C1. P4 Flashcards
How are nerves formed?
The axons of neurons bundle together
What are afferent nerves?
Take information from the extremities of the body towards the spinal cord and brain
What are efferent nerves?
Carry information away from the brain and spinal cord
“All nerves are not the SAME” what is the s and a?
Sensory and afferent
“All nerves are not the SAME” what is the m and e?
Motor and efferent
Where are cranial nerves?
Directly connected to the brain or brainstem
What do cranial nerves do and how many are there?
They carry information for things that happen at the neck and above. There are 12 pairs of cranial nerves
Where are the spinal nerves?
They originate from the neurons in the spinal cord
What do spinal nerves do and how many are there?
They carry sensory information form the parts of the body below the neck to the spinal cord. There are 31 pairs of spinal nerves
What is the central nervous system?
The CNS is made up of the brain and spinal cord. It is the central processor and located in the central part of the body
What is the CNS responsible for?
Incoming information, integrating it with prior information, anticipating future events and consequences, formulating responses, and making decisions
How many neurons are in the spinal cord?
100 billion
What protects the spinal cord?
The vertebral column
What is the peripheral nervous system composed of?
Sensory and motor nerves
What is the primary job of the PNS?
To help the CNS monitor and regulate the internal environment and perceive and respond to the external environment
How does the PNS work?
It relays information from sensory organs to the CNS as well as carry motor information from the CNS to muscles along organs
What are the two branches of the PNS?
Sensory-somatic NS and autonomic NS
What does the SSNS do?
Monitors the external environment by communicating with organs
How does sensory information get to the brain?
Afferent cranial nerves bring information from the sensory system on the head and upper neck
How does information below the neck get to the brain?
Afferent spinal nerves send sensory information to the brain while the brain sends efferent spinal nerves to move muscles
What is a reflex arc?
An involuntary movement that is initiated without instructions from the brain
Can neurons activate muscles before we perceive the signal?
Yes, they can take the short path
What does the autonomic nervous system do?
Carries information to and from a wide range of internal structures to regulate internal organs
What are the three primary jobs of the autonomic nervous system?
Carries messages that regulate the body’s arousal level, carries signals that organize stress response, and alters physiology in accordance with emotions and motivational states
What are the two branches of the autonomic nervous system?
Parasympathetic and sympathetic NS
What effect do the parasympathetic and sympathetic nervous system have on each other?
Antagonistic effect
What does the sympathetic nervous system do?
Increases activity and boosts arousal, it is like a gas pedal
What does the parasympathetic nervous system do?
Acts like brakes, slows down arousal
How do the parasympathetic and sympathetic nervous system work together?
They change the body so we can respond to stress and alter bodily functions to regulate ourselves when we are not stressed
What happens when activity in the parasympathetic nervous system is increased?
Reduces arousal and activates several of the body’s upkeep processes
What is the rest and digest response?
Control of basic bodily functions while one is resting
What system initiates the fight flight freeze response?
Central nervous system
How is the sympathetic nervous system activated?
Threats, shame, bad news, physical damage
What is a result of activity in the sympathetic system?
High arousal of emotions
