Circulatory Pathways

Circulatory pathways are essential for the distribution of oxygen, nutrients, and hormones throughout the body, ensuring the proper functioning of cells and organs. Understanding circulatory pathways systems with the help of a diagram gives a better idea of the pathways.

In this article, we will cover the circulatory pathways in detail. Find the circulatory pathways class 11 notes here.

The human circulatory system, also known as the cardiovascular system, plays an important role in transporting oxygen, nutrients, hormones, and other essential substances throughout the body. Body fluids, including blood, gastric juice, cerebrospinal fluid, saliva, semen, mucus, and urine, circulate within the body. These bodily fluids are categorized into intracellular and extracellular fluids. This circulation is done by blood vessels, including arteries, veins, and capillaries, working together with the heart and lungs to ensure continuous blood flow.

The heart pumps deoxygenated blood from the right ventricle to the lungs by the pulmonary artery. In the lungs, this blood picks up oxygen. Oxygenated blood then travels back to the heart through the pulmonary veins and is pumped by the left ventricle to the body’s tissues and organs through the arteries. Arteries deliver nutrients and oxygen to the tissues, while removing waste products like carbon dioxide. This deoxygenated blood and carbon dioxide are transported back to the heart through the veins and returned to the lungs for elimination through exhalation.

The circulatory system is the network of organs and vessels responsible for transporting blood, nutrients, oxygen, and waste products throughout the body. There are two main types of circulatory systems found in animals: open and closed circulatory systems.

In a closed circulatory system, like the one humans have, blood travels through a closed loop of vessels (arteries, veins, and capillaries). This ensures efficient delivery of oxygen and nutrients throughout the body. In an open circulatory system, blood flows freely through a body cavity and directly bathes the organs before returning to the heart. This type of system is found in some invertebrates, like insects.

Let’s discuss in detail.

A closed circulatory system is a highly efficient system found in vertebrates and some invertebrates like earthworms. In this system, blood travels through a continuous loop of vessels, never leaving the confines of these vessels. This allows for the efficient delivery of oxygen, nutrients, and hormones throughout the body, while also removing waste products like carbon dioxide. Here are the key characteristics of a closed circulatory system:

• Blood Vessels: Blood is contained within a network of vessels: arteries, veins, and capillaries.
• Heart: A muscular pump (the heart) propels blood throughout the circulatory system.
• Double Circulation: Blood passes through the heart twice in one complete circuit:
  • Pulmonary Circulation: Deoxygenated blood is pumped from the right ventricle to the lungs, where it picks up oxygen. Oxygenated blood then returns to the left atrium via the pulmonary veins.
  • Systemic Circulation: Oxygenated blood is pumped from the left ventricle to the body through arteries. Blood delivers oxygen and nutrients to tissues and collects waste products like carbon dioxide. Deoxygenated blood then returns to the right atrium of the heart through veins.
• Capillary Exchange: Arteries branch into tiny capillaries, where oxygen, nutrients, and waste products are exchanged directly between the blood and tissues.
• Efficiency: The closed circulatory system allows for efficient delivery of oxygen and nutrients due to the continuous flow and pressurized blood within vessels.

An open circulatory system, found in some invertebrates like insects and mollusks, is a less complex system compared to a closed circulatory system. In this system, blood, often called hemolymph, flows freely through a body cavity called a hemocoel, bathing the organs directly. Here are the key characteristics of an open circulatory system:

• Hemolymph: The circulatory fluid, hemolymph, is not fully enclosed within vessels and bathes the organs directly in the hemocoel. Hemolymph performs some of the same functions as blood, but it may also play additional roles like transporting waste products directly to excretory organs.
• Heart(s): One or more simple hearts may be present to pump hemolymph throughout the body cavity. However, the pumping action is often less forceful compared to a closed circulatory system.
• No Capillaries: There are no capillaries for direct exchange between hemolymph and tissues. Exchange of gases and nutrients may occur through diffusion across the body wall or specialized structures.
• Limitations: Open circulatory systems are less efficient than closed systems, particularly for larger organisms. The slow and open flow of hemolymph limits the delivery of oxygen and nutrients, restricting body size and activity levels.

Also Read: Difference Between Open and Closed Circulatory System

The diagram of circulatory system is given below:

The function of circulatory pathways are:

• Delivery:
  • Transports oxygen from lungs to tissues.
  • Carries nutrients from digested food to cells.
  • Delivers hormones for regulating body functions.
• Waste Removal:
  • Removes carbon dioxide, a waste product of cellular respiration, and transports it back to the lungs for exhalation.
  • Carries other waste products to the kidneys for elimination through urine.
• Regulation:
  • Helps maintain body temperature by controlling blood flow to different body parts.

In summary, the circulatory pathways of the human body includes the cardiovascular system. It ensure the vital transportation of oxygen, nutrients, hormones, and bodily fluids. This complex network of blood vessels, including arteries, veins, and capillaries, collaborates with the heart and lungs to maintain continuous blood flow. Through the process of pulmonary and systemic circulation, deoxygenated blood is oxygenated in the lungs before being distributed to the body’s tissues and organs. This closed circulatory system optimizes nutrient delivery while efficiently removing waste products like carbon dioxide. Additionally, contrasting with the open circulatory systems found in some invertebrates, the closed circulatory system in vertebrates ensures precise and effective distribution of essential substances, supporting higher metabolic activity and larger body sizes.

What are the 3 Circulatory Pathways?

The three circulatory pathways are systemic circulation, pulmonary circulation, and coronary circulation.

What is Circulatory Pathways Class 11?

Circulatory pathways in Class 11 refer to the routes through which blood flows in the body, including the heart, lungs, and systemic tissues.

What is the Order of the Circulatory Pathway?

The order of the circulatory pathway begins with the pumping of deoxygenated blood from the heart to the lungs in pulmonary circulation, followed by oxygenated blood returning to the heart and then being distributed to the body in systemic circulation.

How many Circulatory Pathways are Present?

Three main circulatory pathways are present: systemic circulation, pulmonary circulation, and coronary circulation.