GI tract #1: Witwer Flashcards
Air sacs in lungs, and vessels= ______ epithelium
simple squamous fx: allows materials to pass through by diffusion, and secretes lubricating substance
Kidney tubules= made of ______ epithelium
simple cuboidal fx: secretes/absorbs
“simple cube in the kidney tube”
Bronchi, uterus, GIT= ______ epithelium
simple columnar (these ciliated tissues are in bronchi, uterine tubes, and uterus smooth muscle(nonciliated) fx: absorbs, it also secretes **mucous/enzymes****
Trachea, upper resp. tract= _____ epithelium
Pseudostratified columnar epith. (=ciliated tissues) fx: Secretes mucous, ciliated tissue moves mucous
Stratified Squamous epithelium lines the:
Esophagus, mouth and vagina –protects against abrasion
Stratified Cuboidal epithelium lines the:
sweat, salivary, and mammary glands –protective tissue
Stratified columnar epithelium lines the:
male urethra –secretes and protects
Transitional epithelium lines the:
genitourinary tract (GUT) (aka bladder, urethra and ureters) –allows the urinary organs to expand and stretch
Gastrointestinal wall has 4 layers (list)
-Mucosa – inner layer -Submucosa -Muscular Layer -Serosa/Adventitia
Describe the Mucosa (of the GI wall)
(inner layer) -Epithelium with glandular elements (goblet cells secreting mucus – lubricates) –highly specialized depending on role, esophagus, stomach (secretion), small bowel (absorption) and large bowel. -Lamina propria is under the epithelium and contains blood vessels, nerves, immune cells -Muscularis mucosae – aids peristalsis
Describe the Submucosa of the GI wall
contains nerves, blood vessels, and elastic and collagen fibers that supports mucosa
Describe the muscular layer of the GI wall
contains both longitudinal and circular smooth muscle – peristalsis.
Describe the Serosa/Adventitia (of the GI wall)
loose CT on outside of the bowel wall
What holds the GI wall (4 layers) in place?
*Mesentery holds all of this in place.
Key components of Generic Bowel:
Mucosa – epithelium protects and lines bowel, secretes mucus , lamina propria supports and nourishes epithelium Submucosa – Supports mucosa, contains glands **Muscularis – muscles of peristalsis **Serosa/Adventitia – serosa secretes fluid to decrease friction of bowel on bowel, adventitia is supporting connective tissue.
Meissner’ Plexus=
aka Submucosal plexus =PNS secretomotor innervation to mucosa **located in Submucosa within bowel wall
(extrinsic!!)
Auerbach’s Plexus=
-aka Mysenteric plexus =PSN and SNS peristalsis motor innervation **located in Muscularis Propria within bowel wall
(**intrinsic)
Mucosa consists of 3 things:
(inner layer) -epithelium -Lamina propria -Muscularis mucosae
Glands contained within the submucosa:
-glands in mucosa -ducts of glands located outside of tract
Muscularis= _____ muscle and ____ muscle
circular muscle and longitudinal muscle
Serosa=
areolar CT and epithelium
Mesentary goes around the ______
peritoneum (comprised of mesenteric folds (includes veins and nerves )
Myenteric Plexus isPart of the _____ Enteric Nervous System -provides BOTH sympathetic and ______
Intrinsic -Meissner plexus= secretomotor -Myenteric plexus (Auerbach) provides both sympathetic and parasympathetic input to the muscular layers of the muscularis – circular and longitudinal muscles of peristalsis -lots located in the large bowel and distal large bowel (areas of peristalsis) (If you cut the vagus nerve, you will still get bowel function and peristalsis due to the intrinsic nervous system. KNOW )
The area of the GIT is about the size of a _____
football field!
Mucous membranes line:
gut, lungs, nose, genitalia, urinary tract, eyes, middle ear
Mucous is composed of:
-*Mucin: Glycoproteins, a central core of protein with thousands of sugar molecules branching off added with water making gel. -Also contains antiseptic enzymes and immunoglobulins
Average human nose produces ____ liters of mucous per day
1 Liter
Phlegm= _______ mucous
respiratory mucous -Green or yellow mucus 2/2 viral or bacterial infection. –*Increased production found in infections, allergies, asthma, increased histamines (movement of mucus via the cilia to the pharynx)
Why don’t the bacteria in the GIT overwhelm the body??
**There are Immune Barriers assisted by a dense mucus layer.
Describe the Immune barriers that are assisted by a dense mucus layer
- There are two layers of mucus on the GIT wall. 2. A thin outer mucus layer that microbes can thrive in. 3. A dense inner mucus layer (yellow in picture below) on top of epithelium that has lots of antimicrobial peptides (AMP secreted by Paneth Cells) and immunoglobulins IgA. 4. And there is an immune cell layer in the intestinal epithelial cells. 5. Reticuloendothelial immune cells in the liver. SFB=segmented filamentous bacteria (Mucous is SO important in the GI tract -problem with cholera– mucous is eliminated, these Pts die primarily from dehydration and vulnerable to superimposed infections that break through mucosa)
In the future: Inflammatory Bowel Disease, ie Ulcerative Colitis and Crohn’s Disease may be secondary to a _____, and imbalance between the patient’s diet, immune system and the intestinal microbiome.
dysbiosis= imbalance b/w Pt’s diet, immune system, and intestinal microbiome
**GI fluid volumes: -Ingest ____ mL/day H20 -saliva= ____mL/day
KNOW FOR EXAM!! -2000 mL/day H20 -1500 mL/day
Bile: ____mL/day Gastric secretions: _____mL/day
-500 - 2000
Pancreatic juices: ____ ml/day produced
1500
Small intestine absorbs ____ mL/day
8500 mL/day
Intestinal secretions: ____ mL/day
1500
Colon absorbs: ____ mL/day
400
____mL of H20 excreted per day
100 mL/day
Pain in Right upper Quadrant ddx:
-R/O gall bladder dz (cholecystitis) -Choledocolithiasis (= gallstones) -****Glisson’s capsule!!= stretching of it= intense pain! -Hepatitis -Pyelonephritis -herpes Zoster -PNA -empyema -Duodenitis
Right lower Quadrant pain ddx:
**appendicitis -ectopic pregnancy -Ovarian cyst -salpingitis -endometriosis -Diverticulitis -Pyelonephritis -hernia perforated ulcer
Epigastric region pain ddx:
(epigastric region=midline) -peptic ulcer -Gastritis -**pancreatitis -duodenitis -gastroenteritis -MI
Left upper quadrant pain ddx
-gastritis -pancreatitis -Splenic enlargement/rupture -Infarction -Pyelonephritis -Nephrolithiasis -Herpes zoster -MI PNA -IBD
Left lower Quadrant pain ddx
-diverticulitis -intestinal obstruction -IBD -appendicitis -Salpingitis
Pt presents with lower mid abdomen pain, do you have to worry about ectopic pregnancy?
YES!!! KNOW for exam
Key components of Generic bowel (again, list 4)
Mucosa – epithelium protects and lines bowel, secretes, lamina propria supports and nourishes epithelium Submucosa – Supports mucosa, contains glands Muscularis – muscles of peristalsis Serosa/Adventitia – serosa secretes fluid to decrease friction of bowel on bowel, adventitia is supporting connective Tissue.
Upper esophageal Sphincter: -Skeletal muscle? -Primary muscle=? KNOW
Upper Esophageal Sphincter: -Skeletal Muscle–> no conscious control -Primary muscle is Cricopharygeus muscle***
**Cricopharyngeus muscle is part of the inferior _______ muscle
Pharyngeal Constrictor muscle
Note _______ of the inferior pharyngeal sphincter/cricopharyngeus
*complexity Remember: the esophagus when it passes the heart, it’s right up against the Right atrium. So an enlarged heart, can cause dysphagia!!!