Anatomy of the liver and pancreas

Transcription

1 Anatomy of the liver and pancreas Prof. Abdulameer Al-Nuaimi

2 Liver

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5 Aorta Pulm. Trunk Rt. At, Duct. Art. Lt. Ven. Rt. Ven. Internal

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7 Posterior Relation of the liver

8 Posterior relations of the liver

9 Blood supply of the liver

10 Histology of Liver The liver is divided into thousands of small units called lobules by thin layer of connective tissue. Each lobule is about 1mm in diameter and roughly hexagonal in shape. The Lobule is composed of radiating double plates of liver cells (Hepatocytes) separated by a Vascular sinusoidal network. Each lobule has a central vein in the middle and portal triads at the vertices. Each portal triad contains branch of hepatic artery, portal vein and Bile duct.

11 Liver Lobules Portal Triad Central Vein

12 Sinusoids have an incomplete lining of highly fenestrated endothelial cells, some of these cells are macrophagic In function (reticulo-endothelial cells), they are called Kupffer cells. The space between endothelium and hepatocytes is called the Space of Disse. In these spaces, lymph is collected and delivered to lymphatic capillaries. Lymph is collecting in hepatic duct outside the liver. Blood from the branches of hepatic artery and portal vein in the Portal triad, drains into sinusoids and then to the central vein. Central Veins carry the blood to hepatic veins which end in the Inferior vena cava. Bile is formed by liver cells and is discharged into the bile canaliculi within layers of the cell plates, and then drains into bile duct of the triads.

13 Histology of Liver

14 Histology of Liver

15 Histology of gall bladder The gall bladder is a simple muscular sac, lined by a simple columnar epithelium. The inner surface of the gall bladder is covered by the mucosa. The sufrace is made up of a simple columnar epithelium. The epithelial cells have microvilli, and look like absorptive cells in the intestine. Underneath the epithelium is the lamina propria. The wall of the bladder does not have a muscularis mucosae and submucosa. The muscularis externa (muscle layer) contains bundles of smooth muscle cells, collagen and elastic fibres. Underneath this, on the outside of the gall bladder is a thick layer of connective tissue, which contains large blood vessels, nerves and a lymphatic network. Where this layer is attached to the liver, it is called the adventia. In the unattached region, there is an outer layer of mesothelium and loose connective tissue (the serosa).

16 Gall bladder

17 The Pancreas Pancreas is a soft lobulated organ located retroperitoneally across the posterior abdominal wall, it sits behind the stomach across the back of the abdomen. It is described as an organ having head, neck, body, and tail. The head is disc-shaped and lies within the concavity of the duodenum. Part of the head extends to the left behind the superior mesenteric vessels, it is called Uncinate process. The body extends to the left side and ends as a tail near the hilus of the spleen. The pancreas is made up of two types of glands, 1-An exocrine gland that secretes digestive enzymes and Sodium bicarbonate into the duodenum through the main and accessory pancreatic ducts. Both ducts are usually interconnected.

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20 2- An endocrine gland, which consists of the islets of Langerhans, secretes hormones into the bloodstream. Islets of Langerhans are named for the German physician Paul Langerhans, who first described them in The normal human pancreas contains about 1,000,000 islets. Cells of islets of Langerhans 1-Beta cells (β-cells), they make about 65-80% of the cells in the islets and produce Insulin. 2-alpha cells (α-cells), 15-20%, they produce an opposing hormone, Glucagon which releases glucose from the liver and fatty acids from fat tissue. 3-Delta cells (δ-cells), 3-10%, they secrete somatostatin a strong inhibitor of somatotropin, insulin, and glucagon; its role in metabolic regulation is not yet clear. Somatostatin is also produced by the hypothalamus and functions to inhibit secretion of growth hormone by the pituitary gland.

21 AcinIi Pancreas

22 Pancreas P

23 Thank You