digestive system

Question 1

digestion

Answer 1

to invest food so as to chemically and physically break it down into monomers and absorb the nutrient molecules and eliminate wastes

Question 2

path of food

Answer 2

• mouth-injest and mechanical digestion
• tongue-shapes food into bolus-and pushes food to back of throat
• tastebuds-evaluate food
• teeth-bite crush tear
• salivary glands- secrete amylase (ph 7) breaks starch into maltose
• pharynx- common pathway for air and food
• epiglottis-flap at larynx that blocks food from entering trachea
• esophagus- pathway to stomach
• cardiac sphincter
• stomach- food storage and only digests proteins– gastric juices and churns food into chime
• pyloric sphincter-
• duodenum- first region of small intestine and it does the most digestion it breaks food down and absorbs it
• liver- makes bile and destroys RBC ( does a lot)
• gall bladder- stores bile
• pancreas-makes digestive juices and enzymes
• small intestine- absorbs food
• appendix- immunity- has some lymph nodes
• large intestine- recovers water and makes vitamins
• rectum- stores and eliminates faces

Question 3

swallowing and peristalsis

Answer 3

oral cavity food is chewed and mixed with saliva the tongue rolls the food into bolus. when you swallow the tongue pushes the bolus into the pharynx and the soft pallet moves up to block the nasal cavity. epiglottis covers the trachea and the bolus enters the esophagus. peristalsis occurs and circular muscles contact, longitudinal muscles relax. the circular muscles in front of the bolus relax and the longitudinal muscles relax this alternate contraction and relaxation pushes bolus to stomach. *** swallowing is a reflex

Question 4

gastric juice

Answer 4

pepsin and pepsinogen. hydrochloric acid. GOBLET CELLS PRODUCE MUCUS. gastric juice breaks down proteins using enzymes and a low ph

Question 5

pancreatic juice

Answer 5

NAHCO3***** CREATES PH OF 8. trypsin lipase and nuclease amylose(further breaks down carbohydrates, lipids and proteins) also neutralizes chime and is released into the duodenum

Question 6

intestinal juice

Answer 6

mucus sodium bicarbonate and water— BRUSH BORDER ENZYMES

Question 7

BRUSH BORDER ENZYMES

Answer 7

peptidase- break peptides into aa

lactase and maltase these are produces by microvilli

Question 8

what does bile do

Answer 8

bile is a salt and it EMULSIFIES FATS which is to physically break fats down. it breaks fat into smaller molecules and surrounds them so that lipase can break them down

Question 9

five functions of liver

Answer 9

stores glycogen
makes bile
detoxifies poisons
coverts nitrogen into urea
makes plasma proteins

Question 10

specialization of small intestine

Answer 10

long– more opportunity and time to digest
villi- increase in sa
circular and longitudinal muscle- movement of food
all the many layers
**length layers villus

Question 11

villus

Answer 11

-absorb monomers- capillaries absorb glucose aa and nucleotides
lacteal- lymph vessel in vili absorbs glycerol and fatty acids
capillaries to mesenteriess to mesentery vein to portal vein
microvilli increase surface area and make brush border enzymes

Question 12

what does e.coli do

Answer 12

makes vitamins

Question 13

gastrin

Answer 13

(hormone) gland- stomach epithelial lining
stimulus- presence of protein
target- gastric glands
action- increase gastric juice

Question 14

secretin

Answer 14

gland- duodenal mucosal epithelium
stimulus- acidic chime
target- pancreas
action- increase pancreatic juice

Question 15

CCK

Answer 15

gland-duodenal mucosal epithelium
stimulus-partially digest proteins and fat
target- pancreas
action- increase pancreatic juice

Question 16

GIP

Answer 16

gland-duodenal wall
stimulus-fat and polypeptides in duodenum
target- gastric glands
action- decrease gastric juice (opposite of gastrin)

Question 17

enzymes ** (probably on final) (8)

Answer 17

-salivary amylase- from salivary glands- convert starch to maltose- ph 7
-pancreatic amylase- from gland pancreas- convert starch into maltose -pH 8
-* pepsin- gland- chief cells in stomach- substrates are proteins and break them into polypeptides pH 2
-*trypsin secreted from pancreas and the substrate is proteins breaking them into polypeptides the pH is 8
lipase- secreted from pancreas substrate is lipids and breaks them into fatty acids and glycerol and the pH is 8
nuclease- from pancreas breaks nucleic acid into nucleotides ph 8
peptidase secreted from stomach lining breaks petite chain into aa and its pH is 2
maltase- microvilli breaks maltose into glucose and pH 8

Question 18

pepsinogen and trypsinogen

Answer 18

pepsinogen + hydrochloric acid makes pepsin– pepsinogen is made in the cell and its the inactive form of pepsin, hydrochloric acid activates it. this is required because if pepsinogen was active in the cells then it would digest proteins
trypsinogen + sodium bicarbonate makes trypsin– same idea but in the duodenum

Question 19

hepatic portal system

Answer 19

1, small intestine absorbs monomers
2. monomers travel in hepatic portal vein to liver
3. liver monitors blood content
4.blood enters general circulation thru hepatic vein
**unique path of blood
it goes from blood vessel to capillaries(small intestine) to vein(anterior mesenteric vein) to another vein(hepatic portal vein) to capillaries(capillaries in liver) to vein (hepatic vein)