Digestion & Blood Glucose

The process of taking food into the digestive tract through the mouth.

The breakdown of food into smaller molecules, both mechanically and chemically.

Physical breakdown of food by chewing and churning.

Breakdown of food by enzymes and acids.

The process of absorbing nutrients, water, and electrolytes into the bloodstream.

The removal of undigested food waste from the digestive tract.

The continuous tube extending from the mouth to the anus, including the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus.

Organs that assist in digestion but are not part of the GI tract, such as teeth, tongue, salivary glands, liver, gallbladder, and pancreas.

Cells in the stomach lining that release mucus and alkaline substances to neutralize the acidic gastric juice.

Cells in the stomach lining that secrete gastrin, a hormone that stimulates gastric acid production and overall stomach activity.

A mixture of partially digested food, gastric juices, and enzymes that is passed from the stomach to the small intestine.

A large gland that produces digestive enzymes and bicarbonate to help neutralize stomach acid.

Inactive forms of enzymes produced by the pancreas, which are activated in the small intestine.

A small sac attached to the liver that stores and concentrates bile.

A greenish fluid produced by the liver that helps emulsify fats for digestion.

Diabetes can damage blood vessels and various parts of the inner ear, leading to hearing loss.

The severity of diabetic hearing loss is directly related to the duration and severity of diabetes.

A leaky gut, characterized by increased permeability for bacterial products, is linked to a higher risk of heart disease.

Bacterial products from a leaky gut can contribute to atherosclerosis (hardening of arteries) and chronic heart failure.

Impaired cardiac function in heart failure can lead to reduced blood flow to the intestines, causing a further weakening of the intestinal barrier.

Type 2 diabetes is a major risk factor for heart failure, increasing the chances of developing this condition.

Understanding the relationship between the gut and the heart can help develop better therapies for both heart disease and gut disorders.

The gut microbiome and its interaction with the immune system play a crucial role in the development of heart disease.

The gastrointestinal tract (GIT) is a complex system responsible for digesting food, absorbing nutrients, and eliminating waste. It is made up of different organs that work together to perform these functions.

The GIT wall is composed of four layers: (1) Mucosa - innermost layer lining the lumen, involved in absorption & secretion; (2) Submucosa - connective tissue layer with blood vessels and nerves; (3) Muscularis propria - smooth muscle layer responsible for peristalsis; (4) Serosa or Adventitia - outermost layer providing protection and anchoring.

Digestion involves two key processes: Mechanical digestion: Physical breakdown of food by chewing, churning, and mixing; Chemical digestion: Breakdown of food molecules by enzymes secreted in saliva, stomach, and small intestine.

The liver plays a central role in metabolism. It filters blood, produces bile, stores glucose, and eliminates waste products. It also synthesizes vital proteins and detoxifies harmful substances

Bile is a fluid produced by the liver and stored in the gallbladder. It helps in fat digestion by emulsifying fat molecules, breaking them down into smaller droplets, making them easier for enzymes to work on.

The large bowel (colon) absorbs water and electrolytes, forms and stores feces. It has three main parts: (1) Ascending colon: absorbs water and electrolytes; (2) Transverse colon: continues water absorption; (3) Descending colon: stores feces

Blood glucose regulation is primarily controlled by two pancreatic hormones: (1) Insulin: lowers blood sugar by promoting glucose uptake by cells; (2) Glucagon: raises blood sugar by stimulating glucose release from the liver

Type 1 diabetes: autoimmune disorder where the immune system attacks the pancreas, leading to insulin deficiency; Type 2 diabetes: characterized by insulin resistance, where cells do not respond properly to insulin, leading to high blood sugar.

The pancreas has two main functions: exocrine secretion and endocrine secretion.

The exocrine function of the pancreas involves the production of pancreatic juice, containing various enzymes like proteases, lipases, and nucleases, which are released into the duodenum through the main pancreatic duct.

The clusters of secretory cells called 'acini' within the pancreas are responsible for producing and releasing pancreatic juice into the duodenum.

The endocrine function of the pancreas involves the release of hormones like insulin and glucagon from the pancreatic islets of Langerhans.

Insulin, produced by β-cells of the islets of Langerhans, lowers blood glucose levels by promoting glucose uptake into cells and glycogenesis (glucose storage).

Glucagon, produced by ⍺-cells of the islets of Langerhans, raises blood glucose levels by triggering glucose release from the liver through glycogenolysis (breakdown of stored glucose) and gluconeogenesis (production of glucose from other sources).

Diabetes Mellitus is a condition where the body cannot properly regulate blood sugar levels, primarily due to malfunctioning insulin.

Type 1 Diabetes (T1DM) is an autoimmune disease where the body mistakenly attacks and destroys insulin-producing β-cells, resulting in insufficient insulin production. Treatment typically involves regular insulin injections to manage blood sugar levels.

Bile salts are crucial for fat digestion. They have a unique structure with a hydrophilic side (attracted to water) and a hydrophobic side (repels water). This allows them to form micelles, tiny spherical structures that enclose fat droplets. These micelles increase the surface area of fat, making it easier for pancreatic lipase, an enzyme that breaks down fats, to do its job.

The small intestine is where most nutrient absorption takes place. It has three main regions: the duodenum, jejunum, and ileum. The duodenum is where the majority of digestion occurs, thanks to enzymes from the pancreas and bile from the liver. The jejunum is the middle section, where most absorption happens. The ileum is the final section, where some final absorption of nutrients and water takes place.

Absorption is the process where digested nutrients move from the digestive tract into the bloodstream or lymphatic system for distribution to the body's cells. This is a critical step in converting food into usable energy and building blocks for the body.

The hepatic portal vein carries blood from the small intestine directly to the liver. The liver acts as a filter and processing center. It monitors the absorbed nutrients, detoxifies harmful substances, and regulates various metabolic processes.

Glycogenesis is the process where glucose (simple sugar) is stored as glycogen (a more complex form of sugar) in the liver. This is done when there is excess glucose in the bloodstream. Glycogenolysis is the reverse process, breaking down glycogen back into glucose when the body needs it.

The liver has many vital functions, including: Storing glycogen, iron, and certain vitamins; Destroying old red blood cells and foreign substances; Detoxifying harmful substances; Acting as a blood reservoir.

The large intestine (also known as the colon) is responsible for absorbing water and salts from the remaining undigested food, forming solid waste. This waste is then passed through the rectum and expelled from the body through the anus in a process called defecation.

The pancreas plays a vital role in digestion by producing both digestive enzymes (exocrine function) and hormones that regulate blood sugar (endocrine function). It secretes enzymes like lipase, amylase, and protease that break down fats, carbohydrates, and proteins, respectively.