Unit 3 AOS1 Nervous System + Stress Flashcards
Nervous system and Stress
What is a neuron?
a neuron is the building block of the human nervous syetm. Neurons are nerve cell that recieve and transmit neural information.
What is a sensory neuron?
- AKA Afferent
- A sensory neuron is a type of neuron that receives sensory information from the PNS’s reciptor sites and sends the information to the CNS along AFFERENT pathways.
What is a motor neuron?
- AKA Efferent
- Motor neurons are a type of neuron that carries motor instruction from the CNS to the PNS via EFFERENT pathways to intitiate a movement.
What is a interneuron?
- Only found in the brain and spinal cord
- Transfers neural information bewteen sensory and motor neurons
What are the structures of a neuron?
- dendrites
- soma (cell body)
- nucelus
- axon
- myelin sheath
- axon terminals
- terminal buttons
What is in the CNS?
Brain and spinal cord
- Recieves sensory neural information from and transmits motor messages to the PNS
What makes up the PNS?
What does it do?
- all of the nerves outside of the CNS
- the Somaic NS (voluntary and reflex actions)
- The autonomic NS (involuntary)
- Carries messages between the CNS to all the muscles, organs and glands throughout the body
- Recieves motor info from the CNS and sends sensor info to the CNS
What makes up the autonomic NS?
- Sympathetic NS (action/ stress)
- Parasympathetic (calm/relaxation)
What are cranial nerves?
nerves apart of the PNS that the brain uses to communcicate directly to various organs and muscles
What is the vagus nerve?
- a cranial nerve that connects the brain directly to the stomach and intestinal tract controlling digestion involving the nerve cells of the enteric NS
- originates in the brain stem
What is the somatic NS?
What does it do/its role?
- contains sensory (afferent) and motor (efferent) neurons
1. carries Afferent information from the five senses to the CNS
2. carries Efferent information from the Central NS to the body involving motor (efferent) neurons
What is the Autonomic Nervous System?
- controls the body’s internal environment in an involuntary/autonomous and self-regulated manner
- it self regulates the body’s internal environment in an involuntary manner.
*directly connects the CNS to organs, glands and viscera; muscles
What is the sympathetic NS?
- dominates when we are under threat, increasing arousal and preparing the body for a quick response (also known as the Fight flight Freeze Response) from psychological or physiological stressful experience.
- self regulates the body’s arousal reponse when it is under threat. Prepares the body for a quick response *FFF for survival and defense
What is the Fight- Flight- Freeze Response?
- the body’s natural reaction to danger.
- fight-or-flight is an active defence response where you fight or flee.
Your heart rate gets faster, which increases oxygen flow to your major muscles. Your pain perception drops, and your hearing sharpens. When these changes occur, the Sympathetic NS is dominant. - Freezing is fight-or-flight on hold, where you further prepare to protect yourself. It’s also called reactive immobility or attentive immobility. You freeze and get ready for the next move
What is the parasympathetic NS?
- helps our body return to its normal state of homeostasis
- self regulates yhr body back to its baseline physiological levels
What is GABA and its role in the NS?
- main inhibitory neurotransmitter in thre NS
- it decreases the likelihood of the post synaptic neuron firing
- useful in the treatment of phobias (calms the NS)
- supresses/slows neural activity