The Division Of The Nervous System (Including Fight-Or-Flight) Flashcards
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What is the nervous system?
A network of nerve cells that carry messages between the CNS and the rest of the body.
What is the central nervous system (CNS)?
The body’s master control unit, concerned with all life functions and psychological processes.
What does the central nervous system (CNS) consist of?
•Brain.
•Spinal cord.
What does the brain do in the CNS?
-Mental processing (e.g. problem solving & planning).
-Body functions (e.g. regulating body temperature & heart rate).
What are the brain’s two functions in the CNS?
-Receives information from sensory receptors.
-Sends messages (electrical signals) to muscle glands.
What does the spinal cord do in the CNS?
It is an extension of the brain, ensuring that signals from the brain are transmitted to the rest of the body via the PNS.
What is the peripheral nervous system (PNS)?
A system that relays sensory information between the CNS and muscles.
What are the two divisions of the peripheral nervous system (PNS)?
•Autonomic Nervous System (ANS).
•Somatic Nervous System (SNS).
What is the autonomic nervous system (ANS)?
A system that controls involuntary actions (e.g. breathing, heart rate). It is also involved in homeostasis.
What are the two divisions of the autonomic nervous system (ANS)?
•Sympathetic.
•Parasympathetic.
What is the somatic nervous system (SNS)?
A system that controls voluntary (conscious) actions (e.g. picking up a cup of tea).
What is sympathomedullary pathway short for?
SAM.
What is the sympathetic nervous system?
A system that increases bodily activities and prepares the body for fight-or-flight situations.
What phrase best describes the sympathetic nervous system?
Fight-or-flight.
What is the amygdala?
The part of the brain that associates sense with emotional processes.
What is the hypothalamus?
A small part of the brain that regulates body drives (e.g. hunger and sex).
What is the adrenal medulla?
A small part of the adrenal glands that releases adrenaline & noradrenaline.
What is an acute stressor?
Sudden, short term stressors.
What is adrenaline?
A hormone that stimulates the nervous system for a quick fight-or-flight response.
What is the 5 step process for acute stressors (sympathetic nervous system)?
- The amygdala identifies a threat and sends a distress signal to the hypothalamus.
- The hypothalamus activates the sympathetic nervous system to trigger a fast response.
- The sympathetic nervous system sends an electrical signal to the adrenal medulla.
- The adrenal medulla releases adrenaline into the bloodstream, triggering the flight-or-flight response (increased heart rate, digestion halted, etc).
- This hormone stimulates the sympathetic ganglia, keeping activity at a high level.
What are the effects of sympathetic nervous system activation on the body?
•Increased heart rate.
•Pupil dilation.
•Digestion halted.
•Saliva inhibited.
•Glucose released.
What does HPA Axis stand for?
Hypothalamus-Pituitary-Adrenal Axis.
What is a chronic stressor?
Prolonged, long term stressors.
What is the pituitary gland known as?
The master gland.
What is corticotrophin-releasing hormone known as?
CRH.
What is adrenocorticotrophic hormone short for?
ATCH.
What is cortisol?
A stress hormone that gives a quick burst of energy and lower sensitivity to pain.
What is the process of chronic stressors (HPA Axis, sympathetic nervous system)?
H) The hypothalamus releases CRH into the bloodstream.
P) On arrival, the CRH causes the pituitary gland to produce and release ATCH (which is transported into the bloodstream to reach its target site - the adrenal glands).
A) ATCH stimulates the adrenal cortex to release cortisol.
What is the parasympathetic nervous system?
A system that counteracts the effects of SNS by decreasing bodily activities (decreased heart rate, digestion stimulated, etc).
What phrase best describes the parasympathetic nervous system?
Rest-and-digest.
What is the effect of the parasympathetic nervous system?
•Decreased heart rate.
•Pupil contraction.
•Digestion stimulated.
•Saliva produced.
•Glucose stored.
