Choose 1 of the following questions to answer by day 3 (Wednesday) and include 2 references (in APA format). Your post should be at least 250 words. Please remember to answer to 2 of your classmates’ discussions (on 2 separate days) by Saturday.  The reply to your classmates should be at least 100 words each.  The references are not included in the word count! Thanks Compare and contrast Formed elements and Plasma. Describe the structure and functions of erythrocytes.

Formed elements and plasma are vital components of blood, but they differ in terms of their composition and functions. Formed elements refer to the cellular components of blood, including erythrocytes, leukocytes, and platelets. On the other hand, plasma is the liquid portion of blood that remains after the removal of formed elements. These two components work together to maintain homeostasis in the body.

When comparing formed elements and plasma, it is important to note that formed elements make up around 45% of blood, while plasma constitutes the remaining 55%. Plasma is a clear, yellowish fluid that consists mainly of water, but it also contains a variety of proteins, such as albumin, globulins, and fibrinogen. Additionally, plasma contains electrolytes, hormones, nutrients, gases, and waste products.

Formed elements, on the other hand, are suspended in plasma and include erythrocytes, leukocytes, and platelets. Erythrocytes, commonly known as red blood cells, are the most abundant formed elements, making up approximately 99% of them. These disc-shaped cells lack a nucleus and most other organelles, allowing them to efficiently carry oxygen. Their unique structure, along with hemoglobin, a protein that binds and transports oxygen, enables erythrocytes to deliver oxygen to body tissues and remove carbon dioxide. This gas exchange is vital for cellular respiration, energy production, and overall physiological functions.

Leukocytes, or white blood cells, are another type of formed element. Unlike erythrocytes, they possess a nucleus and are less numerous in blood, constituting only about 1%. Leukocytes play a crucial role in the immune system by defending the body against pathogens, foreign substances, and abnormal cells. They are further subdivided into two main categories: granulocytes and agranulocytes. Granulocytes, including neutrophils, eosinophils, and basophils, contain granules inside their cytoplasm. These granules contain enzymes and chemicals involved in immune responses. Agranulocytes, on the other hand, lack visible granules and include lymphocytes and monocytes. Lymphocytes are responsible for specific immune responses, such as the production of antibodies, while monocytes act as phagocytes, engulfing and removing cellular debris and pathogens.

Lastly, platelets, also known as thrombocytes, are involved in blood clotting. Although they are not actual cells, platelets are fragments of larger cells called megakaryocytes. When blood vessels are damaged, platelets adhere to the site, form a plug, and release clotting factors to initiate the coagulation cascade. This process prevents excessive bleeding and allows for the eventual repair of damaged blood vessels.

In summary, formed elements and plasma are distinct components of blood that work together to maintain homeostasis in the body. Formed elements comprise erythrocytes, leukocytes, and platelets, while plasma is the liquid portion of blood remaining after the removal of formed elements. Erythrocytes are responsible for oxygen delivery and carbon dioxide removal, leukocytes play a crucial role in immune defense, and platelets are involved in blood clotting. Understanding the structure and functions of formed elements and plasma is essential for comprehending the intricate processes that occur in the bloodstream.

1. Marieb, E. N., Hoehn, K. (2019). Human Anatomy & Physiology (11th ed.). Pearson Education.
2. Tortora, G. J., Derrickson, B. (2017). Principles of Anatomy and Physiology (15th ed.). Wiley.