Sympathetic Nervous System
The following statements are true about the sympathetic nervous system EXCEPT:
What our notes say
- The following statements are true about the sympathetic nervous system EXCEPT: (cat 2 2014 — Source Paper Awaiting Edit)
- The primary stimulus for catecholamine release from the adrenal medulla is sympathetic nervous system activation — triggered by stress, hypoglycaemia, exercise, haemorrhage, pain, or perceived threat (fight-or-flight response). (END YEAR PP1 & PP2 2025 Physiology: MCQs for Medical School Exams)
- Secretion: Released from the adrenal medulla, which is regulated by sympathetic nervous system activity. (Medical Physiology Pp2 Year 2)
- Sympathetic Nervous System Activation:The sympathetic nervous system (SNS) is activated and releases norepinephrine into brown adipose tissue (BAT). (Integrated Tissue Metabolism -LAQs and SAQs)
- The sympathetic nervous system undertakes the following functions EXCEPT: (cat 2 2014 — Source Paper Awaiting Edit)
- State five functional differences between parasympathetic and sympathetic nervous systems (Medical Physiology Assorted SAQs — With Answers (Past Paper Study Guide))
Study material on Sympathetic Nervous System
- Secretions of the Small Intestine and Their Control
- cat 2 2014 — Source Paper Awaiting Edit
- CLINICAL BIOCHEMISTRY LAQs & SAQs
- Integrated Tissue Metabolism -LAQs and SAQs
- Medical Physiology CAT 2 — 2014 (Past Paper)
- Weekly Pharmacology Exam - April 17, 2026 (Section A: MCQs)
Practice questions on Sympathetic Nervous System
The function of which of the following organs or systems is dominated by the sympathetic nervous system?
- Systemic blood vessels
- Heart
- Gastrointestinal gland secretion
- Salivary glands
- Gastrointestinal motility
Answer: A. Systemic blood vessels receive predominantly sympathetic innervation and have minimal parasympathetic innervation. Sympathetic stimulation causes vasoconstriction of most systemic vessels. The other organs listed receive dual innervation from both sympathetic and parasympathetic systems, with varying degrees of dominance. ---
Full activation of the sympathetic nervous system, as in the fight-or-flight reaction, may occur during maximal exercise. Which of the following effects is most likely to occur?
- Bronchoconstriction
- Increased intestinal motility
- Decreased renal blood flow
- Miosis
- Bradycardia
Answer: C. During sympathetic activation, blood is redirected from non-essential organs (including kidneys and GI tract) to skeletal muscles, heart, and brain. This causes decreased renal blood flow. Other sympathetic effects include bronchodilation, decreased GI motility, mydriasis (pupil dilation), and tachycardia. --- ---
Full activation of the sympathetic nervous system, as in the fight-or-flight reaction, may occur during maximal exercise. Which of the following effects is most likely to occur?
- Bronchoconstriction
- Increased intestinal motility
- Decreased renal blood flow
- Miosis
- Bradycardia
Answer: C. During sympathetic activation, blood is redirected from non-essential organs (including kidneys and GI tract) to skeletal muscles, heart, and brain. This causes decreased renal blood flow. Other sympathetic effects include bronchodilation, decreased GI motility, mydriasis (pupil dilation), and tachycardia. --- ---
Which neurotransmitter is released by the postganglionic neurons of the sympathetic nervous system?
- GABA
- Dopamine
- Serotonin
- Norepinephrine
- as their neurotransmitter. This activates adrenergic receptors on target organs, producing the "fight or flight" response…
Answer: D. Most postganglionic sympathetic neurons release norepinephrine (noradrenaline) as their neurotransmitter. This activates adrenergic receptors on target organs, producing the "fight or flight" response characteristic of sympathetic activation. --- ---
Which neurotransmitter is released by the postganglionic neurons of the sympathetic nervous system?
- Acetylcholine
- Norepinephrine
- Dopamine
- Serotonin
Answer: B. With the exception of sympathetic postganglionic neurons innervating sweat glands (which release acetylcholine), most sympathetic postganglionic neurons release norepinephrine.
Full activation of the sympathetic nervous system (fight-or-flight) during maximal exercise will most likely result in:
- Constriction of pupils (miosis)
- Decreased heart rate
- Dilation of bronchioles
- Increased gastric motility
Answer: C. Sympathetic activation causes bronchodilation via beta-2 receptors to improve air flow during exercise.