ANA 209 chapter 15- Adler
insula
Involved in memory and interpretation of taste
parietal lobe
Involved with general sensory functions
temporal lobe
Involved with hearing and smell
caudate nucleus
produces patterned arm and leg movements associated with walking
falx cerebri
projects into longitudinal fissure and separates left and right cerebral hemispheres
medulla oblongata
the most inferior part of the brainstem, is formed from the myelencephalon. It continues with the spinal cord inferiorly.
tectum
the posterior region of the mesencephalon dorsal to the mesencephalic aqueduct. It contains the tectal plate (quadrigeminal plate) containing the superior colliculi (visual reflex centers), and the inferior colliculi (auditory reflex centers).
Fornix
thin tract of white matter that connects hippocampus with other diencephalon limbic system structures
diencephalon (diagram)
components: hypothalamus thalamus epithalamus
lentiform nucleus
composed of putamen and globus pallidus
claustrum
processes visual information at a subconscious level
visual association area
processes visual information; located in the occipital lobe
three regions of the cerebellum
1. An outer gray matter layer of cortex 2. An internal region of white matter, called the arbor vitae 3. Cerebellar nuclei in the deepest layer
Production and Circulation of Cerebral Spinal Fluid
1. CSF is produced by the choroid plexus in the ventricles 2. CSF flows from the third ventricle through the cerebral aqueduct into the fourth ventricle 3. CSF in the fourth ventricle flows into the subarachnoid space by passing through the paired lateral apertures of the single median aperture, and into the central canal of the spinal cord 4. as CSF flows through the subarachnoid space, it removes waste products and provides buoyancy to support the brain 5. excess CSF flows into the arachnoid villi, then drains into the dural venous sinuses. pressure allows the CSF to be released into the blood without permitting any venous blood to enter the subarachnoid space. the greater pressure on the CSF in the subarachnoid space ensures that CSF moves into the venous sinuses
motor areas, sensory areas, association areas
3 functional areas of the cerebral cortex
dura mater, arachnoid mater, pia mater
3 layers of meninges
vermix
A narrow band of cortex along the midline of the cerebellum separates the left and right cerebellar hemispheres. receives sensory input on the torso position and balance. Its output to the vestibular nucleus helps maintain balance.
interthalamic adhesion (or intermediate mass)
A small midline mass of gray matter that connects the right and left thalamic bodies
fissures
Adjacent gyri are separated by shallow sulci or deeper grooves called:
tracts that ascend or descend through the medulla oblongata
All communication between the brain and spinal cord involves:
medial lemniscus
Bands of myelinated fibers composing a ______exit the nucleus cuneatus and the nucleus gracilis and decussate in the inferior region of the medulla oblongata. The medial lemniscus projects through the brainstem to the ventral posterior nucleus of the thalamus.
functions of CSF
Buoyancy—the brain floats in the CSF Protection—CSF provides a liquid cushion from sudden movements Environmental stability—CSF transports nutrients and removes waste from the brain
cerebellar hemispheres
Cerebellum composed of left and right:
brainstem
Connects the forebrain and cerebellum to the spinal cord Is a bidirectional passageway for all tracts extending between the cerebrum and the spinal cord Contains many autonomic centers and reflex centers required for survival Houses nuclei of many of the cranial nerves
cerebellar functions
Coordinates and fine-tunes skeletal muscle movements and ensures that skeletal muscle contraction follows the correct pattern leading to smooth, coordinated movements Stores memories of previously learned movement patterns Adjusts skeletal muscle activity to maintain equilibrium and posture Receives proprioceptive (sensory) information from the muscles and joints and uses this information to regulate the body's position Monitors the position of each body joint and its muscle tone
rostral and caudal
Directional Terms to Describe the Brain
anterior; posterior; primary fissure
Each cerebellar hemisphere consists of two lobes, _____ lobe and _____ lobe, separated by _______
thalamic nuclei
Each part of the thalamus is a gray matter mass composed of about a dozen or more _____ with axons projecting to particular regions of the cerebral cortex.
location and formation of parietal lobe
Forms the superoposterior part of each hemisphere and underlies the parietal bone Terminates anteriorly at the central sulcus, laterally at the lateral sulcus, and posteriorly at the parieto-occipital sulcus
olive; inferior olivary nucleus
Immediately lateral to each pyramid is a bulge called the ____, which contains gray matter called the _____. These nuclei relay ascending sensory impolses, especially proprioceptive information, to the cerebellar cortex.
functions of hypothalamus
Master control of the autonomic nervous system Master control of the endocrine system Regulation of body temperature Control of emotional behavior Control of food intake Control of water intake Regulation of sleep-wake (circadian) rhythms
CN III ; CN IV
Nuclei of oculomotor nerve ___ and trochlear nerve ___ are housed in the mesencephalon
gray matter, white matter
Organization of Neural Tissue Areas in the Brain
epithalamus
Partially forms posterior roof of the diencephalon and covers the third ventricle components include pineal gland and habenular nuclei
Higher-Order Processing Centers
Process incoming information from several different association areas Ultimately direct either extremely complex motor activity or complicated analytical functions Involve functions such as speech, cognition, understanding spatial relationships, and general interpretation Housed in both cerebral hemispheres
occipital lobe
Processes incoming visual information Stores visual memories
cerebellum
Second largest part of the brain Develops from the metencephalon
brain and spinal cord
Sensory and motor tracts are housed within the pons that connect to the _____
thalamus, nuclei
Sensory impulses from all conscious senses except olfaction converge on the _____ and synapse in at least one of its ____
flocculonodular lobes
Slender_____ lie anterior and inferior to each cerebellar hemisphere.
cerebral peduncles
Somatic motor axons descend from the primary motor cortex through the ________ (located on the anterolateral surfaces of the mesencephalon) to the spinal cord
memory; consciousness
Some aspects of cortical function, such as _____ or _____, cannot easily be assigned to any single region
mesencephalon
Superior portion of brainstem
choroid plexus hypothalamus pineal gland
The BBB is markedly missing or reduced in three distinct locations of the CNS:
Caudal
The ____ portion of the medulla oblongata resembles the spinal cord.
pyramids
The anterior surface exhibits two longitudinal ridges called the ____, which house the motor projection tracts called the corticospinal tracts.
rostrally
The central canal of the spinal cord extends ____ through the medulla and enlarges to become the fourth ventricle.
cerebral hemispheres
The cerebrum is composed of two halves called left and right _____
tracts
The hemispheres are separate from one another except at a few locations where bundles of axons called _____ form white matter regions that allow for communication between them
nucleus cuneatus; nucleus gracilis
The medulla oblongata contains the ______ and the _____, which relay somatic sensory information to the thalamus.
longitudinal fissure
The paired cerebral hemispheres are divided by a _____ that extends along the midsagittal plane
CN V; CN VI; CN VII; CN VIII
The pons houses sensory and motor cranial nerve nuclei for the trigeminal _____, abducens ____, and facial ____ cranial nerves. Some of the nuclei for the vestibulocochlear cranial nerve ____ are located in the pons.
gyri
The surface of the cerebrum folds into elevated ridges called:
sensory, somatosensory
The thalamus is a principal and final relay point for ____ information that will be processed and projected to the______ cortex.
infundibulum
The thin, stalklike _____ extends inferiorly from the hypothalamus to attach to the pituitary gland.
hemisphere lateralization
The two hemispheres appear as anatomic mirror images, but they display some functional differences, termed:
CN VIII; CN IX; CN X; CN XI; CN XII
Within the medulla oblongata are cranial nerve nuclei associated with the vestibulocochlear _____, glossopharyngeal ______, vagus ____, accessory ____, and hypoglossal ____ cranial nerves.
opposite sides of the body
With few exceptions, both cerebral hemispheres receive their sensory information from and project motor commands to:
cerebrospinal fluid (CSF)
a clear, colorless liquid that circulates in the ventricles and subarachnoid space
considerable overlap and indistinct boundaries
__________ permit a single region of the cortex to exhibit several different functions.
precentral gyrus
a mass of nervous tissue in the frontal lobe immediately anterior to the central sulcus
Hippocampus
a nucleus shaped like a seahorse; essential in storing memories and forming long-term memory
other nuclei in the medulla oblongata
are involved in coughing, sneezing, salivation, swallowing, gagging, and vomiting
Telencephalon
arises from prosencephalon, eventually forms cerebrum
Metencephalon
arises from rhombencephalon, eventually forms the pons and cerebrum
tegmentum
between the substantia nigra and the periaqueductal gray matter. contains the red nuclei and the reticular formation. integrates information from the cerebrum and cerebellum and issues involuntary motor commands to the erector spinae muscles of the back to maintain posture.
pons
bulging region on the anterior part of the brainstem that forms from part of the metencephalon.
outer layer of cerebrum
called the cerebral cortex and is gray matter
components of cerebral nuclei
caudate nucleus amygdaloid body lentiform nucleus claustrum corpus striatum
ventricles
cavities or expansions within the brain that are continuous with one another and the central canal of the spinal cord. All contain cerebral spinal fluid. There are four in the brain
internal layer of cerebrum
cerebral white matter
Motor Speech Area (Broca's Area)
controls muscular movements necessary for vocalization; located in most individuals within the inferolateral portion of the left frontal lobe
superior cerebellar peduncle
connect the cerebellum to the mesencephalon
inferior cerebellar peduncle
connect the medulla oblongata to the cerebellum
cranial meninges
connective tissue layers that: Separate soft tissue of the brain from bones of cranium enclose and protect blood vessels that supply the brain contain and circulate cerebrospinal fluid form some of the veins that drain blood from the brain
substantia nigra
consists of bilaterally symmetrical nuclei with the mesencephalon. houses clusters of neurons that produce the neurotransmitter dopamine, which affects brain processes that control movement, emotional response, and the ability to experience pleasure and pain. Degeneration of cells in it is a pathology that underlies Parkinson disease.
Capillary endothelial cells and astrocyte perivascular feet
contribute to BBB
motor areas of cerebrum
control voluntary motor functions
frontal eye field
controls and regulates eye movements and binocular vision; located on the superior surface of the middle frontal gyrus, immediately anterior to the premotor cortex
vasomotor center of medulla oblongata
controls blood pressure by regulating the contraction and relaxation of smooth muscle in the walls of arterioles
primary motor cortex (somatic motor area)
controls voluntary skeletal muscle activity; located within the precentral gyrus; axons project contralaterally to the brainstem and spinal cord; innervation to various body parts can be diagrammed as a motor homunculus on the precentral gyrus
frontal lobe location
deep to the frontal bone and forms anterior part of cerebral hemisphere Ends posteriorly at the central sulcus; inferior border marked by the lateral sulcus
location of insula
deep to the lateral sulcus
diencephalon
derives from prosencephalon, eventually forms thalamus, hypothalamus, and epithalamus
myelencephalon
derives from rhombencephalon, eventually forms medulla oblongata
globus pallidus
excites and inhibits activities of thalamus to control and adjust muscle tone
Amygdaloid body
expression of emotions, control of behavioral activities, development of moods
cerebral aqueduct
extends through the mesencephalon and connects third and fourth ventricles surrounded by periaqueductal gray matter
habenular nuclei
help relay signals from the limbic system to the mesencephalon and are involved in visceral and emotional responses to odor
tentorium cerebelli
horizontal fold that separates cerebrum from cerebellum; anterior surface has a gap (tentorial notch) to allow for passage of brainstem
gray matter
houses motor neuron and interneuron cell bodies, dendrites, telodendria, unmyelinated axons forms the cortex, which covers the surface of most of the adult brain forms discrete internal clusters called cerebral nuclei
Volume: 1200-1500 cc Weight: 1.35-1.4 kg
human brain size
autonomic respiratory centers
in the pons the pneumotaxic center and the apneustic center regulate the rate and depth of breathing, and influence the activity of the respiratory center in the medulla oblongata.
location of occipital lobe
in the posterior region of each hemisphere underlying the occipital bone
location of temporal lobe
inferior to the lateral sulcus underlying the temporal bone
association areas of cerebrum
integrate and store information
Gnostic area (common integrative area)
integrates all sensory, visual, and auditory information; composed of regions of the parietal, occipital, and temporal lobes
Somatosensory association area
integrates and interprets sensory information; located in parietal lobe immediately posterior to post central gyrus
Various nuclei in the diencephalon (anterior thalamic nuclei, habenular nuclei, septal nuclei, mammillary bodies)
interconnect other parts of the limbic system and contribute to overall function
limbic system (diagram)
interconnect other parts of the limbic system and contribute to overall function
cingulate gyrus
internal mass of cerebral cortex located within the longitudinal fissure and superior to the corpus callosum; receives input from the other components of the limbic system
auditory association area
interprets characteristics of sound and stores memories of sound; located within temporal lobe posteroinferior to the primary auditory cortex
amygdaloid body
involved in several aspects of emotion, especially fear; helps sort and code memories based on how they are emotionally perceived
frontal lobe
involved with voluntary motor function, concentration, verbal communication, decision making, planning, and personality
postcentral gyrus
is a mass of nervous tissue in the parietal lobe immediately posterior to central sulcus
1. Frontal Lobe 2. Parietal Lobe 3. Temporal Lobe 4. Occipital Lobe 5. Insula
lobes of the cerebrum
white matter
made up of myelinated axons lies deep to the gray matter of the cortex
Cerebrum Diencephalon Brainstem Cerebellum
major regions of the brain
parahippocampal gyrus
mass of cortical tissue associated with the hippocampus
superior olivary complex
nuclei are located in the pons. This nuclear complex receives auditory input and involves pathways for sound localization.
primary gustatory cortex
processes taste information; located in insula
lateral ventricles
one in each hemisphere of the cerebrum, separated by a thin septum pellucidum
Mesencephalon
only primary vesicle that does not form a new secondary vesicle
cerebral nuclei
paired irregular masses of gray matter buried deep within the central white matter in the basal region of the cerebral hemispheres inferior to the floor of the lateral ventricles.
thalamus
paired oval masses of gray matter that lie on each side of the third ventricle.
Olfactory bulbs, olfactory tracts, olfactory cortex
particular odors can provoke certain emotions or be associated with certain emotions
cranial dural septa
partition separate specific parts of the brain and provide stabilization and support: falx cerebri tentorium cerebelli falx cerebelli diphragma selae
falx cerebelli
partition that separates left and right cerebellar hemispheres
Premotor cortex (somatic motor association area)
processes motor information and coordinates learned skilled motor activities; located in frontal lobe immediately anterior to precentral gyrus
sensory areas of cerebrum
provide conscious awareness of sensation
primary olfactory cortex
provides conscious awareness of smell; located in temporal lobe
primary auditory cortex
receives and processes auditory information; located in temporal lobe
primary visual cortex
receives and processes incoming visual information; located in occipital lobe
Primary somatosensory cortex
receives general somatic sensory information from touch, pressure, pain, and temperature receptors; located within the postcentral gyrus; sensory homunculus may be traced on surface
nucleus gracilis
receives sensory innervation from the lower limbs.
nucleus cuneatus
receives sensory innervation from the upper limbs of the same side
Wernicke's area
recognizes and comprehends spoken and written language; typically located within left hemisphere where it overlaps the parietal and temporal lobes
cardiac center of medulla oblongata
regulates heart rate and its strength of contraction
respiratory center of medulla oblongata
regulates respiratory rate and is influenced by the apneustic and pneumotaxic centers of the pons
dural venous sinuses
run within the margins of the dural septa
transverse sinuses
run within the posterior border of the tentorium cerebelli
occipital sinus
runs in the posterior vertical border of the falx cerebelli
inferior sagittal sinus
runs within the inferior margin of the falx cerebri
superior sagittal sinus
runs within the superior margin of the falx cerebri
pineal gland
secretes melatonin, a hormone that helps regulate day-night cycles (circadian rhythm)
diaphragma selae
small septum between pituitary and hypothalamus
blood-brain barrier
strictly regulates what substances can enter the interstitial fluids of the brain
corpus striatum
striped appearance of internal capsule as it passes among the caudate nucleus and lentiform nucleus
limbic system
structures form a ring around around the diencephalon composed of multiple cerebral and diencephalic structures that collectively process and experience emotions. affects memory formation through the integration of past memories of physical sensations with emotional states.
putamen
subconscious muscular movement
hypothalamus
the anteroinferior region of the diencephalon
folia
the cerebellum has a complex, highly convoluted surface covered by a layer of cerebellar cortex with folds called
corpus callosum
the largest tract and the main tract that connects the two cerebral hemispheres
cerebrum
the location of conscious thought processes and the origin of intellectual functions contains a large number of neurons that are needed for complex analytical and integrative functions.
fifth week of development
the three primary vesicles further develop into five secondary brain vesicles by the:
cranial nerves
there are 12 pairs They are numbered with Roman numerals by their position, beginning with the most anteriorly placed nerve. Their names are generally related to function.
Prosencephalon (forebrain) Mesencephalon (midbrain) Rhombencephalon (hindbrain)
three primary brain vesicles
late 4th week of development
three primary brain vesicles have formed by the:
1. Mesencephalon 2. Pons 3. Medulla Oblongata
three regions of the brain stem
cerebellar peduncles
three thick tracts that link the cerebellum with the brainstem
rostral
toward the nose (synonymous with anterior)
caudal
toward the tail (synonymous with posterior)
middle cerebellar peduncle
transverse fibers that connect the pons to the cerebellum.
fourth ventricle
ventricle between the pons and cerebellum
third ventricle
ventricle of the diencephalon