A & P II Exam 5 Flashcards
Liver is divided into two principal lobes by what, and which lobe is larger?
Falciform Ligament. Right lobe.
Slide 2
What are the two sources of blood for the liver and which type of blood is brought?
Hepatic Artery (25%) - Oxygenated blood.
Portal Vein (75%) Deoxygenated blood + Nutrients.
(Slide 2)
Pharynx
After food is first swallowed, it passes from the ____ into the ____
-This funnel shaped tube extends from the _____ to the ____ posteriorly,
Which then travels to the ____ anteriorly.
It is composed of what type of muscle?
What is it lined with?
Mouth; pharynx
Internal nares; Esophagus
Larynx
Skeletal muscle
Mucous membrane
Pharynx:
What are the three parts of the Pharynx?
What is the function of each part?
-After swallowed food passes from the mouth into the ____, it then travels to the ____
What action helps propel the food into the esophagus and then into the stomach?
- Nasopharynx- functions only in respiration
- Oropharynx- function in digestion and respiration
- Hypo/Laryngopharynx- function in digestion and respiration
Oropharynx; laryngopharynx
Muscular contractions
Esophagus:
What type of tube is the esophagus?
Length?
Posterior in relation to the trachea?
Where does it begin/pass through/enter/pierce through/end at
The esophagus pierces through the diaphragm at what location
Occasionally the stomach herniates through what opening?
- Collapsible muscular tube
- Usually 10in long
- Lies posterior to the trachea
- Begins at inferior end of hypo/laryngopharynx, passes through the inferior portion of neck, enters mediastinum, pierces the diaphragm, ends at superior portion of stomach
- Pierces diaphragm through esophageal hiatus
-Sometimes part of the stomach herniates through this
opening (called hiatal hernia)
Esophagus Histology:
What are the (4) layers: Superficial surface to lumen (deep)
-For each section, what does it either attach to or is consisting of
Superficial surface to lumen
- Adventitia
▪ Attaches esophagus to surrounding structures - Muscularis
▪ Superior 1/3 esophagus is skeletal muscle
▪ Middle 1/3 esophagus is skeletal transitioning to smooth muscle
▪ Inferior 1/3 esophagus is smooth muscle - Submucosa
▪ Contains areolar connective tissue, blood vessels, mucous glands - Mucosa (3 layers)
▪ Muscularis mucosae (smooth muscle)
▪ Lamina propria (areolar connective tissue)
▪ Nonkeratinized stratified squamous epithelium
Esophagus Histology:
What layer provides considerable protection against abrasion from food particles?
At the end of the esophagus, what physical feature of the esophagus forms sphincters?
What are the (2) sphincters found in the esophagus?
Mucosa, Layer 4
Muscularis layer thickens forming sphincters
Upper Esophageal Sphincter (UES); Lower esophageal sphincter (LES)
What type of muscle does esophageal sphincter consist of?
What does it sphincter regulate?
Upper esophageal sphincter (UES) which is skeletal muscle
-Regulates movement of food from hypopharynx to esophagus
Lower esophageal sphincter (LES) which is smooth muscle
-Regulates movement of food from esophagus to stomach
What are the (4) Physiology features of the Esophagus
- 2 functions it DOES do
- 2 functions it is NOT involved in
Does:
- Secretes mucous (protective function)
- Transports food to the stomach
Does not:
- Does NOT produce digestive enzymes
- Does NOT participate in absorption
What is the act of swallowing; the movement of food from the mouth into the stomach?
-Deglutition
Deglutition is facilitated by the secretion of ___ and ____
- It involves what (3) other body parts
- What are the (3) phases of swallowing
Saliva; mucous
-mouth, pharynx, esophagus
- The voluntary stage
- The pharyngeal stage
- The esophageal stage
In the Voluntary Stage of Deglutition:
- What (#) stage is this
- Swallowing starts when ___ is forced to the back of the ___ cavity
- This begins to travel backwards towards the ____ by the movement of the tongue upward and backward against the ____
-stage 1
Bolus; oral cavity
Oropharynx; palate
In the Pharyngeal Stage of Deglutition:
-What (3) stage is this
The passage of bolus into the oropharynx travels through what area, and then into the esophagus?
When the bolus stimulates the receptors where are the impulses sent?
-2
Hypo/laryngopharynx
Bolus stimulates receptors here which send impulses to
deglutition center in the medulla oblongata and lower pons
of brain stem
In the Esophageal Stage of Deglutition
- What (#) stage is this
- This stage begins when bolus has entered where?
- During this stage what is the main action that pushes the bolus onward?
- _____ is a progression of coordinated contractions and relaxations of the circular and longitudinal layers of the muscularis
- As the bolus moves down the esophagus, which sphincter relaxes allowing food into the stomach?
- The passage of solid or semisolid food from mouth to stomach takes _____seconds
- Passage of very soft food or liquids take about ____seconds
- 3rd stage
- esophagus
- Peristalsis
- Peristalsis
- Lower sphincter
- 4-8
- 1
Stomach:
A ___ shaped enlargement of the GI tract directly ___ to the diaphragm
- It connects the esophagus to the ___ (first part of the small intestine)
- What does the stomach serve as?
- When food mixes with gastric juices, what does it become?
- The position and size of the stomach varies as it : ____, ____ in response to food or lack thereof
- Is it the most ___ part of the GI tract, can expand and accommodate a large quantity of food. Why is this possible?
L-shaped; inferior
- duodenum
- mixing chamber and holding reservoir
- chyme
- moves with breathing, shrinks or expands
- distensible; mucosa lies in rugae (folds)
What are the (4) main regions of the Stomach
- The cardia
- The fundus
- The body
- The pyloric part (divided into three parts)
The Four regions of the Stomach:
- The cardia
- Surrounds the: ___ - The fundus
Rounded portion of: __ - The body
Inferior to: __ - The pyloric part:What are the three parts/Conenction to each?
_____antrum connects to: __
_____canal leads to: ___
_____connects to: __
- superior opening of the stomach
- superior to and left of the cardia
- the fundus, large central portion
-Pyloric antrum connects to the body of the stomach
Pyloric canal leads to the third region
Pylorus- connects to the duodenum via pyloric sphincter
Stomach Histology:
What are the (4) Layers of the stomach
Superficial to lumen
- Serosa
- Muscularis (three layers of smooth muscle)
- Submucosa (connective areolar tissue)
- Mucosa (lamina propria and muscularis mucosae)
What are the components of the Biliary Tree?
- Bile ducts inside liver
- Common hepatic duct (outside liver)
- Gallbladder and its cystic duct
- Common bile duct
- Ducts of the pancreas
(Slide 5)
What are the three functions of the Biliary Tree?
- Make, Store and Secrete Bile (and pancreatic enzymes)
- Rids liver (and body) of some waste products
- Aids in digestion of foods in small intestine.
(Slide 5)
The Major functional unit of the liver is the ______ lobule and composed of _____. (types of cells)
Hepatic, Hepatocytes
slide 7
In a hepatic lobule: a bile duct, a branch of the hepatic artery and a branch of the portal vein make up what? Where is this found?
Portal Triad. Found at the corners of the lobule.
Slide 7
Hepatocytes form a crucially important cell layer that separates what?
Sinusoidal blood from canalicular bile.
What do hepatocytes synthesize?
- Transport proteins (albumin/fibrinogen)
- Lipoproteins, fatty acids, triglycerides
- Cholesterol
- Bile
(Slide 8)
What are highly permeable blood capillaries between rows of hepatocytes?
Hepatic Sinusoids
Slide 9
In the hepatic sinusoids, what cells are fixed phagocytes that “clean” blood? How do they “clean”?
Stellate reticuloendothelial (Kupffer) cells.
Destroy worn-out red/white blood cells, bacteria, foreign matter.
(Slide 9)
What are the (8) functions of the liver?
- Carbohydrate (starch) metabolism.
- Lipid metabolism.
- Protein synthesis.
- Process drugs/hormones.
- Excretion of bilirubin.
- Storage.
- Phagocytosis.
- Bile synthesis.
(slides 12-14)
When plasma glucose levels are low - ______, and when plasma glucose levels are high - ______ occurs in the liver.
Glycogenolysis, Glycogenesis.
Slide 12
When the liver is processing durgs and hormones, which hormones does it chemically alter or destroy?
Thyroid and steroid hormones: T3/T4, estrogen, aldosterone)
Slide 13
When bilirubin is reabsorbed from broken down RBC’s, it is excreted where?
In the bile produced within the liver.
Slide 13
In addition to glycogen, live also stores what? When are these released?
Vitamins - A, B12, D, E, K
Minerals - Iron, Copper.
Released when needed by the body.
Slide 14
How is bile synthesized in the liver?
Mixture of bile salts, bile pigments, and cholesterol.
Slide 14
Bile plays a major role in digestion and absorption of what?
Fat / Lipids.
Slide 15
Where is bile stored and concentrated? How is it concentrated?
Gallbladder - reabsorbs water and ions.
Slide 15
Gallbladder is located where?
In a depression of the posterior/inferior aspect of the liver.
Slide 18
How does bile collect in the gallbladder?
Between meals - bile released by liver into common hepatic duct and down common bile duct. Accumulates and starts to flow into gallbladder when the ducts are full.
Slide 18
Which GI organ is a large part of our immune system?
Spleen
Slide 22
What are Spleens major functions?
Immune System
Tissue Repair
Hematopoiesis
RBC and Platelet Destruction
Slide 22
Which type of capillaries are in the spleen?
Sinusoids.
Slide 22
How does spleen conduct hematopoiesis?
Monocytes and lymphocytes complete their development and become activated in the spleen.
Fetal development - RBCs are formed in the spleen.
Slide 22
Where does most digestion and absorption of nutrients occur?
Small Intestines
Slide 25
Where does the small intestine begin and end?
Beings - immediately after pyloric sphincter of stomach.
Ends - ileocecal sphincter (valve) where the large intestine begins.
Slide 25
What are the three regions of the small intestines? Which is longest and shortest?
Duodenum (Shortest), Jejunum, Illeum (longest).
Slide 26
Which region of the small intestine is retroperitoneal, starts at pyloric sphincter and merges with the jejunum?
Duodenum.
Slide 26
Where does the Ileum begin and end?
Beings at the jejunum and exteds to ileocecal sphincter, merging with large intestine.
Slide 26
What is a “suspensory muscle” covered by a fold of the peritoneum and is an important landmark?
Ligament of Treitz AKA Suspensory Ligament of the Duodenum.
Slide 27
Where does the ligament of Treitz begin and what does it connect to?
Begins at the diaphragm
Connects to duodenojejunal flexture (suspending it upwards)
Slide 27
What does the ligament of Treitz anatomically signify?
Landmark between Upper and Lower GI
Slide 27
What are the layers of the small intestines?
- Serosa (except proximal aspect of duodenum)
- Muscularis
- Submucosa
- Mucosa
Slide 28
Which layers is the Myenteric Plexus (Plexus of Auerbach between?
Muscularis - Submucosa
Slide 28
Small intestines Submucosa layer contains which gland and plexus?
Burnner’s Glands - secrete alkaline mucous.
Submucosal nerve (Meissner’s) Plexus
Slide 28
The small intestines mucosa layer contain which glands?
Intestinal Glands (Crypts of Lieberkuhun)
Slide 31
What are the miscellaneous cells in Mucosa of small intestines?
Absorptive Cells(Enterocytes)
Goblet Cells
Paneth Cells
Slide 31
What are the Enteroendocrine cells in Mucosa of small intestines?
S Cells
CCK Cells
K Cells
Slide 31
What are the functions of each of the enteroendocrine cells?
S Cells - secrete secretin
CCK Cells - secrete cholecystokinin (CCK)
K Cells - secrete Glucose Dependent Insulinotropic Polypeptide (GDIP)
Slide 31
Where do you see Circular Folds (plicae circulares) in the small intestines?
Begin near proximal portion of duodenum and end near midportion of ileum.
Slide 32
What is the function of Circular Folds?
Increase surface area for absorption
Causes chyme to spiral - allowing for more dissolution.
Slide 32
Mucosal layer of small intestine has these three structural features: _____, ____ and _____.
Circular Folds (plicae circulares), Microvilli and Villi.
Slide 32/35
Define brush border.
When viewing microvilli through a microscope, they are seen as a fuzzy border. This is called brush border.
Slide 35
When chyme enters the small intestines, it contains partially digested carbohydrates, proteins, and lipids. What completes the digestion?
A collaborative effort by pancreatic juice, bile and intestinal juices.
Slide 36
Cells within the microvilli synthesize several digestive enzymes called _______.
Brush-border enzymes.
Slide 36
Carbs, Proteins, and Lipids are digested to what absorbable form and by what in the small intestines?
Carbs - Amylase - Monosaccharides
Proteins - Pancreatic Juices - Amino Acids or up to a tripeptide.
Lipids - Lipase - Fatty Acids and monoglycerides
Slide 38
What organ reabsorbs most of the water in the GI system?
Small intestines.
Slide 39
The Four layers of the Stomach
- Serosa:
-Greater curvature of stomach serosa continues as the __
-Lesser curvature of stomach projects upward towards liver as
the __ - Muscularis (three layers of smooth muscle)
- Contains __(myenteric plexus) - Submucosa (connective areolar tissue)
- Contains ___ (submucosal plexus) - Mucosa (lamina propria and muscularis mucosae)
- Contains __
- Contains __
- Contains an __
- greater omentum
- lesser omentum
- Auerbach’s plexus
- Meissner’s plexus
- gastric glands/pits
- specialized exocrine gland cells
- enteroendocrine cell type
-Slide 158
The Mucosal Layer of the Stomach has what three layers
-external to internal
-The third layer;
What are the (3) main features what define this layer
a. Muscularis mucosae (smooth muscle)
b. Lamina propria (connective areolar tissue)
c. Mucosa
- Form columns of secretory cells:
- called gastric glands that open into the lumen surface (gastric pits)
2. Gastric glands contain three types of exocrine gland cells that secrete their product into stomach lumen a. Mucous neck cells b. Chief cells c. Parietal cells
- Gastric glands also contain enteroendocrine cells
a. G-Cell – secretes a hormone into the BLOODSTREAM, not stomach lumen
b. Enterochromaffin-like cells – secretes hormone into bloodstream
In the Stomach, what are the (2) main types of cells?
-Exocrine cells; Enteroendrocrine cells
Slides 162/163
- In the Stomach: What are the (3) cells that are Exocrine cells that secrete various substances?
- What do each of these cells secrete?
-Mucous cells/neck cells:
Secrete mucous
-Chief cells (zymogenic):
Secrete pepsinogen; an inactive precursor enzyme
Secrete gastric lipase
-Parietal cells (oxyntic):
Secretes hydrocholoric acid (HCl)
Secretes intrinsic factor (IF)
Secretes bicarb
-In the Stomach: What cells fall under Enteroendocrine cells that secrete various substances or hormones?
What are these hormones/substances
G-Cells
- Found in the pyloric antrum
- Secretes hormone Gastrin into bloodstream
- Stimulates HCl acid production (with histamine)
- Stimulates gastric motility
- Stimulates Chief cells to produce more pepsin
Enterochromaffin-like Cells
- Secretes histamine
- activates parietal cells to produce HCl
What are the (2) types of digestion in the stomach?
In Mechanical Digestion of the Stomach:
- _____ in the stomach occur every 15-20 seconds.
- this helps macerate food, mix it with ____ secretions and reduce it to a soupy liquid.
- it is at this point that ___ is formed
- the waves intensify as that substance is moved towards the ___ - ____-approx 3 mL of chyme is ejected into the ___ each wave
- the remainder is pushed back into body of stomach where mixing continues
-Mechanical and Chemical
- Mixing waves/Peristaltic waves
- gastric
- chyme
- pylorus
-Gastric emptying; duodenum
Slide 166
In Chemical Digestion in the Stomach:
- ____- the only proteolytic (protein digesting) enzyme in the stomach
- Prepared as ___ (inactive form) in the chief cells
- HCl or pepsin activates the pepsinogen in the lumen
- Most efficient in ___ environment
- Stomach epithelial cells are protected by a 1-3 mm thick layer of ___ ___
- This helps to prevent the pepsin from ____ - ____ ____- released in very small quantities (usually in face of pancreatic insufficiency)
- If active, digests small quantity of _____
- Majority of lipid digestion occurs in ___
Slide 167
- Pepsin;
- Pepsinogen
- Acidic
- Alkaline mucous
- Digesting the proteins found in the structure of the epithelial cells
- Gastric Lipase
- triglycerides
- small intestines from pancreatic juices
During Digestion in the Stomach:
-During Absorption:
What is the fate of absorption and things that can/cannot be absorbed
What is the timeframe from ingestion of a meal; once the stomach has emptied its contents in the duodenum- what is the timeframe of the various types of meals (carbs, high protein, fat laden)
Slide 168
-Very little occurs as the epithelial cells are impermeable to most substances. However, water, ions, short-chain fatty acids and some drugs (like aspirin and alcohol) can be absorbed
- 2-4 hours;
- Carbohydrates spend least amount of time in stomach
- High-protein foods remain somewhat longer
- Fat-laden meals remain the longest in stomach
The Pancreas is an ___ digestion organ
- What type of gland?
- Size of gland and location
-What are the (2) functions?
Slide 170
Accessory digestive organ
- A retroperitoneal gland
- Approximately 5-6in long and 1in thick
- Lies posterior to the greater curvature of the stomach
Functions as:
1. Exocrine
Acini – clusters of glandular cells that produce digestive enzymes/fluids
- Endocrine
Pancreatic islets –produce hormones
In the Pancreas; What type of fluid and digestive enzymes are secreted by exocrine cells?
- What is another name for the Pancreatic duct?
- This is the ___ duct in pancreas
- It merges with ___
Slide 171
-Pancreatic juices
- Duct of Wirsung
- primary
- common bile duct
In the Pancreas:
- The ___ ___ (ampulla of Vater) if formed after the Pancratic duct (ampulla of Wirsung) merges with the common bile duct
- The Spinchter of ___ surround this ampulla controlling flow of fluids
- This then opens into the ___
An Accessory duct called the ___ is the small duct that branches off of the pancreatic duct
-It drains into the duodenum, just proximal to the ampulla of ___
Slide 171
- Hepatopancreatic ampulla
- Oddi
- Duodenum
- Duct of Santorini
- Vater
What is the amount of Pancreatic Juice that the Pancreas creates daily?
- What are the characteristics of the liquid; what does it consist of
- Which of these substances gives pancratic juice its pH (what is this number)
- This substance above is a main ___ for acidic gastric juices in chyme
- It stops the action of ___ from the stomach
- It creates a proper pH for the action of ___
Slide 173
-1200-1500 mL per day
-clear, colorless liquid consisting mostly of water, some
salts, sodium bicarbonate, several enzymes
-Sodium Bicarbonate (NaHCO3--) gives pancreatic juice slightly alkaline pH (7.1-8.2)
-buffer;
-pepsin
-digestive enzymes in small
intestine
Of the (8) Enzymes that are present in Pancreatic Juice, what type of digestion does each aid in?
Trypsin* – protein digestion ▪ Chymotrypsin* – \_\_\_ digestion ▪ Carboxypeptidase* – \_\_\_\_digestion ▪ Elastase*- \_\_\_digestion ▪ Pancreatic amylase- \_\_\_digestion ▪ Pancreatic lipase – \_\_\_digestion ▪ Phospholipase – \_\_\_digestion ▪ Cholesterol esterase – \_\_\_digestion
Slide 174
Trypsin* – protein digestion
▪ Chymotrypsin* – protein digestion
▪ Carboxypeptidase* – protein digestion
▪ Elastase*- protein digestion
▪ Pancreatic amylase- carbohydrate digestion
▪ Pancreatic lipase – principle triglyceride digestion
▪ Phospholipase – phospholipid digestion
▪ Cholesterol esterase – aids in cholesterol digestion
In the Pancreas:
____enzymes are produce in inactive forms.
-What are these (4) inactive forms; and what are their counter active forms ?
Slide 175
Protein digesting
- Trypsinogen (inactive) – Trypsin (active)
- Chymotrypsinogen (inactive) – Chymotrypsin (active)
- Procarboxypeptidase (inactive) – Carboxypeptidase (active)
- Prolastase (inactive) – Elastase (active)
List off the small intestine Brush Border Enzymes involved in carbohydrate digestion, that are synthesized by the cells within the microvili.
- α-dextrinase
- Maltase
- Sucrase
- Lactase
Slide 41
List off the small intestine Brush-Border Enzymes involved in protein digestion, that are synthesized by the cells within the microvili.
- Aminopeptidase
- Dipeptidase
Slide 41
List off the small intestine Brush Border Enzymes involved in lipid digestion, that are synthesized by the cells within the microvili.
- Phospholipase B1
Slide 41
During the small intestine digestion of carbohydrates, once chyme enters the small intestine, the leftover carbohydrates are digested by _____ _____.
- pancreatic amylase
Slide 42
Where does 90% of all nutrient absorption occur?
- Small Intestine
Slide 42
Amylase has no effect on what indigestible fiber that is a large component of feces?
- Cellulose
Slide 42
When do carbohydrates become absorbable?
- After amylase (whether salivary or pancreatic) has split carbohydrates into monosaccharide molecules, they become absorbable.
Slide 42
What pancreatic juices continue digestion in the small intestine, ending with single or small chains of amino acids that are absorbable?
- trypsin
- chymotrypsin
- carboxypeptidase
- elastase
Slide 42
____ continues lipid digestion in the small intestine, breaking lipids down into fatty acids and monoglycerides so that they are absorbable.
- Pancreatic lipase
Slide 42
_____ (lingual, gastric) begin the digestion of lipids in the stomach
- Lipases
Slide 42
If 9.3L of water enters the small intestine daily how much is excreted in the feces each day?
- .1L
Slide 43
What is considered to be the terminal portion of the GI tract, with the overall functions of:
- Completing the process of absorption
- Produces certain vitamins (vitamin K and biotin)
- Forms feces for excretion
- Excretes the solid waste products from the body
- Large Intestine
Slide 45
List off the four major regions of the Large Intestine and its dimension.
Has four major regions extending from ileum to
- anus
- Cecum
- Colon
- Rectum
- Anal Canal
~5 ft long, ~2.5inches in diameter
Slide 46
How is the large intestine attached to the abdominal wall?
- Attached to the posterior abdominal wall by the mesocolon (peritoneal fold)
Slide 46
What opening from the ileum to the large intestine allow for material to be passed from the small intestine into the large intestine?
- Ileocecal sphincter (valve)
Slide 48
Name the small pouch that is 2.4 inches long and located inferior to the ileocecal vavle?
- Cecum
Slide 48
What is attached to the cecum and 3 inches long?
- Appendix (vermiform appendix)
Slide 48
Name the structure described below:
- Retroperitoneal
- Ascends on right side of abdomen to lower border of liver
- Turns abruptly to the left at the hepatic flexure and continues on as the transverse colon
- Ascending Colon of the Large Intestine
Slide 53
How many portions is the colon divided into and what are they?
- Ascending
- Tranverse
- Descending
- Sigmoid
Slide 54
Name the structure described below:
- Peritoneal
- Crosses the abdomen until left side where it turns inferiorly at the splenic flexure
- Transverse Colon of the Large Intestine
Slide 53
Name the structure described below:
- Retroperitoneal
- Descends on left side to the level of the iliac crest
- Descending Colon of the Large Intestine
Slide 53
Name the structure described below:
- Peritoneal
- Begins near left iliac crest, projects medially to midline
Terminates at rectum (~3rd sacral vertebra)
- Sigmoid Colon of the Large Intestine
Slide 54
What merges with the colon?
- Open end of the Cecum
Slide 53
Name the structure that makes up the last 8 inches of the GI tract, lies anterior to the sacrum and coccyx.
- Rectum
Terminal 1 inch of the rectum is called the anal canal
Slide 55
Mucous membrane of this canal is arranged in longitudinal folds called anal columns.
- Anal Canal
Anal columns contain arteries and veins
Slide 54
What are the two sphincters in the anus and how are they controlled?
- Internal anal sphincter (smooth muscle/involuntary)
- External anal sphincter (skeletal muscle/voluntary)
Slide 55
Anal Canal Pectinate (dentate) line- lies at the inferior most portion of the anal columns
- Above the Pectinate (dentate) line, the upper 2/3rd of the canal is only sensitive to ______.
- Below the Pectinate (dentate) line, the lower 1/3rd of the canal is sensitive to ____, ____ and ___.
This demarcation is important when discussing hemorrhoids
- Stretch
- temperature, touch, and pain
Slide 56
How many layers are there in the large intestine wall and what are their names?
- 4
- Serosa
- Muscularis
- Submucosa
- Mucosa
Slide 60
Muscularis External layer of longitudinal smooth muscle, portions of this layer are thickened, forming three bands called ____ .
- teniae coli
Slide 60
What type of epithelium is the mucosa layer of the large intestine made of?
The mucosa layer also consists of mostly absorptive goblet cells, where are they located?
- Simple columnar epithelium
- Mostly absorptive and goblet cells are located in crypts of Lieberkuhn in intestinal glands.
Slide 61
Are there circular folds (plicae) or villi located in the large intestine?
- No
Slide 61
Teniae coli contract causing the large intestine to gather together forming the _____ , which gives the colon it’s “puckered” or “pouched” appearance
- Haustra
Slide 60
What layer of the large intestine is made of circular smooth muscle?
- Internal Muscularis is made of circular smooth muscle
Slide 60
Are enzymes secreted in the large intestine?
- No enzymes are secreted, mucus is secreted by cells in the colon.
Slide 62
How does chemical digestion in the colon occurs?
- Through the activity of bacteria
Slide 62
What leads to flatus, feces odor, and the brown color of feces in the large intestine?
- Bacteria continue to breakdown any remaining macronutrients, releasing hydrogen, carbon dioxide, and methane gases, leading to flatus (gas)
- Breakdown of macronutrients releases indole, skatole, and hydrogen sulfide giving odor to feces.
- Bacteria also breakdown remaining bilirubin into stercobilin, giving feces normal brown color
Slide 62
How many mL of water are absorbed and excreted by the Large Intestine?
- 900mL absorbed
- 100mL excreted
Slide 63
As chyme remains in large intestine (3-10 hours), it becomes a solid or semisolid due to water _______.
- absorption/reabsorption
Slide 64
Once chyme becomes more solid what is it called?
- Feces
Slide 64
What muscle and types of movements are responsible for the movement of food from the lower esophagus to the rectum?
- Smooth muscle
Types of movement:
- Peristalsis
- Segmentation
Peristalsis and segmentation can occur in alternating sequence
During motility what triggers contraction of muscle that pushes the bolus forward?
- Stretching of the lumen wall by the bolus
Slide 66
True/False: Segmentation helps to mechanicall break down food and mix with digestive juices?
- True
Slide 66
Why does gastric emptying have to be regulated and how is it regulated?
- Regulated due to the volume of the stomach being significantly larger than the duodenum?
- It is regulated by hormonal and nervous system pathways
Slide 67
Name the reflex described below:
- Secretory and motor activity of the stomach send signals to the terminal/distal portion of the ileum early in the meal causing acceleration of movement through the ileocecal sphincter
- Gastroileal Reflex
Slide 68
Name the reflex described below:
- Signals from the small and large intestine distension inhibit stomach motility and secretion to allow for more time to move contents forward
- Enterogastric Reflex
Slide 68
Name the reflex described below:
- Signals from excessive stomach activity (late meal, completion) cause movement of feces in the colon to move forward into the rectum
If paying attention to it, many people can evacuate bowels 45-60 min after a meal
- Gastrocolic Reflex
Slide 68
Name the reflex described below:
- Distention of the rectum triggers baroreceptors that signal the colon and anal canal to contract
This causes the conscious desire to defecate
- Defecation Reflex
Slide 70
What does bowel movement frequency depend on?
What is a normal range of bowl movements for a person?
Depends on various factors such as
- Diet
- Health
- Stress
Normal range
- 1-3 per day
or 3-4 per week
Slide 71
List what could happen to the GI system as a person ages?
- Decreased secretory mechanisms
- Decreased motility of digestive organs
- Changes in neurosensory feedback with enzymes and hormones
- Diminished response to pain and internal sensations
- Reduced sensitivity to mouth irritations and sores
- Periodontal disease
- Loss of taste
- Difficulty in swallowing
- Hiatal hernias
- Gastritis
- Peptic ulcer disease
- Malabsorption/maldigestion
- Appendicitis
- Gallbladder problems
- Jaundice/Cirrhosis
- Acute pancreatitis
- Constipation
- Hemorrhoids
- Diverticular disease
- Cancer of colon or rectum
- Bowel obstructions/impactions
Slides 78-80
What is Nutrition?
food we eat and the nutrients contained within
-“The science of food”
Slide 10
What is Metabolism?
use of the nutrients gained from food to
-Build and maintain the structures of the body
- Provide energy
- Also refers to interactive set of chemical pathways that make life possible
Slide 10
What affects how nutrition is perceived?
differences in individual genetic codes and individual lifestyles and environments
Slide 11
What is the general concept for any diet?
We consume food and water
- It initially goes into the GI tract/lumen
- food is broken down into absorbable molecules (digestion)
- then transported out of the GI lumen and placed into the portal vascular system (Absorption)
- The vascular system takes these molecules to wherever the body needs them
Slide 12
the nutrients in food has to be ______ before it can be used for energy, growth, and maintenance
assimilated
Slide 13
what is it called when nutrient molecules enter cells and undergo many chemical changes?
assimilation
Slide 13
what is the act of breaking food molecules down into smaller molecular compounds that, in-turn, releases energy?
Catabolism (decomposition process)
Slide 13
what is the act of building nutrient molecules into large molecular compounds that requires the use of energy?
Anabolism (a synthesis process)
Slide 13
What is released in frequent, small bursts?
Thermal Energy (heat)
Slide 14
What are two forms energy released in catabolism?
Thermal (heat) and chemical energy
Slide 14
why is thermal energy useless as an energy source?
because it can’t be used to carry out work
it is used to maintain body temperature for homeostasis
slide 14
what is known as the “universal biological currency?”
ATP
what form of energy has to be first transferred into the high-energy molecule of adenosine triphosphate (ATP)?
Chemical energy
slide 14
List the types of nutrients
micronutrients- readily absorbed in original form (vitamins/mineral)
macronutrients- need to be small enough to be absorbed
(proteins, carbohydrates, lipids)
Slide 16
what is the Major source of biologic energy used by organisms?
Carbohydrates
Slide 20
Brain requires ____ as its chief energy source
glucose
Slide 20
What are the forms of carbohydrates?
monosaccharides (absorbable form)
disaccharides
polysacchaarides
Slide 20
what is the enzyme required for carbohydrate digestion?
amylase
Slide 20
what is the absorbable form of carbohydrates? and what are the 3 types?
monosaccharides
glucose, fructose, galactose
Slide 21
what are the characteristics regarding glucose, fructose, galactose?
1) Glucose
- Principle monosaccharide
- Basic source of energy for cells
- Found in things like fruits
2) Fructose
- Principle monosaccharide (converted to glucose by liver)
- Basic source of energy for cells
- Found in things like fruits
3) Galactose
- Principle monosaccharide (converted to glucose by liver)
- Found mostly in dairy products (milk, cheese, butter)
Slide 21
What are 3 types of disaccharides and their characteristics?
1) Sucrose
- Glucose + Fructose
- Ordinary table sugar
2) Lactose
- Glucose + Galactose
- Principle sugar found in milk
3) Maltose
- Byproduct of polysaccharide (starch) digestion
- Found in excess in beer and some liquor (Barley)
Slide 22
What are 3 types of polysaccharides and their characteristics?
1) Starches
- Amylose and amylopectin combined
- Potatoes, Corn, Oats, Rice
2) Glycogen
- The stored form of glucose in the body
- Found in the liver, muscle tissue, and some glial brain cells
3) Cellulose (cannot be absorbed or broken down)
- Chemical name for fiber
- Fruit skins, whole-grain rice , legumes , corn
Slide 23
what are the two classification of carbohydrate in diet?
Simple carbohydrate
complex carbohydrate
Slide 24
what are the characteristics of simple carbohydrates?
- Monosaccharides and disaccharides
- Fast source of energy
- Can be found in fruits and milk, but also additives to things like candy, soda
Slide 24
what are the characteristics of complex carbohydrates?
- More difficult to digest because of longer chain sizes (Polysaccharides)
- Provides a more consistent amount of energy while being broken down (if able to be broken down)
- Can be found in things like whole grains, legumes, starchy vegetables
Slide 24
what is most common form of lipid found in the diet and in the body?
Triglycerides (TAGs)
Slide 26
what are the characteristics of triglycerides (TAGs)?
- Consists of one glycerol subunit that is attached to three fatty acids
- A high-energy nutrient synthesized and stored in adipocytesas well as hepatocytes
- Can be used by most cells in the body to power metabolism
- Triglycerides are required for absorption of fat-soluble vitamins including
- Triglycerides provides constituent molecules for cellular membranes
Slide 26
What are simple lipids?
fatty acids, Triacylglycerols
Slide 27
what are two types of fatty acids?
Saturated – all hydrogen bonds are used (solid at room temp)
Unsaturated – not all hydrogen bonds are used (liquid at room temp)
Slide27
what are two sub-types of unsaturated fatty acids?
Monounsaturated-(Olive, canola, peanut oils
Oils found in almonds, pecans, and avocados)
Polyunsaturated-(Safflower, sunflower, soybean, corn oils)
Slide 27
what is the composition of triacylglycerols?
1 glycerol cluster + 3 fatty acids
slide 27
triacylglycerol is also known as ___
triglycerides or fat
slide 27
triglycerides combined with other components are referred to as____
compound limids
slide 28
list the 3 types of compound lipids and their characteristics
1) Phospholipids
- Fatty acids +phosphorus + nitrogen
- Lipid “bilayer” in cell membranes, part of the nerve sheath
2) Glycolipids
- Fatty acids + carbohydrate + nitroge
- Part of cell membrane, helps to facilitate cellular recognition
3) Lipoproteins
- Chylomicrons
- Very low-density lipoproteins (VLDL’s)
- Low-density lipoproteins (LDL’s)
- High-density lipoproteins (HDL’s)
Slide 28
simple + compound lipids together are referred to as___
derived lipids
slide 29
what are 4 types of derived lipids
steroids
Terpenes
Fat-soluble vitamins
Ketone bodies
slide 29
where are steroids synthesized?
Liver (most common), but can also be made by almost all other cells (to include endothelial cells)
slide 29
what are the functions of steroids?
Helps to build plasma membranes
Precursor in synthesis of Vitamin D
Requires for synthesis of androgens/sex hormones
slide 29
primary form of steroid is?
cholesterol
slide 29
where are steroids found?
Found in egg yolks, red meat, organ meats, shellfish, and dairy products
triglycerides have to be ___ in order to be absorbed at the cellular level
hydrolyzed into smaller components
(fatty acids, monoglycerides)
slide 30
what is the type of enzyme that hydrolyze lipids?
lipase
slide 30
list the characteristics of a chylomicrons (a lipoprotein)
- Small fat droplets found in blood soon after absorption has occurred
- During absorptive state blood may contain so many chylomicrons that it can appear turbid, or yellowish
- In post-absorptive state (usually ~4 hours after meal) few chylomicrons exist in blood
slide 31
what are 3 lipoproteins that are most active in post-absorptive state?
Very low-density lipoproteins
Low-density lipoproteins
High-density lipoproteins
slide 31
where are lipoproteins produced?
Produced mostly in the liver from lipids and proteins
slide 31
Entering blood from adipose tissue or other cells, fatty acids combine with albumin to form ____
Free Fatty Acids (FFA)
Slide 32
when does FFAs levels in blood increase?
When rate of fat-catabolism increases (i.e. starvation)
slide 32
describe characteristics of chylomicrons
- Delivers triglycerides to cells throughout the body
- Synthesized in enterocytes (intestinal cells) from fat and cholesterol absorbed in the small intestine
- Very triglyceride-rich
- Very large particle
why does chylomicrons have to enter lacteals (lymphatic capillaries) which carries them to thoracic duct to be dumped into blood?
because of large size (it is the largest lipoprotein)
slide 34
describe the characteristics of Very low-density lipoproteins (VLDV’s)
- Delivers triglycerides to cells throughout the body
- Synthesized in the liver from excess fats and cholesterol that have made it there from portal circulation
- Very triglyceride rich
- Large particle, smaller than chylomicron
slide 35
describe characteristics of low-density lipoproteins (LDL’s)
- Delivers cholesterol to cells throughout the body
- As VLDL’s are stripped of their triglycerides, the “leftovers” get remodeled in the liver to form LDL’s
- Smaller particles than VLDL’s
slide 35
describe the characteristics of high-density lipoproteins (HDL’s)
- Reverse cholesterol transport for excess cholesterol
- Returns excess cholesterol to the liver for recycling
- Is made in both the liver and the small intestines
slide 35
what is the first step of lipid catabolism?
Triglycerides are first hydrolyzed to yield fatty acids and a glycerol
slide 36
what are fatty acids broken down into?
Fatty acids are broken down into two carbon pieces (acetyl-CoA) by a process called beta-oxidation
slide 36
acetyl-CoA from fatty acid breakdown enters what cycle?
citric acid cycle
slide 36
what is glycerol converted into?
glyceraldehyde-3-phosphate
slide 36
what are two ways glyceraldehyde-3-phosphate can be processed?
Converted to glucose OR
Enters the glycolysis pathway
slide 36
lipid anabolism is also known as _____
lipogenesis
list the synthesis of various types of lipids
Triglycerides
Phospholipids
Cholesterol
Prostaglandins
slide 37
what is required for general growth, repair, and maintenance of tissues?
proteins
slide 39
what is considered to be the “building blocks” of all cells and is involved synthesis of certain neurotransmitters and hormones?
proteins
slide 39
Absorption of proteins requires them to be broken down into any of the following:
Amino acid (single)
Dipeptide (two amino acids linked together)
Tripeptide (three amino acids linked together)
slide 40
how many amino acids is considered too large for absorption and what breaks it down?
3 amino acids
broken down by proteases (pepsin, trypsin etc)
slide 40
what type of amino acids have to be consumed as they cannot be made in the body? what are they?
essential
histidine, isoleucine, leucine, methionine, phenylalanine, threonine, tryptophan, valine, lysine
slide 41,42
what type of amino are only required in times of illness or increased stress on the body? what are they?
conditionally essential
arginine, asparagine, glutamine, glycine, proline, serine, tyrosine
slide 41,42
list the 4 non-essential amino acids?
alanine, asparatate, cysteine, glutamate
what is the process by which amino acids are broken down for energy use?
protein catabolism
slide 43
what is the process by which proteins are synthesized?
anabolism (protein)
slide 43
True or False
every cell synthesizes its own structural proteins
true
what Constitutes the major process for growth, reproduction, tissue repair, and replacement of all cells destroyed by wear and tear?
protein metabolism
slide 44
Both protein ______ and _______ are occurring continually, only their rates differ depending on the need of the body
catabolism; anabolism
slide 44
The digestive system helps to maintain ______ by breaking down food
Homeostasis
slide 47
What is our only source of chemical energy?
Food
slide 47
Food must be broken down into ______ small enough to enter cells
molecules
slide 47
The digestive system consists of the _____ involved in the breakdown of food
organs
slide 48
The digestive system is a _____ system
tubular
slide 48
What are the characteristics of the digestive system that make it a tubular system?
- Extends from the mouth to the anus
- Forms extensive surface area in contact with the external environment
- Closely associated with cardiovascular system because of the blood vessels involved in the digestive system
slide 48
What is the study of the stomach and intestines?
Gastroenterology
slide 48
What is the study of the rectum?
Proctology
slide 48
The cardiovascular system supplies digestive organs with _____ and processes ______
- O2
- Nutrients
slide 49
The ______ system releases hormones to help regulate multiple actions in digestive system
Endocrine
slide 49
What system protects the digestive organs; helps with vitamin D for calcium absorption?
Integumentary
slide 49
_____ of the lymphatic system defends against pathogens; lacteals absorb lipids to be transported into blood stream
MALT
slide 49
The nervous system sensory/motor neurons help regulate _____ and ______ contractions of GI tract.
- secretions
- muscle
slide 49
Which system provides oxygen and waste removal of CO2?
Respiratory
slide 49
The urinary system uses the kidneys to make _____ which aids in calcium absorption in the GI system
Calcitriol
slide 49
The GI tract is also known as the ________
alimentary (nourishment) canal
slide 51
The GI tract travels through thoracic cavity, through ______ cavity
abdominopelvic
slide 51
The GI tract consists of what major players (organs)?
mouth, most of pharynx, esophagus, stomach, small intestines, large intestine (and anus)
slide 51
How long is the GI tract in a living human?
approximately 16-23 feet long in living human
slide 51
The GI tract is in a state of sustained contraction, also called ______
tonus
slide 51
How long is the GI tract in a cadaver? What is the variation from a living human caused by?
- Approximately 23-29 feet
- Loss of muscular tone after death
slide 51
What are the accessory digestive organs of the digestive system, and which ones come into contact with food?
- teeth (contact)
- tongue (contact)
- salivary glands, liver, gallbladder, pancreas (no contact, produce and store secretions that flow into the GI tract through ducts - aid in chemical breakdown of food)
slide 52
What are the 6 basic processes of the digestive system? Define each.
- Ingestion: taking in foods and liquids into the mouth
- Secretion: everyday, cells within the GI tract and accessory organs secrete ~7L of water, acid, buffers, enzymes into lumen of tract
- Mixing and propulsion: alternating contraction/relaxation of smooth muscle in walls of tract mix food and secretions and propel towards anus
- Digestion: mechanical and chemical process to breakdown food into small molecules
- Absorption: entrance of ingested and secreted fluids, ions, and products of digestion into the epithelial cells lining the GI tract
- Defecation: wastes, indigestible substances, bacteria, cells sloughed from lining of tract, digested materials not absorbed leave the body through the anus
slides 53-55
What is the mix and movement of material along tract?
Motility
slide 53
What is mechanical digestion?
Teeth cut and grind food before swallowed, smooth muscles of stomach and small intestine churn food - this helps to mix with enzymes to dissolve food
slide 54
Large carbohydrates, lipids, protein, molecules are split into smaller molecules by enzymes produced by salivary glands, tongue, stomach, pancreas, small intestine that catalyze these catabolic reactions. what is the name of this process? What type of digestion is this?
- Hydrolysis
- Chemical digestion
slide 54
What substances can be absorbed without chemical digestion?
Vitamins, ions, essential fatty acids, and water
slide 54
Absorbed substances pass into _____ or _____ and circulate to various locations in the body
blood or lymph
slide 55
What is eliminated material called?
feces or stool
slide 55
Wall of GI tract from lower ________ to _______ canal has same basic four-layered arrangement of tissue
- esophagus
- anal
slide 57
List the basic outer layer to inner-most layer (contact with tract contents) that can be found from the lower esophagus to anal canal
- Serosa or adventitia (depends on the locations)
- Muscularis
- Submucosa
- Mucosa
slide 57
What is the Serosa layer of the GI tract also called?
visceral peritoneum
slide 60
Which layer of the GI tract has a serous membrane composed of areolar connective tissue and simple squamous epithelium (mesothelium)
Serosa
slide 60
Where is the Adventitia layer found instead of the Serosa layer in the GI tract?
Esophagus and proximal duodenum (single layer of connective tissue)
slide 60
Which layer of the GI tract has voluntary skeletal muscle and involuntary smooth muscle? The smooth muscle is found in all of the GI tract except what locations?
- Muscularis
- mouth, pharynx, superior aspect of esophagus, external anal sphincter (voluntary skeletal muscle)
slide 61
The Muscularis layer of the GI tract contains myenteric plexus. What is the myenteric plexus and what is its AKA name?
- Network of neurons between the circular and longitudinal muscle layers
- Plexus of Auerbach
slide 61
Which layer of the GI tract consists of areolar connective tissue that binds the mucosa to muscularis, and contains many blood and lymph vessels that receive absorbed food molecules?
Submucosa
slide 62
The Submucosa layer of the GI tract contains submucosal plexus. What is the submucosal plexus and what is its AKA name?
- Extensive network of neurons
- Plexus of Meissner
slide 62
Which layer is the inner lining of the GI tract?
Mucosa
slide 63
What are the 3 layers of the Mucosa layer of the GI tract? (superficial to deep)
- Muscularis Mucosae
- Lamina Propia
- Epithelium
slides 63-65
Which layer of the Mucosa layer of the GI tract has a thin layer of smooth muscle fibers, causes the mucous membrane of the small intestines and stomach to have the folded appearance, increase surface area for digestion and absorption, and causes movement that ensures all absorptive cells are fully exposed to contents of GI tract?
Muscularis Mucosae
slide 63
Which layer of the Mucosa layer of the GI tract has areolar connective tissue containing many blood and lymphatic vessels which allow nutrients to reach other tissues of the body, acts a supportive layer, and contains majority of mucosa-associated lymphatic tissue (MALT)?
Lamina Propia
slide 64
Which layer of the Mucosa layer of the GI tract has cells that are replaced by new cells every 5-7 days where the old cells are sloughed off and are secreted?
Epithelium
slide 65
Which layer of the Mucosa layer of the GI tract has exocrine cells and enteroendocrine cells? What are cells’ functions?
- Epithelium
- exocrine: secrete mucous/fluid/enzymes into lumen
- enteroendocrine: secrete hormones into lumen
slide 65
What is considered to be the “brain” of the gut?
Enteric Nervous System
slide 69
The Enteric Nervous System consists of ~100,000,000 neurons that extend from the ______ to the ______
- esophagus
- anus
slide 69
What two plexuses is the Enteric Nervous System arranged in? What are their AKA names? What do they consist of?
- Myenteric (or Auerbach) plexus
- Submucosal plexus (plexus of Meissner)
- Both consist of neurons, interneurons, and sensory neurons
slide 69
Which plexus of the Enteric Nervous System supply motor impulses to longitudinal and circular smooth muscle layers of muscularis? What does this lead to?
- Myenteric (Auerbach) plexus
- plexus controlling the majority of GI tract motility
slide 70
Which plexus of the Enteric Nervous System has motor neurons that supply the secretory cells of the mucosal epithelium? What does this lead to?
- Submucosal (Meissner) plexus
- plexus controlling secretions of the organs of the GI tract
slide 70
What connects the myenteric and submucosal plexuses?
interneurons
slide 71
What type of neurons supply the mucosal epithelium? What do some function as? (2 different types)
- Sensory neurons
- Chemoreceptors and baroreceptors (stretch receptors)
slide 71
What helps regulate the enteric nervous system?
Autonomic Nervous System
slide 73
Which cranial nerve supplies parasympathetic fibers to most parts of GI tract?
Vagus (X)
slide 73
Stimulation of the parasympathetic nerves that innervate the GI tract causes an ______ in GI secretion and motility by increasing activity of the ENS
increase
slide 73
Sympathetic nerves that supply GI tract arise from ______ and _______ regions of the spinal cord. These nerves also form connections with the _______
- Thoracic
- Upper lumbar
- ENS
slide 74
Stimulation of the sympathetic nerves connected to the GI tract cause a _______ in GI secretion and motility by ______ the ENS neurons. What causes this?
- decrease
- inhibiting
- emotions such as fear (fight or flight), anger, anxiety may slow digestion because they stimulate the sympathetic nerves that supply the GI tract
slide 74
What is the largest serous membrane in the body?
Peritoneum
slide 76
The peritoneum consists of a layer of simple squamous epithelium (mesothelium) with underlying layer of ______ connective tissue
areolar
slide 76
What is the peritoneum divided into? What are their functions?
- Parietal peritoneum: lines the wall of the abdominopelvic cavity
- Visceral peritoneum: covers some of the organs in the cavity and is also considered their serosa
slide 76
What is the space between the two layers that contains lubricating serous fluid (small amount)?
Peritoneal Cavity
slide 76
What is the retroperitoneal? What organs are in this space? What are they anteriorly covered by?
- Space that is behind the peritoneum
- Kidneys, ascending colon (large intestine), descending colon (large intestine), duodenum (small intestine), and pancreas
- The peritoneum
slide 77
The peritoneum contains large folds that weave between the ______. What are the functions and what do they contain?
- viscera
- bind organs together and then also to abdominal walls
- blood vessels, lymph vessels, and nerves that supply the abdominal organs
slide 79
What are the 5 major folds of the peritoneum?
- The greater omentum
- Falciform ligament
- Lesser omentum
- Mesentery
- Mesocolon
What is the peritoneal fold that drapes over transverse colon and small intestine, attaches to portions of stomach and duodenum, extending downward, anterior to small intestines, folds and extends upwards to attach to transverse colon, contains considerable amount of adipose tissue which can expand with weight gain, and has many lymph nodes that contribute to macrophages and antibody-producing cells that combat GI tract infections?
The Greater Omentum
slide 80
Which peritoneal fold attaches the liver to the ventral surface (anterior) of the abdominal wall, and has a free border that contains the ligamentum teres (aka round ligament; remnant of the umbilical vein)?
Falciform Ligament
slide 82
What is the only digestive organ attached to the anterior abdominal wall?
Liver
slide 82
Which peritoneal fold arises as anterior fold in the serosa of the stomach and distal duodenum connecting it to the liver, is the pathway for blood vessels entering liver, and contains portal vein, common hepatic artery, common bile duct, and some lymph nodes
The Lesser Omentum
slide 85
Which peritoneal fold binds jejunum and ileum of small intestine to posterior peritoneal wall, is a large fold that adds to abdominal girth when weight is gained, extends from posterior peritoneal wall, wraps around small intestine, and returns to its origin?
Mesentery
slide 87
Which peritoneal fold has two separate folds that bind portions of large intestine to posterior abdominal wall (first binds the transverse colon; second binds the sigmoid colon), carries blood and lymphatic vessels to intestines, and holds small intestines loosely in place allowing slight movement as muscular contractions mix and move contents of the GI tract?
Mesocolon
slide 89
