20 physiological effects the parasympathetic and sympathetic nervous system have on the body

Question 1

Physiological Effects of the Parasympathetic Nervous System

Heart Rate:

Answer 1

• The parasympathetic nervous system decreases heart rate (negative chronotropy) by inhibiting the SA node, slowing down cardiac impulses.

Question 2

Physiological Effects of the Parasympathetic Nervous System

Respiratory Rate:

Answer 2

• Parasympathetic activation reduces respiratory rate and depth by decreasing the activity of the respiratory centres in the brainstem.

Question 3

Physiological Effects of the Parasympathetic Nervous System

Digestion:

Answer 3

• Parasympathetic stimulation increases gastrointestinal motility and secretion, promoting digestion and nutrient absorption.

Question 4

Physiological Effects of the Parasympathetic Nervous System

Salivation:

Answer 4

• Parasympathetic activity stimulates salivary gland secretion, aiding in the breakdown of food and initiating the digestive process.

Question 5

Physiological Effects of the Parasympathetic Nervous System

Genitourinary Function:

Answer 5

• Parasympathetic stimulation promotes bladder contraction (micturition) and relaxation of the internal urethral sphincter for urination.

Question 6

Physiological Effects of the Parasympathetic Nervous System

Eye Function:

Answer 6

• The parasympathetic system constricts the pupils (miosis) for near vision and stimulates accommodation for focusing on close objects.

Question 7

Physiological Effects of the Parasympathetic Nervous System

Glandular Secretion:

Answer 7

• Parasympathetic activation increases secretion from glands such as lacrimal (tear) glands, promoting eye moisture.

Question 8

Physiological Effects of the Parasympathetic Nervous System

Blood Vessels:

Answer 8

• The parasympathetic system has minimal direct effects on blood vessels, but it can cause vasodilation in specific areas like the genitals during sexual arousal.

Question 9

Physiological Effects of the Parasympathetic Nervous System

Immune Response:

Answer 9

• Parasympathetic activity may modulate immune function, supporting anti-inflammatory responses.

Question 10

Physiological Effects of the Parasympathetic Nervous System

Metabolism:

Answer 10

• The parasympathetic nervous system conserves energy and promotes anabolic processes (e.g., glycogenesis, storage of nutrients).

Question 11

Physiological Effects of the Sympathetic Nervous System

Heart Rate and Contractility:

Answer 11

• Sympathetic activation increases heart rate (positive chronotropy) and contractility (positive inotropy), enhancing cardiac output.

Question 12

Physiological Effects of the Sympathetic Nervous System

Respiratory Rate:

Answer 12

• Sympathetic stimulation leads to bronchodilation, increasing airway diameter for improved oxygen intake during fight-or-flight responses.

Question 13

Physiological Effects of the Sympathetic Nervous System

Digestion:

Answer 13

• Sympathetic activity inhibits gastrointestinal motility and secretion, redirecting blood flow away from the digestive system during stress.

Question 14

Physiological Effects of the Sympathetic Nervous System

Salivation:

Answer 14

• Sympathetic activation reduces salivary gland secretion, resulting in dry mouth during stress.

Question 15

Physiological Effects of the Sympathetic Nervous System

Genitourinary Function:

Answer 15

• Sympathetic stimulation relaxes the bladder wall and contracts the internal urethral sphincter, inhibiting urination (bladder retention).

Question 16

Physiological Effects of the Sympathetic Nervous System

Question 17

Physiological Effects of the Sympathetic Nervous System

Eye Function:

Answer 17

• The sympathetic system dilates the pupils (mydriasis) for improved vision in preparation for potential threats.

Question 18

Physiological Effects of the Sympathetic Nervous System

Blood Vessels:

Answer 18

• Sympathetic activation causes vasoconstriction in non-essential organs (e.g., skin, digestive tract) and vasodilation in skeletal muscles and the heart to support increased activity.

Question 19

Physiological Effects of the Sympathetic Nervous System

Metabolism:

Answer 19

• The sympathetic nervous system stimulates catabolic processes (e.g., glycogenolysis, lipolysis) to release energy for immediate use.

Question 20

Physiological Effects of the Sympathetic Nervous System

Adrenal Medulla Activation:

Answer 20

• Sympathetic nerves stimulate the adrenal medulla to release adrenaline (epinephrine) and noradrenaline (norepinephrine) into the bloodstream, amplifying the fight-or-flight response.

Question 21

Conclusion

Answer 21

• These effects illustrate the intricate balance and complementary actions of the parasympathetic and sympathetic nervous systems in regulating physiological functions to adapt to different situations, whether it’s rest and digestion (parasympathetic) or stress and activity (sympathetic). Understanding these responses is fundamental for paramedic students to assess and manage patients experiencing various physiological states or emergencies.