116 terms

EEOB Exam 3

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Digestive System
consists of alimentary canal and associated organs
Digestive System Functions
transport of ingested water and food, secretion of fluids, electrolytes, and digestive enzymes; digestion and absorption of digested products, excretion of indegistable remains
food from mouth to anus
1. bolus formation by oral cativty and salivary glands
2. esophagus
3.stomach where some digestion occurs
4.small intestine where digestion and most absorption occurs
5.large intestine including anus and rectum where absorption and elimination occurs
Oral Cavity
mouth, tongue, teeth, salivary glands, and tonsils
Parotid Gland
largest gland, almost all serous acini, close to ear
Submandibular Gland
mostly serous acini, under mandibues, ducts extend to frond of the gland
Sublingual Gland
mostly mucous acini; multiple ducts
Functions of Saliva
moisten food and oral cavity, chemical digestion, regulate oral pH, antibacterial
Tonsils
aggregations of lymphatic nodules (palatine tonsils, pharyngeal tonsils, lingual tonsils)
Tongue
muscular organ, arrangement of skeletal fibers which allows flexibility essential to human speech, digestion, and swallowing
filiform papillae
slender, conical projections, most numerous, lack tastebuds
fungiform papillae
widely scattered, CT core, narrow base and hemispherical upper portion, taste buds in epithelium
circumvallate papillae
posterior portion of tongue, tastebuds in epithelium on sides
folliate papillae
rudimentary in humans, on sides of tongue
Teeth
essential for beginning of digestive prosses via mastication
Enamel
hard, thin, outermost layer of teeth
Dentin
Dense tissue forming the bulk of a tooth, mineralized
Cementum
a thin layer of bony material that fixes teeth to the jaw.
mucosa of esophagus
stratified squamous epithelium, lumen expands to allow bolus of food through, normal lamina propria, lymphatic tissue throughout, thick muscularis mucosa
submucosa of esophagus
dense irregular CT, has messiner's plexus and diffuse lymphatic tissue
muscularis externa of esophagus
Upper 1/3: Skeletal muscle
Middle 1/3: Mix of skeletal & smooth
Lower 1/3: Smooth muscle
esophagus function
passage from mouth to stomach
stomach function
mixing and partial digestion of food by gastric secretions
Cardiac Region
near esophageal opening, mucosa is 2/3rd gastric pits and 1/3 glands
Pyloric Region
proximal to pyloric sphincter, mucosa is 2/3 gastric pits, 1/3 glands
Fundic Region
largest part of stomach, mucosa is 1/3 gastric pits, 2/3 glands
Rugae
the folds in the mucosa lining the stomach to allow for distension
Cardiac Glands
branched and coiled, lined by mucus-secreting cells and enteroendocrine cells
Fundic Glands
long, straight, 5 cell types
Cells of fundic glands
surface mucous cells
mucous neck cells
parietal cells
chief cells
enteroendocrine cells
Stem Cells
small and undifferentiated
mucous neck cells
irregular shape, granular, mucous secreting
parietal cells
secrete HCl, rounded with central nucleus, very pink staining
chief cells
secrete pepsinogen, stain purple, smaller then parietal cells
enteroendocrine cells
small, basal granules, act as chemoreceptors
Pyloric Glands
large lumen, mucus-secreting cells predominate; also secrete lysozymes
lamina propria of Stomach
relitavely scant, restricted to spaces surrodding gastric pits and glands
muscularis mucosa of stomach
2 thin layers, inner circular and outer longtidunal layer
submucosa of stomach
dense network of CT , also network of lymphatic vessels and numerous blood vessels
muscularis externa of stomach
inner oblique, middle circular, outer longitudinal
small intestine function
digestion and absorption
What happens in the small intestine?
chyme from the stomach enters the duodenum, enzymes from the pancreas and bile from the liver are delivered to continue digestion, enzymes that break down disaccharides and peptides are secreted and then the carb/protein monomers are absorbed, water and electrolytes are reabsorbed
plicae circulares
folds of the small intestine wall
intestinal villi
finger-like projections of the small intestine; increase surface area for absorption of nutrients in the small intestine
Microvilli
projections that increase the cell's surface area
epithelium of small intestine
columnar, with microvilli, has goblet cells, stem cells, and enteroendocrine cells
lamina propira of small intestine
surronds intestinal glands, forms villi core, contains Peyer's patches (lymphoid nodules)
muscularis mucosa of small intestine
thin layer of circumferentially oriented smooth muscle
Crypts of Lieberkuhn
Glands located at the base of the intestinal villus, have paneth cells in walls to defend against bacterial infection
submucosa of small intestine
loose ct, collagen and elastic fibers, adipose cells
Brunner's glands
are found in the sub-mucosa of the duodenum and secrete alkaline mucous
Muscularis of small intestine
inner circular layer, outer longtudinal layer
large intestine function
concentrates indigestible residues by absorbing water and electrolytes
epithelium of large intestine
columnar absorptive cells, goblet cells, enteroendocrine cells
lamina propria of large intestine
many lymphocytes and macrophages
teniae coli
three bands of longitudinal smooth muscle in muscularis
Appendix function
reservoir for good bacteria
Liver functions
produces bile, detoxifies blood, stores vitamins A,D and K, endocrine functions
Blood Supply of liver
carries blood from aaorta into liver, detoxifies, then returns to heart via inferior vena cava
liver structure
hepatocytes are main cell, organized into lobules with a central vein
portal triad
portal vein, hepatic artery, bile duct
Gallbladder function
concentrates and stores bile
Bile movement from liver to gallbladder
1.bile collected by hepatocytes into canaliculi which drain into hepatic ducts
2.hepatic duct carries ile into the cystic dicut which moves bile into the gallbladder
3.bile flows through the cystic and common bile ducts into the duodenum
exocrine pancreas
systhesizes and secretes enzyme into duodenum for digestion
intercalated ducts of pancreas
pale-staining, secrete bicarb
intralobular ducts
collect secretions of intercalated, forund within the lobe
interlobular ducts
between lobes
main pancreatic duct
runs the length of the pancreas and carries enzymes released from pancreatic cells to the duodenum
endocrine pancreas
Islets of Langerhans which produce insulin and glucagon
respiratory system
consists of the lungs and air passages
respiratory system function
exchange of oxygen and carbon dioxide, maintain water balance, portection via mucus, thermoregulation, olfaction, and speech
upper respiratory system
nasal cavities, paranasal sinuses, nasopharynx, and oropharynx
lower respiratory system
larynx, trachea, bronchi
conducting zone
conduits to gas exchange sites
respiratory zone
site of gas exchange
nasal cavities
chambers seperated by a bony and cartolaginous septum, heavily vascularized
nasal conchae
swirls of bone covered by mucosa, provides greater surface area
Nose epithelium
stratified squamous to cubodial to columnar to ciliated stratified squamous
Pharynx
connects nose and mouth to to larynx and esophagus
larynx
passageway for air between oropharynx and trachea, serves as sound producing organ, formed by nine pieces of cartilage
vocal folds
two folds of mucosa that vibrate to produce sound
ventricular folds
have many mechanoreceptors
trachea
flexible tube that extends from larynx to lungs
Trachea structure
pseudostratified ciliated epithelium, dense CT, c shaped hyaline cartilage, smooth muscle
Cells of tracheal epithelium
cilitaed columnar cells, goblet cells, brush cells, basal cells, small granule cells
left lung
2 lobes
right lung
3 lobes
bronchi divisions
primary, secondary, tertiary, bronchioles
bronchi structure
cartilage decreases, eventually disappear, smooth muscle increases, mucous glands decreases
bronchiole divisions
bronchiole to terminal bronchiole to respiratory bronchiole to alveolar duct to alveolar sac to alveoli
Bronchioles
air conductiong ducts measuring less than 1 mm
clara cells
produce surface active agent, to control water and electrolyte transport
respiratory bronchioles
involved in both ari conduction and gas exchange
terminal bronchioles
continuous with alveolar ducts
alveoli
tiny sacs of lung tissue specialized for the movement of gases between air and blood
Type I alveolar cells
allow rapid diffusion of gases through their thin membranes
Type II alveolar cells
secrete surfactant
Brush cells
mechanoreceptors
urinary system
kidneys, ureters, urinary bladder, urethra
function of urinary system
elimination of excess water, salts, and waste products; secretions of erythtropoeiten, renin, vitamin D
filtration
blood filtered to acellular filtrate
reabsorption
the taking back into the blood of substances that had previously been filtered out from it
Excretion
Process by which metabolic wastes are eliminated from the body
kidney
organized into outer cortex and inner medulla
nephron
functional unit of the kidney
glomerulus
A ball of capillaries surrounded by Bowman's capsule in the nephron and serving as the site of filtration in the vertebrate kidney.
proximal convoluted tubule
first section of the renal tubule that the blood flows through; reabsorption of water, ions, and all organic nutrients
Loop of Henle
section of the nephron tubule that conserves water and minimizes the volume of urine
distal convoluted tubule
Between the loop of Henle and the collecting duct; Selective reabsorption and secretion occur here, most notably to regulate reabsorption of water and sodium
collecting duct
A segment of the nephron that returns water form the filtrate to the bloodstream.
ureter, urinary bladder
thin transitional epithelium, surronded by smooth muscle outermost layer longitudinal inner is circular
female urethra
3-5 cm long, 2/3 transitional epithelium, 1/3 stratified squamous
male urethra
20 cm long, carrying both urine and semen
prostatic urethra
passes through the prostate gland, transitional epithelium
membranous urethra
portion of the urethra between the prostate and the penis, columnar epithelium
penile (spongy) urethra
passes through penis, goes from columnar to stratified squamous epithelium
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