1. Simple Squamous Epithelial Tissue
-This comprises a single layer of slender cells, with the cell nuclei (indicated by arrows) being the most prominent and discernible features. Simple epithelia commonly serve as linings for vessels and cavities, controlling the flow of substances into the tissue beneath. The slender cells frequently demonstrate transcytosis.
2. Blood Smear 
-Blood is a distinctive type of connective tissue composed of both cells and a fluid extracellular substance known as plasma. Primarily driven by the rhythmic contractions of the heart, approximately 5 liters of blood circulate in a single direction within the enclosed circulatory system of the average adult. The components known as formed elements, which circulate within the plasma, include erythrocytes (red blood cells), leukocytes (white blood cells [WBCs]), and platelets.
3. Cardiac Muscle 
-Characteristic features of cardiac muscle cells are evident in their structure. Fibers comprise individual cells linked in a series through intercalated discs, featuring abundant desmosomes and adherent junctions for firm adhesion, as well as gap junctions. These cells possess central nuclei and myofibrils, typically less organized than skeletal muscle, and often exhibit branching. This intricate arrangement within fascicles enhances the efficiency of heart contraction.
4. Vein 
-Veins transport blood back to the heart from the body’s microvasculature. Blood within veins moves towards the heart at low pressure, propelled by contractions of smooth muscle fibers in the media and external compressions from surrounding skeletal muscles and organs. Typically categorized as small or medium, veins often run closely and parallel to corresponding muscular arteries.

Reference:
Mescher, A. (2021). Junqueira’s Basic Histology. (Sixteenth Edition). McGraw Hill.