Transcript LB145-lecture11

Announcements
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Tomorrow recitation: Fig focus & quiz
(Bring 2 questions about Wittwer et al)
Exam I will be Wed & Thurs next week
Review Session in class Tuesday,
admission ticket is prewritten question.
Which of the following enzymes work most effecti
at a very low pH?
A.Salivary amylase
B.Trypsin
C.Pepsin
D.Pancreatic amylase
E.Pancreatic lipase
Which of the following organs is incorrectly paired
with its function?
A.Stomach –protein digestion
B.Oral cavity -starch digestion
C.Large intestine –bile production
D.Small intestine –nutrient absorption
E.Pancreas –enzyme production
In zero gravity environment of space, how does food
swallowed by an astronaut reach her stomach?
A.Swallowing hard
B.Running around wheel creates -> artificial
gravity
C.Involuntary muscle contractions
D.IV administration of nutrients
1. Mouth
Salivary glands
Secretes enzymes
that digest
carbohydrates
Liver
Secretes
molecules
required for
digestion of fats
Gall bladder
Stores secretions
from liver; empties
into small intestine
Pancreas
Secretes enzymes
and other materials
into small intestine
2. Esophagus
Transports food
3. Stomach
4. Small intestine
5. Large intestine
Stomach
End of esophagus
Sphincter seals off
stomach from esophagus
Sphincter seals off
stomach from small
intestine
Layers
of muscle
Beginning of
small intestine
Lumen
(interior)
Stomach lining
Canal empties to lumen
Parietal cells
(secrete HCl)
Chief cells
(secrete pepsinogen)
Secretion of HCI by parietal cells
CO2 + H2O
CA
Parietal cell
H2CO3
Canal empties
to lumen
Secretion of HCI by parietal cells
CO2 + H2O
H2CO3
H+
H+
HCO3–
Parietal cell
ATP
Canal empties
to lumen
Secretion of HCI by parietal cells
HCl
to lumen
CO2 + H2O
H2CO3
To blood
H+
H+
HCO3–
Cl–
HCO3–
ATP
Cl–
Cl–
Cl–
Chloride channel
From blood
Parietal cell
Canal empties
to lumen
Stomach -Enzymes, Hormones, other?
•Enzymes: pepsinogen (inactive)-> pepsin (protease)
from chief cells
•Other: HCl -> denature ECM bacteria, from parietal
cells, activator of pepsin
•Other: Mucins/mucus protective from goblet or mucus
cells
•Other: mechanical churning -> acid chyme
•Hormones: Gastrin (+), CCK/secretin (-),
enterogastrone (-- pyloric sphinct)
Enzymes, Hormones, other?
•Your turn
Glycogen
Glucose
Pancreas secretes
INSULIN
If glucose
levels too high
Glucose
levels fall
HOMEOSTASIS
(keeping normal
levels in blood)
Pancreas secretes
GLUCAGON
If glucose
levels too low
Glycogen
Glucose
levels rise
Glucose