Digestive System Lessons 3 Flashcards
what is the small intestine responsible for
the absorption of nutrients
what is one of the pros of the small intestines’ length
it allows for a better absorption of nutrients
what are villi
finger-like projections of epithelial tissue in the small intestine’s lumen
what is the role of villi
to be the position in which the absorption of nutrients takes place
what are micro-villi
the villi’s tiny finger-like projections that increase surface area
why is increasing the surface area in the small intestines good
it contributes to controlling the rate at which a process occurs, and in this case, it speeds up the absorption of nutrients
what does each villus include
a capillary for blood and a capillary for lymphatic fluid(lacteal)
what enters the blood capillaries in a villus
sugars and amino acids
what enters the lacteals in a villus
glycerol and fatty acids packaged together as lipoprotein droplets
what are the sections of the small intestine
duodenum, jejunum, and ileum
what is the duodenum
the first 25cm of the intestine, and it is the site of the common bile duct
what is the common bile duct
a tube that carries bile from the liver and gallbladder, through the pancreas, and into the small intestine
what is the jejunum
the middle portion of the small intestine
what is the ileum
the remaining portion of the small intestine
what does the ileum contain that is important
it contains lymphoid tissue called Peyer’s Patches
what are Peyer’s Patches
lymphoid tissue responsible for monitoring and regulating the presence of potentially pathogenic bacteria
what would the common bile duct do to counteract the acidified contents present in the duodenum
secrete a mixture of bile and pancreatic juice
how does pancreatic juice help with the acidified contents in the duodenum
it contains sodium bicarbonate, which acts as a base to neutralize the acid in the chyme
what performs the final breakdown of food before it is absorbed (in the small intestine)
a combination of digestive secretions/juices(digestive enzymes) and bile
which two hormones control the digestive secretions(digestive enzymes)
secretin and CCK(cholecystokinin)
what is secretin
a hormone that plays a regulatory role in duodenum secretions and water homeostasis in the body
when is secretin released
when a low pH is detected in the duodenum
what is CCK
a hormone that plays a role in the digestion of fats and proteins
when is CCK released
when there are partially digested proteins and fats in the duodenum
what is the large intestine
the final portion of the digestive tract
divide the large intestine into its components
cecum, colon, rectum, anal canal
what is the large intestines’ role in digestion
to absorb water, salts, vitamins, and store undigested material until it can be released as feces
what is the cecum
the first component of the large intestine
what is the function of the colon
the removal of water from digested material
how can the colon be described based on its shape
- ascending colon 2. transverse colon 3. descending colon 4. sigmoid colon 4. rectum
what is digested food material called
feces
how is feces released
when the feces is moved into the rectum by peristalsis, the stretch receptors send a signal to the sphincters at the anus to relax, which allows for the feces to leave
what is feces composed of
3/4 water, 1/4 solid material
what is the solid material in feces composed of
fibre(indigestible material such as cellulose) and bacteria
why do feces smell
because of the solid material counterpart. close to 50 percent of it is dead bacteria.
how does feces get its look
bilirubin that has been broken down
