How do circulatory and respiratory systems interact

It is made of incomplete rings of hyaline cartilage and smooth muscle Figure The trachea is lined with mucus-producing goblet cells and ciliated epithelia. The cilia propel foreign particles trapped in the mucus toward the pharynx. The forced exhalation helps expel mucus when we cough. The end of the trachea bifurcates divides to the right and left lungs. The lungs are not identical. The right lung is larger and contains three lobes, whereas the smaller left lung contains two lobes Figure The muscular diaphragm, which facilitates breathing, is inferior below to the lungs and marks the end of the thoracic cavity.

In the lungs, air is diverted into smaller and smaller passages, or bronchi. Air enters the lungs through the two primary main bronchi singular: bronchus. Each bronchus divides into secondary bronchi, then into tertiary bronchi, which in turn divide, creating smaller and smaller diameter bronchioles as they split and spread through the lung.

Like the trachea, the bronchi are made of cartilage and smooth muscle. At the bronchioles, the cartilage is replaced with elastic fibers. In humans, bronchioles with a diameter smaller than 0. They lack cartilage and therefore rely on inhaled air to support their shape. As the passageways decrease in diameter, the relative amount of smooth muscle increases. The terminal bronchioles subdivide into microscopic branches called respiratory bronchioles.

The respiratory bronchioles subdivide into several alveolar ducts. Numerous alveoli and alveolar sacs surround the alveolar ducts.

The alveolar sacs resemble bunches of grapes tethered to the end of the bronchioles Figure In the acinar region, the alveolar ducts are attached to the end of each bronchiole. At the end of each duct are approximately alveolar sacs, each containing 20 to 30 alveoli that are to microns in diameter.

Gas exchange occurs only in alveoli. Alveoli are made of thin-walled parenchymal cells, typically one-cell thick, that look like tiny bubbles within the sacs.

Alveoli are in direct contact with capillaries one-cell thick of the circulatory system. Such intimate contact ensures that oxygen will diffuse from alveoli into the blood and be distributed to the cells of the body. In addition, the carbon dioxide that was produced by cells as a waste product will diffuse from the blood into alveoli to be exhaled.

This organization produces a very large surface area that is available for gas exchange. The surface area of alveoli in the lungs is approximately 75 m 2. This large surface area, combined with the thin-walled nature of the alveolar parenchymal cells, allows gases to easily diffuse across the cells.

Watch the following video to review the respiratory system. The air that organisms breathe contains particulate matter such as dust, dirt, viral particles, and bacteria that can damage the lungs or trigger allergic immune responses. The respiratory system contains several protective mechanisms to avoid problems or tissue damage. In the nasal cavity, hairs and mucus trap small particles, viruses, bacteria, dust, and dirt to prevent their entry.

If particulates do make it beyond the nose, or enter through the mouth, the bronchi and bronchioles of the lungs also contain several protective devices. The lungs produce mucus —a sticky substance made of mucin , a complex glycoprotein, as well as salts and water—that traps particulates.

The bronchi and bronchioles contain cilia, small hair-like projections that line the walls of the bronchi and bronchioles Figure These cilia beat in unison and move mucus and particles out of the bronchi and bronchioles back up to the throat where it is swallowed and eliminated via the esophagus.

In humans, for example, tar and other substances in cigarette smoke destroy or paralyze the cilia, making the removal of particles more difficult.

In addition, smoking causes the lungs to produce more mucus, which the damaged cilia are not able to move. This causes a persistent cough, as the lungs try to rid themselves of particulate matter, and makes smokers more susceptible to respiratory ailments. Animal respiratory systems are designed to facilitate gas exchange. In mammals, air is warmed and humidified in the nasal cavity. Air then travels down the pharynx, through the trachea, and into the lungs.

In the lungs, air passes through the branching bronchi, reaching the respiratory bronchioles, which house the first site of gas exchange. The respiratory bronchioles open into the alveolar ducts, alveolar sacs, and alveoli. Because there are so many alveoli and alveolar sacs in the lung, the surface area for gas exchange is very large. Several protective mechanisms are in place to prevent damage or infection.

These include the hair and mucus in the nasal cavity that trap dust, dirt, and other particulate matter before they can enter the system. In the lungs, particles are trapped in a mucus layer and transported via cilia up to the esophageal opening at the top of the trachea to be swallowed.

The circulatory system is a network of vessels—the arteries, veins, and capillaries—and a pump, the heart. Blood circulates inside blood vessels and circulates unidirectionally from the heart around one of two circulatory routes, then returns to the heart again; this is a closed circulatory system.

Open circulatory systems are found in invertebrate animals in which the circulatory fluid bathes the internal organs directly even though it may be moved about with a pumping heart. The heart is asymmetrical, with the left side being larger than the right side, correlating with the different sizes of the pulmonary and systemic circuits Figure In humans, the heart is about the size of a clenched fist; it is divided into four chambers: two atria and two ventricles.

There is one atrium and one ventricle on the right side and one atrium and one ventricle on the left side. The electrical impulses in the heart produce electrical currents that flow through the body and can be measured on the skin using electrodes. This information can be observed as an electrocardiogram ECG a recording of the electrical impulses of the cardiac muscle.

The blood from the heart is carried through the body by a complex network of blood vessels Figure Arteries take blood away from the heart. The main artery of the systemic circulation is the aorta; it branches into major arteries that take blood to different limbs and organs.

The aorta and arteries near the heart have heavy but elastic walls that respond to and smooth out the pressure differences caused by the beating heart. Arteries farther away from the heart have more muscle tissue in their walls that can constrict to affect flow rates of blood. The major arteries diverge into minor arteries, and then smaller vessels called arterioles, to reach more deeply into the muscles and organs of the body. Arterioles diverge into capillary beds.

Capillaries are narrow-diameter tubes that can fit single red blood cells and are the sites for the exchange of nutrients, waste, and oxygen with tissues at the cellular level.

Fluid also leaks from the blood into the interstitial space from the capillaries. The capillaries converge again into venules that connect to minor veins that finally connect to major veins. Veins are blood vessels that bring blood high in carbon dioxide back to the heart. Veins are not as thick-walled as arteries, since pressure is lower, and they have valves along their length that prevent backflow of blood away from the heart.

The major veins drain blood from the same organs and limbs that the major arteries supply. As an Amazon Associate we earn from qualifying purchases. Want to cite, share, or modify this book? This book is Creative Commons Attribution License 4. Skip to Content Go to accessibility page. Concepts of Biology My highlights.

Table of contents. The Cellular Foundation of Life. Cell Division and Genetics. Molecular Biology and Biotechnology. Evolution and the Diversity of Life. Animal Structure and Function. By the end of this section, you will be able to: Describe the passage of air from the outside environment to the lungs Describe the function of the circulatory system Describe the cardiac cycle Explain how blood flows through the body. Visual Connection Figure These circulatory and respiratory system interactions are ones that humans and higher animals such as mammals and birds share and that represent one of the basic functions of their bodies.

Only when these two systems work and interact properly can the human or animal carry out other functions such as looking for food or reproducing. Bert Markgraf is a freelance writer with a strong science and engineering background. Online he has written extensively on science-related topics in math, physics, chemistry and biology and has been published on sites such as Digital Landing and Reference. TL;DR Too Long; Didn't Read The circulatory and respiratory systems absorb oxygen from the air and transfer it to all parts of the body while absorbing carbon dioxide from the body and releasing it into the air.

Role of the Lungs. Names of the Structural Components of the Human Heart. Structure of the Cardiovascular System. Respiration in Mammals. Five Major Organ Systems of the Body. The circulatory system provides your brain with a constant supply of oxygen-rich blood while your brain regulates your heart rate and blood pressure.

Even seemingly unrelated body systems are connected. Your skeletal system relies on your urinary system to remove waste produced by bone cells; in return, the bones of your skeleton create structure that protects your bladder and other urinary system organs.

Your circulatory system delivers oxygen-rich blood to your bones. Meanwhile, your bones are busy making new blood cells. Working together, these systems maintain internal stability and balance, otherwise known as homeostasis. Disease in one body system can disrupt homeostasis and cause trouble in other body systems. October 27, September 2,