EXAM 5 Flashcards
which ion is greater concentrated on the inside of the cell
K
which ion is greater concentrated on the outside of the cell
Na
what is the intracellular concentration of Na
10 mM
what is the extracellular concentration of Na
140 mM
what is the intracellular concentration of K
140 mM
what is the extracellular concentration of K
2.5 mM
which ion is permeable across the membrane
K
what is the resting membrane potential
-70 mV
does ATPase pump Na in or out of the cell
Out
does ATPase pump K in or out of the cell
in
how many Na and K are pumped in and out of the cell
3 Na out, 2 K in
what kind of ion channels are located in the cell body and dendrites
ligand or mechanically gated
what kind of ion channels are located in the axons of the neuron
voltage gated ion channels
how are ligand channels in the dendrites opened or closed
by neurotransmitter binding or mechanosensation
how are voltage gated channels in the axons opened or closed
by membrane depolarization 21
what is the importance of refractory periods
establish rate of ap propogation and ensure forward propogation of ap
22
1
To add a row, press TAB or click the button below.
Add Card
first step in generating an action potential
local changes in the cells membrane potential (graded potentials) either hyperpolarize or depolarize
where do graded potential occur
in the dendrites and cell bodies
second step in action potential generation
at the axon hillock, when depolarized to the threshhold value, a population of Na+ voltage gated channels will open, as Na enters, the cell becomes more depolarized causing an action potential to form
3rd step in generation of an action potential
After Na channels open, they close right after
4th step in generation of an action potential
depolarization also causes K voltage gated channels to open, this causes the membrane potential to get negative again
what is the importance of refractory periods
establish rate of ap propagation and ensure forward propagation of ap
1st step of synaptic transmission
ap arrives at the end of synaptic end bulb of presynaptic neuron
2nd step of synaptic transmission
ap opens Ca voltage gated channels
3rst step of synaptic transmission
Ca causes synaptic vessicles to fuse with membrane
4th step of synaptic transmission
neurotransmitters diffuse across membrane and bind to receptors on post syn neuron
5th step of synaptic transmission
neurtransmitters binding cause ion movement across membrane either excitatory or inhibitory
what cells detect odors
olfactory receptor cells
what produces mucus in the nose for chemosensation
olfactory glands
what is the function of supporting cells (olfaction)
provide physical and functional support
what do basal cells do in olfaction
are stem cells for olfactory receptor cells
what does cranial nerve I synapse with in the olfactory bulb
mitral cells
what is the olfaction sensory pathway
olfactory bulb —> Primary olfactory area in cerebral cortex area in the temporal lobes of the cerebral cortex for conscious perception of smell
what are the three types of taste buds
vallate fungiform and filliform
which papillae has the most tastebuds
vallate
what are the specialized sensory cells for gustation
gustatory receptor cells
what is the gustatory pathway
gustatory nucleus in the medulla –> axons carry signal to thalamus and hypothalamus –> primary gustatory area in the parietal lobe of cerebral cortex
what makes up the fibrous tunic
cornea and sclera
what makes up the vascular tunic
choroid, iris, ciliary body
what makes up the neural tunic
retina
what is the function of the cornea
Admits and refracts (bends) light
what is the function of the sclera
Provides shape and protects inner parts.
what is the function of the iris
regulates the amount of light that enters the eye
what is the function of the ciliary body
Secretes aqueous humor and alters shape of lens for near or far vision
what is the function of the choroid
Provides blood supply and absorbs scattered light.
what is the function of the retina
Receives light and converts it into receptor potentials and nerve impulses. Output to brain via axons of ganglion cells, which form optic (II) nerve.
what is the function of the lens
refracts lights
what is the function of the anterior cavity
Contains aqueous humor that helps maintain shape of eyeball and supplies oxygen and nutrients to lens and cornea.
what is the function of the posterior cavity
Contains vitreous body that helps maintain shape of eyeball and keeps retina attached to choroid
in which case does the image fall behind the retina
hyperopia
in which case does the image fall in front of the retina
myopia
what is hyperopia
farsightedness, short eyeball
what is myopia
nearsightedness, long eyeball
