Pre-Quiz 1 Flashcards by Marisa Andersen

within human organism, the two homeostasis-controlling systems are the following:

the CNS and PNS

How well did you know this?

Not at all

Perfectly

The central nervous system consists of

the brain and spinal cord

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

neurons communicate across specialized intercellular spaces or “pipe”-like structures called

synapses

How well did you know this?

Not at all

Perfectly

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.

How well did you know this?

Not at all

Perfectly

what type of synapses are most abundant in the human body?

Chemical synapses

How well did you know this?

Not at all

Perfectly

name the structure of a neuron that is most effective in starting the conduction of electricity

neck, or axon hillock

How well did you know this?

Not at all

Perfectly

name the structure of a neuron that is most efficient in receiving information

dendrites

How well did you know this?

Not at all

Perfectly

the major control space of a neuron which is around the nucleus and is also called a perikaryon is

the soma

How well did you know this?

Not at all

Perfectly

where are nissal bodies found & what are they

they are found in the soma and are the rough ER in the plasmic reticulum

How well did you know this?

Not at all

Perfectly

chemical synapses can be found on which structure of a neuron

the synaptic bulbs

How well did you know this?

Not at all

Perfectly

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.

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

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.

How well did you know this?

Not at all

Perfectly

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.

How well did you know this?

Not at all

Perfectly

the major common function of oligodendrocytes and schwann cells is

they both produce myelin, which acts as insulation for axons

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

which division of the nervous system includes the brain and spinal cord?

the central nervous system, CNS

How well did you know this?

Not at all

Perfectly

within the CNS, clusters of functionally similar/related neurons are called _____.

nuclei

How well did you know this?

Not at all

Perfectly

in the CNS, bundles of axons from the neurons of the nuclei are called _____

tracts

what are the three subdivisions of the PNS

somatic nervous system
autonomic nervous system
enteric nervous system

in the peripheral nervous system, clusters of related neurons (cell bodies or soma) are called _____

ganglia/ganglion

in the peripheral nervous system, bundles of related axons are called _____

nerves

somatic nervous system:

includes the external lining and internal lining (peritoneum) of the body wall (sensory & motor) includes the extremities includes the special senses (smell, taste, vision, hearing, equillibrium)

autonomic nervous system:

Includes: smooth muscle, cardiac muscle, all secretory glands Controls "primitive functions of internal milleu subdivisions of ANS are sympathethic and parasympathetic

enteric nervous system:

Chains of ganglia (plexi/plexus) along several layers of gastro-intestinal tube/alimentary canal Responsible for peristalsis and secretion of GI juices Is influenced/commanded by CNS and ANS

what are the two exceptions to the somatic nervous system

- goose bumps, because they are controlled by arrector pilli ssmooth muscles - sweat glands *both are controled by the ANS

The intrinsic nervous system of the gastro-intestinal tract, which is called the ENS, is represented by the clusters of functionally related and interconnected neurons. These clustrs are subsequently called:

- enteric plexus of meissner (in sub-mucosa of intestines) - myenteric plexus of auerbach (peristalsis in intestines)

what are the two types of electrical signals neurons use to communicate with one another when they are electrically excitable?

- action potentials - graded potentials

what is a resting membrane potential

The resting membrane potential occurs due to a buildup of negative ions in the cytosol along the inside of the membrane and positive ions in the extracellular fluid along the outside of the membrane. In neurons, the resting membrane potential ranges from -40 to -90 with an avg of -70

leakage channels

channels that randomly alternate between open and closed positions for potassium ions. Like a revolving door

voltage channels

open in response to change in membrane potential (voltage); electrical channel & therefore opens by electricity

Ligand channels

open and close in resopnse to a specific chemical stimulus; usually open before electrical channels present in interneurons and motor neurons

mechanical channels

open or close in response to mechanical stimulation present in sensory neurons

light channels

open when affected by entering light (ex: eye retina)

what is the major ion responsible for depolarization and action potentials

sodium

what is the major ion responsible for the guardng/balance of the resting membrane potential

potassium

what ion channels are open during the depolarization phase of action potential

sodium

what ion channels are opening during re-polarization phase of action potential

potassium

the main paths for flow of current across the membrane are called

ion channels

ions more from _____ areas of concentration to _____ areas of concentration

greater; lower

Positively charged cations move towards _____ charged areas and negatively charged anions move towards _____ charged areas

negatively; positively

when the resting membrane potential is considered polarized, this means_

that it has potential to produce work as an electrical current, once movement of ions is allowed. if there is potential, it is considered polarized

what kind of channels have to open or close in order for graded potentials to occur

ligand-gated or mechanically gated channels have to open or close

what happens during the depolarization phase

the resting membrane potential decreases towards 0 (sodium comes in)

what happens during the repolarizing phase

the resting membrane potential is restored (sodium goes out, potassium comes in)

what is a threshold

when depolarization reaches a ceratin level (about -55mV), and voltage gated channels open

what is a refractory period

the period of time after an action potential begins during which an excitable cell cannot generate another action potential

absolute refractory period

a second action potential cannot be initiated, even with a very strong stimulus

relative refractory period

an action potential can be initiated, but only with a larger than normal stimulus

what is the difference between the presynaptic neuron and the postsynaptic neuron

the presynaptic neuron is the neuron sending the signal the postsynaptic neuron is the neuron recieving the message

what are the clusters of neuronal cell bodies located in PNS and CNS? what re the bundles of axons in PNS and CNS?

clusters of neuronal cell bodies PNS: ganglion CNS: nucleus bundles of axon PNS: nerves CNS: tract