1. Introduction to Human Blood Blood is a vital, specialized bodily fluid that circulates through the cardiovascular system , sustaining life by delivering oxygen, nutrients, and hormones while removing waste products. It makes up about 7-8% of an adult's body weight—roughly 4-6 liters (about 1-1.5 gallons) in an average adult. Blood is considered a connective tissue because it's composed of cells suspended in a liquid matrix called plasma . It's constantly in motion, pumped by the heart, and plays a crucial role in homeostasis (maintaining the body's internal balance). Blood's color comes from hemoglobin , a protein in red blood cells that binds oxygen—arterial blood (oxygen-rich) is bright red, while venous blood (oxygen-poor) is darker red or purplish. 2. Composition of Blood Blood is a mixture of liquid and cellular components. When centrifuged (spun in a lab to separate parts), it divides into layers: plasma at the top (55%), a thin "buffy coat" of...
This website provides clear and informative content about human anatomy and the structure of the human body. It explains major organs such as the heart, brain, lungs, liver, kidneys, and digestive system, along with their functions and importance. The site helps students, teachers, and learners understand how different organs and body systems work together to keep the human body healthy and functioning properly. It is a useful resource for learning basic anatomy in a simple and easy way.