids;
b) pelvis;
c) capsules; +
d) the medulla. - With the formation of secondary urine in bloodstream return:
a) water and glucose; +
b) water and salts;
c) water and proteins;
d) all of the above products. - For the first time among vertebrates, glands appear in amphibians:
a) salivary; +
b) sweat;
c) ovaries;
d) sebaceous. - The lactose molecule consists of residues:
a) glucose;
b) galactose;
c) fructose and galactose;
d) galactose and glucose.
- The statement is incorrect:
a) felines - a family of carnivores;
b) hedgehogs - a family of insectivorous order;
c) a hare is a genus of a detachment of rodents; +
d) the tiger is a species of the genus Panthera.
45. Protein synthesis does NOT require:
a) ribosomes;
b) t-RNA;
c) endoplasmic reticulum; +
d) amino acids.
46. The following statement is true for enzymes:
a) enzymes lose some or all of their normal activity if their tertiary structure is destroyed; +
b) enzymes provide the energy needed to stimulate the reaction;
c) enzyme activity does not depend on temperature and pH;
d) enzymes act only once and then are destroyed.
47. The greatest release of energy occurs in the process:
a) photolysis;
b) glycolysis;
c) Krebs cycle; +
d) fermentation.
48. For the Golgi complex, as a cell organoid, the following is most characteristic:
a) increasing the concentration and compaction of intracellular secretion products intended for release from the cell; +
b) participation in cellular respiration;
c) the implementation of photosynthesis;
d) participation in protein synthesis.
49. Cellular organelles that transform energy:
a) chromoplasts and leukoplasts;
b) mitochondria and leukoplasts;
c) mitochondria and chloroplasts; +
d) mitochondria and chromoplasts.
50. The number of chromosomes in tomato cells is 24. Meiosis occurs in a tomato cell. Three of the resulting cells degenerate. The last cell immediately divides by mitosis three times. As a result, in the resulting cells, you can find:
a) 4 nuclei with 12 chromosomes in each;
b) 4 nuclei with 24 chromosomes in each;
c) 8 nuclei with 12 chromosomes in each; +
d) 8 nuclei with 24 chromosomes in each.
51. Arthropod eyes:
a) all are complex;
b) complex only in insects;
c) complex only in crustaceans and insects; +
d) complex in many crustaceans and arachnids.
52. The male gametophyte in the reproduction cycle of pine is formed after:
a) 2 divisions;
b) 4 divisions; +
c) 8 divisions;
d) 16 divisions.
53. The final bud of lime on the shoot is:
a) apical;
b) lateral; +
c) may be subordinate;
d) sleeping.
54. The signal sequence of amino acids necessary for the transport of proteins into chloroplasts is located:
a) at the N-terminus; +
b) at the C-terminus;
c) in the middle of the chain;
d) in different proteins in different ways.
55. Centrioles double in:
a) G 1 -phase;
b) S-phase; +
c) G 2 -phase;
d) mitosis.
56. Of the following bonds, the least rich in energy:
a) the connection of the first phosphate with ribose in ATP; +
b) the bond of an amino acid with tRNA in aminoacyl-tRNA;
c) connection of phosphate with creatine in creatine phosphate;
d) the bond of acetyl with CoA in acetyl-CoA.
57. The phenomenon of heterosis is usually observed when:
a) inbreeding;
b) distant hybridization; +
c) creation of genetically pure lines;
d) self-pollination.
Task 2. The task includes 25 questions, with several answers (from 0 to 5). Place "+" signs next to the indexes of the selected answers. In case of corrections, the "+" sign must be duplicated.
- Furrows and gyrus are characteristic of:
a) diencephalon;
b) medulla oblongata;
in) hemispheres brain; +
d) cerebellum; +
e) midbrain. - In the human body, proteins can be directly converted into:
a) nucleic acids;
b) starch;
c) fats; +
d) carbohydrates; +
e) carbon dioxide and water. - The middle ear contains:
a) hammer; +
b) auditory (Eustachian) tube; +
c) semicircular canals;
d) external auditory meatus;
d) stirrup. + - Conditioned reflexes are:
a) species;
b) individual; +
c) permanent;
d) both permanent and temporary; +
e) hereditary.
5. Centers of origin of certain cultivated plants correspond to specific land regions of the Earth. This is because these places:
a) were the most optimal for their growth and development;
b) were not subject to serious natural disasters, which contributed to their preservation;
c) geochemical anomalies with the presence of certain mutagenic factors;
d) are free from specific pests and diseases;
e) were the centers of the most ancient civilizations, where the primary selection and reproduction of the most productive varieties of plants took place. +
6. One population of animals is characterized by:
a) free crossing of individuals; +
b) the possibility of meeting individuals of different sexes; +
c) similarity in genotype;
d) similar living conditions; +
e) balanced polymorphism. +
7. The evolution of organisms leads to:
a) natural selection
b) variety of species; +
c) adaptation to the conditions of existence; +
d) mandatory promotion of the organization;
e) the occurrence of mutations.
8. The surface complex of the cell includes:
a) plasmalemma; +
b) glycocalyx; +
c) the cortical layer of the cytoplasm; +
d) matrix;
e) cytosol.
9. Lipids included in the composition cell membranes coli:
a) cholesterol;
b) phosphatidylethanolamine; +
c) cardiolipin; +
d) phosphatidylcholine;
e) sphingomyelin.
- Adventitious buds can form during cell division:
a) pericycle; +
b) cambium; +
c) sclerenchyma;
d) parenchyma; +
e) wound meristem. + - Adventitious roots can form during cell division:
a) traffic jams;
b) crusts;
c) phellogen; +
d) phelloderms; +
e) core rays. + - Substances synthesized from cholesterol:
a) bile acids; +
b) hyaluronic acid;
c) hydrocortisone; +
d) cholecystokinin;
e) estrone. + - Deoxynucleotide triphosphates are required for the process:
a) replication; +
b) transcription;
c) translation;
d) dark repair; +
e) photoreactivation. - The process leading to the transfer of genetic material from one cell to another:
a) transition
b) transversion;
c) translocation;
d) transduction; +
e) transformation. + - Oxygen scavenging organelles:
a) the core;
b) mitochondria; +
c) peroxisomes; +
d) Golgi apparatus;
e) endoplasmic reticulum. + - inorganic base the skeleton of various living organisms can be:
a) CaCO 3 ; +
b) SrSO 4 ; +
c) SiO 2 ; +
d) NaCl;
e) Al 2 O 3. - Polysaccharide nature have:
a) glucose;
b) cellulose; +
c) hemicellulose; +
d) pectin; +
e) lignin. - Proteins containing heme:
a) myoglobin; +
b) FeS, mitochondrial proteins;
c) cytochromes; +
d) DNA polymerase;
e) myeloperoxidase. + - Which of the factors of evolution were first proposed by Ch. Darwin:
a) natural selection; +
b) genetic drift;
c) population waves;
d) isolation;
e) struggle for existence. + - Which of the following features that have arisen in the course of evolution are examples of idioadaptations:
a) warm-bloodedness;
b) hairline of mammals; +
c) the external skeleton of invertebrates; +
d) external gills of the tadpole;
e) horny beak in birds. + - Which of the following breeding methods appeared in the 20th century:
a) interspecific hybridization;
b) artificial selection;
c) polyploidy; +
d) artificial mutagenesis; +
e) cell hybridization. +
22. Anemophilous plants include:
a) rye, oats; +
b) hazel, dandelion;
c) aspen, linden;
d) nettle, hemp; +
e) birch, alder. +
23. All cartilaginous fish have:
a) arterial cone; +
b) swim bladder;
c) spiral valve in the intestine; +
d) five gill slits;
e) internal fertilization. +
24. Representatives of marsupials live:
a) in Australia +
b) in Africa;
c) in Asia;
d) in North America; +
d) in South America. +
25. The following features are characteristic of amphibians:
a) have only pulmonary respiration;
b) have bladder;
c) larvae live in water, and adults live on land; +
d) molting is characteristic of adults;
e) chest no. +
Task 3. Task for determining the correctness of judgments (Put a "+" sign next to the numbers of correct judgments). (25 judgments)
1. Epithelial tissues are divided into two groups: integumentary and glandular. +
2. In the pancreas, some cells produce digestive enzymes, while others produce hormones that affect coal water exchange in the body.
3. Physiological, they call a solution of sodium chloride 9% concentration. +
4. During prolonged fasting, with a decrease in blood glucose levels, glycogen disaccharide, which is present in the liver, is cleaved.
5. Ammonia, which is formed during the oxidation of proteins, is converted in the liver into a less toxic substance, urea. +
6. All ferns need water for fertilization. +
7. Under the action of bacteria, milk turns into kefir. +
8. During the dormant period, the vital processes of the seeds stop.
9. Bryophytes are a dead end branch of evolution. +
10. In the main substance of the cytoplasm of plants, polysaccharides predominate. +
11. Living organisms contain almost all the elements of the periodic table. +
12. Pea antennae and cucumber antennae are similar organs. +
13. The disappearance of the tail in frog tadpoles occurs due to the fact that dying cells are digested by lysosomes. +
14. Each natural population is always homogeneous in terms of the genotypes of individuals.
15. All biocenoses necessarily include autotrophic plants.
16. The first terrestrial higher plants were rhinophytes. +
17. All flagellates are characterized by the presence of a green pigment - chlorophyll.
18. In protozoa, each cell is an independent organism. +
19. Infusoria shoe belongs to the type Protozoa.
20. Scallops move in a jet way. +
21. Chromosomes are the leading components of the cell in the regulation of all metabolic processes. +
22. Algae spores can be formed by mitosis. +
23. In all higher plants, the sexual process is oogamous. +
24. Fern spores meiotically form an outgrowth, the cells of which have a haploid set of chromosomes.
25. Ribosomes are formed by self-assembly. +
27. 10 - 11 class
28. Task 1:
29. 1-d, 2-b, 3-d, 4-d, 5-a, 6-d, 7-d, 8-b, 9-d, 10-d, 11-c, 12-d, 13-c, 14-b, 15-c, 16-a, 17-a, 18-d, 19-c, 20-d, 21-a, 22-d, 23-d, 24-b, 25- d, 26-d, 27-b, 28-c, 29-d, 30-d, 31-c, 32-a, 33-b, 34-b, 35-b, 36-a, 37-c, 38–b, 39–c, 40–b, 41–b, 42–d, 43–c, 44–b, 45–c, 46–a, 47–c, 48–a, 49–c, 50– c, 51–c, 52–b, 53–b, 54–a, 55–b, 56–a, 57–b, 58–c, 59–b, 60–b.
30. Task 2:
31. 1 – c, d; 2 – c, d; 3 - a, b, e; 4 – b, d; 5 - d; 6 – a, b, d, e; 7 – b, c; 8 – a, b, c; 9 – b, c; 10 – a, b, d, e; 11 – c, d, e; 12 - a, c, e; 13 – a, d; 14 - d, e; 15 – b, c, e; 16 – a, b, c; 17 – b, c, d; 18 - a, c, e; 19 - a, e; 20 – b, c, e; 21 – c, d, e; 22 – a, d, e; 23 - a, c, e; 24 – a, d, e; 25 - c, d.
32. Task 3:
33. Correct judgments - 1, 3, 5, 6, 7, 9, 10, 11, 12, 13, 16, 18, 20, 21, 22, 23, 25.
constructor Create(aX, aY, aR, aColor, aShapeType)
method change_color (aColor)
method Resize (aR)
method change_location(aX, aY)
method Change_shape_type (aShape_type)
End of description.
Parameter aType_of_figure will receive a value that specifies the drawing method to be attached to the object.
When using delegation, you must ensure that the method header matches the type of pointer used to store the address of the method.
container classes.Containers - they are specially organized objects used to store and manage objects of other classes. To implement containers, special container classes are developed. A container class usually includes a set of methods that allow you to perform certain operations on both a single object and a group of objects.
In the form of containers, as a rule, they implement complex data structures ( different kinds lists, dynamic arrays, etc.). The developer inherits the class from the element class, into which he adds the information fields he needs, and receives the required structure. If necessary, it can also inherit the class from the container class, adding its own methods to it (Fig. 1.30).
Rice. 1.30. Building classes based on
container class and element class
A container class usually includes methods for creating, adding, and removing elements. In addition, it must provide element-by-element processing (eg, searching, sorting). All methods are programmed for member class objects. Methods for adding and removing elements when performing operations often refer to special fields of the element class used to create the structure (for example, for a singly linked list - to the field that stores the address of the next element).
Methods that implement element-by-element processing must work with data fields defined in descendant classes of the element class.
Element-by-element processing of the implemented structure can be done in two ways. The first way - universal - is to use iterators the second is in the definition special method, which contains the address of the processing procedure in the parameter list.
In theory, an iterator should provide the ability to implement cyclic actions of the following form:
<очередной элемент>:=<первый элемент>
cycle-bye<очередной элемент>defined
<выполнить обработку>
<очередной элемент>:=<следующий элемент>
Therefore, it usually consists of three parts: a method that allows organizing data processing from the first element (obtaining the address of the first element of the structure); a method that organizes the transition to the next element, and a method that allows you to check the end of the data. In this case, access to the next portion of data is carried out through a special pointer to the current portion of data (a pointer to an object of the element class).
Example 1.12 Container class with an iterator (List class). Let's develop a container class List that implements a linear singly linked list of objects of the Element class, described as follows:
Class Element:
field Pointer_to_next
End of description.
The List class must include three methods that make up an iterator: method define_first, which should return a pointer to the first element, the method define_next, which should return a pointer to the next element, and the method End of list, which should return "yes" if the list is exhausted.
Class List
implementation
fields Pointer_to_first, Pointer_to_current
interface
method add_before_first(aItem)
method Delete_Last
method define_first
method define_next
method End of list
End of description.
Then element-by-element processing of the list will be programmed as follows:
element:= define_first
cycle-bye not end_of_list
Handle the element, possibly overriding its type
Element: = define _next
When using the second method of element-by-element processing of the implemented structure, the element processing procedure is passed in the parameter list. Such a procedure can be defined if the type of processing is known, for example, the procedure for deriving the values of the information fields of an object. The procedure must be called from a method for each data element. In languages with strong data typing, the procedure type must be declared in advance, and it is often impossible to foresee what additional parameters should be passed to the procedure. In such cases, the first method may be preferable.
Example 1.13 Container class with a procedure for processing all objects (List class). In this case, the List class will be described as follows:
Class List
implementation
fields Pointer_to_first, Pointer_to_current
interface
method add_before_first(aItem)
method Delete_Last
method Execute_for_all(aProcedure_processing)
End of description.
Accordingly, the type of processing procedure must be described in advance, taking into account the fact that it must receive the address of the processed element through parameters, for example:
processing_procedure (aItem)
The use of polymorphic objects when creating containers allows you to create fairly generic classes.
Parameterized classes.Parameterized class(or sample) is a class definition in which some of the used types of class components are defined through parameters. Thus, each the template defines a group of classes, which, despite the difference in types, are characterized by the same behavior. It is impossible to redefine a type during program execution: all type instantiation operations are performed by the compiler (more precisely, by the preprocessor).
Article by professional biology tutor T. M. Kulakova
Blood is the intermediate internal environment of the body, it's liquid connective tissue. Blood is made up of plasma and formed elements.
Composition of the blood It is 60% plasma and 40% formed elements.
blood plasma is made up of water organic matter(proteins, glucose, leukocytes, vitamins, hormones), mineral salts and decay products.
Shaped elements are erythrocytes and platelets
blood plasma is the liquid part of the blood. It contains 90% water and 10% dry matter, mainly proteins and salts.
Metabolic products (urea, uric acid) to be removed from the body. The concentration of salts in plasma is equal to the content of salts in blood cells. Blood plasma mainly contains 0.9% NaCl. The constancy of the salt composition ensures the normal structure and function of cells.
AT USE tests frequently asked questions about solutions: physiological (solution, NaCl salt concentration is 0.9%), hypertonic (NaCl salt concentration above 0.9%) and hypotonic (NaCl salt concentration below 0.9%).
For example, this question:
Administration of large doses medicines accompanied by their dilution with saline (0.9% NaCl solution). Explain why.
Recall that if a cell comes into contact with a solution whose water potential is lower than that of its contents (i.e. hypertonic saline), then water will leave the cell due to osmosis through the membrane. Such cells (eg erythrocytes) shrink and settle to the bottom of the tube.
And if you put blood cells in a solution whose water potential is higher than the contents of the cell (i.e., the salt concentration in the solution is below 0.9% NaCl), red blood cells begin to swell because water rushes into the cells. In this case, the erythrocytes swell, and their membrane is torn.
Let's answer the question:
1. The concentration of salts in the blood plasma corresponds to the concentration physiological saline 0.9% NaCl, which does not cause the death of blood cells;
2. The introduction of large doses of drugs without dilution will be accompanied by a change in the salt composition of the blood and cause cell death.
Remember that when writing an answer to a question, other wordings of the answer are allowed that do not distort its meaning.
For erudition: when the shell of erythrocytes is destroyed, hemoglobin enters the blood plasma, which turns red and becomes transparent. Such blood is called varnish blood.
Osmosis is the movement of water across a membrane towards a higher concentration of substances.
Fresh water
The concentration of substances in the cytoplasm of any cell is higher than in fresh water, so water constantly enters the cells that come into contact with fresh water.
- erythrocyte in hypotonic solution fills up with water and bursts.
- In freshwater protozoa, to remove excess water, there is contractile vacuole.
- plant cell does not allow the cell wall to burst. The pressure of a water-filled cell on cell wall called turgor.
salty water
AT hypertonic solution water leaves the erythrocyte and it shrinks. If a person drinks sea water, then salt will enter the plasma of his blood, and water will leave the cells into the blood (all cells will wrinkle). This salt will need to be excreted in urine, the amount of which will exceed the amount of sea water drunk.
Plants have plasmolysis(departure of the protoplast from the cell wall).
Isotonic solution
Saline is a 0.9% sodium chloride solution. The plasma of our blood has the same concentration, osmosis does not occur. In hospitals, on the basis of saline, a solution for a dropper is made.
One of the terrible diseases that claimed hundreds of thousands of lives every year was. In its dying stage, the human body, due to the continuous loss of water by vomiting, turns into a kind of mummy. A person dies, because his tissues cannot live without the necessary amount of water. It is impossible to enter the liquid through, because it is instantly thrown back due to indomitable vomiting. Doctors have long had an idea: to inject water directly into the blood, into the vessels. However, this problem was solved when the phenomenon called osmotic pressure was understood and taken into account.
We know that the gas, being in this or that vessel, puts pressure on its walls, trying to occupy the largest possible volume. The stronger the gas is compressed, i.e., the more particles it contains in a given space, the stronger this pressure will be. It turned out that substances dissolved, for example, in water, are in a certain sense similar to gases: they also tend to occupy the largest possible volume, and the more concentrated the solution, the greater the strength of this desire. What is the manifestation of this property of solutions? The fact that they greedily "attract" to themselves an additional amount of solvent. It is enough to add a little water to the salt solution, and the solution quickly becomes uniform; it seems to absorb this water into itself, thereby increasing its volume. The described property of the solution to attract to itself is called osmotic pressure.
If we place them in a glass of clean water, they will quickly “swell up” and burst. This is understandable: the protoplasm of erythrocytes is a solution of salts and proteins of a certain concentration, which has an osmotic pressure much higher than pure water, where there are few salts. Therefore, the erythrocyte "sucks" water to itself. If, on the contrary, we place red blood cells in a very concentrated salt solution, they will shrink - the osmotic pressure of the solution will be higher, it will "suck" the water out of the red blood cells. The rest of the body cells behave like red blood cells.
It is clear that in order to introduce a liquid into the bloodstream, it must have a concentration corresponding to their concentration in the blood. Experiments have established that such is a 0.9% solution. This solution is called physiological.
The introduction of 1-2 liters of such a solution intravenously to a dying cholera patient had a literally miraculous effect. A person “came to life” before our eyes, sat up in bed, asked for food, etc. Repeating the introduction of the solution 2-3 times a day, helped the body overcome the most difficult period diseases. Such solutions, containing a number of other substances, are now used in many diseases. In particular, the importance of blood-substituting solutions in war time. Blood loss is terrible not only because it deprives the body of erythrocytes, but above all because the function is disrupted, “tuned” to work with a certain amount of blood. Therefore, in cases where for one reason or another it is impossible, a simple introduction of saline can save the life of the wounded.
Knowledge of the laws of osmotic pressure has great value, because it generally helps to regulate the body's water metabolism. So, it becomes clear why salty food causes: an excess of salt increases the osmotic pressure of our tissues, that is, their “greed” for water. Therefore, patients with edema are given less salt so as not to retain water in the body. On the contrary, workers in hot shops, who lose a lot of water, must be poured with salted water, because with sweat they excrete salt and lose it. If in these cases a person will drink clean water, the greed of tissues for water will decrease, and this will increase. The state of the body will deteriorate sharply.
