Lecture Notes Flashcards

Rate My Professor Reviews

  • The instructor encourages students to submit reviews on Rate My Professor for constructive criticism.

  • Anonymous feedback helps the instructor improve the class.

  • The instructor shares an anecdote about a negative Rate My Professor review a colleague received during her pregnancy.

  • The instructor appreciates reviews that suggest improvements to the class.

  • Positive reviews with a five-out-of-five score are also welcome to improve the professor's overall rating.

Large Intestine

  • Function: storage of feces and water reabsorption.

  • If the large intestine doesn't function correctly, it can lead to diarrhea.

  • Also known as the colon. Entrance regulated by the ileocecal valve.

  • Ileocecal Valve: Regulates the passage of fecal matter from the ileum (small intestine) to the cecum (large intestine).

  • Cecum: A pouch that receives fecal matter.

  • Ascending Colon: Transports fecal matter upwards.

  • Transverse Colon: Moves fecal matter from right to left.

  • Descending Colon: Moves fecal matter downwards.

  • Sigmoid Colon: S-shaped colon (named after the Latin shape Sigma).

    • The sigmoid colon structure requires upward and downward movement of fecal matter.

    • The levator ani muscle assists in defecation by lifting the sigmoid colon to facilitate easier passage of fecal matter.

  • Squatty Potties

    • Help facilitate defecation.

    • Assist the sigmoid colon to have more of a descending shape.

  • Rectum: Stores fecal matter before defecation.

    • Stretch receptors in the walls of the rectum trigger the defecation reflex.

  • Anus: The opening for fecal matter to leave the body, controlled by two sphincters:

    • Internal Anal Sphincter: Made of smooth muscle; relaxes involuntarily when stretch receptors are triggered.

    • External Anal Sphincter: Made of skeletal muscle; can be controlled voluntarily.

    • Smooth muscles are capable of staying contracted for long periods of time without needing to use energy, this is called latched states.

  • Appendix: A vestigial structure with no known function, but can cause problems like appendicitis.

Histology of the Large Intestine

  • Mucosal Epithelium: Made up of simple columnar epithelium and goblet cells.

    • Goblet cells produce mucus, providing a protective layer against bacteria and digestive enzymes in feces.

    • Mucus also lubricates the movement of feces.

  • Intestinal Glands: Produce new cells and goblet cells.

  • Lamina Propria: Areolar connective tissue.

  • Muscularis Mucosae.

  • Submucosa.

  • Muscularis Externa:

    • Circular layer.

    • Outer longitudinal layer is organized into units called taenia coli, which prevent segmentation.

    • Taenia Coli prevent segmentation because in the large intestine, mechanical digestion is unnecessary.

Diarrhea vs. Constipation

  • Diarrhea: Fecal matter moves too quickly through the large intestine, resulting in insufficient water reabsorption.

  • Constipation: Fecal matter moves too slowly, leading to over-reabsorption of water, causing dry and hard feces.

  • Recommendation for constipation: increase fiber intake.

    • Fiber cannot be digested, providing a solid consistency to prevent over-reabsorption of water.

  • Serosa Layer: Visceral peritoneum, parietal peritoneum, and peritoneal cavity filled with serous fluid.

  • The rectum is surrounded by adventitia rather than serosa.

  • The population of bacteria depends on things such as sex, ethnicity, race, location, and food intake.

E. Coli

  • E. Coli is a type of bacteria.

  • Once E. Coli is in the digestive system it will cause immune response, such as vomiting.

Appendicitis

  • Inflammation of the appendix.

  • The appendix walls get thicker as a result, closing the opening from the cecum to the appendix.

  • Bacteria inside produce gas, causing appendix to burst.

  • Burst appendix can lead to peritonitis (inflammation of the peritoneum) which can be fatal if untreated.

  • Most common in ages 18-34. Age is just statistical significance, doesn't mean people outside of that can't experience appendicitis.

  • Treatment: remove the appendix; if the appendix has burst, a longer hospital stay is required to flush out the fecal matter and bacteria from the peritoneal cavity.

  • Some people have a wide opening in their appendix, which prevents appendicitis from occurring.

Diverticulitis

  • Pouches (diverticula) form in the large intestine, which can become inflamed if fecal matter gets stuck inside.

  • Symptoms: pain, constipation, abdominal soreness, nausea, vomiting.

  • These pouches are much stronger than the appendix.

Colitis

  • Inflammation of the entire colon.

  • Associated with diseases like Crohn's disease (autoimmune disorder where the immune system attacks the large intestine).

  • Can also be caused by bacterial or viral infections.

Colon Cancer

  • Rapidly becoming the number one cancer killer in the United States because people dying from lung cancer is dropping.

  • Often asymptomatic, requiring regular check-ups.

  • Statistics: One in six people may develop colon cancer, and 50% of those with colon cancer die from it.

  • Detection methods:

    • Colonoscopy: Tube with a camera is inserted through the anus to look for polyps (growths that can turn into cancer).

    • Fecal Sample: Analyzed for epithelial cells with genetic mutations indicative of cancer.

  • Diverticula are pouches that come out of the large intestine, while polyps projecting into the lumen.

Embedded Tutoring

  • Opportunity to work alongside professors and assist students in understanding course material.

The Liver

  • Largest internal organ with over 500 functions.

  • Makes all blood proteins (clotting factors, albumin, etc.), except antibodies.

  • Regulates blood glucose levels.

  • Processes fats, amino acids, and carbohydrates.

  • Makes cholesterol.

  • Converts hemoglobin into bilirubin, which is used to make bile (an emulsifier for fat).

  • Hepatocytes (liver cells) replicate quickly.

  • A person can donate part of their liver because it grows back. It can only be donated once before abnormal growth.

Liver Lobule Structure/Hepatic Portal Triad

  • Functional Units of the Liver = Liver Lobule.

  • Hepatic Portal Triad consists of:

    • Hepatic artery (brings blood in).

    • Hepatic portal vein (brings blood from the digestive system and spleen).

    • Bile duct.

  • Blood from the hepatic artery and hepatic portal vein is processed in the liver lobule.

  • Central vein returns blood to the inferior vena cava via the hepatic vein.

  • Hepatic sinusoids are the spaces between hepatocytes where blood travels.

  • Hepatocytes process the blood and can remove substances like alcohol.

  • As blood flows, it can enter the hepatocyte and then the hepatocyte can spit back the processed material into the sinusoid.

  • Bile Canaliculi: Structures next to hepatocytes that receive bile.

    • Bile is made from broken-down hemoglobin, bilirubin, cholesterol, etc.

  • Kupffer Cells: Macrophages fixed in the sinusoids that break down red blood cells.

    • Red blood cell parts are then processed by hepatocytes into bile.

Liver Diseases

  • Cirrhosis: Death of liver lobules, often caused by excessive alcohol consumption.

    • Alcohol is a toxic substance that the liver tries to remove, but it damages hepatocytes.

    • The liver can recover if alcohol consumption stops, unless there's significant scar tissue.

  • Hepatitis: Inflammation of the liver, usually due to viral or bacterial infections, leading to the death of hepatocytes and cirrhosis.

  • Liver Cancer also leads to the death of hepatocytes.

Build up of Bilirubin

  • Jaundice: Yellowing of the skin and sclera due to the buildup of bilirubin, an orange-colored substance.

    • Bilirubin build up happens due to the death of hepatocytes, and kupffer cells remain and break down old red blood cells.

    • Jaundice is a sign of liver disease.

    • It isn't the disease itself.

  • Neonatal Jaundice: Common in newborns due to the breakdown of fetal red blood cells.

    • UV light can help remove bilirubin.

Pathway of Bile

  • The liver has four lobes.

  • The Liver makes bile and then sends it to the gallbladder for storage.

  • Left and right hepatic ducts bring bile from the liver and then joins to become the common hepatic duct

  • Cystic duct leads to the gallbladder.

  • Common bile duct - cystic duct as well as the common hepatic ducts are going to be able to send bile over to the duodenum.

  • Sphincter of Oddi - the common bile duct and the pancreatic duct send their secretions to.

  • If Sphincter of Oddi is closed, the bile rises up into the gallbladder.

  • Gallbladder's function other than holding bile is to concentrate bile.

Gallstones

  • If the gallbladder concentrates bile too much, it can crystallize and form gallstones.

  • Gallstones cause pain, and typically the gallbladder is removed by tying off the cystic duct.

  • An incision cannot be done to save the gallbladder, as that may leak bile and cause peritonitis.

  • If no gallbladder =

    • The Liver will be asked to produce more bile quickly.

    • The Liver would just secrete bile, so you'll have to watch out for high fat foods.

Peritoneal Cavity

  • Parietal Peritoneum: Membrane attached to the walls of the abdominal cavity.

  • Visceral Peritoneum: Membrane attached to the gastrointestinal tracts.

  • Mesentery: Formed by the parietal peritoneum; supports blood vessels and nerves.

  • Omentum: Similar to mesentery but larger and surrounds organs like the liver.

  • The visceral peritoneum and the parietal are made up of simple squamous epithelium.

  • The space between the Parietal Peritoneum and Visceral Peritoneum forms the Peritoneal Cavity.

    • Burst appendix affect this a lot.

  • Retroperitoneal Cavity: Space behind the peritoneum.

  • Mid-Sagittal Sections:

    • Peritoneal Cavity - purple region

    • Greater Omentum - yellow structure.

    • Retroperitoneal Cavity - yellow region which has the kidneys and aorta.

    • Infra Peritoneal cavity-red region which has the bladder and uterus.

  • Mesenteries are used to deliver blood vessels and nerves.

  • Nerve endings in the Mesenteries = potential hypotheses for cramps during period.

  • Omentum surrounds organs for compartmentalization.

Urinary System Functions

  • Removal of metabolic wastes like urea.

  • Regulation of ion concentration (sodium, potassium, calcium).

  • Blood pH Balance regulation that is done by hydrogen ion concentration.

  • Regulation of blood volume.

  • Regulation of blood pressure. Blood volume is going to affect Blood pressure.

  • Kidneys found in retroperitoneal space T12-L2.

  • The Adrenal Glands are found on top of the kidneys.

Kidney Structure

  • Renal Capsule: Made of dense irregular connective tissue to protect the kidney.

    • Adipose Tissue cushions the organ, is never use for energy storage.

  • Renal Fascia: Renal fascia of moderately dense connective tissue, anchors the kidney.

  • Renal Cortex: Filters blood (more on function). Renal columns allow blood vessels to travel.

    • Renal Medulla: Process/Create Urine. Has Renald Columns inside and Renal Pyramids in between.

  • Renal Pyramids: Function in processing and production of urine.

  • Calyx: Made from the Renal pyramid the kidney is sent throught the opening which is known as Calyx.

  • Renal Pelvis: urine that we just produced goes into.

  • Ureter: Sends urine from the renal pelvis toward the bladder.

The Retroperitoneal Cavity is the space behind the peritoneum. In mid-sagittal sections, it includes the kidneys and aorta.

Bile is an emulsifier for fat, made by the liver from broken-down hemoglobin, bilirubin, cholesterol, etc.

The liver has four lobes.

  • The Liver makes bile and then sends it to the gallbladder for storage.

  • Left and right hepatic ducts bring bile from the liver and then joins to become the common hepatic duct

  • Cystic duct leads to the gallbladder.

  • Common bile duct - cystic duct as well as the common hepatic ducts are going to be able to send bile over to the duodenum.

  • Sphincter of Oddi - the common bile duct and the pancreatic duct send their secretions to.

  • If Sphincter of Oddi is closed, the bile rises up into the gallbladder.

  • Gallbladder's function other than holding bile is to concentrate bile.