cluster of neuronal cell bodies in the PNS
cluster of neuronal cell bodies in the CNS
a bundle of axons in the CNS
a bundle of axons in the PNS
Depolarization phase of an action potential
sodium gates open
repolarization of action potential
sodium gates begin to close and potassium gates open. (potassium is usually inside the cell)
connects the lateral ventricles
connects the lateral ventricles to the third ventricle.
connects the third ventricle to the fourth ventricle
- made of commissural fibers.
- Connects corresponding gray areas of the 2 hemispheres, allowing them to function as a whole.
- Ex: corpus callosum.
- run vertically
- Ties the cerebral cortex to the rest of the nervous system and to the body’s receptors.
connect different parts of the brain in the same hemisphere
Group A fibers
- largest diameter
- heavily myelinated
- 150 m/s
- motor neurons
Group B fibers
- intermediate diameter
- lightly myelinated
- 15 m/s
- preganglionic autonomic fibers
Group C fibers
- smallest diameter
- 1 m/s
- postganglionic autonomic fibers
islands of gray matter in the cerebral hemispheres
formed by the putamen and globus pallidus
formed by the lentiform nuclei and caudate nuclei
what causes Parkinson's disease?
a degeneration of the dopamine-releasing neurons of the substantia nigra.
the cervical enlargement
the lumbar enlargement
- protects and shapes the eyeball
- gives a study site the attachment of eye muscles
function of cornea
- lets light into eye
- plays a part in the light-bending apparatus of the eye
how does retinal detachment cause blindness?
- Retinal detachment is when the pigmented and neural layers separate, allowing the jellylike vitreous humor to seep between them.
- This deprives the photoreceptors of their nutrient source.
where is the lateral geniculate nucleus located?
the thalamus. helps process vision.
where is the superior colliculi located?
- the diencephalon
- processes vision
what is myopia? how to cure it?
- use concave lenses
- distant objects are focused in front of the retina, rather than on it
what is hyperopia? how to cure it?
- use convex lenses
- nearby objects are focused behind the retina.
- equilibrium receptors found in the saccule and utricle
- respond to the pull of gravity and report on changes of head position
- found in the ampulla at the ends of semicircular ducts
- respond to rotational/angular movements
medial geniculate nucleus
the auditory relay center in the thalamus
the floor of the cochlear duct which supports the organ of Corti.
the gel-like membrane that stereocilia are trapped in
3 nerves that carry info from the tongue to the brain
Facial nerve, glossopharyngeal nerve, vagus nerve.
what is the thalamus relay center for taste?
ventral posterior medial nucleus
name the types of papillae and their location on the tongue.
- Circumvallate (largest and most posterior)
- Foliate (elongated, towards side)
- Fungiform (large, throughout tongue)
what are olfactory hairs
the hairs on ciliated dendrites.
olfactory relay center in the thalamus
- medial dorsal nucleus
- relays to frontal and temporal lobe
bundles of what type of axons form the olfactory nerve?
bundles of what type of axons form the olfactory tract?
mitral cells - second order neurons
biogenic amine hormones
composed of the amino acid tyrosine
composed of cholesterol
what's responsible for the emotional connection to smell?
4 types of supporting cells in the CNS
- astrocytes - forming BBB
- ependymal cells - line ventricles. circulate CBF.
2 types of supporting cells in PNS
- Satellite cells - control chemical environment of cell bodies.
- Schwann cells
why can't severed axons in the CNS regenerate?
- microglia fail to properly clean up damage
- no neurilemma to form a regeneration tube
- presence of growth-inhibiting proteins
absolute refractory period
when the neuron can't respond to any stimuli, no matter how strong
relative refractory period
an exceptionally strong stimulus can reopen the Na+ channels allow another action potential to be generated
discuss pupillary dilation
- activation of sympathetic nervous system
- viewing far objects
discuss pupillary constriction
- activation of parasympathetic nervous system
- viewing close objects
function of the cells in the pigmented layer
- contains melanin which prevents light from scattering inside the eye
- contains vitamin A required for the light-absorbing pigment, retinal.