Unicellular organisms such as Amoeba has a large surface area to volume ratio (SA:V) where substances move short distances by diffusion. Multicellular organisms on the other hand have a small (SA:V) ratio. where substances move a longer distance. Since multicellular organisms are so complex, they require a system to help transport substances much faster. This system is called the Human Circulatory System. This system transports both wasteful and useful substances such as: Water, oxygen, Carbon dioxide, digested food, ammonia, Glucose, Hormones etc.
The circulatory system is made up of three main components 1.The heart, 2.The blood and 3.Blood vessels.
Blood
Blood has 3 main components : Plasma, Red blood cell , White blood cell and platelets. Plasma has 90% water and 10% dissolved substances. Red blood cells transport O2 and CO2 gas to and from the lungs and body. White blood cells are part of the immune system, helping to fight infections or diseases.
Blood Vessels
These are tubes carrying blood to and from the heart around the body its made up of arteries, veins and capillaries. Arteries carries oxygenated blood away from the heart, arterioles branches into a network of capillaries that run throughout the organ, while veins join from the capillaries leading deoxygenated blood to the heart. What are the capillaries function?
Heart
The heart acts like an engine, pumping blood through the blood vessels around the body. It has 4 chambers, 2 small atrium and 2 large ventricles. While the right side pumps deoxygenated blood to the lungs, the left side pumps oxygenated blood to the body.
Capillaries - their function is connecting the arterial system(includes blood vessels that carry blood from the heart) to the venous system( includes the blood vessels that carry blood to the heart). Also the capillaries allow for the exchange of oxygen, nutrients, and waste between blood and tissues.
ReplyDeleteThe human circulatory system is critical for the survival and proper functioning of the body. It ensures the delivery of oxygen and nutrients, the removal of waste products, and supports the immune system and temperature regulation.
ReplyDeleteTransport in unicellular organisms occurs differently than in multicellular organisms because unicellular organisms are single-celled organisms that rely on diffusion to exchange materials with their environment, while multicellular organisms have specialized structures and systems that enable them to transport materials between different parts of their body.
ReplyDeleteIn unicellular organisms, all metabolic activities take place within a single cell. Nutrients, oxygen, and other essential materials enter the cell by diffusion and waste products are eliminated through the same process. Since unicellular organisms have a high surface area to volume ratio, diffusion alone is sufficient for the exchange of materials with their environment.
In contrast, multicellular organisms have many cells that are organized into tissues, organs, and organ systems. The larger size and complex organization of these organisms require a more efficient means of transport to exchange materials between different parts of the body.
Capillaries are small blood vessels that connect arteries to veins, and they have several important functions in the body, including:
ReplyDeleteExchange of nutrients and gases: Capillaries are the site of exchange of nutrients, oxygen, and waste products between the blood and the tissues of the body. They have thin walls that allow for the diffusion of substances into and out of the blood.
Regulation of blood pressure: Capillaries play a role in regulating blood pressure by controlling the flow of blood into tissues. They can dilate or constrict to increase or decrease blood flow as needed.
Very informative and comprehensive piece, Ms Williams. To answer the question on the capillaries function:
ReplyDeleteThe capillaries are the smallest of the vascular structures that make up the human circulatory system. They function as a link venous to the arterial circulation of the body; allowing for the exchange of oxygen, carbon dioxide, absorbed nutrients and waste products.