6.1.2.2.1 Sympathetic Nervous System

• What is the Sympathetic Nervous System a part of?

  Autonomic nervous system
• What happens to the pupils during sympathetic activation?

  Pupils dilate
• What effect does sympathetic activation have on the lungs?

  It relaxes airways
• What are the key differences between the functions of the parasympathetic and sympathetic nervous systems?

  • Parasympathetic system is responsible for "rest and digest" functions, while sympathetic system controls "fight or flight" responses
  • Parasympathetic system conserves and restores energy, sympathetic system mobilizes energy
  • Parasympathetic system slows heart rate, sympathetic system increases heart rate
  • Parasympathetic system stimulates digestion, sympathetic system inhibits digestion
• What hormone does the pituitary gland secrete during the fight-or-flight response?

  ACTH
• What is released by the hypothalamus to activate the adrenal-cortical system?

  CRF
• How does the Sympathetic Nervous System help the body?

  It prepares the body to take action
• Approximately how many hormones are released by the adrenal cortex when stimulated by ACTH?

  30 hormones
• What is released by the adrenal medulla?

  Norepinephrine and epinephrine
• How do the physiological responses of the sympathetic nervous system prepare the body for danger?

  They enable the body to fight or flee
• What effect does norepinephrine have on the body?

  Increases blood pressure, enhances alertness
• How do the sympathetic and parasympathetic systems interact with each other?

  They produce opposing effects on organs
• What is the effect of impulses activating glands and smooth muscles?

  Triggers fight-or-flight
• What are the key effects of the sympathetic and parasympathetic nervous systems?

  • Sympathetic:
  • Increased heart rate (HR)
  • Dilated pupils
  • Relaxed airways
  • Parasympathetic:
  • Slowed heart rate (HR)
  • Constricted pupils
  • Constricted airways
• What are the key differences between the functions of the parasympathetic and sympathetic nervous systems?

  • Parasympathetic system is responsible for "rest and digest" functions, while sympathetic system controls "fight or flight" responses
  • Parasympathetic system conserves and restores energy, sympathetic system mobilizes energy
  • Parasympathetic system slows heart rate, sympathetic system increases heart rate
  • Parasympathetic system stimulates digestion, sympathetic system inhibits digestion
• What are the key differences between the parasympathetic and sympathetic nervous systems?

  • Parasympathetic system constricts pupils, sympathetic system dilates pupils
  • Parasympathetic system stimulates salivation, sympathetic system inhibits salivation
  • Parasympathetic system slows heartbeat, sympathetic system increases heartbeat
  • Parasympathetic system constricts airways, sympathetic system relaxes airways
  • Parasympathetic system stimulates stomach/intestines, sympathetic system inhibits them
• What are the effects of the parasympathetic and sympathetic nervous systems on the body?

  Parasympathetic nervous system:

  • Stimulate salivation
  • Slow heartbeat
  • Constrict airways
  • Stimulate activity of stomach
  • Stimulate gallbladder
  • Stimulate activity of intestines
  • Contract bladder

  
  

  Sympathetic nervous system:

  • Inhibit salivation
  • Increase heartbeat
  • Relax airways
  • Inhibit activity of stomach
  • Inhibit gallbladder
  • Inhibit activity of intestines
  • Secrete epinephrine & norepinephrine
  • Relax bladder
• What are the main functions of the Sympathetic Nervous System?

  • Prepares the body for stress
  • Increases heart rate
  • Dilates airways
  • Inhibits digestion
  • Mobilizes energy stores
• What is the source of norepinephrine?

  Nerve endings
• What effect does the Sympathetic Nervous System have on alertness?

  It heightens alertness
• What is the primary function of the Sympathetic Nervous System?

  Prepares the body for action under stress
• What response does the sympathetic nervous system activate?

  Fight-or-flight response
• How does the Sympathetic Nervous System affect heart rate?

  It increases heart rate
• What system does the hypothalamus activate directly during the fight-or-flight response?

  Sympathetic nervous system
• What is the primary response of the sympathetic nervous system during stress?

  Fight-or-flight response
• What are the two ways the adrenal glands activate during the fight-or-flight response?

  • Adrenal medulla releases quick-acting hormones (epinephrine, norepinephrine)
  • Adrenal cortex releases sustained-release hormones (cortisol)
• What are the key differences between the parasympathetic and sympathetic nervous systems?

  • Parasympathetic system constricts pupils, sympathetic system dilates pupils
  • Parasympathetic system stimulates salivation, sympathetic system inhibits salivation
  • Parasympathetic system slows heartbeat, sympathetic system increases heartbeat
  • Parasympathetic system constricts airways, sympathetic system relaxes airways
  • Parasympathetic system stimulates stomach/intestines, sympathetic system inhibits them
• What two hormones are released by the adrenal medulla during the fight-or-flight response, and where are they released?

  • Norepinephrine and epinephrine
  • Released into the bloodstream
• How do the adrenal glands contribute to the fight-or-flight response?

  They release hormones that prepare the body
• What does the sympathetic nervous system activate?

  Adrenal medulla
• What is the effect of the parasympathetic nervous system on the pupils?

  Constrict pupils
• What is the sequence of the initial hormonal events in the fight-or-flight response?

  • Hypothalamus releases CRF
  • Pituitary gland secretes ACTH
  • ACTH arrives at adrenal cortex
  • Adrenal cortex releases approximately 30 hormones
• What is the primary function of the sympathetic nervous system in the "fight-or-flight" response?

  To prepare the body for danger
• What combines to constitute the fight-or-flight response?

  Hormones and neural activity
• How can the Sympathetic Nervous System be described metaphorically?

  As the body's emergency response team
• What is the overall purpose of the fight-or-flight response?

  To prepare the body to either confront or escape a perceived threat by:

  • Activating the sympathetic nervous system
  • Releasing hormones into the bloodstream
• When does the Sympathetic Nervous System activate?

  When facing something stressful
• Where does ACTH travel to after being secreted by the pituitary gland?

  Adrenal cortex
• What functions does the parasympathetic nervous system trigger?

  Rest-and-digest functions
• How do the physiological changes from sympathetic activation prepare the body for action?

  They maximize oxygen intake, blood flow, and alertness