Ihmissolut

Ihmissolut, meaning "human cells" in Finnish, refer to the basic structural and functional units of the human body. In biology, human cells are eukaryotic cells containing a nucleus with the genome and a system of organelles enclosed by membranes. The human body comprises many cell types—estimates commonly exceed 200—organized into tissues and organs.

Structure and key organelles: The plasma membrane encloses cytoplasm and organelles. The nucleus houses genetic material and regulates gene expression. Mitochondria produce energy through cellular respiration. Ribosomes synthesize proteins. The endoplasmic reticulum and Golgi apparatus participate in protein and lipid processing and trafficking. Lysosomes and peroxisomes break down waste and toxins. The cytoskeleton provides structure and intracellular transport.

Genetic material and division: Most human cells are diploid, with chromosomes organized into the genome. Cell division occurs by mitosis for growth and tissue maintenance, and meiosis for germ cells, enabling sexual reproduction. The cell cycle is controlled by regulatory proteins and checkpoints.

Diversity and function: Cells specialize through differentiation to form tissues such as epithelium, connective tissue, muscle, and nervous tissue. Blood cells, neurons, muscle fibers, and immune cells illustrate functional diversity. Cellular physiology includes metabolism, signaling, and homeostasis, with organ systems coordinating activity across tissues.

Clinical relevance: Abnormalities in human cells underlie many diseases, including cancer, inherited disorders, infections, and degenerative conditions. Cell biology informs diagnostics, therapeutics, and regenerative medicine. Common research methods include cell culture, microscopy, flow cytometry, and molecular assays.