Week 2: Autonomic Nervous System
Anesthesia & the ANS
- Anesthesiology is the practice of _______(1) medicine.
- Drugs that produce anesthesia may also have potent _______(2) side effects.
- The greater part of our training and practice is spent acquiring skills in utilizing or averting the _______(3) (ANS) side effects of anesthetic drugs under a variety of pathophysiologic conditions.
- The success of any anesthetic depends upon how well _______(4) is maintained.
- What happens during DL?
- Produces a lot of _______(5) on the system
Answers:
1. autonomic
2. autonomic
3. autonomic nervous system
4. homeostasis
5. strain
Chassaignac Tubercle
- The most prominent _______(1) in the neck
- The anterior tubercle of the transverse process of the _______(2), against which the carotid artery may be compressed by the finger (i.e., carotid massage).
- Extremely sensitive to stimulation during laryngoscopy.
- How can we avoid a sympathetic response during intubation?
- _______(3)
- Laryngoscopy and endotracheal intubation is the most stimulating procedure leading to acute hemodynamic responses (HDR) lasting for at least 10 min.[1,2] Stretching of pharyngeal and laryngeal mucosal tissue causes sympathoadrenal response resulting in HDR such as an increase in heart rate (HR), blood pressure (BP), and even ischemic ST-segment changes caused by the release of _______(4).
Study the Features Typical For Cervical Vertebrae (ChatGPT is unable to recognize this image)
Answers:
1. tubercle
2. 6th cervical vertebra
3. Give induction Drugs
4. catecholamines
Anesthesia & the ANS
- The ANS includes that part of the central and peripheral nervous system concerned with _______(1) regulation of cardiac muscle, smooth muscle, and glandular and visceral functions.
- ANS activity refers to _______(2) reflexes that function below the conscious level. The ANS is also responsive to changes in somatic motor and sensory activities of the body.
- The main effect of vagal cardiac stimulation to the heart is _______(3). Vagal stimulation decreases the _______(4).
- The main effect of vagal cardiac stimulation to the heart is _______(3). Vagal stimulation decreases the rate of sinoatrial node discharge and decreases excitability of the AV junctional fibers, slowing impulse conduction to the ventricles.
- A strong vagal discharge can completely arrest sinoatrial node firing and block impulse conduction to the _______(5).
Answers:
Anesthesia & the ANS
Answers:
Functional Anatomy:
Answers:
Table 14-1 Homeostatic Balance Between Adrenergic and Cholinergic Effects 12
Organ System | Adrenergic | Cholinergic
Heart
Sinoatrial node | _______(1) | _______(2)
Atrioventricular node | Increased conduction | Decreased conduction
His-Purkinje | Increased automaticity and conduction velocity | Minimal
Myocardium | Increased _______(3), conduction velocity, automaticity | Minimal decrease in _______(3)
Coronary vessels | Constriction (α1) and dilation (β1) | Dilation and constriction
Answers:
Review on your own…
ANS Transmission
- Transmission of excitation across the terminal junctional sites (_________(3)) of the peripheral _______(4) occurs through the mediation of released chemicals
- Transmitters interact with receptors on the end organ to evoke a biologic response.
Answers:
Receptors
Answers:
Autonomic Nervous System Reflexes and Interactions
Please review these sections on your own:
- _______(1) (page 349)
- _______(2) Heart (page 349)
- Interaction of ANS Receptors (page 350)
- Interaction with other regulatory systems to include the _______(3) (RAAS) (Page 350)
- Clinical Autonomic Nervous System Pharmacology (Pages 351 – 356)
Autonomic Syndromes & Autonomic Regulation
- Horner Syndrome
- Diabetic Neuropathy
- Orthostatic Hypotension
- Monoamine oxidase inhibitors (MAOIs)
- Tricyclic antidepressants
- Selective Serotonin Reuptake Inhibitors (SSRIs)
- Great information to review however, I will not include this information on the _______(4) exam
Answers:
CV Pharmacology
Hemodynamic Goals
Answers:
CV Anatomy and Physiology
Study the Schematic illustration of β-adrenoreceptor agonist mechanism of action (ChatGPT is unable to recognize this image)
Answers:
Selection of the Anesthetic
- No _______(1) anesthetic for patients with CAD.
- Choice should depend on the extent of pre-existing myocardial ______(a) and the ______(b) of the drugs.
- Most patients with mid or even moderate dysfunction may _______(c) from some degree of _______(2).
Cardiovascular drugs
- Used to adjust all components of cardiac output and organ perfusion
- Preload (end-diastolic volume) —> _______(3) to tension
- Afterload (vascular tone)
- Inotropy (contractility)
- Chronotropy (heart rate)
- Cardiac output
- Myocardial O2 supply and demand
Answers:
1. ideal
a. dysfunction
b. properties
c. benefit
2. myocardial depression
3. related
Preload
- Determines how well the pump is _______(1).
- Directly related to tension developed in the ventricle.
- Filling pressure of the ventricles at the end of the diastole.
- _______(2) is the product of systemic venous return.
Answers:
Afterload
- Impedance to _______(1) _______(2)
- Can be altered with drugs that _______(3) or ______(a) vascular beds - mostly via arterial vessels
- Arterial vasodilators decrease resistance to ventricular contraction but can also _______(4) _______(5)
- Clinical indicator for right ventricular afterload is _______(6) _______ or (7)
(MPAP – PCWP x 80) / CO = (50-120 dynes/sec/cm-5)
(MAP - RAP X 80) / CO = (800-1200 dynes/sec/cm-5)
NO FORMULAS ON THE TEST PER TOLSON PER ANDREW-SON
WILL NOT ASK FOR FORMULAS ON THIS EXAM PER MASTA TOLSEN
Contractility
- _______(10) of ventricular contraction and is defined as the _______(11) state of the heart.
- _______(12) agents affect the contraction of the heart muscle.
- Factors that influence ______(b)
- Appropriate amounts of _______(13), sodium and calcium
- Sympathetic nervous system via beta 1 receptors stimulation (increased contractility, HR, ventricular automaticity, and myocardial oxygen consumption
- Increased levels of _______(14) _______ or (15)
- Preload and afterload
Answers:
Cardiac output
- Volume of blood that the heart ejects each _______(1).
- CO = SV x HR
- SV = EDV-ESV
- Normal = 4 - 8 L/min
- Cardiac index (CI) adjusts the CO value for an individual _______(2) _______(3).
- CI = CO divided by BSA (2.5 - 4.0 L/min)
- 3 primary factors that determine CO (SVxHR)
- _______(4)
- _______(5)
- _______(6)
Answers:
Myocardial Oxygen Supply & Demand
- Myocardial oxygen supply is determined by oxygen content of _______(1) blood and _______(2) perfusion.
- Coronary perfusion is influenced by heart rate
- (Slower heart rate increases diastolic time thus allowing for increased coronary perfusion)
- Source: Filled during _______(3) via the _______(4)
Answers:
Adrenergic Receptors
- _______(1) is the neurotransmitter responsible for most adrenergic activity of the sympathetic nervous system.
- Norepinephrine is released by _______(2) sympathetic fibers at end ______(a).
- _______(3) synapses near spinal cord, parasympathetic synapses near end organ
- Action of ______(b) is terminated by _______(4) into the _______(5) nerve ending.
- Divided into alpha and beta receptors.
Alpha 1 Receptors
- Located in smooth muscle throughout the body.
- The most important cardiovascular effect of alpha-1 stimulation is _______(6).
- Increase in peripheral vascular resistance.
- Increase in arterial blood pressure.
Answers:
Alpha 2 Receptors
- Located ______(a) on the _______(1) nerve terminals.
- Stimulation of Alpha 2 receptors creates a ______(b) feedback loop that ______(c) further norepinephrine (NE) release. Decreases _______(2). → _______(3) = alpha 2 agonist = hypotension
- ______(d) (blockage) of Alpha 2 receptors causes an enhanced release of NE from nerve endings.
- Note the added complexity and detail in Barash re: _______(4) Alpha 2
Beta 1 Receptors
- Most important Beta 1 receptors are located on _______(5) membranes in the heart
- Stimulation activates _______(6), which converts ______(e)
- Increases heart rate, conduction, and contractility
- “Positive inotrope”
- Positive: Chronotropy, dromotropy (affects the conduction speed in the _______(7) node), inotropy
Beta 2 Receptors
- Located on _______(8) receptors in ______(f).
- Stimulation _______(9) smooth muscle, resulting in bronchodilation, _______(10), and relaxation of the uterus, bladder, and gut.
Answers:
a. CHIEFLY
1. presynaptic
b. negative
c. inhibits
2. vasoconstriction
3. precedex
d. Antagonism
4. postsynaptic
5. post-synaptic
6. adenylyl cyclase
e. ATP to cAMP
7. AV
8. post-synaptic
f. smooth muscle and gland cells
9. relaxes
10. vasodilation
Familiar Drugs and Classifications
Answers
a. Epinephrine
b. Norepinephrine
c. Phenylephrine
d. Methoxamine (Vasoxyl)
e. Clonidine
f. Dexmedetomidine (Precedex)
g. Phentolamine (Regitine)
h. Phenoxybenzamine
i. Prazosin (Minipress)
j. Doxazosin (Cardura)
k. Terazosin (Hytrin)
l. Yohimbine
Catecholamines
A1: N>E>D>I
A2: E>N>D>I
B1: I>E>N>D
B2: I>E>N>D
B3: I>N>E>D
Epinephrine
- Stimulates Alpha 1 + 2, and Beta 1 + 2 receptors
- Alpha 1 stimulation increases coronary and cerebral perfusion pressures and systolic BP. → _______(6) to save ur life so sends blood to heart and brain mainly
- However, stimulation of alpha 1 receptors in the skin, mucosa, and hepatorenal vasculature causes vasoconstriction and _______(7) flow.
- Beta_1 stimulation causes an increase in contractility & heart rate, which leads to increased CO and MVO2 (demand).
- Beta_2 stimulation causes vasodilation in _______(8) and _______(9) smooth muscle; may _______(10) diastolic pressure.
- Volatile anesthetics ______(a) dysrhythmic effects.
- Principal pharmacologic treatment for anaphylaxis and ventricular fibrillation
- Complications include cerebral hemorrhage, coronary ischemia, and ventricular arrhythmias.
- WILL NOT ASK FOR DOSAGES
Answers:
1. dopamine
2. norepinephrine
3. epinephrine
4. isoproterenol
5. dobutamine
6. flows
7. decreases
8. skeletal muscles
9. bronchial
10. decrease
a. potentiate
Norepinephrine
Answers:
1. increases
2. bradycardia
3. increases
4. Beta 2
5. cardiac output
6. limits
7. Decreases
Dopamine
Answers:
Clinical Case Study
Answers:
1. Renal Vasodilation
2. increased myocardial contractility, HR, and CO
3. Dobutamine
4. do
Dobutamine
Answers:
a. dopamine
1. isoproterenol
2. agonist
b. norepinephrine
3. Does not