5.5. Blood vessels

Blood vessels

The blood vessels are the tubes through which flows the blood. There are mainly three types of blood vessels:

The arteries are the blood vessels leading from the heart. It has elastic and resistant walls, as well as a powerful muscular layer that regulates the pressure with which the blood leaves the heart. With ventricular systole, blood leaves the heart filling the artery and the sigmoid valves close so that it cannot back up .

The arteries are made up of three layers, the muscular layer being very thick since its contractions help drive the blood.

The arteries, as they move away from the heart, branch into other thinner and less elastic vessels called arterioles.

Vasos sanguíneos: Las arterias se dividen en arteriolas, éstas en capilares. Los capilares se reúnen en vénulas, y éstas se agrupan en venas

By Kelvinsong (Own work) [CC BY-SA 3.0], via Wikimedia Commons

The capillaries are extremely fine vessels (so called capillaries, to be as thin as hairs) arising from the ramifications of arterioles, which carry blood to all cells of the body .

Its wall is very thin, made up of a single layer of flat cells (called the endothelium), which allows substances from the blood to pass into the cells and their waste into the blood. It is in the capillaries where the exchange of substances between the blood and the interstitial plasma takes place .

The capillaries reach all the cells of the organs, since we have several million blood vessels, about 100,000 km long.

Activity: Blood vessels.

Activity: Crossword on blood vessels.

Experiments with your body: Blood.

Activity: Blood vessels.

Capillaries join to form venules, which group together to form veins, the blood vessels that carry blood to the heart. Its wall is thinner (its muscular layer is smaller) and less resistant than that of the arteries, since the blood circulates through them with less pressure. Instead, they have a larger diameter than arteries because their wall is compliant, with a greater capacity to accumulate blood. Inside they have valves, called venous valves that prevent the backward movement of blood and promote its movement towards the heart.

Válvulas venosas

Answer in your notebook

5.8.- What are the main differences between arteries and veins?

Answer in your notebook

5.9.- Why are the walls of the arteries thicker than the walls of the veins?

Answer in your notebook

5.10.- Why do capillaries have such thin walls?

Answer in your notebook

5.11.- Why is the exchange of nutrients, gases, waste substances, etc., only carried out in the capillaries and not in other blood vessels?

Answer in your notebook

5.12.- What function do the blood vessels that surround the heart have?

Answer in your notebook

5.13.- Why, if the blood comes out of the heart in beats with each beat, does it reach the cells in a continuous flow?

Answer in your notebook

5.14.- What function do the venous valves have?

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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. 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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 » 5.5. Blood vessels Blood vessels The blood vessels are the tubes through which flows the blood. There are mainly three types of blood vessels: The arteries are the blood vessels leading from the heart. It has elastic and resistant walls, as well as a powerful muscular layer that regulates the pressure with which the blood leaves the heart. With ventricular systole, blood leaves the heart filling the artery and the sigmoid valves close so that it cannot back up . The arteries are made up of three layers, the muscular layer being very thick since its contractions help drive the blood. The arteries, as they move away from the heart, branch into other thinner and less elastic vessels called arterioles. By Kelvinsong (Own work) [CC BY-SA 3.0], via Wikimedia Commons The capillaries are extremely fine vessels (so called capillaries, to be as thin as hairs) arising from the ramifications of arterioles, which carry blood to all cells of the body . Its wall is very thin, made up of a single layer of flat cells (called the endothelium), which allows substances from the blood to pass into the cells and their waste into the blood. It is in the capillaries where the exchange of substances between the blood and the interstitial plasma takes place . The capillaries reach all the cells of the organs, since we have several million blood vessels, about 100,000 km long. Activity: Blood vessels. Activity: Crossword on blood vessels. Experiments with your body: Blood. Activity: Blood vessels. Capillaries join to form venules, which group together to form veins, the blood vessels that carry blood to the heart. Its wall is thinner (its muscular layer is smaller) and less resistant than that of the arteries, since the blood circulates through them with less pressure. Instead, they have a larger diameter than arteries because their wall is compliant, with a greater capacity to accumulate blood. Inside they have valves, called venous valves that prevent the backward movement of blood and promote its movement towards the heart. Answer in your notebook 5.8.- What are the main differences between arteries and veins? Answer in your notebook 5.9.- Why are the walls of the arteries thicker than the walls of the veins? Answer in your notebook 5.10.- Why do capillaries have such thin walls? Answer in your notebook 5.11.- Why is the exchange of nutrients, gases, waste substances, etc., only carried out in the capillaries and not in other blood vessels? Answer in your notebook 5.12.- What function do the blood vessels that surround the heart have? Answer in your notebook 5.13.- Why, if the blood comes out of the heart in beats with each beat, does it reach the cells in a continuous flow? Answer in your notebook 5.14.- What function do the venous valves have? 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/
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Blood vessels