Nervous System Physiology Part 11 Flashcards
What are the effects of autonomic nervous system on cellular metabolism and adipose tissue?
Parasympathetic :No effect (no innervation)
Sympathetic:Increases metabolic rate*
What are the effects of autonomic nervous system on adipose tissue?
Parasympathetic :No effect Sympathetic:Stimulates lipolysis
What are the heart and many glands and smooth muscles innervated by?
sympathetic and parasympathetic fibers; that is, they receive dual innervation.
Whatever effect one division has on the effector cells, the other division usually has the
Opposite effect
Sympathetic and Parasympathetic divisions are usually activated….
reciprocally; that is, as the activity of one division increases, the activity of the other decreases.
When does the sympathetic system increase its activity ?
under conditions of physical or psychological stress.
What is the genearalized activation of sympathetic system called?
the fight-or-flight response, describing the situation of an animal forced to either challenge an attacker or run from it.
List 5 physiological changes during the fight-or-flight response.
- Heart rate and blood pressure increase
- Blood flow increases to skeletal muscles, heart, and brain
- Liver releases glucose
- Pupils dilate
- Gastrointestinal activity and blood flow to it are inhibited by sympathetic firing.
What is the reason for increased heart rate during the fight-or-flight response?
To increase blood flow to organs and increase the movement of adrenaline around the body.
Why does breathing rate increase during the fight-or-flight response?
To increase oxygen intake.
What is the purpose of pupil dilation during the fight-or-flight response?
To increase light entry into the eye and enhance vision (especially in the dark).
Why is sweat produced during the fight-or-flight response?
To regulate temperature
Why are non-essential functions (like digestion, urination, and salivation) reduced during the fight-or-flight response?
To increase energy for other essential functions
What are the two divisions of the autonomic nervous system and their roles?
• Sympathetic: “Fight or flight” response
• Parasympathetic: “Rest and digest” state
Is the autonomic nervous system (ANS) under voluntary control?
No, it is regulated by CNS controls including the spinal cord, brain stem, hypothalamus, and cerebral cortex.
What is the integrative center at the top of the ANS control hierarchy?
The hypothalamus
How can the cerebral cortex modify the workings of the ANS?
it does at the subconscious level and by acting through limbic system structures on hypothalamic centers
What autonomic functions are controlled by the brain stem?
Arterial pressure, heart rate, glandular secretion, gastrointestinal peristalsis, and degree of urinary bladder contraction.
Which areas of the brain stem are involved in autonomic control?
Reticular substance, tractus solitarius of the medulla, pons, mesencephalon, and special nuclei.
What is the main integration center of the autonomic nervous system?
The hypothalamus
What functions does the hypothalamus coordinate through the ANS?
Heart activity, blood pressure, body temperature, water balance, and endocrine activity.
How does the hypothalamus mediate our reactions to emotion( fear)?
Via its associations with the amygdala and the periaqueductal gray matter.
How does the limbic system contribute to the fight-or-flight response?
Emotional responses of the limbic system of the cerebrum to danger and stress signal the hypothalamus to activate the sympathetic system to fight-or-flight status.
What role does the hypothalamus play in the emotional-visceral connection?
hypothalamus serves as the keystone of the emotional and visceral brain. Through its centers, emotions influence ANS function and behavior
