Brain & Cranial Nerves Flashcards
three layers of protective tissue called the dura mater, arachnoid mater, and pia mater that surround the neuraxis
meninges
tough outermost membrane enveloping the brain and spinal cord.
dura mater
delicate innermost membrane enveloping the brain and spinal cord.
pia mater
named for its spiderweb-like appearance, is a thin, transparent membrane surrounding the spinal cord like a loosely fitting sac.
arachnoid mater
a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column. it encloses the central canal
spinal cord
a long stem-like structure located in the brainstem. It is anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (involuntary) functions ranging from vomiting to sneezing.
medulla oblongata
part of the brainstem that links the medulla oblongata and the thalamus. is involved in the control of breathing, communication between different parts of the brain, and sensations such as hearing, taste, and balance
pons
(“little brain”) is a structure that is located at the back of the brain, underlying the occipital and temporal lobes of the cerebral cortex. receives information from the sensory systems, the spinal cord, and other parts of the brain and then regulates motor movements. coordinates voluntary movements such as posture, balance, coordination, and speech, resulting in smooth and balanced muscular activity.
cerebellum
(Latin for “tree of life”) is the cerebellar white matter, so called for its branched, tree-like appearance.
arbor vitae
connect the cerebellum to the brain stem. there are six
cerebellar peduncles
structures at the front of the midbrain which arise from the front of the pons and contain the large ascending (sensory) and descending (motor) nerve tracts that run to and from the cerebrum from the pons. composed of white matter and contain important ascending sensory fibers
cerebral peduncles
midbrain, portion of the brainstem that connects the hindbrain and the forebrain. portion of the central nervous system associated with vision, hearing, motor control, sleep/wake, arousal (alertness), and temperature regulation.
misencephalon
the four colliculi—two inferior, two superior—located on the tectum of the dorsal aspect of the midbrain.
corpora quadrigemina
a structure in the midbrain that is part of the brain circuit for the transformation of sensory input into movement output.
superior colliculus
is the principal midbrain nucleus of the auditory pathway and receives input from several peripheral brainstem nuclei in the auditory pathway, as well as inputs from the auditory cortex.
inferior colliculus
a small, pea-shaped gland in the brain. it produces and regulates melatonin.
pineal gland
a small region of the brain. It’s located at the base of the brain, near the pituitary gland. plays a crucial role in many important functions, including: releasing hormones. regulating body temperature.
hypothalamus
an important gland in the body and it is often referred to as the ‘master gland’, because it controls several of the other hormone glands
pituitary gland
a pair of small round bodies, located on the undersurface of the brain that, as part of the diencephalon, form part of the limbic system. located at the ends of the anterior arches of the fornix.
mammillary bodies
a small structure within the brain located just above the brain stem between the cerebral cortex and the midbrain and has extensive nerve connections to both. relay motor and sensory signals to the cerebral cortex.
thalamus
or middle commissure. a flattened band of tissue that connects both parts of the thalamus at their medial surfaces.
intermediate mass
a C-shaped bundle of nerve fibers in the brain that acts as the major output tract of the hippocampus. also carries some afferent fibres to the hippocampus from structures in the diencephalon and basal forebrain. part of the limbic system.
fornix
also callosal commissure, is a wide, thick nerve tract consisting of a flat bundle of commissural fibers, beneath the cerebral cortex in the brain. interconnect the two hemispheres. integrate motor, sensory, and cognitive performances between the cerebral cortex on one side of the brain to the same region on the other side.
corpus callosum
a group of subcortical nuclei, situated at the base of the forebrain and top of the midbrain.
basal nuclei
a ridge or fold between two clefts on the cerebral surface in the brain.
gyrus
a groove or furrow, especially one on the surface of the brain.
sulcus
darker tissue of the brain and spinal cord, consisting mainly of nerve cell bodies and branching dendrites.
gray matter
areas of the central nervous system (CNS) that are mainly made up of myelinated axons, also called tracts.
white matter
is the deep groove that separates the two hemispheres of the vertebrate brain.
longitudinal fissure
divides both the frontal lobe and parietal lobe above from the temporal lobe below.
lateral cerebral sulcus
the part of the brain that controls important cognitive skills in humans, such as emotional expression, problem solving, memory, language, judgment, and sexual behaviors.
frontal lobe
located at the bottom of the brain below the lateral fissure. location of the primary auditory cortex, which is important for interpreting the sounds and language we hear.
temporal lobe
positioned above the temporal lobe and behind the frontal lobe and central sulcus. important in language processing.
parietal lobe
the visual processing center
occipital lobe
a small region of the cerebral cortex located deep within the lateral sulcus, which is a large fissure that separates the frontal and parietal lobes from the temporal lobe.
insula
found in the occipital lobe in both cerebral hemispheres. highly specialized for processing information about static and moving objects and is excellent in pattern recognition.
primary visual cortex
located in the frontal lobe of the brain, along a bump called the precentral gyrus. generate neural impulses that control the execution of movement.
primary motor cortex
located in a ridge of cortex called the postcentral gyrus, which is found in the parietal lobe. situated just posterior to the central sulcus. concerned with the conscious perception of touch, pressure, pain, temperature, position, movement, and vibration, which arise from the muscles, joints, skin, and fascia.
primary somatosensory cortex
is located on the superior temporal gyrus in the temporal lobe and receives point-to-point input from the ventral division of the medial geniculate complex
primary auditory area
a plexus of cells that produces the cerebrospinal fluid in the ventricles of the brain.
choroid plexus
the two largest cavities of the ventricular system of the human brain and contain cerebrospinal fluid (CSF). left and right
lateral ventricles
one of four connected fluid-filled cavities comprising the ventricular system within the mammalian brain. a median cleft in the diencephalon between the two thalami, and is filled with cerebrospinal fluid (CSF). It is in the midline, between the left and right lateral ventricles.
third ventricle
within the midbrain. contains cerebrospinal fluid (CSF), and connects the third ventricle to the fourth ventricle, located dorsal to the pons and ventral to the cerebellum.
cerebral aqueduct
one of four connected fluid-filled cavities comprising the ventricular system within the mammalian brain. to protect the human brain from trauma (via a cushioning effect) and to help form the central canal, which runs the length of the spinal cord. this ventricle has a roof and a floor.
fourth ventricle
allows blood to drain from the lateral aspects of anterior cerebral hemispheres
superior sagittal sulcus
small protrusions of the arachnoid mater (the thin second layer covering the brain) into the outer membrane of the dura mater (the thick outer layer).
arachnoid villi
located in the forebrain of vertebrates that receives neural input about odours detected by cells in the nasal cavity.
olfactory bulbs
a bilateral bundle of afferent nerve fibers from the mitral and tufted cells of the olfactory bulb that connects to several target regions in the brain
olfactory tracts
the first cranial nerve and conveys special sensory information related to smell. it is the shortest of the cranial nerves and passes from its receptors in the nasal mucosa to the forebrain. it enters the skull through the cribriform plate of the ethmoid bone.
olfactory nerves
CN II. transmits visual information from the retina to the brain.
optic nerves
an X-shaped structure formed by the crossing of the optic nerves in the brain.
optic chiasm
a part of the visual system in the brain. it is a continuation of the optic nerve that relays information from the optic chiasm
optic tract
CN III. enters the orbit via the superior orbital fissure and innervates extrinsic eye muscles that enable most movements of the eye and that raise the eyelid.
oculomotor nerves
CN IV. a motor nerve (a somatic efferent nerve) that innervates only a single muscle: the superior oblique muscle of the eye, which operates through the pulley-like trochlea.
trochlear nerves
CN V. a nerve responsible for sensation in the face and motor functions such as biting and chewing; it is the largest of the cranial nerves.
trigeminal nerves
CN VI. controls the movement of the lateral rectus muscle, responsible for outward gaze. a somatic efferent nerve.
abducens nerves
CN VII. emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue.
facial nerves
CN VIII. transmits sound and equilibrium (balance) information from the inner ear to the brain.
vestibulocochlear nerves
CN IX. a mixed nerve that carries afferent sensory and efferent motor information. It exits the brainstem out from the sides of the upper medulla, just rostral (closer to the nose) to the vagus nerve.
glossopharyngeal nerves
CN X. longest and most complex of the cranial nerves. interfaces with the parasympathetic control of the heart, lungs, and digestive tract.
vagus nerves
CN IX. supplies the sternocleidomastoid and trapezius muscles.
accessory nerves
CN IIX. innervates all the extrinsic and intrinsic muscles of the tongue. solely motor function.
hypoglossal nerves
a restriction in blood supply to tissues, causing a shortage of oxygen that is needed for cellular metabolism (to keep tissue alive). generally caused by problems with blood vessels, with resultant damage to or dysfunction of tissue.
ischemia
anything that stimulates the sweat glands.
sudomotor
an irregular heartbeat that’s either too fast or too slow.
sinus arrythmia
