A & P II - Test #2

conspicuous enlargements

found in spinal cord by the cervical and lumbar region

action potential

generated by the movement of ions across membrane

most common cause of metabolic alkalosis

vomiting

4 functions of electrolytes

controlling osmosis

maintaining acid/base balance

carry electrical currents

serve as cofactors

relative refractory period

second action potential can only be initiated by a larger more intense normal stimulus

absolute refractory period

no stimulus can provoke an action potential

main factor that will determine body fluid volume

urinary salt loss

NA/K - atPase

electrogenic pump because contributes to negativity of resting membrane potential

where is CSP found

subarachnoid space

dermatones

areas of skin that provides sensory input to the CNS via one pair of spinal nerves

excitatory vs inhibitory neurotransmitters

excitatory depolarize and inhibitory hyperpolarize the postsynaptic membrane

trigger zone

where the summation of total postsynaptic potential will create an action potential

wallerian degeneration

degeneration of distal end of axon and myelin sheath after nerural injury

chromatolysis

dispersal or disintegration of Nissl bodies (clusters of rough endoplasmic reticulum) within the cell body of neuron

purkinje cells

type of neuron that is found only in the cerebellum

Leak channel

Gated channels that randomly opened and close

Found in nearly all cells

Ligand gated channels

Gated channels opened in response to binding of a ligand chemical stimulus

Dendrites of some sensory motor and inter neurons

Mechanically gated channels

Gated channels that open air response to mechanical stimulus such as touch or pressure

Dates of some sensory neurons

Voltage gated channels

Gated channels are open in response to voltage stimulus

Axons of all neurons

Ependymal cells

Produce CSF

Found in CNS

Astrocytes

Structure supports

Found in CNS

Microglial cells

Immunity from toxins

CNS

Oligodendrocytes

Produce myelin

Found in CNS

Satellite cells

Structural support

Found in PNS

Schwann cells

Produce myelin

Found in PNS

intercostal nerves

only kind of nerves that do enter a plexus but innervate the thoracic cavity

saltatory vs continuous conduction

saltatory: faster because cells are myelinated so jumps from sheath to sheath

continuous: slower because cells are unmyelinated so has to go through the whole thing

3 layers of connective tissue that cover spinal cord

Dura mater: most superficial layer

Arachnoid mater: intermediate layer

Pia mater: deepest layer

largest component of human body

water

Percentages of fluids

Intracellular 2/3 : Extracellular 1/3 →

80% interstitial fluid, 20% blood plasma

respiratory acidosis

Increased carbon dioxide and decrease of pH → depresses nervous system

respiratory alkalosis

Decreased carbon dioxide and increase of pH → hyperactivates nervous system

metabolic acidosis

decreased bicarbonate (byproduct of metabolism) and decrease of pH

Hyperventilation = breathing out more CO2

metabolic alkalosis

Increased bicarbonate and pH

hypoventilation = breathing out less CO2

most abundant ion in body

sodium Na

most abundant ions in intracellular fluid

cation: Potassium/K

anion: hydrogen phosphate/HP04

most abundant ions in extracellular fluid

cation: Sodium/Na

anion: Chloride/Cl

PNS

31 pairs of spinal nerves

12 pairs of cranial nerves

ganglia

PNS systems

somatic nervous: skeletal

automatic: sympathetic, parasympathetic, enteric

reflex arc

sensory receptors → afferent pathway → integration center → efferent pathway → effectors (glands and muscles)

unipolar

most abundant in whole nervous system

sensory detection (touch)

bipolar

senses - gustation, audition, equilibrium, vision, olfaction

multipolar

most abundant in CNS

converging vs diverging circuits

converging: many inputs into one output

diverging: one output into many inputs