Exam 3 Lec Notes Contd Flashcards
digestion essential for any organism’s survival, unless it’s ../..
photosynthetic; autotrophic
digestive system is considered to be … of the body, because it is a …
outside; continuous canal
symptoms that very closely resemble … in terms of physical sensations that patients are experiencing can actually be acid reflux/heartburn
intense bit of pain right in … of the chest
uncontrolled spurting of … into the esophagus, burning the esophagus over time
heart attack;
middle;
HCl
have to break foodstuffs down into small enough pieces that single cells of the digestive tract can … and make them available to the rest of the body
absorb them into the bloodstream
two major groups for organs of digestive system:
alimentary canal/GI tract/gut: continuous series of … that runs from the mouth to the anus; purpose is to … food and … from the lumen of the gut and directly into the blood itself
musculature;
break down;
absorb it
digestion requires a number of other systems in order to aid in the various processes GI tract is engaged in –> … organs
accessory digestive
accessory digestive organs:
not absolutely essential for survival and digestion
e.g. teeth
tongue mostly just … around mouth
gallbladder stores … which helps in the … of … - making fats …, and breaking them into smaller droplets that are more easily absorbed
moves foodstuffs;
bile salts;
emulsification of fats;
smaller
accessory digestive organs:
salivary glands help … food and produce … that help to break down foodstuffs
pancreas produces secretions that help to … foodstuffs - non-essential digestive …
moisten; enzymes;
break down; enzymes
accessive digestive organs:
liver- some of its functions IN TERMS OF DIGESTION are not absolutely essential –> other functions are extremely critical; primarily concerned with producing things being stored in the …
gallbladder
large intestine consists of …, …, and … colon
ascending; transverse; descending
pancreas is …. the stomach
behind
food moves from oral/buccal cavity, down into … and into the … –> the process of moving food down this path is called … (this doesn’t occur exclusively in the …)
esophagus; stomach;
peristalsis; esophagus
two muscle contraction types in GI tract:
peristalsis; moving … of food –> esophagus … food distally along the tract
segment: instead of having one smooth wave that moves from top to bottom, there is … contraction and relaxation
bolus;
squeezes;
alternating
segmentation:
how we’re going to try and help … more of the ingested food; can’t rely fully on chewing/mastication in order to fully break down our food small enough so that we can actively absorb most of the nutrients in that food
mechanically break down
food remains in the stomach around ..-… hours; mixing HCl in the stomach with enzymes and food to physically break it down so that it’s small enough to aid in physical absorption of nutrients
4; 6
segmentation occurs in the … and …
small and large intestine
anything …, containing …, severely … can’t be actively absorbed and is eliminated through defecation
hard; fiber; keratinized
stomach churns for a number of hours before it finally relaxes and ejects the food into the …, where the food undergoes waves of segmentation to …, and food is moved through three divisions of the small intestine and then into the large intestine
small intestine;
mix foodstuffs up
stomach largely there for … and … of food, not really for digestion. stomach not actively involved in absorbing most of the nutrients you intake– absorbed in …
physical mixing; churning;
small intestine
by time food is in large intestine, the … elements have already been absorbed. mostly indigestible materials and things that need to be … from the body in large intestine (e.g. stercobulin)
digestible;
eliminated
digestive system concerned with reclaiming as much … as possible
water
digestive system is incredibly …, moving through segmentation and peristalsis – wanna make sure that it doesn’t flip over itself when one is engaged in physical activity, don’t want it to wrap up around itself to inhibit further movement of material in GI tract.
want to hold digestive organs relatively in place and want to make sure that while they are moving, that movement is as … as possible –> achieved through the …
mobile;
frictionless;
peritoneum
… peritoneum sits on organs themselves
… peritoneum lies on abdominal wall
visceral;
parietal
…: double layer of peritoneum; can extend from … of abdominal cavity to … themselves
mesentery; wall; digestive organs
mesentery:
store more and more … in interior of mesentery as you age
not all organs are located in this mesentery –> … in peritoneum itself, … organs are n the back of the peritoneum
fat;
intraperitoneal;
retroperitoneal
peritonitis: inflammation of peritoneum; for the most part, this occurs due to some major … to GI tract
can be caused by extraordinarily severe … such that stuff from stomach leaks out onto peritoneum
if … this can happen as well –> dumps pathogens, toxic substances
damage;
ulcer;
appendix bursts
peritonitis:
fluid won’t be as effective when this happens and the organs then can’t …
cure: must physically go in and … (from outside and inside if impaled, or from inside if the damage is interior due to ulcer/ruptured appendix)
individual then put on megadoses of antibiotics for weeks to try to kill off anything that has been missed during the debris removal
slide past one another;
remove debris
ulcers are caused by …, not …
proved bc doctor drank a pure culture of the suspected bacteria and developed ulcers and then took antibiotics and cured them
bacterial infection; stress
(layers of alimentary canal) mucosa: actual layer that lines the …/physical dead space of the GI tract
secretes mucus, digestive enzymes, hormones
… from the lumen
protects against infectious disease
lumen;
absorbs
(layers of alimentary canal) mucosa: 3 sublayers: epithelium - secretes mucus to protect cells from harsh environment that is the GI tract, particularly in the stomach, which has ... (otherwise the cells of the stomach would be digested, and the digestive enzymes would impact those cells as well); mucus also helps to trap any ... that may have come in with the bolus the cells of this layer are ...
pH 1 HCl;
pathogens;
columnar
(layers of alimentary canal) mucosa: 3 sublayers: epithelium: mucus also acts as a ... - slippery in presence of ... - helps digestion and helps ease movement of food in that segmentation and peristalsis
physical lubricant;
water
(layers of alimentary canal) mucosa- 3 sublayers:
lamina propria: made up of connective tissue that has holes all over the place; in those holes, there are a huge number of …, which makes absorption very easy, very … layer of tissue that nutrients have to actually pass through
capillaries;
easy
(layers of alimentary canal) mucosa- 3 sublayers:
lamina propria:
MALT also contained here: mucosa - associated lymphoid tissue –> tiny cells that are hollow interiorly, and inside of these hollow … cells are tons of …
sitting there, acting like a tiny garrison fro WBCs – serve similar purpose as … in the mouth
M;
white blood cells;
tonsils
(layers of alimentary canal) mucosa-3 sublayers:
muscularis: smooth muscle that helps with localized …, not involved in physical movement of food (?)
relaxation
(layers of alimentary canal) submucosa: tubes leading into GI tract (e.g. blood vessels, etc)
… blood vessels here, … vessels, lymphoid follicles (like the … of the lymphatic system) and huge amount of nerves which innervate the entire GI track
huge innervation is why …/… is so intense
large; lymphatic; capillaries;
cramps; stomach pain
(layers of alimentary canal) muscularis externa: muscle layer responsible for segmentation and peristalsis
… layer of smooth muscle
this is the layer that gets … and thickens to form .. .that separate out various portions of the GI tract
thickened;
expanded;
sphincters
(layers of alimentary canal) serosa: outermost layer, and is the physical makeup of the visceral peritoneum; sits on … themselves;
in the esophagus, it’s not called serosa, it’s called the … which is a slightly denser connective tissue to hold it in place
digestive organs;
adventitia
separate set of circulatory tissues called hepatic portal circulation that drain directly off of the … and … and travel directly to the liver
done because, if there is any substance in a meal that was eaten that is toxic, you don’t want that going to the rest of the body, want it to be broken down - take that substance, absorb it directly from meal, and brought to liver as quickly as possible to be …
stomach; small intestine;
broken down by enzymes in the liver (differences in these enzymes is why, for example, people can eat chocolate but dogs can’t)
enteric nervous system: NS that innervates all of these organs; called the “…”; huge amount of nerves, has more neurons than spinal cord- this is why we intensely feel what’s going on in GI tract
enteric neurons are very highly … and … frequently
second brain;
connected; communicate
enteric nervous system:
…: main groupings of nerves
submucosal nerve plexus: innervates …
myenteric nerve plexus: primarily concerned with innervating …
nerve plexuses;
submucosa;
muscularis externa
enteric NS:
has two different reflex arcs:
short reflex arcs- reflexes that are going to be primarily responding to small stimuli in the GI tract itself (… triggered by short reflex arc when more … is sensed in the large intestine than should be there- large intestine primarily concerned with absorbing as much water as possible - signal that there’s something wrong (e.g. presence of a pathogen that is secreting a substance that is blocking …, in body’s best interest to flush that pathogenic organism out – this is how … work))
diarrhea;
water;
reabsorption of water;
enema
enteric NS:
has two different reflex arcs:
long reflex arcs: through both … and … innervation
para enhances digestion, sympathetic inhibits it by … out of the GI tract, making it available for .. system
parasympathetic; sympathetic;
squeezing blood
enteric NS:
short reflex arcs look for what’s going on in … itself
chemoreceptors to sense …
mechanoreceptors to make sure things are …
osmoreceptors to sense …
GI tract;
chemicals;
physically moving;
excess water
enteric NS:
long reflex arcs are because of things going on …; will … for a meal (e.g. seeing food, tasting it, smelling it)
outside; prep GI tract
… and … of digestion itself will let GI tract know whether the food should move on in digestion or remain in the place it is at the time
beginning; end products
long reflex arcs can ../… digestion
short reflex arcs - …/… NS controls (doesn’t need info from anywhere else)
long reflex arcs- …, stimulation from the …, from outside of GI tract
activate; inhibit;
intrinsic; enteric;
extrinsic; brain
hormones help control digestive activity - secreted by … and …
stomach; small intestine
cells of …, …, and part of … have extra layers of keratin for protection:
even if they’re damaged, they heal faster than any part of the body
these cells heal themselves in a matter of …, rather than days - important bc there are so many dangerous pathogens that enter mouth constantly
gums; hard palate; tongue;
hours
… is the physical lumen of mouth
oral vestibule
…: physical little pieces of tissue that connect lips to gums
labial frenulum
… takes up vast majority of oral cavity itself
tongue
… bone attaches to epiglottis, which closes when bolus is swallowed to prevent food from entering … and causing obstruction
hyoid;
larynx
soft palate goes back to form
uvula
tongue has two layers of muscle:
intrinsic - a lot of human variation with these (e.g. being able to … one’s tongue - because of how intrinsic muscles are … in interior of tongue - completely …)
extrinsic
roll;
layered;
genetic
tongue attached by floor of mouth by … –> connective tissue that keeps tongue physically anchored, to prevent swallowing of tongue when swallowing food
lingual frenulum
people with severe cases of ankyloglossia can’t physically … past the exterior of oral cavity
makes speech very difficult
but can be fixed rather easily by snipping …, to free tongue up from floor of mouth and make it more …
stick out their tongues;
frenulum;
extendable
saliva allows for physical … of mouth to remove substances that get stuck during mastication, helps … food for taste (dry food doesn’t have intense flavor, because molecules aren’t … at the same speed as when in aqueous environment so not binding to taste receptors as much)
contains … which breaks down carbs/starches –> physically snips individual monomers from carb chains
cleansing;
dissolve;
vibrating;
amylase
most of saliva made by … salivary glands:
…, …, …
extrinsic;
parotid; submandibular; sublingual
… located on either side of the head- huge, produce vast majority of saliva
parotid
parotid duct leaves from where … start to about midway from back row of tooth and secrete saliva from either side of …
cheeks;
oral cavity
submandibular glands have a submandibular duct that comes up right in front of the lingual frenulum
lifting of tongue and movement of jaw …
sublingual gland has a number of ducts
squirts saliva
salivary glands’ proper composed of two types of cells:
serous cells produce most of salvia - the … part, …, … (saliva is fairly … which helps … in the mouth) and mucin
mucous cells: produce mucos
watery; amylase ions; salty; kill microorganisms
mumps: virus that lead to inflammation of … that leads to .. of these glands
spreads through saliva
if you try to eat something acidic, that triggers … and there’s a lot of pain
parotid glands; swelling;
salivary reflex
