The gallbladder is a sac located under the liver. It stores and concentrates bile produced in the liver. Bile aids in the digestion of fat and is released from the gallbladder into the upper small intestine in response to food (especially fats).

The pancreatic acinar cell is the functional unit of the exocrine pancreas. It synthesizes, stores, and secretes digestive enzymes. Under normal physiological conditions, digestive enzymes are activated only once they have reached the duodenum.

The hepatic lobule is the anatomic unit of the liver. In the anatomic model, liver lobules are organized into irregular polygons demarcated by connective tissue and composed of plates of hepatocytes radiating outward from the central vein to the portal triads.

Microvilli on the surface of epithelial cells such as those lining the intestine increase the cell's surface area and thus facilitate the absorption of ingested food and water molecules.

Gland of Colon/Colon Mucosa – Transversely cut glands are seen to consist of simple columnar epithelium surrounded by a tubular lumen and embedded in lamina propria with many free lymphocytes. Lymphocytes can also be seen penetrating the epithelium.

Enamel is the thin outer covering of the tooth. This tough shell is the hardest tissue in the human body. Enamel covers the crown which is the part of the tooth that's visible outside of the gums. Because enamel is translucent, you can see light through it.

In the human skin, melanocytes are present in the epidermis and hair follicles. The basic features of these cells are the ability to melanin production and the origin from neural crest cells.

The prickle cell layer (stratum spinosum) have lots of desmosomes, which anchor the cells to each other, and contain thick tufts of intermediate filaments (keratin). When the cell shrinks slightly, during fixation, the desmosomes from neighbouring cells remain tightly bound to each other, and these connections look like 'prickles' or 'spines',…[Read more]

The vena cava has two parts: the superior vena cava and the inferior vena cava. The superior vena cava carries blood from the head, neck, arms, and chest. The inferior vena cava carries blood from the legs, feet, and organs in the abdomen and pelvis. The vena cava is the largest vein in the body.

Arterioles are considered as the primary resistance vessels as they distribute blood flow into capillary beds. Arterioles provide approximately 80% of the total resistance to blood flow through the body.

Arteries are blood vessels. Most carry oxygen-rich blood away from the heart and deliver it to various organs and tissues. Arteries are a part of the circulatory system, along with the heart and other blood vessels. The circulatory, or cardiovascular, system is essential for transporting blood around the body.

Sympathetic ganglia form long chains on either side of the vertebral column. Sympathetic Ganglion deliver information to the body about stress and impending danger, and are responsible for the fight-or-flight response.

The cerebellum — also called the "little brain" because it looks like a small version of the cerebrum — is responsible for balance, movement, and coordination. The cerebellum, the second largest portion of the brain, is located below the occipital lobes of the cerebrum.

The cerebrum is the largest part of the brain. It is divided into two hemispheres, or halves, called the cerebral hemispheres. Areas within the cerebrum control muscle functions and also control speech, thought, emotions, reading, writing, and learning.