Chapter 1: Nerve Cells and Nerve Impulses (Module 1.1) Flashcards
these cells receive information and transmit it to other
cells
neurons
what are the two kinds of cells that the nervous system consists of?
neurons and glia
a structure that separates
the inside of the cell from the outside environment
plasma membrane/ membrane
the structure that contains the chromosomes.
nucleus
is the structure that
performs metabolic activities, providing the energy that the cell uses for all activities
mitochondria/ mitochondrion
are the sites within a cell that synthesize new
protein molecules
ribosomes
a network of thin tubes that transport newly synthesized proteins to other locations.
endoplasmic reticulum
this neuron receives excitation through its dendrites and conducts impulses along its axon to a muscle
motor neuron
is specialized at one end to be highly sensitive to a particular type
of stimulation, such as light, sound, or touch.
sensory neuron
are branching fibers that get narrower near their end
dendrites
short outgrowths that increase the surface area available for synapses
dendritic spines
what is a dendrite’s surface lined with?
specialized synaptic receptors which allow a dendrite to receive information from other neurons
this contains the nucleus, ribosomes, and mitochondria.
cell body/soma
is a thin fiber of constant diameter.
conveys an impulse toward other neurons, an organ, or a muscle.
axon
what insulating material covers the vertebrate axons?
myelin sheath
are gaps in the myelin sheath coating on the neural axon.
nodes of Ranvier
the swelling on the end of each branch
also known as an end bulb
at this point, the axon releases chemicals that cross through the
junction between that neuron and another cell.
presynaptic terminal
this type of axon brings information away from a structure
afferent axon
this type of axon carries information away from a structure
efferent axon
What are the widely branching structures of a neuron called?
And what is the long, thin structure that carries information
to another cell called?
dendrites, axons
what is the structure that contains a cell’s dendrites and axon called?
interneuron/ intrinsic neuron
this type of glia act as part of the immune system, removing viruses and fungi from the brain
microglia
this type of glia wrap around the synapses of functionally related
axons and shields it from chemicals circulating in the surround
also helps synchronize
closely related neurons, enabling their axons to send messages in waves
astrocytes
these two types of glia build the myelin sheaths that surround and
insulate certain vertebrate axons
oligodendrocytes for the brain and spinal
Schwann cells in the periphery of the body
this type of glia guide the migration of neurons and
their axons and dendrites during embryonic development.
radial glia
What are the four major structures that compose a neuron?
Dendrites,
soma (cell body), axon, and presynaptic terminals
the mechanism that excludes most chemicals from the vertebrate brain
blood-brain barrier
what type of molecules can easily pass through the blood-brain barrier?
small, uncharged
molecules such as oxygen and carbon dioxide
molecules that dissolve in the
fats of the membrane cross easily
what is active transport?
a protein-mediated process that expends energy to pump chemicals from the blood into the brain
Identify one major advantage and one disadvantage of having a blood–brain barrier.
The blood–brain barrier keeps out viruses (an advantage)
and also keeps out most nutrients (a disadvantage)
Which chemicals cross the blood–brain barrier passively?
small unchanged molecules such as oxygen, carbon dioxide, and water
and chemicals that easily dissolve in the fats of the membrane
Which chemicals cross the blood–brain barrier by active transport?
Glucose, amino acids, purines, choline, certain vitamins, and iron.
Why do neurons depend so heavily on glucose?
glucose is the only nutrient that crosses the blood–brain barrier in large quantities.
what does the body need to use glucose
vitamin B1, thiamine
