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
What is neural activity manifested by?
electrical signals known as graded potentials and action potentials.
Is it possible to record the electrical activity in the brain’s neurons?
It is possible to record the electrical activity in the brain’s neurons - particularly those in the cortex near the surface of the brain -from the outside of the head
What are electrodes?
Electrodes are wires attached to the head by a salty paste that conducts electricity
Function of electrodes
pick up electrical signals generated in the brain and transmit them to a machine that records them as the EEG.
What does EEG stand for and what does it measure?
Electroencephalogram; it measures the electrical activity of neurons in the brain, especially those in the cortex.
What is the most prominent EEG wave pattern in an awake, relaxed adult with eyes closed?
The alpha rhythm (8–12 Hz).
What replaces the alpha rhythm when a person is alert or thinking hard?
The beta rhythm, which has a smaller amplitude and higher frequency (>12 Hz).
How does EEG change during sleep
It shifts to lower-frequency, larger-amplitude wave patterns known as Theta rhythm (4–8 Hz) and delta rhythm (slower than 4 Hz).
