This is the region of the nephron downstream the macula densa ,which extends the to convulence of the collecting duct.Due to response to mineralocoticoid aldosterone they can be categorised as Distal Convoluted 1 and Distal convoluted 2. This steroid hormones is responsible for homeostatic control of hyperkalemia.
The DCT cells are simple cuboidal epithelium.The stained or pointed part of the image represented this possess this shape,they are therefore portion of DCT. Besides the stained cells are located above the glomerulus ()in the cortex as indicated,therefore they can not be the proximal which must be below the glomerulus, based on the shape ascending and descending loop of Henle (despite located in the cortex too).
The functions of the DCT is in the absorption and secretions of ions(majorly ca+,Na+ and chloride ions.By secreting hydrogen and reabsorbing HC03 ions ,the pH of the urine is maintained.