Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PSIO202 > PSIO202 Exam 3 - Digestive Regulation and Metabolism > Flashcards

PSIO202 Exam 3 - Digestive Regulation and Metabolism Flashcards

1
Q

What is produced by the G cells of the stomach?

A

gastrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is produced by the enteroendocrine cells of the small intestine?

A

S cells make secretin

CCK cells make cholecystokinin

K cells release GIP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the three phases of digestion and their basic roles?

A

cephalic phase - anticipation
gastric phase - breakdown
intestinal phase - release of chyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the cephalic phase of digestion.

A

sight, smell, taste, ang thought of food (taken in my the cerebral cortex) stimulate the PNS

Facial/glossopharyngeal nerves stimulate the salivary glands to produce more saliva

Vagus nerve stimulates gastric glands to increase HCl production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the stimulus and receptors for the gastric phase of digestion? Is response regulated by endocrine or NS?

A

distension/stretch and pH trigger chemoreceptors and mechanoreceptors

responses come from both NS and Endo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How does the endocrine system play a role in the gastric phase of digestion?

Nervous?

A

Endo releases gastrin which increases activity of the submucosal and myenteric plexus
NS also targets the submucosal and myenteric plexus via the Vagus nerve.

Submucosal/gastric glands will result in increased secretions
Myenteric results in increased motility (contraction of lower esophageal sphincter and stomach muscles) and relaxation of the pyloric sphincter (more churning and emptying)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the stimulus and receptors for the intestinal phase of digestion? Is response regulated by endocrine or NS?

A

distension of duodenum (from increased contents) and lower pH (from the acidic chyme) trigger chemoreceptors and mechanoreceptors

responses come from both NS and Endo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does the endocrine system play a role in the intestinal phase of digestion?

Nervous?

A

Endo releases CCK (decrease stomach emptying) and secretin (decrease stomach secretions) from the enteroendocrine cells of the small intestine.

SNS targets the submucosal and myenteric plexus via the enterogastric reflex. Impulses inhibit parasympathetic stim. of the stomach, stimulate the sympathetic impulses to the stomach, and stimulate parasympathetic impulses to SI and accessory organs (delayed effects)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the more pancreatic functions of CCK and secretin?

A

CCK - fats and proteins in SI cause CCK release, which increases digestive enzyme release by the pancreas

secretin - acidity in SI causes secretin, which increases sodium bicarbonate release by the pancreas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do CCK and secretin regulate bile secretion?

A

After PSNS stimulates production and the chyme entering the SI stimulate CCK and secretin to be released…

  • CCK causes contraction of the gallbladder
  • secretin enhances the flow of bile rich in HCO3- from the liver
  • CCK relaxes the hepatopancreatic ampulla
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the 4 GI reflexes?

A

enterogastric, gastroileal, gastrocolic, and defecation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the enterogastric reflex?

A

regulates the amount of chyme released into the duodenum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the gastroileal reflex?

A

when the stomach is full, gastrin relaxes ileocecal sphincter so SI can empty into the LI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the gastrocolic reflex?

A

when stomach fills, strong perstaltic waves move the contents of the transverse colon into the rectum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the defecation reflex?

A

when rectum fills, stretch receptors signal the sacral spinal cord
- parasympathetic nerves contract muscles of the rectum and relax the internal anal sphincter
- external anal sphincter is voluntarily controlled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is metabolism?

A

chemical processes that occur within an organism to maintain life
converting food to energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the three main uses foe energy gained from metabolism?

A

store it, growth, and reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the overall equation for cellular respiration?

A

C6H12O6 + 6O2 —>
6CO2 + 6H2O + energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the two ways to measure metabolism? What are they each measuring exactly?

A

direct calorimetry - measures melting ice to estimate the latent heat produced

indirect calorimetry (respirometry) - measured gas levels in a closed system (face mask, box, etc.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is BMR?

A

basal metabolic rate
minimum cost of living in an endotherm
measured on a resting, fasted animal with no thermal stress

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the respiratory quotient, and what is it for carbs, fats, and proteins?

A

rate of CO2 produced / rate of O2 consumed

carbs: 1
fats: 0.7
proteins: 0.8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is catabolism?

A

break down of complex compounds, providing energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is anabolism?

A

synthesize complex molecules from small molecules, requiring energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How much ATP is in a cell?

A

about 1 billion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Where (within the molecule) is ATP broken to release energy?

A

a P bond is broken, and energy is released but over half is lost as heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are oxidation and reduction?

A

oxidation - decrease in energy of a molecule, electrons are lost, plus H+

reduction - increase in energy of a molecule, electrons gained, plus H+

they are always coupled in the body (but sometimes an intermediate molecule is involved in the electron transfer, called a coenzyme)

27
Q

What are the 4 steps of glucose catabolism? How many ATP are generated?

A

glycolysis
formation of acetyl co a
krebs cycle
electron transport chain

36-38 ATP

28
Q

Describe glycolysis

A

glucose (6 carbon) is broken down to pyruvic acid (3 carbon) as well as ATP and NADH

29
Q

Describe the formation of acetyl co A

A

pyruvic acid (3 carbon) breaks down to acetyl co-A (2 carbon) as well as NADH and CO2

30
Q

Describe the Krebs Cycle

A

acetyl co-A (2 carbon) is broken down to CO2, ATP, NADH, and FADH2

31
Q

Describe the electron transport chain

A
  • NADH and FADH2 bring high energy electrons to the ETC
  • electrons are passed along the membrane, and their energy is used to pump protons out (build up a gradient)
  • at some point, the electrons in the chain reduce oxygen to water and oxidize NADH/FADH2 back to NAD/FADH
  • when hydrogen ions move back in (since the concentration outside is high), they come in through an ATP synthase, which turns ADP and P to ATP
32
Q

Overall, when oxygen is present, glucose is completely broken down into —–, ——, and ——.

A

CO2
H2O
high energy electrons

33
Q

What are the two main ways that proteins and lipids can be used to make ATP?

A
  • broken down into amino acids or FAs/glycerol which can enter the Krebs cycle
  • turn them into carbs for the normal 4 step process
34
Q

What is glycolysis? (basic definition)

A

break down of glucose to pyruvate or lactic acid

35
Q

What is glycoenolysis?

A

break down of glycogen to glucose

36
Q

What is glycogenesis?

A

formation of glycogen from glucose

37
Q

What is gluconeogenesis?

A

formation of glucose from other substrates

38
Q

What are the 4 major classes of lipoproteins?

A

chylomicrons
VLDL - very low density
LDL - low density
HDL - high density

39
Q

What is the composition and role of chylomicrons?

A

2% protein, 85% TG
form in the intestinal epithelial cells to transport dietary fats to adipose cells

40
Q

What is the composition and role of VLDLs?

A

10% protein, 50% TG
form in hepatocytes to transport TGs to adipose cells

41
Q

What is the composition and role of LDLs?

A

25% protein, 50% “bad” cholesterol
carry blood cholesterol to body cells

42
Q

What is the composition and role of HDLs?

A

40% protein, 20% “good” cholesterol
carry cholesterol from cells to liver for elimination

43
Q

What are the 3 main ways lipids can be used in the body?

A

oxidized to produce ATP, excess stored in adipose/liver, and used to synthesize molecules/structures

44
Q

What can lipids be used to synthesize?

A

phospholipid plasma membranes, lipoproteins that transport cholesterol, thromboplastin, myelin sheaths, and cholesterol for bile salts/steroid hormones

45
Q

What is lipolysis?

A

triglycerides broken down to glycerol and fatty acids in the liver or adipose tissue (stimulated by Epi, NE, or cortisol)

46
Q

What is beta oxidation?

A

fatty acids broken down into 2 carbon acetyl co-A to be used in the Krebs cycle/produce ATP

47
Q

What is lipogenesis?

A

in the presence of insulin, triglycerides are synthesized in the liver and adipose tissue from amino acids or glucose

acetyl co-A and glucose can also synthesize fatty acids and glycerol

48
Q

Describe how lipids are used for gluconeogenesis and ATP production?

A

triglycerides broken down to glycerol and fatty acids

glycerol turns into glucose, which then goest through glycolysis (breaks into pyruvic acid), beta oxidation (breaks into acetyl co-A), and Krebs cycle to produce ATP

fatty acids are beta oxidized to acetyl co-A which enters the Krebs cycle and produces ATP

49
Q

When blood glucose is high, (lipolysis/lipogenesis) will occur

A

lipogenesis

50
Q

What is ketogenesis?

A

occurs in the liver cells, ketone bodies are used by heart muscle and kidney cortex to produce ATP

51
Q

What are fuel sources for lipogenesis?

A

amino acids, glycolysis metabolites, ketone bodies for fatty acid production from acetyl co-A

glycolysis metabolites for glycerol production

52
Q

What is the fate of proteins?

A

broken down into amino acids which are transported to the liver

amino acids can be deaminated, transaminated, used to synthesize new proteins, converted into glucose or triglycerides, or absorbed into body cells if stimulated by insulin/IGFs

53
Q

What are the 4 ways that amino acids can be used for ATP production?

A

they can turn into 2C acetyl co-A and enter the Krebs cycle, they can act as intermediates they can deaminate and ammonia can turn into urea, and they can form glucose (which can then form glycogen, glycerol, or fatty acids)

54
Q

What are the 4 ways the liver contributes to carbohydrate metabolism?

A

amino acids —> glucose (gluconeogenesis)
triglycerides —> glucose
(gluconeogenesis)
excess glucose —> glycogen stored in the liver
(glycogenesis)
glycogen —> glucose (glycogenolysis)

55
Q

What are the main 4 ways the liver contributes to lipid metabolism?

A

synth. cholesterol, synth. lipoproteins that transport FAs and cholesterol, store fat (lipogenesis), and break down some fatty acids (beta oxidation)

56
Q

What are the main ways that the liver contributes to protein metabolism?

A

deamination and transamination

57
Q

Describe deamination

A

in the liver, the amine is removed from an amino acid
the carbon skeleton is later used to make ATP
the ammonia turns into urea which is excreted by the kidney

58
Q

Describe transamination

A

transfer of an amine to another amino acid, converts one AA to another AA
synthesizes proteins for clotting and immune systems

59
Q

What is hepatitis and cirrhosis?

A

hepatitis: inflammation of the liver caused by viruses, drugs, alcohol, and can lead to cirrhosis
cirrhosis: scarred liver caused by chronic inflammation due to hepatitis, chemicals, parasites, or alcohol

60
Q

What is the absorptive state?

A

the time when there is a lot of nutrients in the blood

61
Q

What is the post-absorptive state?

A

the time when absorption is complete but blood sugar still needs to be maintained

62
Q

What is absorbed first in the absorptive state? What takes longer, and why?

A

carbohydrates (glucose) and proteins (amino acids) are first because they go through the hepatic portal system
lipids take longer because they are carried by lacteals, then eventually reach general circulation

63
Q

What 5 main actions occur during the absorptive state?

A

storage of excess fuels in hepatocytes, adipocytes, and skeletal muscle

dietary lipids stored in adipose tissue

most glucose converted to glycogen or triglycerides

amino acids are deaminated to enter the Krebs cycle, or are converted to glucose/fatty acids

amino acids not taken up by hepatocytes or other cells are used for synthesis of proteins

64
Q

What are the main actions occurring in the postabsorptive state?

A

putting glucose back in/alternative fuel sources:

glycogenolysis (glycogen to glucose) or gluconeogenesis (amino acids, lactic acid, glycerol all to glucose)
fatty acids into Krebs or as acetyl co-A
oxidation of ketone bodies in the heart and kidneys

PSIO202 (27 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions