Lab Exam 1 Notes Flashcards
the central canal of the neural tube, which remains continuous throughout the brain and cord, enlarges in four regions of the brain, forming chambers called …
ventricles
the cerebral hemispheres are divided by a single deep fissure, the …
longitudinal fissure
the … divides the frontal lobe from the parietal lobe, and the … separates the temporal lobe from the parietal lobe
central sulcus; lateral sulcus
the … on the medial surface of each hemisphere divides the occipital lobe from the parietal lobe
parieto-occipital sulcus
a fifth lobe of each cerebral hemisphere, the …, is buried deep within the lateral sulcus, and is covered by portions of the temporal, parietal, and frontal lobes
insula
the … is located in the postcentral gyrus of the parietal lobe. impulses traveling from the body’s sensory receptors are localized in this area of the brain
primary somatosensory cortex
immediately posterior to the primary somatosensory area is the …, in which the meaning of incoming stimuli is analyzed
somatosensory association cortex
the visual areas are in the posterior portion fo the … lobe and the auditor area is located in the … lobe in the gyrus bordering the later sulcus
occipital; temporal
the olfactory area is deep within the temporal lobe along its medial surface, in a region called the …
uncus
the …, which is responsible for conscious or voluntary movement of the skeletal muscles is located in the precentral gyrus of the frontal lobe
primary motor cortex
a specialized motor speech area called … is found at the base of the precentral gyrus just above the lateral sulcus. damage to this area reduces or eliminates the ability to articulate words
broca’s area
many areas involved in intellect, complex reasoning, and personality lie in the anterior portions of the frontal lobes, in a region called the …
prefrontal cortex
a rather poorly defined region at the junction of the parietal and temporal lobes is …, an area in which unfamiliar words are sounded out
Wernicke’s area
the left hemisphere is typically the … brain, bc it houses centers associated with … and …
language; language; speech
the right hemisphere is more concerned with …, …, or … processes - skills associated with artistic/creative pursuits
abstract; conceptual; spatial
the cell bodies of cerebral neurons involved in these functions are found only in the outermost gray matter of the cerebrum, the …
Most of the balance of cerebral tissue – the deeper .. – is composed of fiber tracts carrying impulses to or from the cortex
cerebral cortex; cerebral white matter
… is at the synapse point of cranial nerve I
… is cranial nerve II
… is where the fibers of the optic nerves partially cross over
olfactory bulbs;
optic nerves;
optic chiasma
…: fiber tracts in the midbrain connecting the pons below with cerebrum above
cerebral peduncles
… consists primarily of motor and sensory fiber tracts connecting the brain with lower CNS centers
pons
the lowest brain stem region, the …, is also composed primarily of fiber tracts. you can see the …, a crossover point for the major motor tracts (pyramidal tracts) descending from the motor areas of the cerebrum to the cord on its surface
medulla oblongata; decussation of pyramids
the medulla houses many vital autonomic centers involved in the control of …, …, and … as well as involuntary centers involved in …, .., and so on
heart rate; respiratory rhythm; blood pressure; vomiting; swallowing
the … is located on the posterior aspect of the midbrain, seen when cerebellum is removed
the two superior prominences are the … (visual reflex centers); the two smaller inferior prominences are the … (auditory reflex centers)
corpora quadrigemina;
superior colliculi;
inferior colliculi
the fiber tracts found int he cerebral hemisphere white matter are called … if they connect two portions of the same hemisphere, … if they run between the cerebral cortex and lower brain structures or spinal cord and … if they run from one hemisphere to another
association tracts; projection tracts; commissures
…: major commissure connecting the cerebral hemispheres, which arches above the diencephalon and roofs over the lateral ventricles
corpus callosum
…: a bandlike fiber tract concerned with olfaction as well as limbic system functions
fornix
…: separates the lateral ventricles of the cerebral hemispheres
septum pellucidum
In addition to the gray matter of the cerebral cortex, there are several clusters of neuron cell bodies called… buried deep within the white matter of the cerebral hemispheres. One important group of cerebral nuclei, called the … or … flank the lateral and third ventricles.
nuclei; basal nuclei; basal ganglia;
The basal nuclei, part of the … pathway, are involved in regulating … motor activities.
indirect; voluntary
the most important of the basal nuclei are the arching, comma-shaped …, the …, and the …
caudate nucleus; putamen; globus pallidus
the …, located at the tip of the caudate nucleus, is part of the limbic system
amygdaloid body
the …, a spray of projection fibers coursing down from the precentral gyrus, combines with sensory fibers traveling to the sensory cortex to form a broadband of fibrous material called the …, which passes between the diencephalon and the basal nuclei and through parts of the basal nuclei, giving them a striped appearance
corona radiata; internal capsule
bc of the pattern due to the internal capsule, the caudate nucleus and the putamen are sometimes referred to collectively as the …, or …
striatum; striped body
The… consists of two large lobes of gray matter that laterally enclose the shallow third ventricle of the brain.
thalamus
A slender stalk of thalamic tissue, the … or intermediate mass, connects the two thalamic lobes and bridges the ventricle. The thalamus is a major integrating and relay station for sensory impulses passing upward to the cortical sensory areas for localization and interpretation.
interthalamic adhesion;
…, a tiny opening connecting the third ventricle with the lateral ventricle on the same side.
interventricular foramen
The… makes up the floor and the inferolateral walls of the third ventricle. It is an important autonomic center involved in regulation of body temperature, water balance, and fat and carbohydrate metabolism as well as in many other activities and drives (sex, hunger, thirst).
hypothalamus;
…, which hangs from the anterior floor of the hypothalamus by a slender stalk, the infundibulum. Usually not present in preserved brain specimens. In life, the pituitary rests in the hypophyseal fossa of the sella turcica of the sphenoid bone
pituitary gland;
…: relay stations for olfaction that bulge exteriorly from the floor of the hypothalamus just posterior to the pituitary gland
mammillary bodies
… forms the roof the third ventricle and is the most dorsal portion of the diencephalon
epithalamus
important structures in the epithalamus are the … (a neuroendocrine structure) and the … of the third ventricle- knotlike collections of capillaries within each ventricle, which form the CSF
pineal gland; choroid plexus
…: slender canal traveling through the midbrain; it connects the third ventricle to the fourth ventricle in the hindbrain
cerebral aqueduct
cerebellum is composed of two lateral hemispheres, each with three lobes connected by a midline lobe called the ..
.vermis
the treelike branching of the cerebellar white matter is referred to as the …, or “tree of life”
arbor vitae
The cerebellum is concerned with unconscious coordination of skeletal muscle activity and control of … and ….
balance; equilibrium
The brain and spinal cord are covered and protected by three connective tissue membranes called…
meninges
the outermost meninx is the leathery .., a double layered membrane. one of its layers (the … layer) is attached to the inner surface of the skull, forming the periosteum. the other (the … layer) forms the outermost brain covering and is continuous with the dura mater of the spinal cord
dura mater; periosteal; meningeal
The dural layers are fused together except in three places where the inner membrane extends inward to form a septum that secures the brain to structures inside the cranial cavity. One such extension, the …, dips into the longitudinal fissure between the cerebral hemispheres to attach to the crista galli of the ethmoid bone of the skull. The cavity created at this point is the large …, which collects blood draining from the brain tissue
falx cerebri; superior sagittal sinus
the …, separating the two cerebellar hemispheres, and the …, separating the cerebrum from the cerebellum below, are two other important inward folds of the inner dural membrane
falx cerebelli; tentorium cerebelli
the middle meninx, the weblike …, underlies the dura mater and is partially separated from it by the subdural space
arachnoid mater;
threadlike projections bridge the subarachnoid space to attach the arachnoid to the innermost meninx, the …
pia mater
the delicate pia mater is highly … and clings tenaciously to the surface of the brain, following its convolutions
vascular
the subarachnoid space is filled with CSF. specialized projections of the arachnoid tissue called … protrude through the dura mater, which allow the CSF to drain back into the venous circulation via the superior sagittal sinus and other dural sinuses
arachnoid villi
…, inflammation of the meninges, is a serious threat to the brain bc of the intimate association between the brain and meninges. should infection spread to the neural tissue fo the brain itself, life-threatening .. may occur. the first condition is often diagnosed by taking a sample of CSF from the subarachnoid space
meningitis; encephalitis
CSF is continually formed by the …, small capillary knots hanging from the roof of the ventricles of the brain. CSF in and around the brain forms a watery cushion that protects the delicate brain tissue against blows to the head
choroid plexuses
Within the brain, the cerebrospinal fluid circulates from the two lateral ventricles (in the cerebral hemispheres) into the third ventricle via the …, and then through the cerebral aqueduct of the midbrain into the fourth ventricle in the hindbrain
interventricular foramina
Ordinarily, cerebrospinal fluid forms and drains at
a constant rate. However, under certain conditions—for example, obstructed drainage or circulation result- ing from tumors or anatomical deviations—cerebrospinal fluid accumulates and exerts increasing pressure on the brain which, uncorrected, causes neurological damage in adults. In infants,… is indicated by a gradually enlarging head. The infant’s skull is still flexible and contains fontanelles, so it can expand to accommodate the increasing size of the brain
hydrocephalus
The … are part of the peripheral nervous system and not part of the brain proper
cranial nerves
the 12 pairs of cranial nerves primarily serve the … and …
head; neck
only one pair of cranial nerves, the … nerves, extends into the thoracic and abdominal cavities
vagus
all but the first two pairs of cranial nerves (… and … nerves) arise from the brain stem and pass through foramina in the base of the skull to reach their destination
olfactory; optic
Most cranial nerves are… nerves (containing both motor and sensory fibers)
mixed
three pairs of cranial nerves (…, …, and …) are purely sensory in function.
optic, olfactory, and vestibulocochlear
(cranial nerves) ... ... ... ... ... ... ... ... ... ... ... ...
olfactory optic oculomotor trochlear trigeminal abducens facial vestibulocochlear glossopharyngeal vagus accessory hypoglossal
(cranial nerves) NERVE ONE
olfactory:
fibers arise from olfactory epithelium and run through cribriform plate of ethmoid bone to synapse in …
function– purely … - carries afferent impulses associated with sense of smell
testing- person is asked to sniff … substances, such as clove oil and vanilla and to identify them
olfactory bulbs; sensory; aromatic
(cranial nerves) NERVE 2
optic:
fibers arise from … of eye to form the optic nerve and pass through optic canal of orbit. fibers partially cross over at the … and continue on to the thalamus as the optic tracts. final fibers of this pathway travel from the thalamus to the visual cortex as the optic radiation
function - purely … - carries afferent impulses associated with vision
retina; optic chiasma; sensory
(cranial nerves) NERVE 2
optic:
testing - vision and visual field are determined with … and by testing the point at which the person first sees an object moving into the …
fundus of eye viewed with ophthalmoscope to detect papilledema (swelling of optic disc, or point at which optic nerve leaves the eye) and to observe blood vessels
eye chart; visual field
(cranial nerves) NERVE 3
oculomotor :
Fibers emerge from dorsal midbrain and course ventrally to enter the orbit. They exit from skull via superior orbital fissure.
function: Primarily…—somatic motor fibers to inferior oblique and superior, inferior, and medial rectus muscles, which direct eyeball, and to levator palpebrae muscles
of the superior eyelid; parasympathetic fibers to
iris and smooth muscle controlling… (reflex responses to varying light intensity and focusing of eye for near vision).
motor; lens shape
(cranial nerves) NERVE 3
oculomotor contd
testing-
Pupils are examined for …, …, and …. Pupillary reflex is tested with penlight (pupils should constrict when illuminated)….
for near vision is tested, as is subject’s ability to follow objects with the eyes.
size; shape; equality; Convergence
(cranial nerves) NERVE 4
trochlear:
Fibers emerge from midbrain and exit from skull via superior orbital fissure.
function: Primarily…—provides somatic motor fibers to superior oblique muscle that moves the ….
Tested in common with cranial nerve…
motor; eyeball; III
(cranial nerves) NERVE 5
trigeminal:
Fibers run from… to … and form three divisions: mandibular division fibers
pass through foramen ovale
in sphenoid bone, maxillary division fibers pass via foramen rotundum in sphenoid bone, and ophthalmic division fibers pass through superior orbital fissure of eye socket.
face; pons
(cranial nerves) NERVE 5
trigeminal:
…—major sensory nerve of face; conducts sensory impulses from skin of face and anterior scalp, from mucosae of mouth and nose, and from surface of eyes; mandibular division also contains motor fibers that innervate muscles of… and muscles of floor of mouth.
Mixed; mastication;
(cranial nerves) NERVE 5
trigeminal:
Sensations of …, …, and … are tested with
safety pin and hot and cold objects. …tested
with wisp of cotton. Motor branch assessed by asking person to … the teeth, open mouth against …, and move
… side to side.
pain ;touch; temperature; corneal reflex; clench; resistance; jaw
(cranial nerves) NERVE 6
abducens:
Fibers leave inferior pons and exit from skull via superior orbital fissure to run to ….
function: Carries somatic motor fibers to lateral rectus muscle that moves the….
Tested in common with cranial nerve ….
eye; eyeball; III
(cranial nerve) NERVE 7
facial:
Fibers leave pons and travel through temporal bone via internal acoustic meatus, exiting via stylomastoid foramen to reach the face.
function:…—supplies somatic motor fibers to muscles
of … and parasympathetic motor fibers to lacrimal and salivary glands; carries sensory
fibers from … of anterior portion of tongue.
Mixed; facial expression; taste receptors
(cranial nerve) NERVE 7
facial:
Anterior two-thirds of tongue is tested for ability to taste … (sugar), …, … (vinegar),
and … (quinine) substances. … of face is checked. Subject is asked to close eyes, smile, whistle, and so on. … is assessed with ammonia fumes.
sweet; salty; sour; bitter;
symmetry;
tearing
(cranial nerve) NERVE 8
vestibulocochlear:
Fibers run from inner-ear equilibrium and hearing apparatus, housed in… bone, through internal acoustic meatus to enter pons.
Purely…—vestibular branch transmits impulses associated with sense of equilibrium from vestibular apparatus and semicircular canals; cochlear branch transmits impulses associated with… from cochlea.
temporal; sensory; hearing
(cranial nerve) NERVE 8
vestibulocochlear:
Hearing is checked by …using tuning fork.
air and bone conduction
(cranial nerve) NERVE 9:
glossopharyngeal
Fibers emerge from medulla and leave skull via jugular foramen to run to….
…—somatic motor fibers serve pharyngeal muscles, and parasympathetic motor fibers serve salivary glands; sensory fibers carry impulses from pharynx, tonsils, posterior tongue (taste buds), and from chemoreceptors and pressure receptors of carotid artery.
throat; Mixed
(cranial nerve) NERVE 9:
glossopharyngeal
A tongue depressor is used to check the position of the…
… and … reflexes are checked. Subject is asked to … and … Posterior third of tongue may be tested for …
uvula; gag; swallowing; speak; cough; taste
(cranial nerve) NERVE 10:
vagus
Fibers emerge from medulla and pass through jugular foramen and descend through neck region into .. and …
function: …—fibers carry somatic motor impulses to pharynx
and larynx and sensory fibers from same structures; very large portion is composed of parasympathetic motor fibers, which supply heart and smooth muscles of abdominal visceral organs; transmits sensory impulses from ….
thorax; abdomen;
mixed; viscera
(cranial nerve) NERVE 10:
vagus
testing:
As for cranial nerve … (these are tested in common, since they both innervate muscles of … and …).
IX; throat; mouth
(cranial nerve) NERVE 11:
accessory
Fibers arise from the superior aspect of spinal cord, enter the skull, and then travel through jugular foramen to reach muscles of… and …
function:… (but primarily … in function)—provides somatic motor fibers to sternocleidomastoid and trapezius muscles and to muscles of soft palate, pharynx, and larynx (spinal and medullary fibers respectively).
neck; back; Mixed; motor
(cranial nerve) NERVE 11:
accessory
testing - Sternocleidomastoid and trapezius muscles are checked for strength by asking person to …and … against resistance.
rotate head; shrug shoulders
(cranial nerve) NERVE 12:
hypoglossal
Fibers arise from medulla and exit from skull via hypoglossal canal to travel to….
function: … (but primarily motor in function)—carries somatic motor fibers to muscles of tongue.
testing: Person is asked to… and … tongue. Any deviations in position are noted.
tongue; mixed; protrude; retract
Enclosed within the vertebral canal of the spinal column, the spinal cord extends from the foramen magnum of the skull to the first or second lumbar vertebra, where it terminates in the cone-shaped …
conus medullaris
Like the brain, the cord is cushioned and protected by meninges. The dura mater and arachnoid meningeal coverings extend beyond the conus medullaris, approximately to the level
19 of S2, and the …, a fibrous extension of the pia mater, extends even farther into the coccygeal canal to attach to the posterior coccyx.
filum terminale
…saw-toothed shelves of pia mater, secure the spinal cord to the bony wall of the vertebral column all along its length
Denticulate ligaments,
…: analysis of the CSF which can provide important info about suspected bacterial or viral infections of the spinal cord or meninges
lumbar tap
caudal anesthesia for childbirth is normally administered between … and …
L3 and L5;
31 pairs of … arise from the spinal cord and pass through intervertebral foramina to serve the body area at their approximate level of emergence. the cord is about the size of a finger in circumference for most of its length, but there are obvious enlargements in the … and … areas where the nerves serving the upper and lower limbs issue from the cord
spinal nerves; cervical; lumbar
Because the spinal cord does not extend to the end of the vertebral column, the spinal nerves emerging from the inferior end of the cord must travel through the vertebral canal for some distance before exiting at the appropriate intervertebral foramina. This collection of spinal nerves passing through the inferior end of the vertebral canal is called the …
cauda equina
in cross section, the … of the spinal cord looks like a butterfly or the letter H. the two dorsal projections are called the … The two ventral projections are the …
gray matter; dorsal (posterior) horns; ventral (anterior) horns
In the thoracic and lumbar regions of the cord, there is also a lateral outpocketing of gray matter on each side referred to as the ….
lateral horn;
The central area of gray matter connecting the two vertical regions is the…which surrounds the central canal of the cord.
gray commissure,
the dorsal horns contain interneurons and sensory fibers that enter the cord from the body periphery via the … the cell bodies of these sensory neurons are found in an enlarged area of the dorsal root called the …
dorsal root; dorsal root ganglion
the ventral horns mainly contain cell bodies of motor neurons of the … NS, which send their axons out via the … of the cord to enter the adjacent spinal nerve.
somatic; ventral root
bc they are formed by the fusion of the dorsal and ventral roots, the spinal nerves are … nerves containing both sensory and motor fibers
mixed
the lateral horns, where present, contain nerve cell bodies of motor neurons of the … NS, … division. their axons also leave the cord via the ventral roots, along with those of the motor neurons of the ventral horns
autonomic; sympathetic
the white matter of the spinal cord is nearly bisected by fissures. the more open ventral fissure is the …, and the dorsal one is the shallow …
ventral median fissure; dorsal median sulcus
the white matter of the spinal cord is composed of … and … fibers
myelinated; nonmyelinated
bc of the irregular shape of the gray matter, the white matter on each side of the cord can be divided into three primary regions or …: the … (…), …, and … (…) …
white columns; the dorsal (posterior), lateral, and ventral (anterior) funiculi
each funiculus contains a number of fiber tracts composed of axons with the same …, … and …
origin; terminus; function
tracts conducting sensory impulses to the brain are called … or … tracts; those carrying impulses from the brain to the skeletal muscles are … or … tracts
ascending; sensory; descending; motor
When the cord is transected (or severely traumatized), both motor and sensory functions are lost in body areas normally served by that region and lower regions of the spinal cord. Injury to certain spinal cord areas may even result in a permanent flaccid paralysis of both legs, called…, or of all four limbs, called …
paraplegia; quadriplegia
31 pairs of human spinal nerves arise from the fusions of the ventral and dorsal roots of the spinal cord: 8 pairs of ... nerves (...-..) 12 pairs of ... nerves (... - ...) 5 pairs of ... nerves (... - ...) 5 pairs of ... nerves (... - ...) 1 pair of ... (...)
cervical; C1- C8 thoracic; T1-T12; lumbar; L1-L5; sacral; S1-S5; coccygeal; Co1
The first through seventh pairs of cervical nerves emerge … the vertebra for which they are named; C8 emerges between C7 and T1. The remaining spinal nerve pairs emerge from the spinal cord area … the same-numbered vertebra.
above; below
almost immediately after emerging from the spinal cord, each nerve divides into … and …
dorsal; ventral rami
The rami, like the spinal nerves, contain both motor and sensory fibers. The smaller dorsal rami serve the skin and musculature of the… body trunk at their approximate level of emergence. The ventral rami of spinal nerves T2 through T12 pass anteriorly as the intercostal nerves to supply the muscles of intercostal spaces, and the skin and muscles of the… and … trunk.
posterior; anterior; lateral
the ventral rami of all other spinal nerves from complex networks of nerves called …, which primarily serve the muscles and skin of the limbs
nerve plexuses
The … arises from the ventral rami of C1 through C5 to supply muscles of the shoulder and neck. The major motor branch of this plexus is the…., which arises from C3 through C4 (plus some fibers from C5) and passes into the thoracic cavity in front of the first rib to innervate the….
cervical plexus; phrenic nerve; diaphragm
The primary danger of a broken neck is that the …may be severed, leading to paralysis of the diaphragm and cessation of breathing
phrenic nerve
The …. is large and complex, arising from the ventral rami of C5 through C8 and T1. The plexus, after being rearranged consecutively into trunks, divi- sions, and cords, finally becomes subdivided into five major peripheral nerves
brachial plexus;
brachial plexus nerves:
The …., which serves the muscles and skin of the shoulder, has the most limited distribution.
The large … passes down the posterolateral surface of the arm and forearm, supplying all the extensor muscles of the arm, forearm, and hand and the skin along its course.
axillary nerve;
radial nerve
brachial plexus nerves:
The … passes down the anteromedial surface of the arm to supply most of the flexor muscles in the forearm and several muscles in the hand (plus the skin of the lateral surface of the palm of the hand).
The …supplies the arm muscles that flex the forearm and the skin of the lateral surface of the forearm.
The… travels down the posteromedial surface of the arm.
median nerve;
musculocutaneous nerve;
ulnar nerve
Severe injuries to the brachial plexus cause … or … of the entire upper limb. Such injuries may occur when the upper limb is pulled hard and the plexus is stretched, and by blows to the shoulder that force the humerus inferiorly
weakness; paralysis
The… plexus, which serves the pelvic region of the trunk and the lower limbs, is actually a complex of two plexuses, the .. plexus and the … plexus
lumbosacral; lumbar; sacral
The ….arises from ventral rami of L1 through L4 (and sometimes T12). Its nerves serve the lower abdomi- nopelvic region and the anterior thigh. The largest nerve of this plexus is the… which passes beneath the inguinal ligament to innervate the anterior thigh muscles. The cutaneous branches of the femoral nerve supply the skin of the anteromedial surface of the entire lower limb
lumbar plexus; femoral nerve,
Arising from L4 through S4, the nerves of the…
supply the buttock, the posterior surface of the thigh, and virtually all sensory and motor fibers of the leg and foot
sacral plexus
the major peripheral nerve of the sacral plexus is the …, the largest nerve in the body. it leaves the pelvis through the greater sciatic notch and travels down the posterior thigh, serving its flexor muscles and skin
sciatic nerve
in the popliteal region, the sciatic nerve divides into the … and the …., which together supply the balance of the leg muscles and skin, both directly and via several branches
common fibular nerve; tibial nerve
injury to the proximal part of the sciatic nerve, as might follow a fall/disc herniation, results in a number of lower limb impairments. …, characterized by stabbing pain radiating over the course of the sciatic nerve, is common. when the sciatic nerve is completely severed, the leg is nearly useless. the leg cannot be flexed and the foot drops into plantar flexion, a condition called …
sciatica; footdrop
reflexes are rapid, predictable, involuntary motor responses to stimuli; they are mediated over neural pathways called …
reflex arcs
… or … reflexes are wired into our nervous system and are unlearned
… or … reflexes result from practice or repetition
inborn; intrinsic; learned; acquired
… or … reflexes are mediated through the ANS, and we are not usually aware of them. these active smooth muscles, cardiac muscle, and the glands of the body, and they regulate body functions such as digestion, elimination, BP, salivation, and sweating
autonomic; visceral
… reflexes include all those reflexes that involves stimulation of skeletal muscles by the somatic division of the nervous system
somatic
… is an important diagnostic tool for assessing the condition of the NS. distorted, exaggerated, or absent responses may indicate degeneration or pathology of portions of the NS
reflex testing
If the spinal cord is damaged, the easily performed …can help pinpoint the area (level) of spinal cord injury. Motor nerves… the injured area may be unaffected, whereas those at or … the lesion site may be unable to participate in normal reflex activity
reflex tests; above; below
reflex arcs have 5 basic components:
- the … is the site of stimulus action
- the … transmits afferent impulses to the CNS
- the … consists of one or more neurons in the CNS
- the … conducts efferent impulses from the integration center to an effector organ
- the …, a muscle fiber or a gland cell, responds to efferent impulsed by contracting or secreting, respectively
receptor; sensory neuron; integration center; motor neuron; effector
The simple patellar or knee-jerk reflex is an example of a simple, two-neuron,… (liter- ally, “one synapse”) reflex arc.
monosynaptic
most reflexes are more complex and…, involving the participation of one or more interneurons in the reflex arc pathway. An example of a poly- synaptic reflex is the flexor reflex
polysynaptic
Since delay or inhibition of the reflex may occur at the synapses, the more synapses encountered in a reflex pathway, the more… is required for the response.
time
Many … reflexes that are initiated and completed at the spinal cord level, occur without the involvement of higher brain centers. Generally these reflexes are present in animals whose brains have been destroyed, as long as the spinal cord is functional.
spinal reflexes,
although many spinal reflexes do not require the involvement of higher centers, the brain is “advised” of spinal cord reflex activity and may alter it by …. or … the reflexes.
facilitating; inhibiting
somatic reflexes: ... ... ... ... ...
stretch crossed-extensor superficial cord corneal gag
… are important postural reflexes, normally acting to maintain posture, balance, and locomotion.
Stretch reflexes
Stretch reflexes are initiated by tapping a tendon or ligament, which stretches the muscle to which the tendon is attached This stimulates the muscle spindles and causes … of the stretched muscle or muscles. Branches of the afferent fibers from the muscle spindles also synapse with… controlling the antagonist muscles. The inhibition of those interneurons and the antagonist muscles, called …, causes them to relax and prevents them from resisting (or reversing) the contraction of the stretched muscle.
reflex contraction; interneurons; reciprocal inhibition
stretch reflexes:
impulses are relayed to higher brain centers to advise of muscle .., … of shortening, and the like—information needed to maintain muscle … and ….
length; speed; tone; posture;
Stretch reflexes tend to be hypoactive or absent in cases of … damage or ventral horn disease and hyperactive in …lesions. They are absent in deep … and ….
peripheral nerve; corticospinal tract ; sedation; coma
(patellar/knee-jerk reflex) the leg swings forwards as the … muscles contract. the … are reciprocally inhibited.
the … nerve is carrying the impulses
quadriceps; hamstrings; femoral
(patellar/knee-jerk reflex) mental distraction yields a response that is .. than the first one. mental distraction seems to .. the reflex response
greater; increase
(patellar/knee-jerk reflex) the response during other muscle activity is usually more … due to increased …
vigorous; facilitation in the spinal cord
(patellar/knee-jerk reflex) muscle fatigue results in a … response. muscle function is responsible. this is probably due to changes in …, …, and … levels in the muscle. … is hindered, reducing the response of the muscle cells to nervous stimulation
less vigorous; pH; ATP; Ca2+; excitation-contraction coupling
the … or … reflex assesses the first two sacral segments of the spinal cord –> plantar flexion due to contraction of the … (… and … muscles) is the result. contraction of the gastrocnemius muscle usually results in plantar flexion of the foot
calcaneal tendon; ankle-jerk; tricepts surae; gastrocnemius; soleus
crossed-extensor reflex is more complex than the stretch reflex. consists of a …, or …, reflex followed by … of the opposite limb
flexor; withdrawal; extension
crossed-extensor reflex:
the subject withdraws the pricked hand by flexion of the …, then the other …
the … part of the reflex is relatively slow, probably due to the fact that many … neurons are involved
elbow; elbow extends; extensor; association
The superficial cord reflexes (abdominal, cremaster, and plantar reflexes) result from … and … changes. They are initiated by stimulation of receptors in the … and …. The superficial cord reflexes depend both on functional upper-motor pathways and on the cord-level reflex arc
pain; temperature; skin; mucosae;
The plantar reflex, an important neurological test, is elicited by stimulating the … in the sole of the foot. In adults, stimulation of these receptors causes the toes to… and move … together. Damage to the corticospinal tract, however, produces …, an abnormal response in which the toes flare and the great toe moves in an upward direction. In newborn infants, it is normal to see Babinski’s sign due to incomplete… of the nervous system.
cutaneous receptors; flex; closer; Babinski’s sign; myelination;
plantar reflex:
normal response is … and … of the toes
downward flexion (curling); adduction
The corneal reflex is mediated through the… nerve (cranial nerve V). The absence of this reflex is an ominous sign because it often indicates damage to the …resulting from compression of the brain or other trauma.
trigeminal; brain stem
corneal reflex:
touching subject’s cornea with wisp of cotton
response is that subject …, with the function being to protect the eye
subject experiences discomfort/pain bc the cornea lacks … receptors but is richly supplied with … receptors
blinks;
pressure; pain
The gag reflex tests the somatic motor responses of cranial nerves … and …. When the oral mucosa on the side of the uvula is stroked, each side of the mucosa should…, and the amount of elevation should be …. The uvula is the fleshy tab hanging from the roof of the mouth just above the root of
the tongue.
IX and X; rise; equal;
gag reflex:
the … elevate as .. muscles contract, and the subject gags
posterior pharyngeal walls; pharyngeal;
The autonomic reflexes include the …, …, and … reflexes, as well as a multitude of other reflexes.
pupillary; ciliospinal; salivary;
… and … reflexes
retina of the eye is receptor, optic nerve contains the afferent fibers, oculomotor nerve conducts efferent impulses to the eye, and smooth muscle of the iris is the effector
pupillary light reflex; consensual reflex
pupillary reflex
… reflex, indicates that there is some connection between the pathways for each eye.
this is a test of the … nervous systems
these responses protect the retina from damage by bright light
contralateral; parasympathetic
pupillary light response, or any reflex occurring on the same side stimulated, is referred to as an … response
ipsilateral
ciliospinal reflex also involves observing pupillary response –> stroking left side of back of subject’s neck, close to the hairline
proper response is …, consistent with pupillary changes occurring when the … is stimulated
only left pupil responds, indicating that sympathetic innervation of the irises is not as … as parasympathetic innervation
pupillary dilation; sympathetic NS; closely integrated
…: salivary glands secrete varying amounts of saliva in response to reflex activation
salivary reflex
salivary reflex:
volume of saliva is … after stimulation with lemon juice
the … division of the ANS mediates reflex release of saliva
much greater; parasympathetic
if responses are a simple reflex arc, the response time is short. learned reflexes involve more neural pathways and higher intellectual activities, which … response time
addition of a signal word … reaction time bc it takes time to discriminate the words
large variation in rxn time is due to variation in ability of subject to formulate a response to stimulus word
lengthens; increases
