Small knowledge of structure

Knowledge of human body structure.

Human Body Structure-Introduction

The basic unit of human structure is the cell. There is a non-cellular substance between cells, called intercellular substance.

Cells can be divided into three parts: cell membrane, cytoplasm and nucleus. Cell membrane is mainly composed of protein, lipids and sugars, which can protect cells, maintain the stability inside cells and control the material exchange inside and outside cells. Cytoplasm is the center of cell metabolism, which is mainly composed of water, protein, RNA, enzymes and electrolytes. There are also various organelles suspended in the cytoplasm. The main organelles are mitochondria, endoplasmic reticulum, lysosomes and centrosomes. The nucleus is surrounded by a nuclear membrane, which contains nucleoli and chromatin. Chromatin contains nucleic acids and protein. Nucleic acid is a substance that controls biological inheritance.

Human body structure-composition

Nerve tissue is composed of neurons and glial cells, which is highly sensitive and conductive. Neurons consist of cell bodies, dendrites and axons. Dendrites are short and branched, and their function is to transmit impulses to cell bodies; Axons are very long and have nerve endings at their ends. Their function is to transmit the impulses of cell bodies to the outside world.

Muscle tissue consists of muscle cells. Muscle cells have the function of contraction. Muscle tissue can be divided into skeletal muscle, smooth muscle and myocardium according to morphology and function.

Connective tissue consists of cells, intercellular substance and fibers. It is characterized by loose cell distribution and more intercellular substances. Connective tissue mainly includes loose connective tissue, dense connective tissue, adipose tissue, cartilage, bone, blood and lymph. They have the functions of support, connection, nutrition, defense and repair respectively.

Belgian doctor Vesaliua Uss published the book Human Body Structure, which challenged Galen's "Trinity" theory. Spanish doctor Servit discovered the small circulation system of blood, which proved that blood flows from the right ventricle to the lungs and reaches the left ventricle through a tortuous route. Harvey, a British anatomist, published the theory of heart-blood movement through a large number of animal anatomy experiments, which systematically explained the law of blood movement and the working principle of the heart. He pointed out that the heart is the center of blood movement and the source of strength. This great discovery made him the founder of modern physiology.

2. What are the basic knowledge of building structure?

(1) Brick-concrete structure Brick-concrete structure is a mixed structure system with brick walls as load-bearing members and reinforced concrete beams and columns.

Suitable for small bay depth, small room area, multi-storey or low-rise buildings. 1) longitudinal bearing system: the main load transfer route is: plate+beam+longitudinal wall+foundation+foundation 2) transverse bearing system: plate+transverse wall+foundation+foundation 3) internal frame bearing system: plate-beam-external longitudinal wall/column-foundation-foundation (2) frame.

The wall of a house with frame structure only plays the role of enclosure and separation, and is generally made of prefabricated aerated concrete, expanded perlite, hollow brick or perforated brick or assembled with plates. Frame building has the advantages of flexible space separation and light weight, which is beneficial to earthquake resistance and material saving, can flexibly cooperate with building layout, and is beneficial to the layout of building structures that need larger space.

However, the stress concentration of frame joints is significant; The lateral stiffness is small, the horizontal displacement of the structure is large, the consumption of steel and cement is large, and the construction is greatly affected by the season and environment. .

3. How to systematically summarize anatomical knowledge?

6. short answer 1. What is the function of bones? (1) Bone is connected with bone to form the scaffold of human body, so it has the function of bearing.

(2) It has a protective function, such as the skull protecting the brain; The chest protects the heart, lungs, etc. (3) Bone is the lever of human movement and the attachment point of muscle.

(4) Bone is the storage warehouse of calcium and phosphorus. (5) Intraosseous red bone marrow has hematopoietic function.

2. What are the characteristics of children's bones? The characteristics of children's bones can be summarized as follows: more organic matter and less inorganic matter; More cartilage, less bone; Osteoporosis is dense. 3. What are the good effects of physical exercise on bones? Under the condition of long-term physical exercise, due to the strengthening of metabolism, the blood supply has been improved, the shape, structure and performance of bones have changed well, and the bone density has thickened, making bones thicker.

According to the different pressure and tension, the arrangement of trabecular bone is more neat and regular to meet the requirements of exercise. The muscle attachment protrusions on the bone surface are more obvious.

These changes make bones stronger and stronger, thus improving the bending, flexing, compression and torsion characteristics of bones. 4. What is the growth and development pattern of long bones? There are two ways to grow and develop long bones: long and thick.

Epiphyseal cartilage can make bones longer. Because the chondrocytes on the surface of epiphyseal cartilage are constantly dividing, proliferating and ossifying, the length of bone is also increasing. Periosteum can make bones grow thicker, because there are osteoblasts and osteoclasts in periosteum. Osteoblasts have the potential to generate new bones. Osteoclasts continue to destroy old bones and expand bone marrow cavities, which can make bones grow thicker.

5. What kinds of osseointegration can be divided into? Bone is connected with bone through connective tissue, cartilage tissue and bone tissue. According to the way of bone connection, the whole body bone connection can be divided into fixed joint, movable joint and semi-joint.

6. What are the main and auxiliary structures of joints? The main structures of joints are articular surface, articular capsule and articular cavity. These structures are necessary for every movable joint.

The auxiliary structures of the joint include synovial sac, synovial folds, articular lip (glenoid margin), intra-articular cartilage and articular ligament. 7. What are the factors that affect joint flexibility and stability? The factors that affect the stability and flexibility of the joint are: (1) the area difference between the two joint surfaces.

If the area difference is large, the flexibility of the joint is large, on the contrary, the flexibility is small. (2) The tightness and thickness of joint capsule.

The joint capsule is thick and tight, with small joint flexibility and high stability; The joint capsule is thin and loose, with high elasticity and low stability. (3) The number and strength of joint ligaments.

Ligaments are numerous and strong, and joint stability increases, so flexibility is small; Ligaments are few and weak, joint stability is small and flexibility is great. (4) The number and strength of muscle groups around joints.

There are many and strong muscles around the joint, the joint is stable, the muscles around the joint are few and weak, or have good extensibility and elasticity, and the flexibility of the joint is increased. In addition, the bone process around the joint, gender, age, exercise and training level are all factors that affect the stability and flexibility of the joint.

8. What are the motion forms of joints? The shape of the articular surface determines the motion axis of the joint, and the motion axis of the joint can also determine its motion form. The motion forms of joints can be summarized as flexion and extension, adduction, abduction, internal rotation, external rotation and circular rotation.

9. What are the physical characteristics of muscles? The physical characteristics of muscles are ductility, elasticity and stickiness. 10. What are the characteristics of skeletal muscle in children and adolescents? (1) The skeletal muscle of children and adolescents is underdeveloped, and the muscle weight is less than that of adults.

(2) In early childhood, there is more water in muscle tissue, less protein, sugar and inorganic salts, thinner muscle fibers and relatively more connective tissue between muscle fibers. (3) Young children's muscle development is uneven, while large muscles of the body develop late and grow fast and slowly.

(4) After 8-9 years old, children's muscle development speed is accelerated, and muscle strength is also increasing rapidly, but after 18 years old, muscle strength growth slows down. (5) When children are young, the storage of muscle glycogen and the number of capillaries are less than those of adults. In addition, due to neuromodulation, muscle working endurance is not as good as that of adults, and it is easy to get tired. However, due to vigorous metabolism, muscle recovery after work fatigue is faster than that of adults.

1 1. What good effect does physical exercise have on skeletal muscle? Reasonable physical exercise will have a good effect on skeletal muscle. (1) The muscle volume is obviously increased (muscle fibers become thicker, and myofibrils in muscle fibers increase), which makes muscle contraction strong and lasting.

(2) Connective tissue in muscle increases and tendons and ligaments thicken, thus improving tensile strength. (3) There are more capillaries in the muscle, thus improving the metabolic capacity of the muscle.

Long-term exercise is good for muscles. (4) The number and volume of mitochondria in muscle fibers increase, providing more energy for muscle contraction to meet the needs of endurance.

(5) The chemical composition of muscle changes. Long-term physical exercise can increase the contents of muscle glycogen, myosin, actin, myoglobin and water. The increase of these substances not only improves the contraction ability of muscles, but also supplies energy to muscles in time, so that muscles can continue to work under the condition of high oxygen consumption.

(6) Improve the control of nerves on muscles and increase the number of muscle fibers participating in activities, thus increasing muscle strength. (7) The motor endplate can be enlarged and enlarged, which is beneficial to improve muscle mobility.

(8) Physical exercise, especially endurance events such as long-distance running, can reduce the fat in muscles, thus improving the contraction efficiency of muscles. 12. What is the significance of anatomical and physiological cross sections of muscles? In spindle muscle, the anatomical cross section and physiological cross section of muscle are equal; However, in pinnate muscle, the anatomical cross section is smaller than the physiological cross section, because in pinnate muscle, the anatomical cross section cannot pass through all muscle fibers, so the anatomical cross section cannot be used as an index to explain the degree of muscle development.

The physiological cross section of muscle can explain the quantity and thickness of muscle fibers in muscle, that is, the degree of muscle development. Therefore, the larger the physiological cross section of the muscle, the greater the applied force.

13. What is the function of intervertebral disc? In addition to connecting the vertebral body, the intervertebral disc also has the functions of increasing the range of motion of the spine, bearing pressure, buffering vibration and protecting the brain and spinal cord. At the same time, it can make the height of human body change 1~3cm every morning and evening.

This is of practical significance for measuring human height. 14. What is the structure of the spine? What is the appearance? What's the role? The spine consists of 24 vertebrae, 1 sacrum and 1 vertebra.

4. Knowledge of human body structure

The basic unit of human structure is the cell. There is a non-cellular substance between cells, called intercellular substance.

[Edit this paragraph] Eight systems

Digestive system, nervous system, exercise system, immune system, endocrine system, genitourinary system, circulatory system and respiratory system.

[Edit this paragraph] Chemical composition of human body

Water accounts for 65% of human body weight. An adult weighing 70kg weighs only 25kg after dehydration, including 3kg of carbohydrate, 7kg of fat, 3kg of protein 12kg and 3kg of mineral salt.

[Edit this paragraph] Blood liquid

The total blood volume of human body is about 8% of body weight. If a blood loss exceeds 20% of the blood volume in the human body, life activities will be blocked. Healthy people can generally recover quickly when the blood loss at one time does not exceed 10%. A drop of blood circulates in the human body for 22 seconds.

[Edit this paragraph] Muscle

The human body has about 639 muscles. It consists of about 6 billion muscle fibers, the longest is 60 cm, the shortest is only about 1 mm, the big muscle weighs 2000 grams, and the small muscle is only a few grams. The average person's muscle accounts for 35%-40% of the body weight. The total length of capillaries in muscle can reach 654.38+ million kilometers, which can circle the earth twice and a half times.

[Edit this paragraph] The brain hole is big

The brain is composed of about 65.438+0.4 billion cells, weighing about 654.38+0.400 g, and the thickness of the cerebral cortex is about 2-3mm, with a total area of about 2,200 square centimeters. It is estimated that 654.38+0000 to 654.38+000 million brain cells die every day (the more unused brain cells, the more brain cells die). The information storage capacity of a person's brain is equivalent to 10,000 libraries10,000 books. The person who is best at using his brain only uses 65,438+00% of his brain capacity in his life. The main component in the human brain is water, accounting for 80%. Although it only accounts for 2% of human body weight, its oxygen consumption accounts for 25% of the whole body oxygen consumption, and its blood flow accounts for 15% of the cardiac output. The blood flowing through the brain is 2000 liters a day. If the energy consumed by the brain is expressed by electric power, it is equivalent to about 25 watts.

5. How to build a reasonable knowledge structure

The five principles of a reasonable knowledge structure are as follows:

Openness: it has certain openness, open structure, open system, numerous entrances, passages and acceptance attitude; There is enough capacity to reflect the degree of opening "mind volume"; Its openness will directly lead the communication process between life systems and cosmic information energy, and it is also a sign of the degree and level of cultivation.

Inclusiveness: It is inclusive, its structure is based on openness, and it has no self-restriction. Positive and negative, yin and yang, right and wrong, good and bad can be tolerated, and it has enough cultivation and mentality; Its inclusiveness will directly lead to life's abandonment of persistence and wisdom, affect the communication process between various systems and cosmic information energy, and is also a symbol of the degree and level of cultivation.

Orderliness: there is a certain order, the structural support points of the knowledge structure are distributed reasonably, and the knowledge system belongs to different categories, which is orderly and conducive to the most efficient memory-storage and retrieval; The degree of its organization is also the degree that directly guides life to conform to the "Tao" and can be reached, and it is also a sign of the degree and level of self-cultivation.

Accommodation: there is a certain accommodation, and all kinds of knowledge systems belong to their own places and blend with each other to become a whole system (unified); Its structure is in the primitive state of life, and its compatibility reflects the degree of "from avenue to simplicity" and "from knowledge to wisdom", which is also a symbol of the degree and level of cultivation.

Life: complementary and cooperative, "self-organization" is an organic life universe unity, and gradually evolves into a life intelligence system; Gradually have a unified ideological guidance and intelligent thinking system; Its organic degree embodies the level of life intelligence, great wisdom, big machine and great use.

"Self-organization" is a concept that synergetics reveals that nature is orderly and regular in the process of natural migration, and gradually evolves into intelligence and intelligence to create life function mechanism.

For example, many people swim in the swimming pool without unified command. Everyone is swimming in any direction. Every collision will naturally adjust the direction. With the collision adjustment again and again, they will naturally choose a way that will not collide with each other, that is, everyone will naturally swim around a central circle. The whole natural phenomenon has become orderly and regular, showing intelligent characteristics. Nature is a self-organizing intelligent evolution process.

6. Structural requirements of knowledge structure

In modern society, professional posts require higher and higher knowledge structure and cultural quality of job seekers. In order to meet the needs of the development of modern society and survive and develop in the fierce market economy competition, the employer must rationally allocate the human resources of the enterprise. Therefore, as far as knowledge structure is concerned, on the one hand, there are more and more requirements for the diversity of knowledge structure; On the other hand, there is a growing demand for the practicality of knowledge structure.

7. Encyclopedia of scientific and technological knowledge

What are the three parts of sunlight? Among the eight planets, Jupiter is the largest freshwater lake in China and the first of the five mountains in Poyang Lake. The rotation of Mount Tai is around the earth axis passing through the north and south poles, and the direction is from west to east. The farther away from the poles, the faster the speed. The largest mammal in the world is the blue whale. Which city is called the foggy capital of the world? 2 1 what is the main energy source in London in the century? What kind of pollution is called windmill power generation kingdom in Denmark? What kind of pollution is called the world's number one killer? Which country's Mercury Green Mud Observatory is the closest planet to the sun? Dry ice in Britain is carbon dioxide. Bi Sheng of China invented movable type printing in the Northern Song Dynasty. It is also a maritime power. With a vast territory of 9.6 million square kilometers, China is the largest country in Asia and one of the largest countries in the world, ranking third in the world after Russian and Canadian countries.

The coastline of Chinese mainland starts from the mouth of Yalu River in the north and ends at the mouth of Beilun River in the south, with a total length of18,000 kilometers and an island coastline of more than 32,000 kilometers. There are more than 6,500 islands; According to the relevant provisions of the United Nations Convention on the Law of the Sea and China's proposition, the sea area under the jurisdiction of China is about 3 million square kilometers. China has vast sea areas and abundant resources, so China is also a maritime power.

Why is space junk so harmful? They have become potential killers of satellites and orbiting space stations, seriously threatening the safety of astronauts. You know, space junk runs at the speed of the universe.

An oncoming metal particle with a diameter of 0.5 mm is enough to pierce the sealed flight suit; Dust that people can't distinguish with the naked eye (such as paint chips and paint powder) can also kill astronauts; A fragment the size of an aspirin tablet can "paralyze" a satellite and send a spacecraft costing hundreds of millions of dollars into a dead end. Because of the huge amount of tiny space debris, it will seriously change the surface performance of spacecraft; Slightly larger space debris will damage the surface materials of spacecraft, cause impact pits and damage surface devices; The high-speed impact of space debris will vaporize itself and the surface material of the spacecraft being hit into plasma clouds, which will eventually lead to the failure of the spacecraft.

Interesting technology once, Newton was so absorbed in his experiment in the laboratory that he forgot the time to eat. His assistant took some eggs and sent them to the laboratory. He said to Newton, "Here are some eggs. Do it yourself. "

Newton said, "OK, thank you. Please put the eggs there. " After that, he immersed himself in the experiment.

After a long time, Newton was hungry and remembered that he hadn't had lunch yet. So, he took a small pot, put the eggs in the pot, put them on the stove, and began to do experiments again.

Half an hour later, Newton finished the experiment. At this moment, he remembered the eggs in the pot.

He opened the lid and found there were no eggs in it, only a pocket watch. Newton was surprised and looked up. The eggs are still on the table, but the pocket watch on the table is missing.

It turned out that Newton was absorbed in the experiment and cooked the pocket watch as an egg. 1, who knows how the sea freezes? Everyone thinks that the sea water is salty and won't freeze.

In fact, after the temperature is lowered, the solubility of water will also decrease, that is, salt will be precipitated. In this way, the water freezes.

2. Who knows if Altair has it now? What we are seeing now is the "light" it gave off a long time ago. As for whether it exists now, only people in the Altair galaxy know that the light we observe from the earth is still the light from a stable star.

In addition, the average life span of stars exceeds 6 billion years. So now the solar cell phone battery that Altair should still exist has come out. This kind of battery is a combination of ordinary lithium battery and other solar cells. Technicians stick a thin layer of crystalline silicon photoelectric conversion sheet on the back of lithium battery. Single crystal silicon receives the current generated by illumination and charges the lithium battery through the protection circuit. In fact, as long as there is light outside the sun, the solar cell phone battery can be automatically charged, and no matter how long the exposure time is, it will not be overcharged because of the holding circuit.

Although it is introduced, this battery can generate 1 minute of electricity when exposed to the sun for 5 minutes, and it can also be used for two or three days when exposed to a desk lamp for one night. In addition, this kind of battery also has the function of ordinary mobile phone battery. If the light is weak, you can use the mobile phone charger to charge.

Sandstorm Sandstorm is a disastrous weather phenomenon in which wind and sand interact. Its formation is closely related to global greenhouse effect, El Nino phenomenon, sharp decline of forests, vegetation destruction, species extinction, climate anomalies and other factors. Among them, overexploitation, excessive logging and excessive reclamation of natural resources caused by population expansion are the main reasons for sandstorms.

As a kind of high temperature disaster, sandstorm does not happen in all windy places. Sandstorms only occur in areas with dry climate and sparse vegetation. * * * The topsoil of the land is easily rolled up by a big storm to form a sandstorm or even a strong sandstorm. Sandstorms do no less harm to people and buildings than typhoons and tornadoes.

Recently, sandstorms have appeared in northwest and even northeast China, especially in northwest China, which has been hit by sandstorms for more than 20 times. Why is the air by the sea so fresh? The waves constantly beat the coast every day, and the tides rise and fall, bringing beautiful scenery, pleasant waves and humid coastal air to the coastal area.

The air in the seashore contains a lot of negative oxygen ions, which are called "air vitamins". They can enter the human body through breathing, improve the ventilation function of the lungs, and increase the inhalation of oxygen and the exhalation of carbon dioxide. In urban public places, negative oxygen ions 10-20 per cubic centimeter, indoor 40-50, green lawn 100-200, and coastal 100000, which are hundreds of times more than indoor ones! Negative oxygen ions are negatively charged ions, which have bactericidal effect and can inhibit the reproduction of bacteria in the air.

A large number of negative oxygen ions improve the function of human sympathetic nerve, make people refreshed and energetic, and also increase the content of hemoglobin in blood. Therefore, there are many sanatoriums on the seashore, because the seashore air has a therapeutic effect on people suffering from emphysema, hypertension, neurasthenia, asthma, anemia and other diseases, which is beneficial to human health and makes people refreshed.

8. What is the knowledge of building structure?

Building structures are mainly divided into the following categories: 1, wood structure (residence): refers to the vertical load-bearing structure of buildings with brick or block masonry, and the floor and roof truss are wood structures.

2. Brick-concrete structure (residence): The walls and columns of the vertical load-bearing structure in the building are built with bricks or blocks, and the columns, beams, floors and roof slabs are built with reinforced concrete structures. Generally speaking, brick-concrete structures are supported by a small number of reinforced concrete and most brick walls.

3. Reinforced concrete (residence): It means that the main load-bearing structures such as walls, columns, beams, floors, roofs and roof panels in buildings are made of reinforced concrete, and the non-load-bearing walls are filled with bricks or other materials. This structure has good seismic performance, strong integrity, strong fire resistance, durability and corrosion resistance.

4. Steel structure (residence): The main load-bearing structure in the building is steel. Suitable for super high-rise buildings.

Self-respect is the lightest. Structure can be divided into the above four categories, among which reinforced concrete structure can be further subdivided: 1, frame structure, building load-bearing structure composed of beams, plates and columns, and walls are only used for separation and heat preservation.

2. Shear wall structure is a building load-bearing structure composed of beams, plates and walls, and some walls are stressed in the structure. Combined with the above two subclasses, it is derived: frame shear wall structure, frame-supported shear wall structure and so on.

At present, the new housing market in Wuhan, real estate is basically brick-concrete structure, frame structure. The difference between them lies in the bearing mode. The bearing capacity of brick-concrete structure is composed of slab and wall, and the weight of cast-in-place concrete floor is transferred to the wall, which in turn is transferred to the foundation.

Frame structure is a load-bearing structure composed of floor, beam and column. The floor transmits the force to the beam, then to the column, and then to the foundation. Theoretically speaking, frame structure is superior to brick-concrete structure: first, the space is open, because the structure of beams and columns makes the space of frame structure more than 6 meters, while brick-concrete structure is not bad because of the limited bearing capacity of bricks; Second, the story height, brick-concrete structure can only reach 6 stories at most, while the frame structure can reach the height of 100 meters or more.

Therefore, before 2004, many houses in Wuhan chose brick-concrete structure in their development and construction because of their multi-storey and small high-rise buildings. After 2004, due to the increase of land cost, citizens gradually accepted small high-rise and high-rise residential buildings, and new residential buildings in urban areas were mainly frame structures, but there were still many brick-concrete structures in Wuhan suburbs such as Jiangxia and Caidian. Because of the material, the service life and seismic strength of frame structure are higher than that of brick-concrete structure.

However, in practice, the state has standards for the seismic performance of buildings, and the buildings in a region must meet the seismic index. Therefore, when developers design buildings, they are all based on meeting this seismic index, and even the frame structure will not increase the cost and improve the seismic performance. So in terms of firmness, brick-concrete houses are similar to frame houses.

Practically speaking, because the frame structure adopts the infilled wall, it can be convenient for users to decorate in the future, unlike the brick-concrete structure, which is subject to many restrictions, so many consumers are more willing to buy a house with a frame structure.