Autonomic Nervous System Flashcards
sympathetic division parasympathetic division dynamic antagonism Origin of fibres preganglionic fibers postganglionic fibers (13 cards)
Describe the role of the parasympathetic division in the autonomic nervous system.
The parasympathetic division promotes maintenance functions and conserves body energy, often referred to as the ‘rest and digest’ system.
Explain the sympathetic division’s function during physical activity.
The sympathetic division mobilizes the body during activity, preparing it for exercise, excitement, and emergencies, often called the ‘fight or flight’ system.
How do the parasympathetic and sympathetic divisions interact to maintain homeostasis?
Both divisions generally innervate the same organs but have opposite effects, creating a dynamic antagonism that helps maintain homeostasis.
What physiological changes occur during the ‘rest and digest’ state?
During rest, heart rate and blood pressure decrease, pupils constrict, and the body promotes digestion, defecation, and diuresis.
What are the three Ds associated with the parasympathetic division?
The three Ds are Digestion, Defecation, and Diuresis.
What happens to the body during the ‘fight or flight’ response?
During excitement, heart rate and blood pressure increase, visceral blood vessels constrict, pupils dilate, and bronchiole diameter increases while gastrointestinal activity decreases.
Define the term ‘dynamic antagonism’ in the context of the autonomic nervous system.
Dynamic antagonism refers to the opposing effects of the sympathetic and parasympathetic divisions on the same organs, which helps regulate bodily functions and maintain homeostasis.
How does the body prepare for emergencies according to the sympathetic division?
The body prepares for emergencies by mobilizing energy stores, increasing heart rate and blood pressure, dilating pupils, and enhancing airflow in the lungs.
What is the significance of the autonomic nervous system being partially active at all times?
The partial activity of both divisions ensures that the body can quickly respond to changes in the environment and maintain homeostasis.
Describe the origin of the parasympathetic fibers.
Parasympathetic fibers originate in the brainstem (cranial fibers) or sacral spinal cord.
Explain the length of preganglionic and postganglionic fibers in the parasympathetic system.
In the parasympathetic system, the preganglionic fibers are long and the postganglionic fibers are short.
Where are the ganglia located in the parasympathetic system?
The ganglia in the parasympathetic system are located with or near visceral effector organs.
Describe the origin of the sympathetic fibers.
Sympathetic fibers originate in the thoracic and lumbar spinal cord.
