chapter 2 Flashcards
(86 cards)
Definition of neuron
nerve cell that transmits information from one part of the body to another via neural impulses
- 1 billion in spinal cord
- 100 billion in brain
Genetic information is found in what part of the neuron
The Soma or cell body
correct neural sequence
dendrite, cell body, axon, synapse
names and functions of the neuron
- neural impulse: change in electrical charges
- ions: electrically charged atoms & molecules
- resting potential: inactive (-70mV)
- action potential: brief change in neurons electrical charge (+40mV)
- all–or–none principle: stimulated neuron either will or will not fire at all
- Neurothreshold: minimum amount of stimulation
— if not met (-60mV) continue to be inactive (-70mV)
how many neurons are in the human brain
100 billion neurons
what is the speed of a neuron… myelinated versus unmyelinated
200 mph
150 m/s — myelinated
0.5-10 m/s — unmyelinated

What is neurogenesis and where does it occur
- growth and development of neurons
- occurs in lower region or base of brain
ions help neurons do what
fire, by giving them “fuel” by transferring ions (sodium potassium and chloride) outside of the neurons to inside 
what is the mV rating for a neuron at rest and at its neural threshold
rest: -70mV
neural threshold: -60mV
describe the all-or-none principle
The neuron either fires or it doesn’t
- requires rest before another fire
Synapse
The junction between the axon terminal and the dendrite of the next neuron
- neuron communicate with other cells
Vesicles containing what
Neurotransmitters (chemical messengers)
the “washing away” or “vacuuming affect” a neurotransmitters is technically called what
Re-uptake
what are the different divisions of the nervous system and what do they do
-CNS- brain and spinal cord
— Receives, stores, transmits, and processes sensory information
-PNS- connects all parts of the body with CNS
— somatic and autonomic
— sends and receives sensory information from the outer (peripheral parts) of the body and back to the CNS

What is the endocrine system and what does it do
- glands that secrete chemicals into the bloodstream to help control bodily functions
- partner to the nervous system
What are hormones and how do they work
- chemicals release into blood stream
- deliver messages to the body like neurotransmitters
- fight or flight response: adrenaline released during stressful events
Neurons in the spinal cord in the effects of injuries to his neurons
- sensory: carry impulses to brain/spinal cord
- motor: carry impulses away from brain/spinal cord and two muscles and glands
- interneurons: within the CNS
What is the knee-jerk response and where is it processed
- urgent “pain” messages I responded to by the neurons and the spinal cord
- spinal cord
lower/mid region of the brain and what its responsible for
-lower: medulla pons cerebellum
— unconscious but essential functions; heart rate and breathing
— cross lateralization
— balance, alertness, focus, and sleep
-mid: reticular activating system
— filters out unwanted stimuli
— nerve fibers involved in maintaining levels of arousal
— reticular formation
Upper region of the brain and its responsibilities
- limbic system: emotion, motivation, memory
— amygdala: emotion
— hippocampus: memory - thalamus: relay station
- hypothalamus: Basic biological needs
— Controls ANS (metabolic rate, glucose levels) - basal ganglia: slow movements and motor responding
— Parkinson’s, Huntington’s, OCD by deterioration
what does the brain stem include
- medulla: controls involuntary functions (coughing, sneezing)
- pons: relay station for sensory messages from the spinal cord and face, up to higher brain centers; high impulses from upper brain to lower body - cross lateralization: fiber on one side of the body connects to opposite side of the brain
what is the medulla responsible for
unconscious essential functions
- freezing, heart rate, digestion
What is cross lateralization
when the right hemisphere controls the left side of the body and vice versa
- reasons are unknown
The reticular activating system or RAS is responsible for what
complex network of nerve fibers involved in maintaining levels of arousal
- keeps you at certain level of awareness
- filters out unwanted stimuli
- reticular formation