5.2. The blood

The blood

Blood is a liquid connective tissue that circulates in the blood vessels of all vertebrates. It is red because red blood cells have hemoglobin, a protein to which oxygen binds.

Composition of blood

An adult person has about 5.5 liters of blood, which is made up of:

The blood plasma, yellowish liquid consisting of water in which many dissolved substances are: mineral salts, nutrients (glucose, amino acids, vitamins), waste substances, hormones, etc.
The cells blood, which are of three types:
- Red blood cells or red blood cells or erythrocytes: These are the most numerous cells (about 5 million per mm³ of blood). They have no nucleus and contain hemoglobin, an iron-containing red pigment, which carries O₂.
- White blood cells or leukocytes: There are several types of white blood cells and they have a defensive function. We have about 6000-7000 white blood cells per mm³ of blood.
- Platelets or thrombocytes: They are not really cells, but fragments of cells. They intervene in blood clotting, preventing blood from being lost in any hemorrhage. We have 200,000 to 300,000 platelets per mm³ of blood.

Componentes de la sangre

By Illu_blood_components.svg: MesserWolandderivative work: Ninovolador (Illu_blood_components.svg) [CC BY-SA 2.5-2.0-1.0, CC-BY-SA-3.0 or GFDL], via Wikimedia Commons

Functions of blood

The main functions of blood are:

It carries nutrients to all cells in the body.
Carries respiratory gases. The oxygen is bound in the lungs, the hemoglobin in red blood cells to form oxyhemoglobin, deep red, and is carried to the cells. There, as there is a lower concentration of oxygen inside the cell, the oxygen is released and passes into the cells. Carbon dioxide, on the other hand, dissolves well in blood plasma, and goes from cells to the lungs.
It collects the waste products of metabolism, which it takes to the excretory system to eliminate them, in addition to the CO₂ that it eliminates through the lungs.
It takes part in the defense of the organism.
It carries hormones, substances secreted by the endocrine system.
Regulates the temperature, distributing the heat from warmer areas to colder ones. In this way, it achieves a body temperature of about 37 ºC, the best for the development of chemical reactions of metabolism.

Answer in your notebook

5.1.- Name the components of blood and explain the function of each component.

Answer in your notebook

5.2.- In places that are at high altitude, the oxygen pressure is lower. Why do some athletes prepare in these places before a major competition?

Interactive activity: The blood.

Interactive activity: Diagnostic value of the blood test.

Interactive animation: Interpretation of a blood test.

Interactive activity: Challenge yourself with this test on the circulatory system.

Biological music: Blood.

Activity: Word search about the circulatory system.

Activity: Crossword about blood.

Licensed under the Creative Commons Attribution Share Alike License 4.0

BIOLOGÍA - GEOLOGÍA . COM
1st ESO	3rd ESO	4th ESO	Biology 2nd Baccalaureate
Index by courses	Forums	Geología 2º Bach.

Skip navigation Biology and Geology 3rd compulsory secondary education Biology and Geology 3rd ESO 01. General organization of the human body 1.1. Levels of organization of the human body 1.2. The cell 1.2.1. The prokaryotic cell 1.2.2. The eukaryotic cell 1.2.2.1. The eukaryotic animal cell 1.2.2.2. The eukaryotic plant cell 1.3. Tissues 1.4. Organs, systems and apparatus 1.5. Bibliography and student work 02. Food and health 2.1. Feeding and nutrition 2.2. Nutrients 2.2.1. Types of nutrients 2.2.2. The energy of nutrients 2.3. The food 2.4. Diets 2.5. Food consumption 2.5.1. Labelled 2.5.2. How to shop and cook 2.6. Food preservation and hygiene 2.7. Food production 2.7.1. Intensive agriculture 2.7.2. Intensive livestock 2.7.3. Aquaculture 2.7.4. Transgenic foods 2.7.5. Organic food 2.8. Eating-related illnesses 2.9. Bibliography and student work 03. The digestive system and digestion 3.1. Nutrition function 3.2. Digestive system 3.2.1. Ingestion 3.2.1.1. Chewing 3.2.1.2. Insalivation 3.2.1.3. Swallowing 3.2.2. Digestion 3.2.3. Absorption 3.2.4. Expulsion or egestion 3.3. Diseases of the digestive system 3.3.1. Diseases in the mouth 3.3.2. Diseases in the stomach 3.3.3. Diseases in the intestine 3.3.4. Liver disease 3.4. Healthy habits related to the digestive system 3.5. Bibliography and student work 04. The respiratory system and respiration 4.1. Respiratory tract and lungs 4.1.1. Airways 4.1.2. Lungs 4.1.3. The gaseous exchange 4.2. Respiratory activity 4.3. Diseases of the respiratory system 4.4. Healthy habits related to the respiratory system 4.5. Bibliography and student work 05. The circulatory system and circulation 5.1. General organization of the circulatory system 5.2. The blood 5.3. The heart 5.4. Heart movements 5.5. Blood vesels 5.6. Blood pressure 5.7. The blood circulation 5.8. Lymph and lymphatic system 5.9. Diseases of the circulatory system 5.9.1. Diseases of the blood vessels 5.9.2. Heart disease 5.9.3. Blood diseases 5.10. Healthy habits for the circulatory system 5.11. Bibliography and student work 06. The excretory system and excretion 6.1. Excretion 6.2. Urinary system 6.2.1. Kidneys 6.2.2. Urine formation 6.2.3. Urinary tract 6.3. Kidney disease 6.4. Healthy habits for the excretory system 6.5. Bibliography and student work 07. The nervous system 7.1. Relationship function and the nervous system 7.2. Cells of the nervous system 7.2.1. Neuron 7.2.2. Glia 7.3. Nerve impulse 7.4. Organization of the nervous system 7.4.1. The Central Nervous System 7.4.1.1. Encephalon 7.4.1.2. Spinal cord 7.4.2. The Peripheral Nervous System 7.4.2.1. Somatic Nervous System 7.4.2.2. Autonomic nervous system 7.5. Nervous acts 7.6. Nervous system diseases 7.6.1. Brain injuries 7.6.2. Spinal cord injuries 7.6.3. Neuropsychological diseases 7.6.4. Pathologies related to lifestyle 7.7. Healthy habits and mental health 7.8. Drug addiction 7.8.1. Common characteristics of drugs 7.8.2. Classification of drugs 7.9. Bibliography and student work 08. The endocrine system 8.1. The types of responses 8.2. The endocrine system 8.2.1. Endocrine glands 8.2.2. Hormonal control 8.3. Endocrine system diseases 8.4. Bibliography and student work 09. Sensory receptors. The sense organs 9.1. Perception: sensory receptors 9.1.1. The touch and the pain 9.1.2. The sense of smell 9.1.3. Taste 9.1.4. The eye and vision 9.1.5. The ear: hearing and balance 9.2. Healthy habits for the sense organs 9.3. Bibliography and student work 10. Effector organs. The locomotor system 10.1. The skeleton 10.1.1. The bones 10.1.1.1. Bones of the human body 10.1.2. Joints 10.2. Musculature 10.2.1. Muscles of the human body 10.3. Healthy habits of the locomotor system 10.4. Musculoskeletal disorders 10.5. Bibliography and student work 11. Human sexuality and reproduction 11.1. Human reproduction 11.1.1. The male reproductive system 11.1.2. Spermatozoon 11.1.3. The female reproductive system 11.1.4. The ovule 11.1.5. The menstrual cycle 11.1.6. Fertilization, pregnancy and childbirth 11.1.6.1. Fertilization 11.1.6.2. Pregnancy 11.1.6.3. Birth 11.2. Natality control 11.2.1. Contraceptive methods 11.2.2. Reproduction techniques 11.2.2.1. Exploratory techniques 11.2.2.2. Assistance techniques in childbirth 11.2.2.3. Assisted reproductive techniques 11.3. Adolescence and sexuality 11.4. Main sexually transmitted diseases and prevention 11.5. Prevention and sexual hygiene 11.6. Bibliography and student work 12. Health and disease 12.1. What is health? 12.1.1. Health indicators 12.1.2. Health determinants 12.2. The disease and types of diseases 12.3. Infectious diseases 12.3.1. Types of infectious diseases 12.3.2. Immunity and immune system 12.3.3. Prevention and cure of infectious diseases 12.4. Non-infectious diseases 12.5. First aid 12.6. Transplants and donation of cells, blood and organs 12.7. Bibliography and student work 13. Ecosystems 13.1. Ecosystem components 13.2. Types of ecosystems 13.3. Factors influencing the ecosystem 13.4. Balance in ecosystems 13.5. The soil as an ecosystem 13.6. Bibliography and student work 14. The external geological activity of the Earth 14.1. Solar energy on Earth 14.2. External geological processes 14.2.1. Weathering 14.2.2. Erosion, transport and sedimentation 14.3. Factors that condition the modeling of the relief 14.4. Forms of relief modeling 14.4.1. Wild or stream waters 14.4.2. Torrential modeling 14.4.3. River modeling 14.4.4. Karst modeling. Groundwater 14.4.5. Littoral modeling 14.4.6. Glacier modeling 14.4.7. Wind or desert modeling 14.5. Geological action of living beings 14.6. Geological action of the human being 14.7. Bibliography and student work 15. The internal geological activity of the Earth 15.1. The internal energy of the Earth 15.2. Volcanoes 15.2.1. Types of volcanoes 15.2.2. Volcanic risk 15.3. Earthquakes 15.3.1. Seismic risk 15.4. Bibliography and student work « Previous \| Next » 5.2. The blood The blood Blood is a liquid connective tissue that circulates in the blood vessels of all vertebrates. It is red because red blood cells have hemoglobin, a protein to which oxygen binds. Composition of blood An adult person has about 5.5 liters of blood, which is made up of: The blood plasma, yellowish liquid consisting of water in which many dissolved substances are: mineral salts, nutrients (glucose, amino acids, vitamins), waste substances, hormones, etc. The cells blood, which are of three types: Red blood cells or red blood cells or erythrocytes: These are the most numerous cells (about 5 million per mm³ of blood). They have no nucleus and contain hemoglobin, an iron-containing red pigment, which carries O₂. White blood cells or leukocytes: There are several types of white blood cells and they have a defensive function. We have about 6000-7000 white blood cells per mm³ of blood. Platelets or thrombocytes: They are not really cells, but fragments of cells. They intervene in blood clotting, preventing blood from being lost in any hemorrhage. We have 200,000 to 300,000 platelets per mm³ of blood. By Illu_blood_components.svg: MesserWolandderivative work: Ninovolador (Illu_blood_components.svg) [CC BY-SA 2.5-2.0-1.0, CC-BY-SA-3.0 or GFDL], via Wikimedia Commons Functions of blood The main functions of blood are: It carries nutrients to all cells in the body. Carries respiratory gases. The oxygen is bound in the lungs, the hemoglobin in red blood cells to form oxyhemoglobin, deep red, and is carried to the cells. There, as there is a lower concentration of oxygen inside the cell, the oxygen is released and passes into the cells. Carbon dioxide, on the other hand, dissolves well in blood plasma, and goes from cells to the lungs. It collects the waste products of metabolism, which it takes to the excretory system to eliminate them, in addition to the CO₂ that it eliminates through the lungs. It takes part in the defense of the organism. It carries hormones, substances secreted by the endocrine system. Regulates the temperature, distributing the heat from warmer areas to colder ones. In this way, it achieves a body temperature of about 37 ºC, the best for the development of chemical reactions of metabolism. Answer in your notebook 5.1.- Name the components of blood and explain the function of each component. Answer in your notebook 5.2.- In places that are at high altitude, the oxygen pressure is lower. Why do some athletes prepare in these places before a major competition? Interactive activity: The blood. Interactive activity: Diagnostic value of the blood test. Interactive animation: Interpretation of a blood test. Interactive activity: Challenge yourself with this test on the circulatory system. Biological music: Blood. Activity: Word search about the circulatory system. Activity: Crossword about blood. Licensed under the Creative Commons Attribution Share Alike License 4.0 « Previous \| Next » You can ask, comment, contribute, get in touch with other users in the forum of this course. This course is translated from https://biologia-geologia.com/BG3/
Legal warning	Blog	Download	Contact

Follow us if it has been useful to you biologia-geologia.com. Biology and Geology teaching materials for Compulsory Secondary Education (ESO) and Baccalaureate students.

BIOLOGÍA - GEOLOGÍA . COM

The blood

Composition of blood

Functions of blood