Composition of the peripheral blood
Composition of the Peripheral Blood[edit | edit source]
Introduction[edit | edit source]
Peripheral blood is a specialized connective tissue circulating through the cardiovascular system. It transports gases, nutrients, hormones, waste products, immune cells, and maintains homeostasis.
Main Components of Peripheral Blood[edit | edit source]
Blood is composed of:
1. Plasma (~55%)
2. Formed elements (~45%): erythrocytes, leukocytes, thrombocytes.
Plasma[edit | edit source]
Plasma is 90% water and contains proteins (albumin, globulins, fibrinogen), electrolytes, nutrients, hormones, lipids, and waste products.
Erythrocytes (Red Blood Cells)[edit | edit source]
Erythrocytes are anucleate biconcave cells rich in hemoglobin. They transport oxygen and carbon dioxide. Normal lifespan ≈120 days.
Leukocytes (White Blood Cells)[edit | edit source]
Leukocytes defend against infection. They include granulocytes (neutrophils, eosinophils, basophils) and agranulocytes (lymphocytes, monocytes).
Thrombocytes (Platelets)[edit | edit source]
Platelets are cytoplasmic fragments from megakaryocytes. They mediate primary hemostasis through clot formation and granule release.
Bottom Line Summary[edit | edit source]
Peripheral blood consists of plasma (≈55%) and formed elements (≈45%), including erythrocytes, leukocytes, and thrombocytes. Each component has distinct microscopic features and functions essential for transport, immunity, and hemostasis.
References[edit | edit source]
1. Junqueira’s Basic Histology, 16th Ed.
2. Ross & Pawlina – Histology: A Text and Atlas, 8th Ed.
3. Wheater’s Functional Histology, 7th Ed.
4. Gartner & Hiatt – Color Textbook of Histology, 4th Ed.
