BIOD 152 A&P 2 Lab 6 Exam (Graded A+)

BIOD 152 A&P 2 Lab 6 Exam (Graded A+). A&P 2 Lab 6- Histology of Body Systems LOOKING AT THE LIVER UNDER THE MICROSCOPE  Liver is made up of a lot of cylinders called Hepatic lobules.  The hepatic lobules are made up of sheets of liver cells called Hepatocytes  There is a center vein that passes through the middle of the hepatic lobules that drain the blood from the microscopic structures and then eventually the liver itself.  The interior of the liver under the microscope- think of spreading open a book cover to cover o The whole represents the central vein o Each page of the book represents a sheet of the hepatocyte  In between each sheet of hepatocyte there are channels called Sinusoids. o Sinusoids are blood channels that lead away from the central vein in the hepatic lobules. o Sinusoids contain some phagocytic cells (can’t see under the microscope)  Kupffer Cells- work to clean the blood and remove any debris from the blood in the liver  Hepatic Lobule under the microscope at the lowest power: o The white dot in the center of the lobule is the central vein (will eventually drain into the hepatic vein) o Increasing the magnification:  The red-ish areas are the hepatocytes. The white lines in between the red areas are the sinusoids. LOOKING AT THE PANCREAS UNDER THE MICROSCOPE  Pancreas is a gland in the digestive system and considered endocrine and exocrine glands. o The endocrine portion- secretes hormones like insulin and glucagon to control the blood sugar levels in our body o The exocrine portion- secretes digestive enzymes and juices that help to complete the digestive process. o lowest power: can see several oddly shaped lobules. Each lobule has a boundary of a white line around it. o Higher magnification: Some of the cells are different colors.  The darker cells that are stained a dark pink- Acini Cells (digestive cells)  98-99% of the pancreas is made up of the acini cells; they make up the exocrine portion of the gland  They secrete the pancreatic juices and enzymes that help with digestive  The lighter color larger pink cell is called the Islets of Langerhan.  It’s the endocrine portion of the gland that will produce insulin and glucagon hormones to regulate our blood sugar levels. LOOKING AT THE SMALL INTESTINE UNDER THE MICROSCOPE  The small intestine absorbs all of our nutrients and passes them into the bloodstream.  Has 4 tunics (layers) of tissue: o Serosa- outer most layer. A very thin layer that covers the organs in the digestive tract. o Muscularis externa- next layer in. It’s a relatively thick layer (solid dark pink). Make up of longitudinal and circular layers. o Submucosa- contains Brunner's glands which secrete a bi-carbonate substance that will help to neutralize the material in the stomach. It softens the acidity in the stomach.  Also see some lymphocytes (b-cells and t-cells) that will help to intercept and destroy any pathogens in the intestinal tract before it enters the blood stream) o Mucosa- inner most layer. Made up of Villi (finger like projections). They help to increase the surface area so there is an increased area for absorption.  Also see Plicae Circulares- microscopic structures; intestinal/circular folds in the wall that serve to increase the surface area to allow for increased absorption o o SEROSA o MUSCULARIS EXTERNA o SUBMUCOSA o MUCOSA AND THE VILLI