Somatic Nervous System
Describe the difference between sensation and perception
Sensation: detection of a stimulus, at receptor level
Perception: interpretation of the stimulus, in the CNS/cortex
Describe 2 differences between rods and cones
Rods: see non-color, dim light
Cones: see color, bright light
Explain the functions of the outer, middle, and inner ear
Inner ear: sound transduction, senses equilibrium of the body
True or False: Cholinergic fibers are only found in the parasympathetic nervous system.
False
A receptor detects chemical changes in the blood. Classify this receptor by location and stimulus.
Location: Interoceptor
Stimulus: Chemoreceptor
When light hits a rhodopsin/photopsin complex, _________ turns into __________, beginning the process of phototransduction.
11-cis-retinal turns into all-trans-retinal
Explain the differences in function of the otolith organs and the semicircular canals
Otolith organs: detect linear acceleration
Semicircular canals: detect rotational movement
What is the difference between nicotinic and muscarinic receptors?
Nicotinic receptors are found on ALL postganglionic cell bodies, also respond to nicotine.
Muscarinic receptors are found on parasympathetic target organs, also respond to muscarine.
What is the role of the basal nuclei in terms of central control of movement?
A lesion to the optic chiasma would cause what degree of vision loss?
Give an example of conductive vs sensorineural hearing loss.
Conductive: fluid in the ears, foreign objects, ruptured eardrum, allergies, earwax
Sensorineural: aging, excessive loud noise damage, drug side effects, tumors, genetics
What happens when norepinephrine binds to beta-2 receptors on the bronchioles of the lungs?
Bronchodilation
The spinothalamic tract is a(n) (ascending/decending) pathway that relays information about ____________. Information ends up in ______________.
Ascending; noxious stimuli; the primary somatosensory cortex/post-central gyrus
Describe the pathway of information from the optic nerve to the visual integration center in the brain.
Optic nerve --> optic chiasma --> optic tract --> lateral geniculate nucleus of the thalamus --> primary visual cortex
Describe how sounds are sensed in the cochlea
Stapes pushes on oval window, moving perilymph in the scala vestibuli. Sound waves go through cochlear duct, vibrating basilar membrane, deflecting hair cells. Hair cells hit tectorial membrane, opening/closing ion channels, which sends signals through the vestibulocochlear nerve.
Describe the pathway of parasympathetic neurons from the spinal cord to target organ, including classifications of the fibers, whether they are short/long, NTs released, receptors
Long pre-ganglionic neuron originates in the craniosacral region of the spinal cord, releases ACh to nicotinic receptors on the cell body of the post-ganglionic neuron. Post-ganglionic neuron is short, releases ACh to muscarinic receptors on the target organs.
The pyramidal tracts are (ascending/descending) pathways that relay information about ___________. Information ends up in ___________.
Descending; voluntary movement; skeletal muscles
Describe the steps of signal transmission in the cells of the retina when exposed to light.
cGMP-gated channel on photoreceptor (rod/cone) is closed, causing hyperpolarization
No glutamate (neurotransmitter) is released from photoreceptor
Bipolar cell is depolarized (due to lack of inhibitory glutamate)
Bipolar cell releases excitatory NT to ganglion cell
EPSPs sum up in ganglion cell, AP is generated and propagated along optic nerve
Describe the pathway of information from the hair cells to the auditory integration center in the brain.
Hair cells
Spiral ganglion cells
Cochlear nerve
Pons
- Superior olivary nucleus
Midbrain
- Inferior colliculus
Thalamus
- Medial geniculate nucleus
Cortex
- Primary auditory cortex
Give an example of where each type of adrenergic receptor is found, and what happens when NE binds to it.
alpha-1: peripheral blood vessels; vasoconstriction
alpha-2: pre-synaptic neuron terminals; inhibits NE release (regulates NT release)
beta-1: heart; increased HR and contractility
beta-2: lungs (bronchioles); bronchodilation