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Autonomic Nervous System
Kari O.
11
Pharmacology
Graduate
01/21/2011

Additional Pharmacology Flashcards

 


 

Cards

Term
Describe how milrinone and amrinone produce their pharmacologic effects.
Definition

Epi/Nepi and other catecholamines stimulate BAR --> BAR linked to G(+) regulatory protein in the cell wall --> which activate the enzyme AC --> AC catalyzes the conversion of ATP to cAMP

 

Intracellular cAMP levels increase as less cAMP is broken down

Term
What is the half-life of IV adenosine?
Definition
Less than 10 seconds
Term
Where does adenosine that naturally stimulates cardiac adenosine receptors come from?
Definition
  • Epi/Nepi and other catecholamines synthesized in the adrenal glands stimulate BAR on cardiac muscle
  • Stimulating G proteins activating AC within the cell membrane
  • ATP --> cAMP --> AMP --> Adenosine
  • Adenosine is highly lipid soluble and can readily diffuse through phospholipid bilayer into circulating blood system
Term
How do adenosine and Ach modulate sympathetic response?
Definition

1. cAMP increases --> increase in sympathetic response (increase in HR/contractility)

2. cAMP decreases --> sympathetic response decreases

3. Epi/Nepi will increase cAMP

  • by increasing AC activity via G-proteins with link BAR to AC

4. Adenosine/Ach will decrease cAMP

  • by decreasing AC activity via inhibitory G-proteins which link ADO receptors to AC
Term
Why does the body have two similarly acting neurotransmitters (adenosine and Ach) that modulate sympathetic response?
Definition

Local: During an MI there is damage to a portion of the heart muscle. The body tries to perseve the heart muscle by either increasing the O2 supply or decreasing the O2 demand. The heart also tries to decrease HR and O2 consumption at the local level by decreasing the production of ATP --> decreasing cAMP through adenosine

 

Systemic: Ach is stimulated from brain in response to baroreceptors in the aorta and signals in the kidneys.

Term
Describe how Epi, Nepi, adenosine and Ach affect Beta-receptors, g-proteins and cAMP.
Definition

Epinephrine: increased levels of cAMP are what cause the physiological effects of Epi

Epi -> BAR -> G proteins -> AC -> ATP -> cAMP -> AMP -> ADO


Norepinephrine: local response that yields similar results as Epi does b/c it causes stimulation of BAR --> increase of cAMP

Nepi -> BAR -> G proteins -> AC -> ATP -> cAMP -> AMP -> ADO


Adenosine: product of ATP metabolism after BAR is stimulated by Epi/Nepi. Too much stimulation causes ADO to diffuse lipid bilayer and stimulate ADO receptors on outside inhibiting the G proteins activating AC preventing further production of cAMP --> AMP --> ADO


Acetylcholine: released systemically by PNS stimulating Ach receptor inhibiting G-proteins stimulation of AC preventing further production of cAMP --> AMP --> ADO

Term

Which of the following have local effects and which have more general effects:

  • Acetylcholine
  • Norepinephrine
  • Epinephrine
  • Adenosine
Definition

Epinephrine: general effects b/c adrenal medulla is only producer regulated by SNS


Norepinephrine: made locally at the site and only has local effects b/c it either diffuses away or participates in reuptake


Adenosine: only has local effects d/t very short half life


Acetylcholine: systemic effects, release is stimulated by PNS

Term

1. What effect does Nepi have on intracellular cAMP production?

2. How does Nepi produce these effects?

Definition

1. Nepi increases cAMP production --> increased HR and contractility

 

2. Nepi --> BAR --> G-proteins --> AC --> ATP --> cAMP --> AMP --> ADO

Term

1. What is cAMP broken down to?

2. What more readily traverses cellular membranes and why: 

  • Adenosine
  • Adenosine phosphate

 

Definition

1. cAMP --> AMP --> Adenosine

 

2. Adenosine more readily traverses the cell membrane because it is lipid soluble. The phosphate molecule causes the adenosine phosphate to be more polarized and water soluble.

Term

Question 3.1 from book:

 

Which of the following statements concerning the parasympathetic nervous system is correct?

Definition

THE PARASYMPATHETIC DIVISION IS INVOLVED IN ACOMMODATION OF NEAR VISION, MOVEMENT OF FOOD AND URINATION


The PNS maintains essential body functions such as vision, movement of food and urination. It uses Ach as a neurotransmitter and it discharges as discrete fubers that are activated separately. The postganglionic fibers of the PNS are short compared to those of the SNS and the adrenal medulla is under the control of the SNS.

Term

Question 3.2 from the book:

 

Which of the following is characteristic of parasympathetic stimulation?

Definition

CONTRACTION OF SPHINCTER MUSCLE IN THE IRIS OF THE EYE (MIOSIS)


The PNS is essential in the maintenance activities such as digestion and waste removal. Increased intestinal motility to facilitate peristalsis, relaxation of the urinary bladder sphincters to cause urination and increased bronchial secretions.

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