Regulation and Integration of Metabolism

Question 1

the ___ system controls the body’s organ systems

Answer 1

nervous system

Question 2

describe top-down oversight/control that the nervous system has over the body’s organ system

Answer 2

• nervous system has direct or indirect control over the entire body’s organ system
• it is metabolically demanding

Question 3

what type of control is the autonomic nervous system?

Answer 3

direct control

Question 4

what are the two pathways for nervous system control of organ function, and what controls these pathways?

Answer 4

• autonomic nervous system
• neuroendocrine system
• controlled by the hypothalamus

Question 5

the hypothalamus provides ___ organ system control

Answer 5

descending

Question 6

describe the 2 pathways of control that the hypothalamus provides

Answer 6

• direct
  
  • autonomic
  • innervation of pre-ganglionic neurons
• indirect
  
  • hormonal
  • release of pituitary and adrenal cortex hormones

Question 7

describe the 3 parts of the autonomic nervous system

Answer 7

• sympathetic nervous system
  
  • fight or flight
  • response to stressful or harmful stimuli
  • ACh used in pre-ganglionic signals
• parasympathetic nervous system
  
  • rest and digest
  • replenishment of the body’s resources
• enteric nervous system
  
  • digestive system function
  • movement of food through the gut

Question 8

“direct innervation of organ systems to unconsciously coordinate their function” describes what nervous system?

Answer 8

autonomic nervous system

Question 9

what 2 receptors feed back to the nucleus of the solitary tract in autonomic control of cardiac function, and what do they detect?

Answer 9

• chemoreceptors detect blood O2/CO2 composition
• baroreceptors detect blood pressure

Question 10

describe sympathetic vs parasympathetic autonomic control of cardiac function

Answer 10

• sympathetic
  
  • NE
  • increases heart rate and vasoconstriction
• parasympathetic
  
  • cholinergic
  • decreases heart rate and vasodilation

Question 11

what are the effects of increased vs decreased blood pressure in relation to sympathetic/parasympathetic cardiac function?

Answer 11

• increased BP inhibits tonic sympathetic activity and activates vagal parasympathetic activity
• decreased BP activates vagal sympathetic activity and inhibits parasympathetic activity

Question 12

describe the enteric nervous system

Answer 12

• governs gastrointestinal function
• mesh-like neuronal network surrounding the gut
• roughly 100 million neurons
• sympathetic and parasympathetic oversight
• can function independently of the CNS

Question 13

what are the main organs involved in the neuroendocrine system?

Answer 13

• thyroid
• parathyroid
• adipose tissue
• adrenals
• pancreas
• ovaries/testes

Question 14

what are the 3 key players of the HPA axis?

Answer 14

• hypothalamus
• pituitary
• adrenal glands

part of the neuroendocrine system

Question 15

the neuroendocrine system responds to what?

Answer 15

• responds to peripheral sensory information and higher brain centers

Question 16

the neuroendocrine system is initiated by what?

Answer 16

the release of hormones and signals from the hypothalamus

Question 17

T or F:

the neuroendocrine system provides diffuse, system wide endocrine signaling

Answer 17

true

Question 18

describe the HPA axis

Answer 18

hypothalamus - pituitary - adrenal axis regulates hormone release

realize that cortisol is changing the metabolism of its targets

Question 19

describe the major HPA axis hormones and their targets

Answer 19

Question 20

what type of hormone is insulin and glucagon?

Answer 20

• peptide hormone
• proteolytic processing of prohormone
• plasma membrane receptors; second messengers

Question 21

what type of hormone is epinephrine?

Answer 21

• catecholamine
• from tyrosine
• plasma membrane receptors; second messengers

Question 22

what are eicosanoids?

Answer 22

• hormones formed from arachidonate
• plasma membrane recetpors; second messengers
• ex. PGE1
• blocked by NSAIDs

Question 23

what are the major organs that influence metabolism?

Answer 23

• brain
• cardiac muscle
• lymphatic system
• adipose tissue
• skeletal muscle
• small intestine
• portal vein
• liver
• pancreas

Question 24

describe how the brain influences metabolism

Answer 24

• transports ions to maintain membrane potential
• integrates inputs from body and surroundings
• sends signals to other organs

Question 25

describe how cardiac muscle influences metabolism

Answer 25

* uses ATP generated aerobically to pump blood

Question 26

describe how the lymphatic system influences metabolism

Answer 26

* carries lipids from intestine to liver

Question 27

describe how adipose tissue influences metabolism

Answer 27

* synthesizes, stores, and mobilizes triacylglycerols

Question 28

describe how skeletal muscle influences metabolism

Answer 28

uses ATP generated aerobically or anaerobically to do mechanical work

Question 29

describe how the small intestine influences metabolism

Answer 29

* absorbs nutrients from the diet * moves them into blood or lymphatic system

Question 30

describe how the portal vein influences metabolism

Answer 30

carries nutrients from intestine to liver

Question 31

describe how the liver influences metabolism

Answer 31

* processes fats, CHOs, and proteins from the diet * synthesizes and distributes lipids, ketone bodies, and glucose for other tissues * converts excess nitrogen to urea

Question 32

describe how the pancreas influences metabolism

Answer 32

secretes insulin and glucagon in response to changes in blood glucose concentration

Question 33

describe carbohydrate liver metabolism

Answer 33

* remember, pyruvate can be obtained from the cori cycle

Question 34

describe the roles of the liver, pancreas, and gallbladder in the regulation of CHO, AA, and lipid metabolism

Answer 34

* liver * blood sugar * CHO storage (glycogen) and regulation * AA content * lipid formation and mobilization * first pass metabolism * pancreas * insulin release during high blood sugar * glucagon release during low blood sugar * large intestine pH buffering * protease release * gallbladder * bile salts release to degrade lipids

Question 35

describe amino acid liver metabolism

Answer 35

Question 36

describe the glucose-alanine cycle

Answer 36

alanine transports amine groups to the liver

Question 37

describe fatty acid liver metabolism

Answer 37

Question 38

describe how hormone signaling controls feeding

Answer 38

don't need to know the specifics, just the main pathways and what they do

Question 39

describe how blood glucose levels directly regulate insulin release

Answer 39

Question 40

glucagon is constitutively released at ___ glucose levels

Answer 40

low

Question 41

insulin and somatostatin inhibit ___ release

Answer 41

glucagon

Question 42

reduced ___ incites glucagon release and inhibits insulin release

Answer 42

glucose

Question 43

describe glucagon's role in response to low blood glucose

Answer 43

Question 44

describe somatostatin's role in response to high blood glucose

Answer 44

Question 45

describe how insulin drives glucose uptake, glycogen storage, and lipid synthesis

Answer 45

Question 46

describe how glucagon drives glucose release, and amino acid and fatty acid breakdown

Answer 46

Question 47

describe fuel sources during starvation

Answer 47

Question 48

what are the normal available metabolic fuels?

Answer 48

* triacylglycerols (adipose tissue) * proteins (mainly muscle) * glycogen (muscle, liver) * circulating fuels (glucose, fatty acids, triacylglycerols)

Question 49

describe the relationship between grehlin, plasma glucose, and insulin in relation to eating a meal

Answer 49

Question 50

describe what happens in the liver during starvation

Answer 50

end up having to break down musculature in order to get glucose to the brain