Unit 2: Part 1 Flashcards
A nerve cell is the basic building block of the nervous system
Neuron
The part of a neuron that contains the nucleus; cells life support center
Cell Body (Soma)
A Neurons often bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell body
Dendrites
The neuron extension passes messages through its branches to other neurons or to muscles and/or glands
Axon
A fatty tissue layer segmentally encasing the axons of the same neurons
Myelin sheath
Cells in the nervous system support, nourish, and protect neurons; they also play a role in learning, thinking, and memory
Glial cells
A neural impulse; is a brief electrical charge that travels down an axon
Action Potential
The level of stimulation required to trigger a neural impulse
threshold
In neural processing a brief resting pause that occurs after a neuron has fired; action potentials cant occur until its back to its resting state
refractory period
A neurons reaction of either firing or not firing
all or nothing response
The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap.
Synapse
Chemical messengers cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron thereby influencing whether that neuron will generate a neural impulse
Neurotransmitters
A neurotransmitter reabsorption by a sending neuron
reuptake
“the morphine within”-natural opiate-like neurotransmitters linked to pain, control, and pleasure
endorphins
a molecule that increases the activity of a neurotransmitter like opiates
agonist
A molecule that inhibits or blocks the actions of a neurotransmitter like botox
antagonist
The body’s speedy, electrochemical communication network consisting of all the nerve cells of the peripheral and central nervous system
nervous system
The brain and spinal cord; oversee the sensory and movement of reflexes
central nervous system(CNS)
Sympathetic and parasympathetic movement,sensory and motor output
peripheral nervous system(PNS)
Bundled axons of many neurons form neural cables connecting the central nervous system with muscles, glands, and sense organs
nerves
Contain afferent nerve fibers; carry information from the sense organs to the CNS
sensory (afferent) neurons
contain efferent neurons; carry messages from the CNS to the muscles and glands
motor (efferent) neurons
neurons within the brain and spinal cords that communicate internally and process info between sensory inputs and motor outputs
interneurons
controls skeletal muscles
somatic nervous system
controls glands and muscles of internal organs
autonomic nervous system (ANS)
flight, fright, or freeze
sympathetic nervous system
sense receptors in the skin send signals to interneurons (calming)
parasympathetic nervous systems
Sense receptors in the skin send signals, interneurons receive signal such as moving away from a fire after feeling heat
reflex
The body’s slow chemical communication system; is a set of glands that secrete hormones, into the bloodstream
endocrine
Chemical messengers that are manufactured by the endocrine glands travel through the bloodstream and affect other tissue
hormones
a pair of endocrine glands that sit just above the kidney and secrete hormones that help arouse the body in times of stress
Adrenal glands
The endocrine system’s most influential gland under the influence of the hypothalamus regulates growth and controls other endocrine glands
Pituitary gland