Neurophysiology Flashcards
What kind of sensation do root hair plexi detect best?
initial contact and subsequent movement of regions of the body that have hair.
CSF occupies the space between the ____ mater (the middle layer of the brain cover, meninges) and the ____ mater (the layer of the meninges closest to the brain).
arachnoid; Pia
Where are b2-adrenergic receptors located, and what type of response do they mediate?
smooth muscle in vessels of heart and skeletal muscle, intestinal muscle, lungs and bronchi. Inhibition, relaxation.
How does the autonomic nervous system regulate the adrenal medulla? What receptor subtype is used?
the sympathetic division uses nicotinc receptors to cause the adrenal medulla secrete epinephrine and norepinephrine.
How many taste receptors (aka gustatory cells) are in a typical taste bud?
about 40
Proprioceptive information reaches our conscious awareness via the ___ pathway. Proprioceptive information that is outside of our awareness is delivered to the cerebellum via the ___ pathway.
posterior column; spinocerebellar
Where are a2-adrenergic receptors located, and what type of response do they mediate?
sympathetic neuroeffector junctions. Inhibition of effector cells.
T/F: Vitamin A provides opsin that becomes rhodopsin in the eyes.
false. vitamin A becomes retinal, a pigment that is combined with the opsin protein to become rhodopsin.
Name the sites of Pacinian corpuscles and their function.
deeper layers of the skin, ligaments, joint capsules, serous membranes and mesenteries involved in pressure, coarse touch, vibration and tension
Does significant peripheral adaptation occur to painful stimuli?
no
Which dermatome is important for early appendicitis pain referral to the umbilicus?
T10
How large is the hypothalamus, typically?
about the size of an almond
T/F: As a result of absorbing a photon, the photoreceptor membrane potential becomes more negative. (hyperpolarized)
true
Name the three types of mechanoreceptors.
tactile, baroreceptors, proprioceptors
What range of frequencies can the tympanic membrane resonate with?
20Hz to 20,000Hz
Traditionally which area the brain was thought to be responsible for speech comprehension?
wernicke’s area
Pressure waves distort the ___ on the way to the round window of the tympanic duct.
basilar membrane
Which components of the vestibular complex rely on the weight of the capula (a thick gelatinous fluid) to distort the hair cells?
semicircular ducts
List the cranial nerves that transmit purely motor information.
CN 3, CN 4, CN 5, CN 6, CN 7
Where is the L1 dermatome?
at the inguinal ligament
What type of reflex is described as sensory input from the muscle spindles and Golgi tendon organs to spinal the motor system?
spinal reflex
Cold receptors are three to four times ___ numerous than warm receptors.
more numerous
In general, only ___ -soluble compounds can diffuse into the interstitial fluid of the brain and spinal cord.
lipid
Which components of the vestibular complex, when coupled with visual input, accounts for our perception of acceleration/deceleration?
the saccule and the utricle
Which part of the PNS uses nicotinic ACh receptors? Which part tends to use muscarinic receptors?
when stimulated, the preganglionic nerve releases ACh ath the ganglion, which acts on nicotinic receptors of postganglionic neurons. The postganglionic nerve then releases ACh to stimulate the muscarinic receptors of the target organ.
What kind of sensation are Ruffini corpuscles most suited for?
continuous pressure and distortion (twisting, tugging) of the skin
What kind of sensation are Meissner’s corpuscles specially suited to detect?
fine touch and pressure (exact location, shape, size, texture). Also particularly good at detecting low-frequency vibrations.
How many taste buds does a filliform papilla contain?
none
Describe the parasympathetic function of CN 7.
parasympathetic input to the salivary and lacrimal glands.
Which part of the limbic system is involved in signaling the cortex regarding reward and fear in addition to social functions such as mating?
amygdala
T/F: The number of hair cells responding in a given region of the organ of Corti provides information about the volume of a sound.
true
Name three classes of nociceptor.
sensitive to temperature, sensitive to mechanical damage, sensitive to dissolved chemicals
Describe the frequency and location of beta brain waves. When do they normally occur?
12-30 Hz; both sides, symmetrical distribution, most evident frontally; normal when alert, active or concentrating.
List the sensory cranial nerves that also carry motor information.
CN 5, CN 7, CN 9, CN 10
Where do axons leaving the olfactory epithelium terminate?
the olfactory bulbs of the cerebrum
Name some important structures that are usually considered part of the limbic system. (7)
amygdala, hippocampus, parahippocampal gyrus, cingulate gyrus, fornix, hypothalamus, thalamus
What range of wavelength of light are our eyes sensitive to?
400-700nm
How many taste buds does a circumailate pailla typically contain?
about 100
Is the stretch reflex monosynaptic or polysnaptic? Cranial or spinal
spinal, monosynaptic reflex
Choroid plexus is present in all components of the ventricular system except for the ___ and the occipital and frontal horns of the lateral ventricles.
cerebral aqueduct
Which nerve root is responsible for the achilles reflex?
S1
T/F: The parasympathetic nervous system uses only acetylcholine (ACh) as its neurotransmitter.
true
Which adrenergic receptor subtypes increase or enhance lipolysis in adipocytes?
b1, b2, and b3
Describe the law of reciprocal innervation as it pertains to a reflex arc.
flexor and extensor reflexes of the same limb cannot contract simultaneously.
CSF returns to the vascular system by entering the dural ___ via the arachnoid ____.
venous sinuses; granulations/villi
In the dark, the cGMP gated sodium channels in photoreceptors are kept ____(open/closed), and the transmembrane potential is appropriately ____mV.
open; -40 mV
Which components of the vestibular complex provide information concerning movement of the head?
semicircular ducts
Movement of the ____ bone at the oval window establishes pressure waves in the perilymph of the vestibular duct.
stapes
How does the autonomic nervous system increase and decrease heart rate (chronotropic)? What receptor subtypes are used?
sympathetic division increases via b1. Parasympathetic decreases via M2.
Which dermatome is found at the level of the belly button?
T10
How does the autonomic nervous system regulate pupil size? Which receptor subtypes are used?
sympathetic division dilates via a1, causing mydriasis (this is contraction of the dilator muscle). Parasympathetic constricts via M3 causing miosis (relaxation of the dilator muscle).
How does the autonomic nervous system regulate beta and alpha cells of the pancreas? Which receptor subtypes are used?
the sympathetic division uses a 2 to decrease secretion from beta cells and increases secretion from alpha cells. The parasympathetic division uses M3 to increase secretion from alph cells and beta cells.
T/F: The circadian rhythm is actually 25 hours.
false
Where are nociceptors commonly found?
superficial portion of the skin, joint capsules, periostea of bones and around the walls of blood vessels
What are some important functions of the limbic system? (5)
feeding, fighting, feeling, flight and sex (The five Fs)
Which nerve root is responsible for the triceps reflex?
C7
T/F: There are four choroid plexus in the brain, one in each of the ventricles.
true
Where are a1-adrenergic receptors located, and what type of response do they mediate?
widespread, found in most tissue but not in heart. Excitation, stimulation of metabolism
Are receptor potentials graded or all-or-none phenomenon?
graded
Where do the sensory afferents of the taste buds converge?
the nucleus solitarius of the medulla oblongata
Describe the sensory component of CN VII.
receives the special sense of taste from the anterior 2/3 of the tongue.
Where are thermoreceptors found? (4)
dermis of the skin, skeletal muscle, liver, hypothalamus
Where is the C3 dermatome?
neck (high turtleneck shirt)
Stimulation of a nociceptor causes depolarization of a sensory neuron whose axon synapses on an interneuron, whose axon crosses the spinal cord to ascend within the ___ tract
lateral spinothalamic tract
What dermatome is found at the knee caps?
L4
Which part of the limbic system carries signals form the hippocampus to the mammilliary bodies and septal nuclei?
fornix
T/F: There is one kind of opsin in rods, and three types for the cones (one that detects red, one that detects blue, and one that detects green).
true
T/F: Temperature sensation is conducted along the same pathways that carry pain sensation.
true
Describe the primary function of the basal ganglia.
the basal ganglia mediates voluntary movements and postural adjustments
How does the autonomic nervous system increase and decrease cardiac contractility? What receptor subtypes are used?
sympathetic division increases via b1. Parasympathetic decreases via M2.