Auto-Pilot Mode
Which situation BEST demonstrates autonomic homeostasis?
a. Voluntary blinking during bright light
b. Increased heart rate while running
c. Reflex increase in BP during standing
d. Conscious control of breathing
C. Reflex increase in BP during standing
Damage to which structure would MOST directly impair coordination of SNS and PNS activity?
a. Thalamus
b. Hypothalamus
c. Cerebellum
d. Hippocampus
B. Hypothalamus
Which fiber releases acetylcholine BUT does NOT act on muscarinic receptors?
a. Sympathetic preganglionic
b. Parasympathetic postganglionic
c. Parasympathetic preganglionic
d. Somatic motor neuron
A. Sympathetic preganglionic
Which finding is MOST consistent with sympathetic activation?
a. Increased bowel sounds
b. Pupillary constriction
c. Bronchodilation
d. Increased salivation
C. Bronchodilation
Stimulation of which nerve MOST likely causes decreased heart rate?
a. Phrenic
b. Vagus
c. Accessory
d. Hypoglossal
B. Vagus
Which statement BEST distinguishes the ANS from the somatic nervous system?
a. ANS uses two neurons in series
b. ANS uses only acetylcholine
c. ANS innervates only smooth muscle
d. ANS is completely involuntary
A. ANS uses two neurons in series
A patient with hypothalamic damage is MOST likely to have difficulty regulating which processes?
a. Voluntary movement
b. Body temperature
c. Memory formation
d. Language
B. Body temperature
Activation of which receptor will MOST directly decrease heart rate?
a. M2
b. α1
c. β1
d. β2
A. M2
Which sympathetic effect is mediated primarily by circulating hormones rather than direct nerves?
a. Pupil dilation
b. Increased sweating
c. Vasoconstriction in skin
d. Increased cardiac output
D. Increased cardiac output
Which anatomical feature BEST explains why parasympathetic effects are more localized?
a. Short preganglionic fibers
b. Long postganglionic fibers
c. Ganglia near target organs
d. High neurotransmitter diffusion
C. Ganglia near target organs
Modified TRUE or FALSE
All autonomic motor pathways use only one neuron.
False
Uses two neurons
Modified TRUE or FALSE
The spinal cord alone controls autonomic activity.
False
Hypothalamus is the main controller
Modified TRUE or FALSE
Nicotinic receptors are G-protein coupled receptors.
False
Ligand-gated ion channels
Modified TRUE or FALSE
Sympathetic postganglionic neurons release acetylcholine to most organs.
Norepinephrine
Modified TRUE or False
Parasympathetic postganglionic neurons act on nicotinic receptors.
False
Muscarinic receptors
Identify the two neurons in an autonomic pathway.
Preganglionic and Postganglionic neurons
Identify the reflex that maintains blood pressure.
Baroreceptor reflex
What is the receptor responsible for bronchodilation?
β2-adrenergic receptor
What is the ganglia located anterior to the vertebral column?
Prevertebral ganglia
Identify the response: Pupillary constriction, increased digestion.
Parasympathetic response
What is the ANS principle explaining constant baseline activity?
Autonomic tone
Identify the pathway: CN IX → Medulla → Vagus → Heart.
Baroreceptor reflex pathway
What is the receptor blocked by atropine?
Muscarinic receptor
What is the structure that releases epinephrine directly into blood?
Adrenal medulla
A patient has salivation, urination, diarrhea, and bradycardia. What is the dominant division?
Parasympathetic Nervous System