Mechanism of Transportation in Higher Animals: Learn how transportation occurs in higher animals through the circulatory and lymphatic systems, including the roles of the heart, blood, vessels, and lymph in maintaining life.
Mechanism of Transportation in Higher Animals
Table of Contents
- Introduction
- The Need for Transportation in Higher Animals
- Components of the Transport System
- The Circulatory System
- Blood and Its Functions
- The Heart: Structure and Function
- Blood Vessels and Their Roles
- Double Circulation in Mammals
- Lymphatic System
- Revision questions and answers
- Conclusion
Introduction
In higher animals, life is sustained by the continuous movement of essential substances like oxygen, nutrients, hormones, and waste materials throughout the body. This process is known as transportation or internal transport. Without an efficient transport mechanism, cells would be deprived of nutrients and oxygen, and toxic waste would accumulate, leading to malfunction or death.
This blog explains the mechanism of transportation in higher animals, focusing on the circulatory and lymphatic systems and how they work together to maintain internal balance.
READ ALSO – Types of Fertilization in Animals; meaning, differences and advantages
The Need for Transportation in Higher Animals
As animals increase in size and complexity, simple diffusion becomes insufficient for moving substances across their bodies. Multicellular organisms have specialized transport systems that ensure all cells, regardless of their location, receive the materials they need and can get rid of waste efficiently.
Transportation in higher animals ensures:
- Delivery of oxygen and nutrients to tissues
- Removal of carbon dioxide and metabolic wastes
- Circulation of hormones
- Maintenance of body temperature
- Defense against pathogens
Components of the Transport System
The transport system in higher animals includes:
- The circulatory system (blood, heart, and blood vessels)
- The lymphatic system (lymph, lymph nodes, and lymph vessels)
Together, these systems ensure that essential substances are distributed and unwanted substances are removed effectively.
The Circulatory System
The circulatory system is the main transport system in higher animals. It is also called the cardiovascular system because it involves the heart (cardio) and blood vessels (vascular). This system is responsible for circulating blood throughout the body.
There are two types of circulatory systems:
- Open circulatory system: Found in insects and other invertebrates. Blood is not always confined to vessels.
- Closed circulatory system: Found in vertebrates including humans. Blood moves within vessels at all times. Higher animals possess this type.
Blood and Its Functions
Blood is the main transport fluid in higher animals. It is made up of:
- Plasma: The liquid part that carries dissolved substances like glucose, amino acids, hormones, and waste.
- Red blood cells (RBCs): Transport oxygen using a pigment called hemoglobin.
- White blood cells (WBCs): Fight infections and protect the body against disease.
- Platelets: Help in blood clotting.
Functions of blood:
- Transports oxygen from the lungs to the tissues
- Carries nutrients from the digestive system
- Transports waste products to excretory organs
- Distributes hormones from glands to target organs
- Maintains body temperature and pH
The Heart: Structure and Function
The heart is a muscular organ that pumps blood throughout the body. In mammals, including humans, it has four chambers:
- Two atria (upper chambers)
- Two ventricles (lower chambers)
The heart functions as a dual pump:
- The right side pumps deoxygenated blood to the lungs (pulmonary circulation).
- The left side pumps oxygenated blood to the rest of the body (systemic circulation).
The rhythmic contraction and relaxation of the heart, known as the heartbeat, ensures the continuous flow of blood.
Blood Vessels and Their Roles
There are three main types of blood vessels involved in transportation:
- Arteries: Carry blood away from the heart. They have thick, muscular walls to withstand high pressure.
- Veins: Carry blood towards the heart. They have thinner walls and contain valves to prevent backflow.
- Capillaries: Tiny vessels where exchange of gases, nutrients, and waste takes place between blood and tissues.
The structure of these vessels ensures that blood flows efficiently to all parts of the body, even the smallest cells.
Double Circulation in Mammals
Higher animals, particularly mammals, have a double circulatory system, which means blood passes through the heart twice during each complete circulation of the body.
There are two circuits:
- Pulmonary circulation: Carries blood from the heart to the lungs and back, allowing oxygenation.
- Systemic circulation: Distributes oxygenated blood from the heart to the body tissues and returns deoxygenated blood.
This separation ensures that oxygen-rich and oxygen-poor blood do not mix, increasing the efficiency of oxygen delivery.
Lymphatic System
In addition to the circulatory system, higher animals also have a lymphatic system, which plays a role in fluid balance and immunity.
Lymph is a clear fluid derived from blood plasma. It contains:
- White blood cells
- Proteins
- Fats absorbed from the intestine
Functions of the lymphatic system:
- Returns excess tissue fluid to the bloodstream
- Helps in absorption of fats in the small intestine
- Plays a crucial role in immune defense
The lymphatic system includes lymph nodes, which filter lymph and trap pathogens, and lymph vessels, which transport the lymph.
Revision questions with answers on Mechanism of Transportation in Higher Animals
1. Why do higher animals need a transport system?
Answer: Because diffusion alone is not sufficient to distribute oxygen, nutrients, and remove waste in large, complex organisms.
2. What are the main components of the transport system in higher animals?
Answer: The circulatory system (heart, blood, and blood vessels) and the lymphatic system.
3. What is the function of red blood cells in the circulatory system?
Answer: To transport oxygen from the lungs to body tissues using the pigment hemoglobin.
4. Name the fluid that circulates in the lymphatic system.
Answer: Lymph.
5. What is the difference between arteries and veins?
Answer: Arteries carry blood away from the heart under high pressure; veins carry blood to the heart under lower pressure and have valves to prevent backflow.
6. What is double circulation?
Answer: A circulatory system where blood passes through the heart twice—once for pulmonary circulation (to the lungs) and once for systemic circulation (to the body).
7. Which organ pumps blood in higher animals?
Answer: The heart.
8. What is the function of capillaries?
Answer: To allow exchange of gases, nutrients, and waste products between blood and body tissues.
9. What are the two main circuits in a double circulatory system?
Answer: Pulmonary circulation and systemic circulation.
10. State one function of the lymphatic system besides fluid transport.
Answer: It supports immune defense by filtering pathogens through lymph nodes.
READ ALSO – Parturition in Farm Animals, Signs and Stages
Conclusion on Mechanism of Transportation in Higher Animals
The mechanism of transportation in higher animals is a highly organized and efficient system that ensures every cell receives what it needs to function. The circulatory system, driven by the heart and consisting of blood and blood vessels, is responsible for moving vital substances throughout the body. The lymphatic system complements it by managing fluid balance and supporting immune defense.
Together, these systems form a complex yet coordinated network that maintains internal stability, supports life processes, and protects the body from disease.