Autonomic Nervous System Flashcards
The knee-jerk reflex is mediated by ___ nerves.
somatic
These reflexes are mediated by the autonomic nervous system (ANS).
Visceral reflexes (vis-er-uhl)
Regulate organ function.
Visceral reflexes (vis-er-uhl)
Controls heart rate, blood pressure, body temperature, digestion, airflow through respiratory passages, elimination, and pupillary (eye) responses.
Visceral reflexes (vis-er-uhl)
A visceral reflex is mediated in a manner similar to the knee-jerk reflex: activation of a ___, transmission of ___ information to the central nervous system (CNS), the processing of the information by the central nervous system (CNS), and the ___ response sent to the ___ organ(s).
receptor
sensory
motor
effector
A sudden decrease in blood pressure activates pressure ___ (baroreceptors). The information about the low blood pressure is carried to the medulla oblongata in the brain stem by ___ nerves. The medulla oblongata determines that the blood pressure is low and sends ___ signals to the visceral ___ organs (heart and blood vessels). The ___ response results in changes in the heart and blood vessels that elevate blood pressure.
receptors
sensory
motor
effector
motor
A sudden decrease in blood pressure stimulates a ___ reflex that restores blood pressure to normal. All this has been accomplished without ___ input.
visceral (vis-er-uhl)
conscious
The autonomic nervous system (ANS) is the part of the ___ nervous system that supplies motor activity to the effector organs: glands, smooth muscles within organs and tubes, and the heart.
peripheral
The two divisions of the autonomic nervous system (ANS) are the ___ and ___ nervous systems.
sympathetic
parasympathetic
The distribution of sympathetic and parasympathetic nerves to the viscera varies. A single organ most often receives fibres from both divisions of the autonomic nervous system (ANS); this is called:
dual innervation (in-nerve-ation).
The effects of autonomic stimulation are either antagonistic or cooperative because of ___ ___.
dual innervation (in-nerve-ation)
True or false: in most instances, stimulation of one division of the autonomic nervous system (ANS) causes a specific effect, whereas stimulation by the other division causes an antagonistic or opposing effect.
True
The cells of the heart that determine heart rate receive both sympathetic and parasympathetic fibres. Stimulation of the sympathetic fibres ___ heart rate, whereas stimulation of the parasympathetic fibres ___ heart rate.
increases
decreases
In a few organs that receive dual innervation, the effects of sympathetic and parasympathetic activity are ___ rather than antagonistic. For example, in the male, erectile activity is regulated by the parasympathetics, whereas ejaculation is regulated by the sympathetics. The sympathetics and parasympathetics work in a ___ way to achieve the desired effect: penetration of the female and ejection of the sperm.
cooperative x2
Finally, not all organs have dual innervation. For example, the blood vessels are innervated only by the ___ nervous system. Regulation of blood vessel diameter is achieved through an adjustment of ___ activity. Increased ___ activity causes constriction of the blood vessels, and decreased ___ activity causes the blood vessels to dilate.
sympathetic x4
