Anatomy Week 3 Flashcards
Peritoneum:
A large, serous membrane that lines the abdominal cavity.
Describe the structure of the peritoneum:
A single layer of simple, squamous epithelium (mesothelium)
How is the peritoneum divided?
Parietal Peritoneum: Lines the body wall anteriorly and posteriorly.
Visceral Peritoneum: Surrounds and supports abdominal organs.
Intra-peritoneal vs Retro-peritoneal:
- Intra-peritoneal: Organs that are completely surrounded by peritoneum (and mesentery) and suspended in abdominal body wall.
- Retro-peritoneal: Organs that are attached to the posterior body wall and not completely surrounded by mesentery.
List the 5 major peritoneal folds:
- Greater Omentum
- Falciform Ligament
- Lesser Omentum
- Mesentery
- Mesocolon (Transverse and Sigmoid)
What is unique about the falciform ligament?
It attaches the liver to the VENTRAL body wall. The rest attach organs to the posterior abdominal wall (retro-peritoneal structures).
What is another name for the Greater Omentum?
The policeman of the abdomen: Because it is freely moving, it can migrate to cover any inflamed/infected regions of the abdomen to protect them from spreading to the rest of abdomen.
2 Components of the Lesser Omentum:
- Hepato-Duodenal Ligament
2. Hepato-Gastric Ligament
What is the Omental Foramen?
An opening into the lesser omental sac, which can accumulate fluid.
What is the “root” of the mesentery?
The attachment of the mesentery to the posterior wall.
2 Components of the Mesocolon:
- Transverse Mesocolon: Attaches transvere colon to posterior wall.
- Sigmoid Mesocolon: Attaches sigmoid colon to posterior wall.
Peritoneal Cavity:
The space between the parietal and visceral peritoneum.
Peritonitis:
Inflammation of the peritoneal membrane, most commonly due to infection resulting from an injury that punctures the abdominal or abdominal organs.
What is another name for the GI Tract?
The Alimentary Canal
Esophagus to Anal Canal
4 layers of GI Tract:
- Mucosa
- SubMucosa
- Muscularis Externa
- Serosa
Peristalsis:
The simultaneous constriction of the GI tube by Circular muscle and shortening of the tube by Longitudinal muscle to push and propel contents forward.
The serosa is the mesothelium that is continuous with _______, and it is a ______ membrane.
- The Mesentery
2. Serous
Serosa vs Adventitia:
Adventitia is LOOSE connective tissue that attaches parts of the GI tract without a serosa layer to the body wall.
Name the 4 structures that possess an Adventitia Layer:
- Thoracic Esophagus
- 2nd, 3rd, and 4th parts of duodenum
- Asc./Desc. Colon
- Rectum/Anal Canal
Esophagus:
Muscular tube that connects:
Pharnyx –> Stomach
The first cartilaginous structure of the larynx is the _______, which is also called the _______. It is followed by the _______.
- Thyroid Cartilage “Adam’s Apple”
2. Cricoid Cartilage
The Cricoid cartilage is followed by the _______ which forms part of the ______.
- Crico-pharyngeal Muscle
2. Esophageal Sphincter
What is seen at the point where the trachea splits off into the 2 main bronchi?
The Aorto-bronchial constriction
Esophageal Hiatus:
Opening of the diaphragm that the esophagus passes through to reach the stomach.
Pyrosis:
Heartburn caused by acid reflux into the esophagus from the stomach.
If pyrosis progresses, it can become _______. If THIS progresses, it can become _______, which is _______.
- GERD
2. Barrett’s Esophagus: Metaplasia of cells
Esophagogastric Junction:
The abrupt change in lining of the esophagus epithelium when it becomes the stomach epithelium.
(Strat. Squam. –> Simple Columnar)
What is the FUNCTIONAL difference in epithelium that occurs at the esophagogastric junction?
The “protective” epithelium of the esophagus transitions into more “secretory” epithelium in the stomach.
Barrett’s Esophagus:
Stratified squamous epithelium of the lower esophagus becomes simple columnar epithelium due to constant stimulus from the stomach.
Adenocarcinoma:
Malignant growth of GLANDULAR origin.
Description and Function of Rugae:
- Longitudinal Folds of the mucosa and submucosa inside the stomach.
- Allow distension/relaxation of the stomach.
Main function of stomach:
Secretion of HCl and gastric enzymes to begin digestion and mix contents.
(i.e. Bolus –> Chyme)
3 Layers Of Stomach Musc. Externa:
- Internal Oblique
- Middle Circular
- Outer Longitudinal
What regulates the flow of chyme from the stomach to the duodenum of the small intestine:
The Pyloric Sphincter
What peritoneal structure hangs below the stomach?
The Greater Omentum
What 2 structures lie to the anatomical left of the stomach:
- The Spleen
2. The Left Colic Flexure (as the transverse colon becomes the descending colon)
Give the 5 cell types of Gastric glands and their secretion:
- Surface Mucous Cell: Mucous
- Neck Mucous Cell: Mucous
- Parietal Cell: HCl and Intrinsic Factor
- Chief Cell: Pepsinogen + Gastric Lipase
- G-Cell: Gastrin
What other cell type is found in the neck of the gastric gland besides neck mucous cells?
Stem cells for rapid turnover of epithelium
What is Pernicious Anemia?
A disease resulting from lack of Vitamin B12 absorption due to lack of Intrinsic Factor.
Gastrin Functions: (2)
- Activate Parietal cells to secrete HCl and Intrinsic Factor
- Stimulate Gastric Motility (mixing via contraction)
Function of HCl in stomach:
Convert Pepsinogen –> Pepsin
What are Enteroendocrine cells? Give an example:
Hormone producing cells of the enteric system.
Ex: G-Cells in stomach produce Gastrin which travels through the blood to distant targets to elicit an effect.
Ulcer:
An erosion of the mucosa of the GI tract wall.
Chronic Peptic Ulcer:
An ulcer that has degraded the mucosa, submucosa, and part of the muscularis externa.
Perforation:
Complete opening into peritoneal cavity
releasing stomach contents into peritoneum can cause infection/inflammation
Hemorrhage:
Tissue necrosis of peptic ulcer and stomach contents leaking reaches large arteries and causes bleeding.
Obstruction:
Fibrous scarring builds up from repeated attempts at repairing necrosis, causing narrowing or complete blockage of the lumen.
3 Levels of Chronic Peptic Ulcer Complications:
- Perforation
- Hemorrhage
- Obstruction
Main site of absorption/digestion in GI tract:
Duodenum of Small Intestine
Plicae Circularis: (Give other name as well)
- Valves of Kerckring
- Circular, transverse, PERMANENT folds of the submucosa of the jejunum that function to increase surface area for absorption.
List the 3 structures used to increase surface area for absorption within the small intestine and where each are located:
- Plicae Circularis: SubMucosa of distal duodenum and jejunum.
- Villi: Mucosa of jejunum
- Microvilli: Apical projections at brush border of duodenal epithelium
At the center of each villus is a _______, contained within the _______.
- Central Lacteal
2. Lamina Propria
Describe Microvilli: (What are they composed of?)
- Apical projections of the simple columnar epithelium that form the “brush border”, or stratified border facing the lumen of the small intestine.
- Composed of Actin core
Major Duodenal Papilla:
Opening into 2nd part of duodenum for delivery of:
- BILE from Liver/Galbladder via Common Bile Duct
- PANCREATIC JUICES from Pancreas via Main Pancreatic Duct
Stimulus for secretion of bile and pancreatic juices into duodenum:
Entry of Chyme into ampulla
Located right in the center of the C-shape of the duodenum is the ________.
Head of the Pancreas
The duodenum is suspended by the _______ which anchors it to the ________. Within this suspending tissue are what three structures?
- Hepato-duodenal Ligament
- Liver
- Three Structures:
- Common Bile Duct
- Hepatic Portal Vein
- Hepatic Artery Proper
What is unique about the submucosa of the duodenum?
It possesses Brunner’s Glands, which secrete mucous to protect the epithelium of the duodenum from acidic secretions.
The Jejunum begins at the _________.
Duodenal-Jejunal Junction
Goblet Cells: (2)
- Secrete mucous onto surface of epithelium
2. More numerous in the jejunum
4 Distinguishing Features of the Jejunum:
- Plicae Circularis
- Villi
- Increased goblet Cells
- NO Submucosal Glands
2 Distinguishing Features of the Ileum:
- Peyer’s Patches
2. Decreased Plicae Circularis
Peyer’s Patches:
Immune tissue in the lamin propria of the ileum that form large lymphatic aggregates
Describe the 4 main cell types of the small intestine:
- Enterocyte: Absorptive cells with microvilli
- Goblet Cell: Glandular cells that secrete mucous
- Enteroendocrine: Produce Paracrine/Endocrine hormones.
- Paneth Cell: Secrete bacteria-degrading enzymes
What is the important role of tight junctions between enterocytes?
They allow for selective absorption, blocking bacteria and unwanted substances from moving between cells across the plasma membrane.
The ______ and ______ come together to form the Common Bile Duct.
- Cystic Duct (Galbladder)
2. Hepatic Duct (Liver)
What is unique about Paneth cells?
They stain pink because they are filled with pink granules containing lysozyme, an anti-bacterial enzyme.
Haustra:
Sac-like divisions of the large intestine formed by the Teniae Coli.
Teniae Coli:
Extensions of longitudinal muscle from the muscularis externa of the colon, which divide it into haustra that can contract to shorten and propel contents forward.
Omental Appendices:
Small, fatty projections of the colon
2 Main functions of Large Intestine:
- Reabsorption of Water/Electrolytes
2. Elimination of waste
Most common cause of appendicitis:
Obstruction: Complete blockage or narrowing of the appendix opening to due chronic ulcers causes infection and inflammation
The rectum is structurally a ______ structure.
Retro-peritoneal
Hirschsprung Disease:
A congenital defect in the migration of neural crest cells to the distal colon, causing lack of dev. of submucosal and myenteric plexuses to innervate that region. This leads to constipation which will cause noticeable distension.
The ________ leads into the Major Duodenal Papilla.
Ampulla of Vater
Sphincters of Oddi:
Allow contents from Ampulla of Vater into duodenum
i.e. Bile and Pancreatic Secretions
Falciform Ligament:
Attaches Liver to Ventral Body Wall
Ligamentum Teres:
The “round ligament”, the remnants of the umbilical vein.
List the 4 Lobes of the Liver:
Right
Left
Caudate (next to Vena Cava)
Quadrate (next to Galbladder)
List the 3 Types of Liver Lobules:
Hepatic Lobules
Portal Lobules
Hepatic Acinus
Describe the location of the Superior Mesenteric Artery:
Travels deep to the Pancreas, but in front of the Small Intestine to supply all mid gut structures.
Why are digestive proteases secreted as inactive zymogens?
Because if they were secreted as active enzymes, they would start degrading every protein they came in contact with along the path to the duodenum.
Aminopeptidases function to breakdown: ______ in the ________.
- Di-Peptides
2. Cytoplasm of the cells that absorb them
Enteropeptidase Function:
To truncate inactive zymogen proteases when they reach the duodenal lumen to activate them.
Once enteropeptidase has activated _______, it can go on to _______.
- Trypsin
2. Activate all the other zymogens
What molecule serves as the ACCEPTOR of Amino Groups?
Alpha-KG —> Glutamate
Name the amino group acceptor in Alanine Transaminase and Aspartate Transaminase reactions respectively:
- Alanine Transaminase:
Alpha-KG —> Glutamate - Aspartate Transaminase:
Oxaloacetate —> Aspartate
Describe how the ratio of AST to ALT would appear in:
-Viral Hepatitis: _____
-Alcohol Hepatitis: _____
What is the normal Ratio?
- Viral Hepatitis: ALT > AST
- Alcohol Hepatitis: AST > ALT
Normal Ratio: AST:ALT = 1.3
Describe the role of Glutamate Dehydrogenase:
This MITOCHONDRIAL enzyme, found in liver and kidney cells, performs Oxidative DeAmination of Glutamate and Aspartate to yield Alpha-KG and FREE NH3 to be excreted. (Using NAD+ or NADP+).
What happens to free NH3 resulting from oxidative deamination?
It goes on to enter the Urea Cycle.
What role do ADP and ATP play in the conversion of Glutamate back into Alpha-KG and NH3?
They are ALLOSTERIC regulators. When ADP signals a low-energy state, the reaction will proceed in the direction of Glutamate being degraded to yield energy.
Describe the function of D-Amino Acid Oxidase:
Uses Vitamin B2, water, and FADH to convert D-Amino Acids into Alpha-Keto Acids while releasing free NH3 and FADH2.
What is Receptive Relaxation? What is another name for it?
- The relaxation (decrease in pressure) of the Orad portion of the stomach to allow food to pass through it.
- Also called Accommodation.
Differentiate between the 2 major portions of the stomach:
- Orad: Thin-walled to allow receptive relaxation
2. Caudad: Thick-walled, to contract for mixing and breakdown to form chyme, and to propel into duodenum.
Retropulsion:
Closing of the pyloric sphincter to propel chyme BACK into the stomach for further mixing and breakdown.
What 2 factors SLOW gastric motility propelling food into the duodenum? How are each regulated?
- Fat in the duodenum
- Regulated by CCK: Slows gastric emptying - Acid excess in the duodenum
- Regulated by Secretin: Secretes BiCarb.
- Regulated ALSO by ENS reflexes: Sensory neurons detect pH change and slow gastric emptying
Describe the BER:
Basic Electrical Rhythm: Rhythmic fluctuations of membrane potential, “slow waves”, are initiated by Interstitial Cells of Cajal (Pacemaker cells of the ENS) and set the pace for A.P.’s and contractions in the intestines.
What two processes allow the intestines to mix and propel food?
- Segmentation: Mixing with digestive enzymes
2. Peristalsis: Propulsion into lg. int.
What hormones/neurotransmitters control each portion of peristalsis in the sm. int.?
Orad Contraction: ACh and Substance P
Caudad Relaxation: VIP and NO
Describe MMC’s:
Migrating (Myo-electric) Motor Complexes: Slow, rhythmic GI contractions occurring every 90 minutes during the fasting state.
What controls MMC’s and how are they stopped?
Motilin: Regulates MMC’s to begin during fasting state and to stop when next meal is received.
Describe the 3 reflexes of the Small Intestine and what each is controlled by:
- Gastro-Ileal Reflex: Increased Ileal motility in response to gastric emptying. Controlled by Gastrin and Vagus Stimulation.
- Ileogastric Reflex: Decreased gastric emptying in response to fat in ileum. Controlled by Neurotensin.
- Intestino-Intestinal Reflex: Distension in any segment of sm. int. causes decreased motility in all other segments. Controlled by Extrinsic Innervation.
Describe the 2 reflexes of the Large Intestine and what each is controlled by:
- Colono-colonic Reflex: Same as intestino-intestinal reflex, controlled by Symp. Innervation.
- GastroColic Reflex: Increased motility in colon and increased Mass Mvmt.’s upon stomach filling. Controlled by Gastrin and CCK.
Valsalva Maneuver:
Expiring against a closed glottis to increase intra-abdominal pressure and help propel feces for defecation.
Law of the Gut:
Must have peristaltic contraction BEHIND the bolus, and peristaltic relaxation AHEAD of the bolus to achieve propulsion in the direction of the anus.
Describe the structure of the Pericardium:
- Outer Fibrous Layer: Tough connective Tissue
- Inner Serous Layer: Thin, has 2 layers within:
a.) Outer Parietal Layer: Attached to Fibrous
b.) Inner visceral Layer: Attached to Heart
^ (A.K.A. Epicardium)
Where is the Pericardial Cavity and what is its importance?
- In between the Epicardium and the Parietal layer of the serous pericardium.
- It contains serous fluid that allows lubricated expansion and relaxation of the heart.
Pericardio-phrenic Ligaments:
Pericardium —> Diaphragm
Pectinate Muscles:
Atrial contractile muscles that allow ventricular filling
Fossa Ovalis:
Occluded RIGHT ATRIAL structure that is only open in fetuses for blood supply.
Trebeculae Carneae:
Thick Ventricular Muscle
Right Auricle:
Anterior Extension of Right Atrium
The “Semi-Lunar” Valve is another name for the _______ valve.
Aortic AND Pulmonary Valves
The “Bicuspid” Valve is another name for the _____ valve.
Mitral Valve
_______ are the major artery type responsible for vasoconstriction and vasodilation that regulates blood flow into capillaries.
Arterioles
Venous valves are extensions of the _______.
Tunica Intima
Smooth muscle in veins is located in the _________.
Tunica Adventitia
What type of artery is the aorta?
An Elastic Artery
Anastomosis:
A linkage of 2 vessels to one another
