week 10 (digestive system - structure & function ; accessory organs) Flashcards
carbohydrates (polysaccharides)
Carbohydrates, or carbs, are sugar molecules. Along with proteins and fats, carbohydrates are one of three main nutrients found in foods and drinks
fats (lipids)
A lipid is any of various organic compounds that are insoluble in water. They include fats, waxes, oils, hormones, and certain components of membranes and function as energy-storage molecules and chemical messengers
Proteins (amino acids)
Amino acids are organic compounds composed of nitrogen, carbon, hydrogen and oxygen, along with a variable side chain group.
ingestion
ingestion is the consumption of a substance by an organism
movement in relation to digestive system
Food moves through your GI tract by a process called peristalsis. The large, hollow organs of your GI tract contain a layer of muscle that enables their walls to move. The movement pushes food and liquid through your GI tract and mixes the contents within each organ.
secretion
In the course of a day, the digestive system secretes around 7 liters of fluids. These fluids include saliva, mucus, hydrochloric acid, enzymes, and bile. Saliva moistens dry food and contains salivary amylase, a digestive enzyme that begins the digestion of carbohydrates.
digestion
s the breakdown of large insoluble food molecules into small water-soluble food molecules so that they can be absorbed into the watery blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the blood stream.
absorption
The process of one material (absorbate) being retained by another (absorbent); this may be the physical solution of a gas, liquid, or solid in a liquid, attachment of molecules of a gas, vapour, liquid, or dissolved substance to a solid surface by physical forces
defaction
the discharge of feces from the body.
Mucosa GI tract
- *epithelium**
s: starts as stratified squamous epithelium in the esophagus and changes to simple columnar epithelium
f: barrier
- *lamina propria**
s: loose connective tissue - *muscularis mucosae**
s: smooth muscle
Submucosa GI tract
s: the layer of dense, irregular connective tissue or loose connective tissue
f: that supports the mucosa
Muscularis GI tract
s: smooth muscles
f: muscles contractions, peristalsis in the eposgus
Serosa/Adventitia GI tract
serosa
s: loose connective tissue/muscosa
f: helps with no rubbing
adventita
s: loose connective tissue/moscosa
f: helps w friction
The serosa is present if the tissue is within the peritoneum, and the adventitia if the tissue is retroperitoneal.
peritoneum
Parietal peritoneum is that portion that lines the abdominal and pelvic cavities. Those cavities are also known as the peritoneal cavity.
Visceral peritoneum covers the external surfaces of most abdominal organs, including the intestinal tract.
peritoneum cavity
greater omentum
The greater omentum (also the great omentum, omentum majus, gastrocolic omentum, epiploon, or, especially in animals, caul) is a large apron-like fold of visceral peritoneum that hangs down from the stomach.
lesser omentum
The lesser omentum is the double layer of peritoneum that extends from the liver to the lesser curvature of the stomach, and to the first part of the duodenum
falciform ligament
The falciform ligament is the thin, sickle-shaped, fibrous structure that connects the anterior part of the liver to the ventral wall of the abdomen. … The falciform ligament attaches to the liver between the right and left lobes as well as attaching to the inferior diaphragmatic surface
mesentery
a fold of membrane that attaches the intestine to the abdominal wall and holds it in place
mesocolon
sigmoid colon provides a major avenue for spread of disease between the abdominal cavity and the pelvis. It is directly continuous with the posterior bare area of the colon, the bare area of the rectum, and in females, the broad ligament.
buccal cavity
a. structures forming the roof, floor and sides of cavity : tooth, tounge, soft/hard plalete, tonsils, gums
b. location of uvula: middle of mouth
c. division of pharynx into which it opens: oropharynx
Epiglottis
close over the windpipe (trachea) while you’re eating to prevent food entering your airway.
Rugae (stomach)
s: a series of ridges produced by folding of the wall of an organ.
f: A purpose of the gastric rugae is to allow for expansion of the stomach after the consumption of foods and liquids
the mucosal and submucosal layers of the stomach
Omentum (part of the peritoneum) (stomach)
s: large flat adipose tissue layer covered by visceral peritoneum
f: Besides fat storage, omentum has key biological functions in immune-regulation and tissue regeneration
Gastric pits and glands (stomach)
Gastric pits are indentations in the stomach which denote entrances to 3-5 tubular shaped gastric glands.
secrete gastric juice and protective mucus.
sphincters (stomach)
cardiac sphincter (lower esophageal sphincter) pyloric sphincter
lower esophageal sphincter, or cardiac sphincter, at the upper portion (cardia) of the stomach. This sphincter prevents the acidic contents of the stomach from moving upward into the esophagus
The pyloric sphincter serves as a kind of gateway between the stomach and the small intestine. It allows the contents of the stomach to pass into the small intestine. It also prevents partially digested food and digestive juices from reentering the stomach.
duodenum
The first part of the small intestine. It connects to the stomach. The duodenum helps to further digest food coming from the stomach. It absorbs nutrients (vitamins, minerals, carbohydrates, fats, proteins) and water from food so they can be used by the body.
jejunum
The middle part of the small intestine. It is between the duodenum (first part of the small intestine) and the ileum (last part of the small intestine).
The primary function of the jejunum is to absorb sugars, amino acids, and fatty acids. Both the jejunum and ileum are peritoneal.
ileum
last portion of the small intestine
The ileum absorbs any remaining nutrients that did not get absorbed by the duodenum or jejunum, in particular vitamin B12, as well as bile acids that will go on to be recycled
ileocecal valve
is a sphincter muscle valve that separates the small intestine and the large intestine.
its function is to allow digested food materials to pass from the small intestine into your large intestine.
villi and microvilli
The only function of villi is to increase the surface area of absorption in the intestines.
simple columnar epithelium
plicae circularis
The lining of the small intestine consists of a series of permanent spiral or circular folds, termed the plicae circulares, which amplify the organ’s surface area, promoting efficient nutrient absorption.
intestinal crypts and glands
is a gland found in between villi in the intestinal epithelium lining of the small intestine and large intestine
to produce a mucus-rich, alkaline secretion (containing bicarbonate) in order to neutralize the acidic content of chyme that is introduced into the duodenum from the stomach
crypt cells:provide stem cells for renewal of the intestinal epithelium
mucosa-associated lymphatic tissue (MALT) and Peyer’s patches
also called mucosa-associated lymphatic tissue, is a diffuse system of small concentrations of lymphoid tissue found in various submucosal membrane sites of the body
Peyer’s patches are small masses of lymphatic tissue found throughout the ileum region of the small intestine. Also known as aggregated lymphoid nodules, they form an important part of the immune system by monitoring intestinal bacteria populations and preventing the growth of pathogenic bacteria in the intestines
mesentery (a part of the peritoneum)
a fold of membrane that attaches the intestine to the abdominal wall and holds it in place
mesocolon (partisoum)
holds the colon in place by attaching to abdominal wall
haustra
the small segmented pouches of bowel separated by the haustral folds
tounge
s: mucosa. Tiny bumps called papillae. Thousands of taste buds cover the surfaces of the papillae.
f: taste and help with mechanical digestion
salvivary glands
#/name of them: 3, parotid glands, the sublingual glands, and the submandibular glands
location: sublingualar by/under the tounge, submaniable, by the manible bone, parotid, behide the face, by the ears
function: helps moisten food and chemically digest it with saliva
salvia functions
a. water
98% of salvia, helps moisten
b. chlorides
initiates the fluid secretion process
c. bicarbonate and phosphates
neutralization of acidic gastric contents during reflux episodes.
d. mucin
to provide a protective coating about the hard and soft tissues of the mouth
e. lysozyme
important component of antibacterial
f. amylase
digest starch into smaller molecules
g. lingual lipase
catalyzes the first reaction in the digestion of dietary lipid
liver
a. abdominopelvic region and quadrant in which it lies
upper, right quadrant
b. number and names of lobes
four lobes: right, left, caudate, and quadrate
c. name and type of tissue of supporting framework
Reticular fibres are interwoven proteins found in reticular connective tissue.
d. names and source of the two main blood vessels entering the liver
The first is the hepatic artery which delivers oxygenated blood from the general circulation. The second is the hepatic portal vein delivering deoxygenated blood from the small intestine containing nutrients.
e. location of sinusoids and Kupffer cells
in the space of Disse between sinusoidal endothelial cells (EC) and hepatocytes
hepatic portal circulation role
responsible for directing blood from the region of the gastrointestinal tract between the esophagus and rectum and also includes venous drainage from the supplementary organs such as the spleen and pancreas.
liver metabolic processes
a. three metabolic processes related to carbohydrates
In the metabolism of carbohydrates, the liver helps to ensure that the level of sugar in your blood (blood glucose) stays constant. If your blood sugar levels increase, for example after a meal, the liver removes sugar from blood supplied by the portal vein and stores it in the form of glycogen. If someone’s blood sugar levels are too low, the liver breaks down glycogen and releases sugar into the blood. As well as sugar, the liver also stores vitamins and minerals (iron and copper), and releases them into the blood when needed
b. two metabolic processes related to fats
liver cells break down fats and produce energy.
c. one metabolic process related to amino acids
liver cells change amino acids in foods so that they can be used to produce energy, or make carbohydrates or fats.
storage/manufacturing of liver cells
a. four of the vitamins and two minerals stored
vitamin A, D, E, K and B12,
b. four kinds of substances detoxified
blood to remove large toxins, synthesizes and secretes bile full of cholesterol and other fat-soluble toxins, and enzymatically disassembles unwanted chemicals
c. two substances filtered from blood by stellate reticuloendothelial (Kupffer) cells
remove protein complexes, small particles, senescent red blood cells, and cell debris from portal blood flow through pattern recognition receptors
d. four blood proteins manufactured and their functions
albumin, alpha-, beta-, and gamma-globulin
e. one anticoagulant substance manufactured by mast cells
Heparin cofactor I1
f. one substance formed which aids in fat digestion
bile
bile
a. Bile salts
f: help break down fats, aid digestion, absorb important vitamins, and eliminate toxins.
b. Bile pigments (bilirubin and biliverdin)
f: Bilirubin. is orange or yellow in color. Biliverdin is green in color.
c. Cholesterol
f:to maintain the integrity and fluidity of cell membrane
gall bladder
d. modification of the mucous membrane layer related to the activities of the gallbladder
since the gall bladder has bile which is very acidic, it needs more mucouos membrane layer to make sure that the bile does not digest the gall bladder itself
e. relationship between the smooth muscle layer and the activities of the gallbladder
bile needs to be able to get out of the cystic sphincter and it is with the help of the smooth muscle layer found in the gallbladder.
pancreas tissues
exocrine
endocrine
