Pre-Quiz 1 Flashcards
within human organism, the two homeostasis-controlling systems are the following:
the CNS and PNS
The central nervous system consists of
the brain and spinal cord
what are the two major classes of nervous system cells
- neurons: carry/transmit information by the conduction of electrical impulses/action potentials
- glia (neuroglia): provide support and maintenance functions for neural tissue. *unable to transmit potentials
neurons communicate across specialized intercellular spaces or “pipe”-like structures called
synapses
what are the two types of synapses
- electrical: no interruptions between neurons; action potentials conduct directly between adjacent cells through gap junctions
- chemical: the plasma membranes of a presynaptic and postsynaptic neuron in a chemical synapse do not touch one another directly. The space bewteen the neurons is called a synaptic cleft which is filled with interstitial fluid. A neurotransmitter must diffuse through the interstitial fluid in the cleft and bind to receptors on the postsynaptic neuron.
what type of synapses are most abundant in the human body?
Chemical synapses
name the structure of a neuron that is most effective in starting the conduction of electricity
neck, or axon hillock
name the structure of a neuron that is most efficient in receiving information
dendrites
the major control space of a neuron which is around the nucleus and is also called a perikaryon is
the soma
where are nissal bodies found & what are they
they are found in the soma and are the rough ER in the plasmic reticulum
chemical synapses can be found on which structure of a neuron
the synaptic bulbs
what are the three types of neurons
- motor/efferent (descending [from brain to organs]): they are coming out from the CNS and PNS to the effector organs and tissues. ex: contraction of skeletal muscles. They make things happen
- sensory/afferent (ascending): they bring information from the effector organs and tissues to the PNS—> CNS for interpretation
- associative/interneurons: complie a “balance sheet.” you can consider the a middle man. they are the majority of neurons. They connect neurons together.
within the CNS, what type of glia cells (neuroglia )can be found?
- oligodendrocytes: insulating and resist regeneration within CNS.
- astrocytes: within CNS; form the blood-brain barrier
- microglia: within the CNS; considered to be the sanitation department
- ependymal cells: within the CNS; secrete CSF within brain ventricles; provide brain-CSF barrier
within the PNS, what type of glia cells (neuroglia) can be found?
- satellite cells: within the PNS; provide support within ganglia (clusters of functionally united neurons)
- schwann cells: insulating (organized into myelin), and assist regeneration/repair of axons within PNS
the principal difference between the functions of neurons versus glia is what?
neurons transmit information by the conduction of electrical impulses/action potentials. Glia provide support and maintenance functions for neural tissue and are unable to transmit potentials.
why is the structure of neurons’ nodes of ranvier important?
because schwann cells tightly insulate axons and allow the conduction of electricity to jump from node to node. It improves the speed of electricity.
the major common function of oligodendrocytes and schwann cells is
they both produce myelin, which acts as insulation for axons
the major functional difference between oligodendrocytes and schwann cells is
schwann cells are found in the PNS and assist regeneration of axons; oligodendrocytes are found in the CNS and resist regeneration of axons
axons with nodes of ranvier are _____; axons without nodes of ranvier are _____. Which combination is most efficient in terms of conduction speed?
myelinated, unmyelinated; axons with nodes of ranvier
which division of the nervous system includes the brain and spinal cord?
the central nervous system, CNS
within the CNS, clusters of functionally similar/related neurons are called _____.
nuclei