Unit 2 Flashcards
Sensory neurons
Neurons that carry incoming information from the sense receptors to the central nervous system
Neuron
A nerve cell; basic building block of the nervous system
Motor neurons
Neurons that carry outgoing information from the central nervous system to the muscles and glands
Interneurons
Central nervous system neurons that internally communicate and intervene between the sensory inputs and motor outputs
Dendrite
The bushy branching extensions of the neuron that receive message sand conduct impulses towards the cell body
Axon
The extension of a neuron
Myelin sheath
Fatty tissue encasing axon
Action potential
Neural impulse
Threshold
The level of stimulation required to trigger a neural pulse
Synapse
The junction between the axon tip of the sending neuron and the dendrite or or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap
Neurotransmitters
Chemical messengers that traverse the synaptic gaps between neurons
Reuptake
When the neurotransmitters are reabsorbed by the axon terminal
Endorphins
“The morphine within” natural opiate like neurotransmitters linked to pain control and pleasure
Central nervous system
The brain and spinal cord
Peripheral nervous system
The sensory and motor neurons that connect the central nervous system to the rest of the body
Somatic nervous system
The division of the peripheral nervous system that controls the body’s skeletal muscles. Also called the skeletal nervous system
Autonomic nervous system
Part of the peripheral nervous system that controls the glands and the muscles of the internal organs such as the heart, INVOLUNTARY
Sympathetic nervous system
The division of the auto gnomic nervous system that arouses the body, mobilizing its energy in stressful situations
Parasympathetic nervous system
The division of the autonomic nervous system that calms the body, conserving it’s energy
Endocrine system
The body’s “slow”chemical communication system; a set of glands that secrete hormones into the bloodstream
Hormones
Chemical messengers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another
Adrenal glands
A pair of endocrine glands just above the kidneys. The adrenals secrete the hormones epinephrine(adrenaline) and norepinephrine which help to arouse the body in times of stress
Pituitary gland
The endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands
Lesion
Tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue
Electroencephalogram
An amplified recording of the waves of electric activity that sweep across the brain surface
CT scan
Scanning of tissues
Pet scan
A visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task
MRI
A technique that uses magnetic fields and radio waves to produce computer-generated images; allows us to see structures within the brain
fMRI
A technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans. MRIs scans show brain anatomy; fMRI scans show brain function
Split brain
A condition in which the two hemispheres of the brain are isolated by cutting the connective fibers (mainly those of the corpus callosum) between them
