PEP seventh grade biology outline Volume II

The second volume of grade seven-biology review outline (question-and-answer review) (available for junior high school grade 20 12)-2065438+00 April 15 day system.

Chapter I Human life needs nutrition

Section 1 Nutritional components of food

1. What are the nutrients in the food? Which ones are more abundant? ****

1) There are six nutrients in food * * * are:

Protein, sugar, fat (the above three can be transformed into each other), vitamins, inorganic salts and water, each of which is essential to the human body. .

2) Nutritional components in food, among which the contents are higher:

Sugar, protein and fat. They are all organic substances that the human body needs most, which are extremely important and are called "three major nutrients".

2. Can you tell what effects various nutrients have on human body? ****

Protein: The basic substance of human cells, which provides energy for human physiological activities, contains 20 kinds of amino acids.

Sugar: the most important energy-supplying substance, and also the component of cell membrane;

Fat: an important energy storage substance, which plays the role of heat preservation and buffering;

Vitamins: Less in content and more in variety. Lack will affect normal life activities and even get sick. And can only be obtained from food.

Inorganic salt: an important substance that constitutes human tissues and has great functions.

Water: the source of life.

3. What are the contents of various nutrients in different foods? ****

A: Sugar, protein and fat are the constituent elements of tissues and cells, and they can also provide energy for life activities.

Sugar energy-fat energy (standby)-protein is the basic substance of cells.

Sugar: There are three kinds: polysaccharide, disaccharide and monosaccharide. Foods rich in sugar: cereals and root foods are rich in sugar.

Protein: It consists of 20 kinds of amino acids. Foods containing more protein: lean meat, fish, milk, eggs and beans contain more protein.

Fat: divided into animal fat and vegetable fat, both of which are composed of glycerol and fatty acids. Fatty foods: egg yolk, peanuts, beans and hard fruits are rich in fat.

Children and adolescents grow fast and need a lot of protein; Eat more milk, eggs, fish and meat.

There is also a "seventh nutrient element" in food, called dietary fiber.

4. What kinds, sources (in food) and shortages of vitamins are there? ****

There are many kinds of vitamins and few contents, which can only be obtained from food.

Vitamin A: It comes from animal liver, cod liver oil, corn and carrot. Lack, rough skin and night blindness.

Vitamin B 1: coarse grains such as cereals and roast beef. Lack of neuritis, beriberi, loss of appetite, growth retardation.

Vitamin c: vegetables and fruits. Such as tomatoes, green peppers and cucumbers. When lacking, scurvy, decreased resistance and bleeding gums.

Vitamin d: animal liver, cod liver oil, eggs. When lacking, children's rickets (such as chicken breast, X-shaped or O-shaped legs, etc. ) and osteoporosis.

5. Test question: Which vegetables and fruits contain the most vitamin C?

Fresh vegetables or fruit juice were respectively dropped into 0.0 1% potassium permanganate solution for comparison. (See P6)—— Use the same dropper during the test and clean it before use.

6. What are the functions of water and inorganic salts? ****

Water: accounting for about 60%~70% of body weight, it is the main component of cells, and all kinds of physiological activities of human body are inseparable from water. If the human body lacks more than 20% water, it will be life-threatening! People need to take in about 2 liters of water every day.

Inorganic salts: Important substances that constitute human tissues, such as calcium, phosphorus (for bones and teeth) and iron (for hemoglobin).

Children with calcium deficiency are prone to rickets, middle-aged and elderly people with calcium deficiency are prone to osteoporosis, long-term iron deficiency is prone to anemia, iodine deficiency is prone to childhood dementia, and zinc deficiency affects appetite. ****

Section II, Digestion and Absorption

Water, inorganic salts and vitamins can be absorbed directly, but starch, fat and protein must be digested before they can be absorbed and utilized by human body. Digestion and absorption are completed by the digestive system.

1. What is the digestive system made of? ****

Answer: The digestive system consists of digestive tract (seven kinds) and digestive gland (two kinds) as follows:

The digestive tract is a long tube: it consists of seven parts: mouth, pharynx, esophagus, stomach (temporarily accommodated), small intestine (digested and absorbed), large intestine and anus.

Digestive gland: one is composed of the largest digestive gland, such as salivary gland, pancreas and liver; One is composed of small glands in the digestive wall, such as intestinal glands and gastric glands in the stomach wall.

2. Test type: (Eating steamed bread) See book P11* *.

1) Why do we use 37-degree warm water in the experiment?

A: Because 37 degrees is close to the oral temperature, the activity of the enzyme is the strongest.

2) What are the functions and connections of teeth, tongue and saliva during the digestion of steamed bread? ****

The process in which food is broken down into small molecules in the digestive tract is called digestion.

Physical digestion: chewing teeth, stirring tongue and gastrointestinal peristalsis, grinding and stirring food and mixing it with digestive juice. The teeth are fully ground, and tongue stirring belongs to physical digestion, which is a morphological change.

Chemical digestion: through the action of various digestive enzymes, various components in food are decomposed into absorbable nutrients. Because saliva contains amylase, a small amount of starch in food can be decomposed into maltose, and the change is chemical digestion.

3. Which is more scientific, chewing slowly or wolfing down? ***

A: Chewing slowly can be fully ground, which is beneficial to digestion.

4. How is food digested in the stomach? *****

There are many gastric glands in the stomach wall, which can secrete a lot of gastric juice. Gastric juice is strongly acidic, and pepsin has a preliminary digestive effect on protein. At the same time, the peristalsis of the stomach grinds and stirs the food to form porridge chyme, which is sent to the small intestine for digestion and absorption in batches.

5. How does the small intestine digest food? *****

The small intestine is 6 meters long and surrounds the abdominal cavity. Bile secreted by the liver and pancreatic juice secreted by the pancreas flow into the small intestine to further digest food.

6. What is the effect of bile on fat? ****

The liver is the largest digestive gland in human body, secreting bile and participating in fat digestion.

Bile does not contain digestive enzymes, but it can emulsify fat into fat particles, increase the contact surface of fat and facilitate digestion.

7. Please explain the digestion process of starch, fat and protein? ****

Starch is digested in the mouth and small intestine: starch (by digestive enzymes)-maltose (by digestive enzymes)-glucose.

Protein digestion is in the stomach and small intestine: protein (through digestive enzymes)-amino acids.

Fat is digested in the small intestine: fat (through bile)-fat particles (through digestive enzymes)-glycerol+fatty acids.

As shown in the figure below:

Secretion of digestive juice: salivary amylase, enzymes (gastric juice, pancreatic juice, intestinal juice) and bile (liver).

Digestive gland, salivary gland, stomach gland, intestinal gland, pancreas and liver.

Digestive juice saliva gastric juice intestinal juice pancreatic juice bile

Organs from which digestive juice is discharged: mouth, stomach and small intestine.

Digestive Enzymes Saliva amylase protease contained in digestive juice digests sugar, protein and fat without digestive enzymes.

8. What are the structure and characteristics of the small intestine? ****

Structure: Small intestine is the main organ for digesting food and absorbing nutrition. Intestinal wall structure (from inside to outside): mucosa, submucosa, muscle layer and serosa.

The small intestine is suitable for digestion and absorption;

1) is the longest; 6 meters.

2) there are folds and small intestinal villi on the inner surface (greatly increasing the area of digestion and absorption);

3) There are capillaries and lymphatic capillaries in the villi of small intestine, and the walls of villi, capillaries and lymphatic capillaries are very thin, which are only composed of a layer of epithelial cells, which is beneficial to the absorption of nutrients;

4) There are various digestive juices.

9. Which organs are responsible for the absorption of nutrients? ****

The process of nutrients entering the circulatory system through the digestive tract wall is called absorption.

The oral cavity, pharynx and esophagus cannot absorb nutrients, but the stomach, small intestine and large intestine absorb nutrients.

Stomach-absorbs a small amount of water and alcohol (non-nutritive)

Small intestine-(main absorption site): glucose, amino acids, glycerol, fatty acids, most water, inorganic salts and vitamins. Most of the fat components are absorbed from the lymphatic capillaries (glycerol, fatty acids) of intestinal villi; Others enter the blood circulation from the capillaries of intestinal villi.

Large intestine-a small amount of water, inorganic salts and some vitamins.

10. Graphic problem (important, see P16 in this book): * * * *

1 1. Why can't patients with liver disease eat more greasy food? (understand)

Because greasy food is rich in fat. Patients with liver disease have less bile secretion and indigestion of fat, so don't eat too much greasy food.

Section 3 Reasonable Diet and Food Safety

1. Design reasonable nutrition to ensure food safety.

1) Eat on time, with reasonable nutrition, no partial eclipse, no picky eaters, no overeating, and eat five kinds of food in a balanced way (balanced diet pagoda). The energy intake for breakfast, lunch and dinner accounts for 30%, 40% and 30% respectively.

2) Food safety Vegetables and fruits must be cleaned. Don't eat poisonous food (rotten food, sprouted potatoes). Buy food that has passed quarantine inspection, and keep the kitchen and cookware clean.

3) The recipe for three meals a day: see book (P20)****

Chapter II Needs of Human Life-Air

Section 1 Gas exchange between human body and the outside world

1. Which organs are the respiratory system composed of (P24 in the reference book)? ****

The human respiratory system includes respiratory tract and lungs.

1) respiratory tract: it consists of nasal cavity, pharynx, larynx, trachea and bronchus; Nose hair and mucous membrane (with capillaries inside) have the functions of cleaning, moistening and warming the inhaled air.

2) The lung is the most important respiratory organ: it is a place for gas exchange.

2. Why is the lung the most important respiratory organ? ****

It is determined by the following three points:

1) lung location: in the chest cavity, one on the left and one on the right.

2) Structure of the lung: The outer alveoli are surrounded by capillaries, and the walls of alveoli and capillaries are very thin, only consisting of a layer of epithelial cells, which is suitable for gas exchange.

3) Lung function: gas exchange

3. How do you talk? (understand)

There are two vocal cords in the laryngeal cavity, and there is a narrow gap between them. When speaking, the vocal cords tighten, the glottis narrow, and the exhaled gas impacts the vocal cords, making them vibrate and sound. The length, thickness and relaxation of vocal cords determine the size of the sound.

4. How do alveoli exchange gas with the outside world? ****

1) is accomplished by breathing movements (including inhalation and exhalation).

2) principle of alveolar gas exchange: when inhaling, intercostal muscle and diaphragm contract and chest expands; On the contrary, when exhaling, the intercostal muscle and diaphragm expand, the thorax contracts, and the thorax expands and contracts rhythmically, thus completing inhalation and exhalation, which is the breathing movement. ****

5. Gas exchange in the body: (Understand the two graphic problems of P28 inspiratory expiratory diagram and P30 in the book, and do it! )

(1) Understanding principle: P28.

(2) Gas exchange in alveoli: Understanding P29.

(3) Gas exchange in tissues: Understanding P29.

Section 2 How does the human body get energy

1. The energy needed by human body comes from food (organic nutrients in it).

Sugar, fat and protein can provide energy for human body. ****

Sugar (17. 15 kj/g), protein (17. 15 kj/g) and fat (38.9 1 kj/g).

2. Understand P35-thinking and contact in the book.

Section 3 Air Quality and Health

1) Air quality affects human health. Pollutants in the atmosphere are very harmful to human health, and harmful substances can cause respiratory diseases.

2) Understand the local air quality and the causes of local air pollution, and measure the dust particles in the air.

3) Hazards of smoking: Smoking will damage the respiratory system, cause cancer, and seriously damage many organs of the human body (such as the nervous system).

Four, the transport of substances in the human body

Section 1 Carrier of Goods Transportation

1. Composition and function of blood:

1) Blood containing anticoagulant (sodium citrate) will be stratified.

Blood can be divided into plasma and blood cells. The most abundant component in plasma is water (90%). The main function of plasma is to transport blood cells, nutrients and wastes.

Blood cells can be divided into red cells, white cells and platelets.

Quantitative function-related diseases

Erythrocyte male: 5.0 x 10 12 /L (hemoglobin 120- 160 g/L)

Female: 4.2 x 10 12 /L (hemoglobin110-150g/l) is used to transport oxygen and oxygen.

Partial low carbon dioxide: anemia

White blood cells (4- 10) ⅹ 109/L phagocytosis, too much defense and protection: inflammation.

Platelets (1-3) ⅹ101/l stop bleeding too little, blood coagulation accelerates: bleeding does not stop.

2) Hemoglobin is a kind of ferritin, which is red and determines the color of blood. Its characteristics are: it is easy to combine with oxygen in places with high oxygen content, and it is easy to separate from oxygen in places with low oxygen content.

3) Blood type: ABO system includes four blood types: A, B, AB and O. The principle of blood transfusion is: transfusion of homologous blood.

1, 4) Function of blood: 1) Function of transporting oxygen and carbon dioxide, nutrients and wastes. 2) defense and protection 3) thermoregulation.

Anemia refers to a small number of red blood cells or hemoglobin. The former is due to malnutrition, and the latter is due to iron deficiency. We should eat more foods rich in iron and protein.

Adults can donate 200-300ml； blood each time; High altitude hypoxia can lead to dyspnea; Anemia should eat more foods rich in iron and protein.

Section 2 Material Transportation Organization

1. Vascular-vascular (see this table for details) * * * *

Vascular types, functional distribution, vascular wall characteristics, lumen characteristics, blood flow velocity and hemostasis methods

Arterial centrifugal blood transfusion is deeply distributed, with large wall thickness, small elasticity and the fastest.

Spray-like, bright red near the heart to stop bleeding

Capillaries exchange a lot of substances.

Widely distributed and thinnest (consisting of only one layer of flat cells), smallest and slowest.

After exudation, bright red disinfection and dressing.

Intravenous infusion to the heart has a shallow distribution,

Some have deep distribution, thin walls, small elasticity, large volume and slow speed.

(dark red) distal hemostasis

The five capillaries with the most: 1) the thinnest wall 2) the slowest blood flow 3) the widest distribution 4) the largest number 5) the smallest lumen.

2. Blood pump-heart

1) Structure and function of the heart: located in the middle of the chest, to the lower left, between the left and right lungs.

There are four chambers: left ventricle-aorta (thinnest wall-aorta (arterial blood).

Right ventricle-pulmonary artery (venous blood)

Left atrium-pulmonary vein (arterial blood)

Right atrium-superior and inferior vena cava (venous blood)

Valves-divided into atrioventricular valves and arterial valves. Prevent blood from flowing backwards.

Function of the heart: It is the power organ of blood circulation.

The activity relationship of atrium, ventricle and valve: once the heart beats, it means once the heart contracts, once relaxes and beats repeatedly.

Normal adult heart rate-60- 100 beats per minute.

Someone has an upper arm injury and bleeding, but the bleeding is slow. (This is capillary bleeding);

When the baby was born, the left and right ventricles were not completely closed. (In this case, arterial blood and venous blood cannot be completely opened, resulting in insufficient oxygen supply to the body. )

Section 3 Mode of Material Transportation

1. The concept and mode of blood circulation:

Concept: Blood circulates in the pipeline composed of the heart and all blood vessels.

Blood circulation includes systemic circulation and pulmonary circulation. The schematic diagram is as follows:

histocyte

Waste such as oxygen and nutrient carbon dioxide.

Left ventricle aorta systemic circulation artery capillary network vein superior and inferior vena cava right atrium

Left atrial pulmonary vein pulmonary capillary network pulmonary artery right ventricle

Oxygen and carbon dioxide

pulmonary alveolus

Summary: 1) Each cycle begins in the ventricle and ends in the atrium.

2) Arterial blood flows out of systemic circulation and venous blood returns; Venous blood flows out of the pulmonary circulation and arterial blood flows back.

3) Two circulations are carried out at the same time, and finally meet in the heart to form a complete circulatory pathway.

4) At the capillaries of tissues and cells in the whole body: blood changes from arterial blood to venous blood.

At the capillaries of the lungs: blood changes from venous blood to arterial blood.

5) Arterial blood flows on the left side of the heart and venous blood flows on the right side.

6) Red is arterial blood and blue is venous blood. (The above should be carefully recorded according to the figure! )

2. Blood pressure and pulse

Blood pressure: it is the lateral pressure produced by blood flowing on the blood vessel wall.

Pulse: refers to the pulse of the artery.

What we usually call blood pressure is the arterial blood pressure of systemic circulation. The expression is: Systolic blood pressure/diastolic blood pressure can be measured at brachial artery of upper arm with sphygmomanometer. Its value is usually expressed in kilopascals (kilopascals).

When the heart contracts, the highest value of arterial blood pressure is called systolic pressure. The lowest diastolic arterial blood pressure is called diastolic blood pressure. The normal systolic blood pressure of healthy adults is 12 ~ 18.7 kPa, and the diastolic blood pressure is 8 ~ 12 kPa.

The blood circulation system consists of the heart and blood vessels. The "blue veins" on the hand refer to veins.

The blood volume of adults is about 7%-8% of their body weight, and blood loss exceeding 1200ML will be life-threatening. Blood loss less than 400ML at a time will not affect health. Advocate blood donation without compensation. Donate 200-300ML at a time.

Pulse refers to the pulse of the artery, the number of which is the same as the heart rate. When the human body is sick, it often changes the speed and intensity of the heartbeat and shows it on the pulse. Pulse cutting-the measured part is in the radial artery (outside the left wrist).

Some people say that arterial blood flows in arterial blood vessels and venous blood flows in venous blood vessels. No, because blood circulation includes systemic circulation and pulmonary circulation. As shown in the figure ...)

The fourth quarter pays attention to cardiovascular health

1. Factors affecting cardiovascular health

Common cardiovascular diseases include arteriosclerosis, hypertension, coronary heart disease, myocarditis and congenital heart disease.

Besides heredity and congenital factors, cardiovascular diseases are also related to inappropriate lifestyles.

Alcohol-alcohol contains alcohol. Excessive drinking makes fat deposit on the blood vessel wall, narrows the lumen, increases blood pressure, accelerates arteriosclerosis and increases the incidence of coronary heart disease. But moderate drinking is good for health.

Tobacco-Nicotine in tobacco will increase the number of red blood cells in blood vessels, thicken blood, cause fat deposition in the heart and blood vessel walls, and cause arteriosclerosis and hypertension.

Long-term stress and lack of physical exercise are easy to induce cardiovascular diseases.

2. Develop good living habits and maintain cardiovascular health;

1) Physical exercise: such as running, playing ball ..., but avoid excessive exercise to damage heart function.

2) Overcome the bad eating habits of partial eclipse, anorexia and overeating;

3) Don't smoke or drink too much;

4) Maintain a positive and optimistic attitude.

Chapter IV Discharge of Wastes in Human Body

1. Formation and excretion of urine

1) concept: the process of discharging wastes such as carbon dioxide, urea and excess water generated during the decomposition of substances in the body.

Pathway: 1) skin: excrete water, inorganic salts and urea in the form of sweat.

2) Respiratory system: carbon dioxide and water are discharged in the form of gas.

3) Urinary system: Water, inorganic salts and urea are discharged in the form of urine.

2) Composition of urinary system

Kidney: the place where urine forms.

ureter

Bladder urination channel, bladder has the function of urine storage.

urethra

3) Structure and function of nephron

Glomerulus: dozens of capillaries branched from input arterioles are bent and coiled, and the other ends converge into output arterioles.

Nephron renal capsule: the blind end of renal tubule is partially depressed, and the capsule wall is divided into two layers, the inner layer is close to glomerulus and the outer layer is connected with renal tubule.

Renal tubule: the cavity between the inner and outer layers of the renal capsule communicates with the renal tubule.

4) Formation of urine

(1) Glomerular filtration: Except protein of blood cells and macromolecules, all plasma components can be filtered to form protourine.

(2) Renal tubular reabsorption: substances useful to human body, including most water, all glucose and some inorganic salts.

(3) Renal tubular secretion: Renal tubular epithelial cells secrete ammonia and other substances to form urine.

Section 2 Formation and Elimination of Sweat

* * Difference: blood, plasma, urine, urine.

Chapter V Adjustment of Human Life Activities

1. Hormone regulation in human body

2. The structural basis of neuromodulation

3. Basic ways of neuromodulation

4. Human perception of the external environment

5. Health care of nervous system

1) human vision and hearing

(1) structure and function of eyeball

Epidural cornea: the front part of the outer membrane, colorless and transparent, can transmit light.

Scleral: white, protecting the inside of eyeball.

Iris: The front of the medium is colored, and the center is the pupil, which is transparent.

Ciliary body: The posterior part of the iris contains smooth muscle, which can contract and relax and adjust the curvature of the lens.

Choroid: It occupies the posterior part of 2/3 of the media, with blood vessels (nourishing the eyeball) and pigment cells (shading, forming a "dark room" inside the eyeball).

Intima: retina with a large number of photoreceptor cells.

aqueous humor

Content lens: a biconvex lens connected to the ciliary body through ligaments.

vitreous body

Accessory structures: eye muscles, eyelids, eyelashes, conjunctiva, lacrimal apparatus (lacrimal gland, lacrimal punctum, nasolacrimal duct)

(2) the formation of vision:

Propagation along the optic nerve by refraction.

External light is imaged on the retina to produce nerve impulse visual center (forming vision).

(3) eye care:

Myopia: Because the anterior and posterior diameter of eyeball is too long, or the curvature of lens is too large, the object image falls in front of retina.

Correction: wear concave lenses

Hyperopia: Because the anterior and posterior diameter of eyeball is too short, or the curvature of lens is too small, the object image falls behind retina.

Correction: wear a convex lens

Trachoma: The inner conjunctiva of eyelid infected by Chlamydia trachomatis.

Structure and function of the ear:

The outer ear and auricle collect and conduct sound waves.

external auditory meatus

Tympanic membrane: receives sound waves and produces vibration.

(1) Middle ear tympanum: There is an eustachian tube communicating with the pharynx to keep the air pressure balance inside and outside the eardrum.

Auditory ossicles: three pieces, which transmit the vibration of tympanic membrane to the inner ear.

semicircular canal

Vestibule of inner ear

Cochlea: There are auditory receptors inside, which can receive stimulation and produce nerve impulses.

(2) The formation of hearing along the external auditory canal and hearing along the auditory accessory pathway.

Acoustic wave tympanic membrane produces vibration cochlea produces nerve impulse auditory pathway bone conduction related nerve (forming hearing).

2, the composition of the nervous system

1) Composition of the nervous system Central nervous system: brain and spinal cord.

Peripheral nervous system: cranial nerve and spinal nerve.

2) Structure and function of neurons:

(1) structural cell body

Protruding axon: a long but few branch.

Dendrite: Several short tree branches.

Axons are assembled into bundles and covered by connective tissue membranes.

Myelin nerve fiber (the tiny branches at the end are nerve endings) nerve

(2) Function: Feel stimulation, generate excitement, and get excited (excitement is carried out in the form of nerve impulses)

* * Distinguish the central nervous system: including the brain and spinal cord.

Nerve center: In the gray matter of the central nervous system, neurons with the same function gather together to regulate a corresponding physiological activity of people, which is called nerve center.

3. Basic ways of neuromodulation

Concept of reflex: Animals (including people) produce various external or internal stimuli through the nervous system.

Conventional reactions are different from irritability.

The concept of arc: neural structure involving reflection

Composition: receptor, afferent nerve, nerve center, efferent nerve, effector (book P8 1).

The process of knee jerk reflex: buckle: ligament below the knee.

Phenomenon: the calf suddenly jumps up.

Receptors: sensory nerve endings in quadriceps femoris and tendons.

Nerve center: located in the gray matter of spinal cord.

Effector: quadriceps femoris and its motor nerve endings.

3) The type of reflection is simple reflection

Complex reflection

Hormone regulation

1), the location and name of the main endocrine glands in human body:

Pituitary gland, thyroid gland, islet, adrenal gland, gonad and thymus gland.

2) Hormone: chemical substances secreted by endocrine gland cells that have special effects on the body.

3) Pituitary gland: secreting growth hormone, thyroid stimulating hormone and gonadotropin can regulate the activities of other endocrine glands.

4) Growth hormone, thyroid hormone and insulin:

5) Relationship between nerve regulation and hormone regulation: The regulation of human life activities is mainly regulated by the nervous system, but also by hormones.

Chapter VI Immunity and Health

Section 1 Human Immune Function

Section 2 Infectious Diseases and Their Prevention

Section 3 Safe Drug Use

Chapter VII The Role of Man in the Biosphere

Section 1 Human Dependence on the Biosphere

The influence of human beings on biosphere in the second quarter

Section 3 Protecting Our Homestead

Example analysis of human activities destroying ecological environment

Human activities improve the ecological environment-"Three North" shelter forest

Human activities have destroyed the ecological environment, and forests have been severely cut down.

The sandstorm is serious.