digestive sys lab Flashcards
hollow tube extending form mouth to anus only in contact with cells that line the tract
alimentary canal
___ food must first be physically broken down by chewing and churning
ingested
next food must be chemicalled broken dodwn thru enzymatic ___ into smaller diffusible molecules (process is called digestion)
hydrolysis
process: digested end products can then pass thru the epithelial cells lining the tract into the blood for distribution to the body cells.
absorption
digestive system organs are separated into 2 major groups called :
alimentary canal (gastrointestinal tract) and the accessory digestive organs
consists of the mouth, pharynx, esophagus, stomach, and small/large intestines
alimentary canal
structures include the teeth, slaivary glands, gallbladder, liver, and the pancreas
accessory digestive
4 layers of the alimentary canal walls =
mucosa, submucosa, muscularis externa, and either serosa or adventitia
the wet epithelial membrane lining the lumen with a surface epithelium, lamina propria, and a muscularis mucosae
mucosa
functions are secretion (enzymes, mucus, hormones, etc.) and absorption of digested foods and protection against bacterial invasion
mucosa
superficial to the mucosa and is a moderately dense connective tissue containing blood vessels, lymphatic vessels, scattered lymph nodules, and nerve fibers
submucosa
intrinsic nerve supply of submucosa is called the
submucosa plexus
this layer is also known as the muscularis and is usually a bilayer of smooth muscle
muscularis externa
serosa is the outermost layer and is the visceral peritoneum. contains mesothelium associated with a think layer of areolar connective tissue. in areas outside the abdominopelvic cavity, the __ replaces the serosa
adventitia
layer of coarse fibrous connective tissue that binds the organ to surrounding tissues. the serosa functions to reduce friction and the adventitia anchors and protects the surrounding organ
adventitia
food enters digestive tract thru the ___ ___ that contains the gums, teeth, tongue,a nd openings of the salivary gland ducts
oral cavity
comprises the roof of the mouth
palate
fingerlike projection of the soft palata is known as the ____ extending inferiorly from its posterior margin
uvula
floor of the cavity is covered by the tongue which is supported by the ____ muscle
mylohyoid
membranous __ ___ secures the inferior midline of the tongue to the floor of the mouth
lingual frenulum
the space betwn the lips and cheeks and the teeth and the oral cavity proper is the area that lies within the teeth and the gingiva (gums)
vestibule
lips and gingiva (gums) are connected by ____ ____
labial frenula
masses of lymphoid tissue, located posteriorly on both sides of the mouth
palantine tonsils
occurs when palantine tonsils become inflamed and enlarged. this swelling partially block the posterior entrance to the pharynx resulting in difficulty and pain when swallowing
tonsilltis
___pharynx : behind the nasal cavity
nasopharynx
___pharynx: behind the oral cavity extending from the soft palate to the epiglottis overlying the larynx
oropharynx
extending from the epiglottis to the base of the larynx
laryngopharyx
pharyngeal walls contain 2 layers of skeletal muscles: an inner layer of longitudinal muscle( ___ ___) and an outer layer of circular constrictor muscles
levator muscles
passage into the esophagus is controlled in the laryngopharynx by the ___ __ ___
upper esohpageal sphincter
esophagus extends from the pharynx to the ___ __ ___ in the stomach
lower esophageal sphincter
a thickening of smooth muscle at the esophagus-stomach junction, controls food passage into the stomach
lower esophageal spincter
stomach regions include:
cardiac region, fundus, body, and plyoric region
___ is the concave medial surface of the stomach and __ is the convex lateral surface
lesser curvature / greater curvature
extends from the liver to the lesser curvature of the stomach
lesser omentum
saclike and extends from the greater curvature of the stomach downward and blends with the mesocolon
greater omentum
opening of the small intestine controlled by the __ ___
plyoric sphincter
__ ___ of the mucosa secrete hydrochloric acid and hydrolytic enzymes which breakdown proteins
gastric glands
secrete a viscous mucus that prevents the stomach from digesting itself
mucosal glands
food gets broken down into ___, a creamy mass , and then enters the small intestine
chyme
small intestine is suspended by a double layer of periotneum, fan shaped ____, from posterior abdominal wall
mesentary
3 small intestine subdivisions:
duodenum, jejunum, and ileum
ileum joins the large intestine at the ___ ___
ileocecal valve
deep folds of the mucosa and submucosa layers that force the chyme thru the intesttine
plicae circulares
fingerlike projections of the mucosa tunic in small intestine
villi
are minute projections of surface plasma membranes of the columnar epithelial lining cells of the mucosa
microvilli
also found in the small intestine are ___ ___, nodules of lymphoid tissue
peyer’s patches
large intestine extends from the ileocecal valve to the anus and encircles the small intestine on 3 side and consists of the __, ___,__,__,and ___
cecum, vermiform appendix, colon, rectum, and anal canal
colon regions include:
ascending colon, transverse colon, descending colon, and sigmoid colon
longitudinal muscle layer of the large intestine is reduced to 3 longitudinal muscle bands called the __ ___
teniae coli
teniae coli cause the wall to pucker into small saces called ___
haustra
fat filled pouches of visceral peritoneum that hang from the teniae coli
epiploic appendages
first set of teeth are called __ ___ and appear btwn 6 months and 2.5 yrs begining with lower central incisors
deciduous teeth
deciduous teeth begin to be lost by 6 and are replaced by ___ teeth
permanent
teeth are classified as :
incisors, canines/cuspids, premolars/bicuspids, and molars
dental formula for deciduous teeth is
2,1,0,2/2,1,0,2 x2=20
permanent teeth dentition formular
2,1,,2,3/2,1,2,3 x2=32
tooth consists of __,__,__
crown, root, and neck
___covers the tooth and underneath is the ___ that composes the bulk of the tooth
enamel ; dentin
___ __central portion of the tooth and extends into distal portions of the root becomes the root canal
pulp cavity
3 pairs of glands secrete into the oral cavity:
parotid, submandibular, sublingual
__ __ begins the digestion of starch by breaking it into disaccharids and glucose
salivary amylase
largest gland in body with 4 lobes
liver
digestive function of liver is to produce __ that leaves thru the common hepatic duct and enters the duodenum thru the bild duct. bile emulsifiies fat
bile
when digestive activity not occuring, bile backs up into __ ___ and enters the ___ where it is stored until needed.
cystic duct; gallbladder
left and right lobes of liver are separated by the __ ___
falciform ligament
if bile backs up into liver it is forced into the bloodstream resulting in ___
jaundice
inflammation of the liver, usually cased by a pathogen
hepatitis
hardening of the liver, usually caused by heavy alcohol consumption, but not always
cirrhosis
__ ___ line the sinusoids of the liver and are phagocytic cells that remove bacteria and other debris form the blood as it flows by
kupffer cells
has both an endocrine function (insulin and
glucagon) and an exocrine (enzyme-producing) function.
• The pancreatic juice neutralizes the acidic chyme entering the
duodenum from the stomach (optimal pH in the stomach is very
acidic, while for the small intestine is slightly alkaline).
pancreas
are the major means of propelling food through most of the digestive viscera. Waves of contraction followed by waves of relaxation squeeze foodstuffs through the alimentary canal.
peristaltic movements
local constrictions that occur rhythmically, mainly to mix food with digestive juices and to inc rate of absorption
segmental movements
primary digestive function of the ileum is
absorption
folds of the stomach mucosa that increase surface area are called
rugae
__ ___ attached mesocolon to lesser greater curvature of stomach
greater omentum
path of urine drainage
collecting duct, minor calyx, major calyx, renal pelvis, ureter, urinary bladder
kidney is referred to as an excretory organ bc it excretes what kind of waste
nitrogenous
cuplike areas that enclose the apexes of the medullary pyramids and collect urine draining form the pyramidal tips into the pelvis
minor calyces
arteries most distal to renal artery and thus the smallest
interlobular arteries
internal uretheral sphincter made up of ___ muscle and therefore is not under conscious control
smooth
blood flow thru kidney
renal artery segmental arteries interlobar arteries arcuate arteries interlobublar arteries afferent arterioles glomulerular capillaries efferent arterioles peritubular capillaries interlobular veins arcuate veins interlobar veins segmental veins renal vein
flow of urine
glomerulus bowmans capsule proximal convoluted loop of henle distal convoluted collecting duct papillary duct minor calyx major calyx renal pelvis ureter urinary bladder urethra
responsible for raising the tongue superior and posterior during the swallowing process
mylohyoid muscle
peristalsis movements happen in ___ &__/ segmental is in __
esophagus and ureters/ stomach
