Exam 4: Digestion Flashcards
which nerve controls swallowing?
CN IX glossopharyngeal
by what vessel are monosaccharides carried to the liver?
hepatic portal vein
where is the control center for the swallowing reflex?
medulla oblongata
fats are not absorbed directly into the blood–they go through which system first?
lymphatic system
which organ absorbs a lot of water?
large intestine
protein digestion begins with ________ in the ________
pepsin; stomach
when do we start calling bolus “chyme?”
when it enters the stomach
type of lipoprotein: deliver lipids to adipose tissue for storage
very low density lipoproteins (VLDLs)
what does bile do to stomach acid?
neutralizes it
where are amino acids mainly absorbed?
duodenum and jejunum
phase of gastric regulation: increased volume in stomach further increases acid secretion, continuing to stimulate gastrin and histamine; vagus nerve stimulated to further gastric secretion
gastric phase
type of lipoprotein: transport cholesterol/lipids to peripheral tissues (ex: artery walls)
low density lipoproteins (LDLs)
which layer of the GI tract is covered in villi and microvilli?
mucosa
what 2 hormones regulate pancreatic juice?
secretin and cholecystokinin (CCK)
what stimulates the release of Gastrin?
parasympathetic neurons
what stimulates the release of gastric juices?
gastrin
what do lipids pick up that allows them to bind to receptors on the capillary endothelium within muscles and adipose tissue?
apolipoprotein
where are there no enzymes but a lot of bacteria?
large intestine
when micelles break down into fatty acid and glycerol, what are they packaged into?
chylomicrons
what kind of innervation supplies the salivary reflex?
parasympathetic
what is required to convert pepsinogen into pepsin?
HCl
phase of gastric regulation: stimuli from beginning of small intestine influence acid secretion in stomach; hormones inhibit gastric secretions
intestinal phase
what enzyme produced in the pancreas aids in carbohydrate digestion?
pancreatic amylase?
which enzymes of the intestinal cells break down carbohydrates?
lactase, sucrase, maltase
which cells of the gastric glands release gastric lipase, intrinsic factor, and hydrochloric acid?
parietal cells
what stimulates increased production of bile?
arrival of food in the duodenum
what is another name for swallowing?
deglutition
which organ is responsible for the complete digestion of carbs, proteins, and fats, and for the absorption of nutrients
small intestine
this substance released by the gastric glands kills microbes in food and converts pepsinogen to pepsin
hydrochloric acid
fat digestion begins in the _________ with __________
small intestine; pancreatic lipase
what is also known as the “brain of the gut?”
enteric nervous system
hormone produced by adipose tissue; when levels increase, appetite is suppressed
leptin
after absorption, monosaccharides leave the epithelial cells by ________ _________ into the blood capillaries
facilitated diffusion
in higher levels, what does insulin do to appetite?
suppresses it
which substances produced by the pancreas aid in protein digestion?
trypsin, chymotrypsin, carboxypeptidase
where does the lymphatic system drop chylomicrons into the bloodstream?
at the thoracic duct
what are the 3 stages of swallowing reflex?
voluntary, pharyngeal, esophageal
what stimulates parasympathetic neurons to release Gastrin?
sense of food
type of lipoprotein: returns excess cholesterol to the liver; takes it away from artery walls
high density lipoproteins (HDLs)
digestive enzyme that breaks down carbohydrates
salivary amylase
chemical digestion of chyme in the small intestine is dependent on which accessory digestive organs?
pancreas, liver, gallbladder
which enzyme of the intestinal cells breaks down fats?
intestinal lipase
amino acids: enter epithelial cells of small intestine via ___________ (co transport with _________)
active transport; sodium
what do bile salts do?
emulsify fats
large spherical particles (lipid) coated with proteins
chylomicrons
which enzyme of the intestinal cells breaks down proteins?
enterokinase
at what point do the accessory digestive organs deliver secretions to the duodenum?
sphincter of Oddi
what is the product of mastication
bolus
monosaccharides: absorbed via _________ into small intestine epithelium (cotransport with ________)
active transport; sodium
passage of small food molecules through the cells lining the stomach and intestines into the blood and lymph
absorption
pancreatic juice contains what buffer that collects acid from chyme?
potassium bicarbonate
what is the mixing and holding chamber for food?
stomach
what do micelles break down into?
fatty acid and glycerol
what are the 4 layers of the GI tract, from innermost to outermost?
mucosa, submucosa, muscularis, serosa
what is the product when bile salts emulsify larger lipids?
micelles
by what lymphatic vessel do chylomicrons enter?
lacteal
phase of gastric regulation: increased parasympathetic activity to ENS to release gastrin and histamine (stimulating acid secretion); occurs when you see, smell, taste, or chew food
cephalic phase
where does carbohydrate digestion begin?
the oral cavity
what are the 3 phases of gastric regulation?
cephalic, gastric, intestinal
feature of the small intestine that increases the surface area for absorption of nutrients
villi
what is the main purpose of digestion?
absorption
which cells of the gastric glands release inactive gastric enzyme, pepsinogen, and lipase?
chief cells
