Identify the four accessory structures or accessory organs of the human digestive system; describe the functio?

answers1: Accessory Structures Of An Organ
answers2: Accessory Organs <br>
The salivary glands, liver, gallbladder, and pancreas are not part of
the digestive tract, but they have a role in digestive activities and
are considered accessory organs. <br>
<br>
Salivary Glands <br>
<br>
Three pairs of major salivary glands (parotid, submandibular, and
sublingual glands) and numerous smaller ones secrete saliva into the
oral cavity, where it is mixed with food during mastication. Saliva
contains water, mucus, and enzyme amylase. Functions of saliva include
the following: <br>
<br>
It has a cleansing action on the teeth. <br>
It moistens and lubricates food during mastication and swallowing. <br>
It dissolves certain molecules so that food can be tasted. <br>
It begins the chemical digestion of starches through the action of
amylase, which breaks down polysaccharides into disaccharides. <br>
Liver <br>
<br>
The liver is located primarily in the right hypochondriac and
epigastric regions of the abdomen, just beneath the diaphragm. It is
the largest gland in the body. On the surface, the liver is divided
into two major lobes and two smaller lobes. The functional units of
the liver are lobules with sinusoids that carry blood from the
periphery to the central vein of the lobule. <br>
<br>
The liver receives blood from two sources. Freshly oxygenated blood is
brought to the liver by the common hepatic artery, a branch of the
celiac trunk from the abdominal aorta. Blood that is rich in nutrients
from the digestive tract is carried to the liver by the hepatic portal
vein. <br>
<br>
The liver has a wide variety of functions and many of these are vital
to life. Hepatocytes perform most of the functions attributed to the
liver, but the phagocytic Kupffer cells that line the sinusoids are
responsible for cleansing the blood. <br>
<br>
Liver functions include the following: <br>
<br>
secretion <br>
synthesis of bile salts <br>
synthesis of plasma protein <br>
storage <br>
detoxification <br>
excretion <br>
carbohyrate metabolism <br>
lipid metabolism <br>
protein metabolism <br>
filtering <br>
Gallbladder <br>
<br>
The gallbladder is a pear-shaped sac that is attached to the visceral
surface of the liver by the cystic duct. The principal function of the
gallbladder is to serve as a storage reservoir for bile. Bile is a
yellowish-green fluid produced by liver cells. The main components of
bile are water, bile salts, bile pigments, and cholesterol. <br>
<br>
Bile salts act as emulsifying agents in the digestion and absorption
of fats. Cholesterol and bile pigments from the breakdown of
hemoglobin are excreted from the body in the bile. <br>
<br>
Pancreas <br>
<br>
The pancreas has both endocrine and exocrine functions. The endocrine
portion consists of the scattered islets of Langerhans, which secrete
the hormones insulin and glucagon into the blood. The exocrine portion
is the major part of the gland. It consists of pancreatic acinar cells
that secrete digestive enzymes into tiny ducts interwoven between the
cells. Pancreatic enzymes include anylase, trypsin, peptidase, and
lipase. Pancreatic secretions are controlled by the hormones secretin
and cholecystokinin. <br>
<br>

answers3: These are the PARTS and FUNCTIONS of the DIGESTIVE SYSTEM
highly simplified: Mouth > Where the food enters the body. This is
also where initial digestion occurs. Pharynx > Where the food becomes
a bolus (mass of chewed food), and it is conducted to the esophagus.
Esophagus > Where the bolus is transported from the pharynx to the
stomach. Stomach > Where digestion of carbohydrates and fats are
performed. *Liver > Releases bile into the gall bladder, which stores
it until fats are passed from the stomach into the duodenum. *Pancreas
> Releases enzymes which further degrade carbohydrates and proteins.
Both the liver and the pancreas release their products to the Duodenum
through the Major Duodenal Papilla. Duodenum > Where protein digestion
occur. Absorption of nutrients such as carbohydrates and most minerals
occur here. Jejunum > Longest segment of the digestive tract.
Absorption of carbohydrates and proteins continue here. Ileum > Where
calcium, iron, fats, and bile salts get absorbed. This is also where
lymph nodes protect the body from the remaining undigested and
unabsorbed foodstuff. Cecum > Where there are good bacteria which help
ferment cellulose and undigested lactose. The bacteria here produce a
substance called "raffinose", which is the compound responsible for
the putrid odor of fart. Ascending, Transverse, Descending, and
Sigmoid Colon > Where water and electrolytes are absorbed. Rectum >
Where the feces is stored before expulsion. Anal Canal > A very short
passageway connecting the rectum and the anus. This is the junction of
the visceral (internal body organs) and the integument (external body
organs such as the skin). Anus > The last stage of the digestive
system and the opening into the outside world (duh?!) Hope I helped
you!