4A mitochondrion, Fibers of the cerebral cortex ( Brodmann area 4 ), Two types of bacteria: *Pseudomonas aeruginosa* and a type of *Staphylococcus* , A cluster of granulocytes, including eosinophils and basophils, The nucleus of an oocyte in meiotic prophase I, An adipocyte containing triglycerides, Fibroblast cells exhibiting fibrosis, Nerve terminals releasing neurotransmitters ( acetylcholine and dopamine ), A capillary with red blood cells flowing through it, The Golgi apparatus of a cell, showing ribosomes attached to the rough ER, An inflammatory reaction site featuring macrophages and neutrophils, A vacuole containing digestive enzymes from the pancreas, Fragments of collagen fibers arranged in a reticular pattern, Two epithelial cells with junctional complexes ( tight junctions ), Bundles of axons ( motor neurons ) from the spinal cord, An unidentified, worm-like structure (~1.5 mm long), A cluster of lipid droplets containing very-low-density lipoproteins, Fibrous tissue composed of bundles of collagen and elastin fibers, The nucleus of a mature platelet, Tubular structures resembling the proximal convoluted tubules (PCT) of the kidneys, An aggregation of melanocytes, possibly in a sun-damaged area, Fibrous strands resembling those found in *amyloidosis*, A cluster of epithelial cells from the small intestine ( villus ), A type of *Langerhans cell*, a dendritic cell involved in antigen presentation