Nervous System Part 2 Flashcards
afferent nerves
sensory nerves that carry signals to brain
efferent nerves
motor nerves that carry signals away from brain to muscles
somatic reflexes
spinal or cranial, ex. withdrawal of arm in response to heat & pain sensations; based on skeletal muscle contraction
deep tendon reflex
aka as stretch reflex, knee jerk reflex
superficial reflex
gentle stim to skin & causes contraction
two divisions of the autonomic nervous system
sympathetic (fight or flight) & parasympathetic (rest & digest)
enteric nervous system
controlling smooth muscle & glandular tissue in the digestive system
autonomic nervous system
regulates organ systems through circuits that resemble reflexes described in somatic nervous system; targets cardiac & smooth muscle/glandular tissue
the CNS contains all except
spinal nerves
sensory nervous system transmits info from
peripheral sensors to CNS
receptors that register the sense of pain are termed
nociceptors
nerves that carry info pertaining to voluntary muscle action in response to sensory signals are termed
efferent
nerves that carry info about sensory signals to the CNS are termed
afferent
knee-jerk reflex is a particular example
deep tendon reflex
which nervous system controls interpretation of sensory signals & voluntary skeletal muscle reactions
somatic
when a motor neuron is inhibited, which of the following occurs
the muscle it innervates is relaxed
which receptor interprets chemical stimuli such as smell and taste
chemoreceptor
osmoreceptors respond to what
solute concentrations of body fluids
mechanoreceptor interprets which type of stimuli
physical (pressure & vibration)
general sense
distributed throughout body & has receptor cells w/in structures of organs; ex. mechanoreceptors
special sense
has specific organ devoted to it ex eye, inner ear, tongue, nose
sensory modality
sense & refers to way that info is encoded, how each is transduced
submodalities
specific category of major five senses
somatosensation
general sense of touch & can be separated into light pressure, deep pressure, vibration, itch, pain, temp, hair movement
processing of sensory info into cognitive pattern by CNS
perception
mechanoreceptors are stimulated by all of the following stimuli except
temp
receptor that is physically positioned close to a stimulus in the environment is
exteroceptor
receptors that respond to changes in fluid concentrations in the body are termed
osmoreceptors
when an internal or external stimulus activates sensory receptors, a ___ is generated
sensation
transmembrane protein receptors of target cells are activated by
ligands
gustation
special sense associated w/tongue
unami refers to the “savory” taste activated by L-glutamate when foods rich in ___ are ingested
proteins
alkaloids are antimicrobial molecules found in plant-based foods (like wine & coffee) that are rich in
nitrogen
the perception of hydrogen ions in the papillae generates the taste of ___ in the oral cavity
sour
steps for how ears hear: 1
- sound wave enters ear
- sound wave causes tympanic membrane to vibrate
- this vibration is amplified as it moves across the malleus, incus, and stapes
- amplified vibration is picked up by the oval window
- pressure bends the membrane in the cochlear duct causing hair cells to vibrate
utricle & saccule of the vestibule are sensitive to changes in
head position
otoliths move….
in the direction of gravity
vestibule is primarily responsible for the sense of
proprioception
what is the function of the auricle or external pinna
to funnel sound waves into the auditory canal
what is the function of the eustachian tubes
to equalize air pressure across the tympanic membrane
wave-like motion of sound is transmitted into neural signals by the
organs of corti
photoreception occurs at the
retina
photoisomerization refers to
shape changes of transmembrane proteins of photosensitive opsin pigments
physical location where the optic nerve connects at the retina is termed the ____ of the eye
blind spot
the six extraocular muscles function to
move eyeballs in order to focus on an object
Cranial attachment points of the soft tissue of the eyeballs is the
orbit
snellen test demonstrates differences in
visual acuity
what is unique about vision at fovea
has the greatest sharpness of detail
merkel cells
mechanoreceptors that sense low-frequency vibrations aka type I cutaneous mechanoreceptors
bulbous corpuscles
transduces stretching of the skin
two types of somatosensory signals that are transduced by free nerve endings
pain & temp
topographical arrangement
location of the sensory receptor relates to the location of the axon in the nerve
spinal nerves entering the dorsal root contain stimulation from
sensory neurons
sensations below the neck and thus conducted by spinal nerves are contralateral, meaning that
left side of brain is connected to right side of body & vice versa
when are nociceptors activated
when mechanical, chemical, thermal stimuli pass a set threshold
lamellated corpuscles in the hypodermis/subcutaneous respond to stimuli of
deep pressure
muscle spindles are receptors that function to
prevent over-contraction of a muscle & thus tearing
trigeminal cranial nerves conduct ___ to the brain for interpretation
somatosensation of the face
merkel cells in the epidermis function to
relay stimuli of mechanoreception
where is the left visual field processed in the brain
right visual cortex
where does visual processing occur in the brain
temporal & parietal lobes
what is the function of the thalamus
relay sensory information to the cerebral cortex
sensory topography & mapping refers to
identifying the locations of sensory receptors by the somatosensory cortex
the reason we perceive vision in 3D space is due to
monocular & binocular depth cues
the term homunculus refers to
physical areas of the cerebellum & their corresponding motor neurons
spinothalamic tract pathway is most associated w/
thermoreception & nociception
when neurons decussate, this refers to
neurons crossing one another, as seen when they cross the midline of the medulla before reaching the spinal cord
sound localization refers to
differences in the interaural time & intensity of sound reaching the ears
fasciculus gracilis contains axons located in the
lower legs & lower body
what is the optic chaism
area where optic nerves from each eye cross before entering the brain
gustation pathway travels along the ___ and ___ cranial nerves to the brain for interpretation
glossopharyngeal & facial
auditory stimuli are processed in the brain by the
temporal lobe of the cerebral cortex
when neurons decussate, this refers to
neurons crossing one another, as seen when they cross the midline of the medulla before reaching the spinal cord
dorsal root ganglion are most associated w
mechanoreception & proprioreception
axons of the corticospinal tract are contralateral, meaning that
right motor cortex controls muscles on the left side of the body, and vice versa
in which area of the cerebrum are motor functions primarily controlled
frontal lobe
expressive aphasia limits the ability to
produce speech
primary motor cortex allots most of its physical space for muscles that
perform fine motor movements
motor neurons send their signals from the cortex to the spinal cord ia
descending tracts
what is the prefrontal lobe associated w/ control of
attention & distraction inhibition
what determines the number of muscle fibers that comprise a motor unit
amount of precision of control required by the muscle
how does the cerebellum contribute to motor control by the frontal cortex
it compares cerebral motor commands w/ proprioceptive feedback
what is meant by a “coeloem”
fully-lined body cavity
sensory stimuli relay their impulses to the CNS via
ascending pathways
what is the thoracolumbar system responsible for
influencing effector organs of the sympathetic nervous system
signaling molecules that create physiological changes in the adrenal glands reach their effector organ via
bloodsteam
somatic nervous system controls ___, whereas the autonomic nervous system controls ___
voluntary skeletal muscle contraction, involuntary cardiac & smooth muscle contraction
the ___ nervous system prepares the body for “fight-or-flight” immediate activity, while the ___ nervous system restores homeostasis of the body w/ “rest-and-digest” method
sympathetic… parasympathetic
what is the thoracolumbar system responsible for
influencing effector organs of the sympathetic nervous system
where are the central neurons of the parasympathetic system located
on either side of the thoracolumbar region of the spinal cord
another name for “adrenaline” is
epinephrine
an autonomic system synapse where norepinephrine is released is termed
adrenergic
the axons in the parasympathetic system are in close proximity to their target effectors. this allows for which of the following?
short postganglionic fibers
what does it mean that the autonomic system has “dual innervation”
sympathetic & parasympathetic divisions have competing inputs
in regards to the pupillary reflex, dilation is the result of the neurotransmitter ___, whereas constriction is the result of the neurotransmitter ___
norepinephrine … acetylcholine
blood pressure is affected by the vessel’s response to
norepinephrine
what type of receptor does norepinephrine bind to
adrenergic
autonomic tone is the resting state of organs
where sympathetic & parasympathetic input is specifically balanced
which of the following relays the emotional states of fear & anxiety to the hypothalamus
amygdala
autonomic & endocrine functions are under the control of the
hypothalamus
limbic system is primarily concerned with
emotions
where does the optic nerve project to in the brain before reaching the cerebral cortex for interpretation
thalamus & hypothalamus
autonomic & endocrine functions are under the control of the
hypothalamus
which of the following increases blood pressure & breathing rate in response to exercise
autonomic nervous system
the main pathways for the hypothalamus are the ____ and ___
medial forebrain bundle & dorsal longitudinal fasciculus
smooth & cardiac muscle of the cardiovascular center are under the direction of
medulla
which muscle type is capable of generating its own action potentials
cardiac
which of the following describes the role of nicotine when taken into the body
acts as an acetylcholine analog and binds to ACh recptors
mydriasis refers to
dilation of the pupil
what type of drug enhances adrenergic function
sympathomimetic
which of the following is a component of decongestant drugs because of its ability to dilate the bronchioles & help to clear mucus out of the lower respiratory tract
phenylephrine
