Lecture 18 – NS IV – Forebrain, cranial nerves Flashcards
the forebrain consists of the ___ and ___
diencephelon and telencephalon
the telencephalon develops into the ___
cerebrum
the ___ develops into the cerebrum
telencephalon
the diencephalon is composed of 4 main components…
thalamus
hypothalamus
subthalamus
epithalamus
the thalamus is the…
sensory relay station
the hypothalamus is the…
major control center of endocrine and autonomic nervous systems
the subthalamus regulates…
motor functions
the epithalamus regulates…
emotions and circadian rhythms
the subthalamus consists of…
a large subthalamic nucleus that is functionally considered part of the basal ganglia
the diencephalon is located in the ___ of the brain
center
each side of the brain has a ___
thalamus
the thalamus is known as the…
“gateway to the cerebral cortex”
nearly all input to cerebrum synapses in…
thalamic nuclei (“screen out information”)
primary role of thalamus:
relay and modulate information (limbic, motor, and all sensory modalities besides olfaction) incoming from the periphery to the cerebral cortex
the 5 major functional groups of thalamic nuclei:
lateral group
medial group
anterior group
ventral group
posterior group
thalamus:
lateral group (function)
somatosensory output to association areas of cortex
thalamus:
medial group (function)
emotions
thalamus:
anterior group (function)
part of limbic system
memory and emotion
thalamus:
ventral group (function)
somatosensory output to primary cortex (postcentral gyrus)
signals from cerebellum and basal nuclei to motor areas of cortex
thalamus:
posterior group (function)
relay of signals
visual – to occipital lobe (visual cortex)
auditory – to temporal lobe (auditory cortex)
thalamus:
parts of posterior group
lateral geniculate nucleus –> visual-to occipital lobe (visual cortex)
medial geniculate nucleus –> auditory-to temporal lobe (auditory cortex)
thalamus:
nuclei are…
clusters of neuronal cell bodies
epithalamus is composed mainly of…
very small mass of tissue
components of epithalamus:
habenula
pineal gland
the epithalamus is wired with the ___ and ___
limbic system
basal ganglia
epithalamus:
habenula is…
a relay from the limbic system to the midbrain
epithalamus:
pineal body (gland) is…
endocrine gland
the epithalamus produces ___
melatonin
the epithalamus…
participates in regulation fo the body’s circadian (24-hr) rhythms
overall function of hypothalamus is…
integration of body functions for the maintenance of homeostasis
hypothalamus maintains ___ by controlling…
homeostasis
by controlling endocrine, automatic, and somatic behavior
the hypothalamus receives internal stimuli via receptors for ___
circulating hormones
the hypothalamus receives ___ via receptors for circulating hormones
internal stimuli
the hypothalamus senses external stimuli via the ___ (pain and temperature info)
spinal thalamic tract
the hypothalamus senses ___ via the spinal thalamic tract (pain and temp info)
external stimuli
the hypothalamus is a ___ collection of ___ (__)
bilateral collection of nuclei (11)
LO6: Associate each hypothalamic function with the nuclei groups that are most closely linked to their execution:
suprachiasmatic nucleus –what is its function?
biological clock
LO6: Associate each hypothalamic function with the nuclei groups that are most closely linked to their execution:
biological clock –what is its nuclei group?
suprachiasmatic nucleus
LO6: Associate each hypothalamic function with the nuclei groups that are most closely linked to their execution:
mammillary nucleus –what is its function?
memory formation –relay b/n limbic system and thalamus
LO6: Associate each hypothalamic function with the nuclei groups that are most closely linked to their execution:
memory formation –relay b/n limbic system and thalamus –what is its nuclei group?
mammillary formation
LO6: Associate each hypothalamic function with the nuclei groups that are most closely linked to their execution:
dorsomedial nucleus –what is its function?
rage and other emotions
LO6: Associate each hypothalamic function with the nuclei groups that are most closely linked to their execution:
rage and other emotions –what is its nuclei group?
dorsomedial nucleus
LO6: Associate each hypothalamic function with the nuclei groups that are most closely linked to their execution:
neurons of the ___ of the hypothalamus monitor body temperature
prepoptic area (POA)
LO6: Associate each hypothalamic function with the nuclei groups that are most closely linked to their execution:
neurons of the preoptic area (POA) of the hypothalamus monitor ___
body temperature
LO6: Associate each hypothalamic function with the nuclei groups that are most closely linked to their execution:
the hypothalamus also regulates ___ behavior
feeding (sensations of hunger and satiety)
LO6: Associate each hypothalamic function with the nuclei groups that are most closely linked to their execution:
regulate feeding behavior (sensations of hunger and satiety):
ventromedial nucleus (function)
“satiety center”
glucose sensing
full –> eat less
LO6: Associate each hypothalamic function with the nuclei groups that are most closely linked to their execution:
regulate feeding behavior (sensations of hunger and satiety):
satiety center/glucose sensing
glucose sensing
full –> eat less
– (nuclei group)
ventromedial nucleus
LO6: Associate each hypothalamic function with the nuclei groups that are most closely linked to their execution:
regulate feeding behavior (sensations of hunger and satiety):
lateral (complex) nucleus – (function)
“feeding center = hunger”
hungry –> eat more
LO6: Associate each hypothalamic function with the nuclei groups that are most closely linked to their execution:
regulate feeding behavior (sensations of hunger and satiety):
“feeding center = hunger”
hungry –> eat more
– (nuclei group)
lateral (complex) nucleus
the ___ receives signals from GI tract and adipose tissue (leptin) and regulates both satiety and feeding centers
arcuate nucleus
the arcuate nucleus receives signals from ___ and ___ and regulates both satiety and feeding centers
GI tract
adipose tissue (leptin)
the arcuate nucleus receives signals from GI tract and adipose tissue (leptin) and regulates both ___ and ___
satiety and feeding centers
LO6: Associate each hypothalamic function with the nuclei groups that are most closely
linked to their execution:
hormone secretion:
arcuate nucleus:
releases hypothalamic hormones secreted by axon terminals into the hypophyseal-portal veins to control anterior pituitary hormone release
LO6: Associate each hypothalamic function with the nuclei groups that are most closely
linked to their execution:
hormone secretion:
(medial) preoptic nucleus:
releases gonadotropin-releasing hormone (GnRH) - which stimulates release of luteinizing hormone and (LH) and follicle-stimulating hormone (FSH) by pituitary gland
LO6: Associate each hypothalamic function with the nuclei groups that are most closely
linked to their execution:
hormone secretion:
the paraventricular (PVN) and supraoptic nuclei both produce the peptides oxytocin and ADH (antidiuretic hormone or vasopresin), which are released from neuronal axons into the capillaries of the ___
posterior pituitary
LO6: Associate each hypothalamic function with the nuclei groups that are most closely
linked to their execution:
hormone secretion:
the paraventricular (PVN) and supraoptic nuclei both produce the peptides ___ and ___, which are released from neuronal axons into the capillaries of the posterior pituitary.
oxytocin and ADH (antidiuretic hormone or vasopresin)
LO6: Associate each hypothalamic function with the nuclei groups that are most closely
linked to their execution:
hormone secretion:
the ___ and ___ both produce the peptides oxytocin and ADH (antidiuretic hormone or vasopresin), which are released from neuronal axons into the capillaries of the posterior pituitary
paraventricular (PVN) and supraoptic nuclei
LO6: Associate each hypothalamic function with the nuclei groups that are most closely
linked to their execution:
hormone secretion:
oxytocin and ADH (antidiuretic hormone or vasopresin) are both ___ and ___
hormones and neurotransmitters
LO6: Associate each hypothalamic function with the nuclei groups that are most closely
linked to their execution:
hormone secretion:
___ and ___ are both hormones and neurotransmitters
oxytocin and ADH (antidiuretic hormone or vasopresin)
LO6: Associate each hypothalamic function with the nuclei groups that are most closely
linked to their execution:
hormone secretion:
the paraventricular nuclei (PVN) also release ___ in response to stressor signals
corticotropin-releasing hormone (CRH)
LO6: Associate each hypothalamic function with the nuclei groups that are most closely
linked to their execution:
hormone secretion:
the paraventricular nuclei (PVN) also release portico-releasing hormone (CRH) in response to ___, which stimulates release of ACTH (adrenocorticotropic hormone) by pituitary gland
stressor signals
LO6: Associate each hypothalamic function with the nuclei groups that are most closely
linked to their execution:
hormone secretion:
the ___ also release portico-releasing hormone (CRH) in response to stressor signals, which stimulates release of ACTH (adrenocorticotropic hormone) by pituitary gland
paraventricular nuclei (PVN)
LO6: Associate each hypothalamic function with the nuclei groups that are most closely
linked to their execution:
hormone secretion:
the paraventricular nuclei (PVN) also release portico-releasing hormone (CRH) in response to stressor signals, which stimulates release of ___ by ___
ACTH (adrenocorticotropic hormone)
by pituitary gland
LO6: Associate each hypothalamic function with the nuclei groups that are most closely
linked to their execution:
hormone secretion:
the paraventricular nuclei (PVN) also release portico-releasing hormone (CRH) in response to stressor signals, which stimulates release of ___ by ___
ACTH (adrenocorticotropic hormone)
by pituitary gland
LO7: State the main functions of the 5 lobes of cerebrum:
what are the 5 lobes:
frontal
parietal
occipital
temporal
insula
LO7: State the main functions of the 5 lobes of cerebrum:
frontal lobe (function)
planning judgment
speech production (Broca’s area)
voluntary motor control
LO7: State the main functions of the 5 lobes of cerebrum:
which lobe is in charge of:
planning judgment
speech production (Broca’s area)
voluntary motor control
frontal lobe
LO7: State the main functions of the 5 lobes of cerebrum:
parietal lobe (functions)
integrates general senses and taste information
(pain, temp, touch, pressure, vibration, proprioception)
LO7: State the main functions of the 5 lobes of cerebrum:
which lobe?
integrates general senses and taste information
parietal lobe
LO7: State the main functions of the 5 lobes of cerebrum:
occipital lobe (functions)
principal visual center of brain
LO7: State the main functions of the 5 lobes of cerebrum:
which lobe?
principal visual center of brain
occipital lobe
LO7: State the main functions of the 5 lobes of cerebrum:
temporal lobe (functions)
hearing
smell
memory (verbal, visual, auditory)
language comprehension (Wernicke’s area)
LO7: State the main functions of the 5 lobes of cerebrum:
which lobe?
hearing, smell, memory, language comprehension
temporal lobe
LO7: State the main functions of the 5 lobes of cerebrum:
insula lobe (functions)
(hidden by other regions)
visceral sensation
empathy
LO7: State the main functions of the 5 lobes of cerebrum:
which lobe?
visceral sensation, empathy
insula lobe
LO8: Describe the 3 types of white matter tracts within the brain and give examples:
most of the volume of cerebrum is ___
white matter (myelinated fibers bundled into large tracts)
LO8: Describe the 3 types of white matter tracts within the brain and give examples:
most of the volume of cerebrum is ___
white matter (myelinated fibers bundled into large tracts)
LO8: Describe the 3 types of white matter tracts within the brain and give examples:
most of the volume of ___ is white matter (myelinated fibers bundled into large tracts)
cerebrum
LO8: Describe the 3 types of white matter tracts within the brain and give examples:
the white matter tracts are classified according to…
direction they run
LO8: Describe the 3 types of white matter tracts within the brain and give examples:
white matter tracts in the cerebrum:
1) association tracts – function
connect (“associate”) different regions w/in the same cerebral hemisphere (intrahemispheric tracts)
LO8: Describe the 3 types of white matter tracts within the brain and give examples:
white matter tracts in the cerebrum:
the association tracts make up the ___
cingulum – core part of the limbic system
latin = “encircling structure”
LO8: Describe the 3 types of white matter tracts within the brain and give examples:
white matter tracts in the cerebrum:
2) projection tracts – function
extend vertically b/n higher and lower brain spinal cord centers
LO8: Describe the 3 types of white matter tracts within the brain and give examples:
white matter tracts in the cerebrum:
2) projection tracts may be ___ or ___ tracts
efferent or afferent
LO8: Describe the 3 types of white matter tracts within the brain and give examples:
white matter tracts in the cerebrum:
2) projection tracts make up 2 structures:
corona radiata (e.g. corticospinal tract)
fornix – main efferent system of the hippocampus and important part of the limbic system
LO8: Describe the 3 types of white matter tracts within the brain and give examples:
white matter tracts in the cerebrum:
what is the fornix?
made up of projection tracts
main efferent system of the hippocampus and important part of the limbic system
LO8: Describe the 3 types of white matter tracts within the brain and give examples:
white matter tracts in the cerebrum:
3) commissural tracts cross from 1 cerebral hemisphere to the other thru bridges called ___
commissures
LO8: Describe the 3 types of white matter tracts within the brain and give examples:
white matter tracts in the cerebrum:
3) commissural tracts – function
> 200 million fibers that interconnect the corresponding regions of almost all parts of the 2 hemispheres
LO8: Describe the 3 types of white matter tracts within the brain and give examples:
white matter tracts in the cerebrum:
3) commissural tracts – make up the structure…
anterior commissure
LO8: Describe the 3 types of white matter tracts within the brain and give examples:
white matter tracts in the cerebrum:
anterior commissure (what is it)
made up of commissural tracts
plays role in the inter hemispheric transfer of olfactory information b/n temporal lobes
LO8: Describe the 3 types of white matter tracts within the brain and give examples:
white matter tracts in the cerebrum:
corona radiata (describe)
composed by projection tracts (afferent and efferent fibers)
“radiating crown”
formed by nerve fibers (white matter) that make up the inner capsule –> a region that connects the cerebral cortex to lower areas of the brain and spinal cord
LO9: describe the distinctive cell types and histological arrangement of the cerebral cortex:
how is neural integration carried out?
by gray matter of the cerebrum
LO9: describe the distinctive cell types and histological arrangement of the cerebral cortex:
cerebral cortex (describe)
a layer covering the surface of hemispheres
only 2-3 mm thick
~40% of brain mass
could be viewed as concentric rings of allocortex, mesocortex, and isocortex
LO9: describe the distinctive cell types and histological arrangement of the cerebral cortex:
neocortex AKA isocortex (describe)
highly convoluted outer layer of the brain
last cortex region to evolve
6 layers
LO9: describe the distinctive cell types and histological arrangement of the cerebral cortex:
neocortex AKA isocortex – 2 principal types of neurons:
small pyramidal cells
stellate cells
LO9: describe the distinctive cell types and histological arrangement of the cerebral cortex:
small pyramidal cells (explain)
pyramid-shaped
axons leave the cortex and connect w/ other parts of the CNS
LO9: describe the distinctive cell types and histological arrangement of the cerebral cortex:
stellate cells (explain)
star-like shape
receive sensory input, process information locally
LO10: name the basal nuclei and indicate their location and function(s):
basal ganglia (basal nuclei) –> describe position
a group of nuclei (clusters of neurons) buried deep in the white matter, lateral to the thalamus
LO10: name the basal nuclei and indicate their location and function(s):
basal ganglia (basal nuclei) –> describe function
involved in motor control – receive input from the substantial nigra of the midbrain and motor areas of the cortex (and send signals back)
LO10: name the basal nuclei and indicate their location and function(s):
parts of the basal ganglia:
“corpus striatum or striatum”
caudate
putamen
globus pallidus
LO10: name the basal nuclei and indicate their location and function(s):
related nuclei of basal ganglia
subthalamus (diencephalon)
substantia nigra (midbrain)
LO10: name the basal nuclei and indicate their location and function(s):
related nuclei of basal ganglia
subthalamus (diencephalon)
substantia nigra (midbrain)
LO11: identify structures related to the limbic system
limbic system is important center of…
emotion and learning
LO11: identify structures related to the limbic system
most limbic system structures have centers for both:
gratification (sense of pleasure or reward)
aversion (unpleasant sensations: fear, sorrow)
LO11: identify structures related to the limbic system
structure of limbic system:
limbus = “border”
limbus structure lies along a horseshoe shaped area of the cortex that appears to be a border b/n the cerebral cortex and the subcortical structures of the diencephalon
LO11: identify structures related to the limbic system
function of medial prefrontal and orbitofrontal cortex:
regulate impulses, compulsions, and drives
LO11: identify structures related to the limbic system
function of amygdala
emotion center
LO11: identify structures related to the limbic system
function of hippocampus
explicit (conscious) memories
LO12: list the 12 cranial nerves by name and number
cranial nerves arise primarily from…
base of brain
LO12: list the 12 cranial nerves by name and number
cranial nerves are numbered…
I to XII
LO12: list the 12 cranial nerves by name and number
most cranial nerves carry fibers…
b/n the brainstem and ipsilateral receptors
(a lesion in 1 side of the brainstem causes a sensory or motor deficit on the same side of the head – exceptions II and IV)
LO14: characterize such nerves as predominantly sensory, motor, or mixed:
which cranial nerves are traditionally sensory nerves?
I, II, VIII
LO14: characterize such nerves as predominantly sensory, motor, or mixed:
which cranial nerves are traditionally motor nerves?
III, IV, VI, XI, XII
LO14: characterize such nerves as predominantly sensory, motor, or mixed:
which cranial nerves are traditionally mixed nerves?
V, VII, IX, X
LO13: describe the function(s) of each cranial nerve and associated impairments
old opie occasionally tries trigonometry and feels very gloomy, vague, and hypoactive
olfactory (I)
optic (II)
oculomotor (III)
trochlear (IV)
trigeminal (V)
abducens (VI)
facial (VII)
vestibulocochlear (VIII)
glossopharyngeal (IX)
vagus (X)
accessory (XI)
hypoglassal (XII)
LO13: describe the function(s) of each cranial nerve and associated impairments
(I) – which nerve, characterize, function, and impairment
olfactory nerve (I)
sensory nerve
sense of smell
damage: anosmia
LO13: describe the function(s) of each cranial nerve and associated impairments
(II) – which nerve, function, and impairment
optic nerve (II)
sensory nerve
transmits visual signals from retina of eye to brain
damage: blindness
LO13: describe the function(s) of each cranial nerve and associated impairments
(VIII) – which nerve, function, and impairment
vestibulocochlear nerve (VIII)
sensory nerve
hearing and equilibrium
damage: sensorineural deafness, nystagmus
LO13: describe the function(s) of each cranial nerve and associated impairments
(III) – which nerve, function, and impairment
oculomotor nerve (III)
motor nerve
innervation to the pupil and lens (focusing and pupillary diameter), the upper eyelid, and the eye muscles that allow for visual tracking and gaze fixation
damage: fixed and dilated pupil
LO13: describe the function(s) of each cranial nerve and associated impairments
(IV) – which nerve, function, and impairment
trochlear nerve (IV)
motor nerve
eye movement: direct the gaze slightly downward and rotate the top of the eyeball toward the nose (compensating for head movements)
damage: double vision
LO13: describe the function(s) of each cranial nerve and associated impairments
(VI) – which nerve, function, and impairment
abducens nerve (VI)
motor nerve
eye movement: directs the gaze laterally (control the lateral rectus muscle)
LO13: describe the function(s) of each cranial nerve and associated impairments
(XI) – which nerve, function, and impairment
accessory nerve (XI)
motor nerve
not a true cranial nerve – it arises from the upper spinal cord
controls swallowing and neck and shoulder muscles
LO13: describe the function(s) of each cranial nerve and associated impairments.
cranial nerve learning aid:
old opie occasionally tries trigonometry and feels very gloomy, vague, and hypoactive
LO13: describe the function(s) of each cranial nerve and associated impairments
(XII) – which nerve, function, and impairment
hypoglassal nerve (XII)
motor nerve
controls tongue movements of speech, food, manipulation, and swallowing
LO13: describe the function(s) of each cranial nerve and associated impairments
(V) – which nerve, function, and impairment
trigeminal nerve (V)
mixed nerve
the largest cranial nerve
the most important sensory nerve of face
damage
LO13: describe the function(s) of each cranial nerve and associated impairments
describe 3 branches of trigeminal nerve (V)
ophthalmic division (V1) – sensory
maxillary division (V2) – sensory
mandibular division (V3) – mixed –> mastication
damage to one of these divisions results in loss of sensation from the respective region of the face
damage to V1 (ophthalmic division) –> absence of blink reflex
damage to V2 (maxillary) and V3 (mandibular) –> loss of sense of touch, pain, and temp
LO13: describe the function(s) of each cranial nerve and associated impairments
(VII) – which nerve, function, and impairment
facial nerve (VII)
mixed nerve
sensory for taste
5 branches:
temporal
zygomatic
buccal
mandibular
cervical
LO13: describe the function(s) of each cranial nerve and associated impairments
(IX) – which nerve, function, and impairment
glossopharyngeal nerve (IX)
mixed nerve
head, neck, and thoracic region
damage: difficulty swallowing, loss of bitter and sour taste sensations
LO13: describe the function(s) of each cranial nerve and associated impairments
(X) – which nerve, function, and impairment
vagus nerve (X)
mixed nerve
has the most extensive distribution of any cranial nerve
major role in control of cardiac, pulmonary, digestive, and urinary function – swallowing, speech, regulation of viscera
damage causes:
hoarseness or loss of voice
impaired swallowing
fatal if both are cut
